An overview of new approaches to deep desulfurization for ultra clean gasoline diesel fuel
Catalysis Today86(2003)
211–263
An overview of new approaches to deep desulfurization for ultra-clean gasoline,diesel fuel and jet fuel?
Chunshan Song?
Clean Fuels and Catalysis Program,Department of Energy and Geo-Environmental Engineering,The Energy Institute,
Pennsylvania State University,University Park,PA16802,USA
Received6May2003;received in revised form17June2003;accepted18June2003
Abstract
This review discusses the problems of sulfur reduction in highway and non-road fuels and presents an overview of new approaches and emerging technologies for ultra-deep desulfurization of re?nery streams for ultra-clean(ultra-low-sulfur) gasoline,diesel fuels and jet fuels.The issues of gasoline and diesel deep desulfurization are becoming more serious because the crude oils re?ned in the US are getting higher in sulfur contents and heavier in density,while the regulated sulfur limits are becoming lower and lower.Current gasoline desulfurization problem is dominated by the issues of sulfur removal from FCC naphtha,which contributes about35%of gasoline pool but over90%of sulfur in gasoline.Deep reduction of gasoline sulfur(from330to30ppm)must be made without decreasing octane number or losing gasoline yield.The problem is complicated by the high ole?ns contents of FCC naphtha which contributes to octane number enhancement but can be saturated under HDS conditions.Deep reduction of diesel sulfur(from500to<15ppm sulfur)is dictated largely by 4,6-dimethyldibenzothiophene,which represents the least reactive sulfur compounds that have substitutions on both4-and 6-positions.The deep HDS problem of diesel streams is exacerbated by the inhibiting effects of co-existing polyaromatics and nitrogen compounds in the feed as well as H2S in the product.The approaches to deep desulfurization include catalysts and process developments for hydrodesulfurization(HDS),and adsorbents or reagents and methods for non-HDS-type processing schemes.The needs for dearomatization of diesel and jet fuels are also discussed along with some approaches.Overall, new and more effective approaches and continuing catalysis and processing research are needed for producing affordable ultra-clean(ultra-low-sulfur and low-aromatics)transportation fuels and non-road fuels,because meeting the new government sulfur regulations in2006–2010(15ppm sulfur in highway diesel fuels by2006and non-road diesel fuels by2010;30ppm sulfur in gasoline by2006)is only a milestone.Desulfurization research should also take into consideration of the fuel-cell fuel processing needs,which will have a more stringent requirement on desulfurization(e.g.,<1ppm sulfur)than IC engines. The society at large is stepping on the road to zero sulfur fuel,so researchers should begin with the end in mind and try to develop long-term solutions.
?2003Elsevier B.V.All rights reserved.
Keywords:Desulfurization;Gasoline;Fuels;Diesel fuel;Jet fuel;Catalysis;Adsorption
?Based on a keynote lecture at the international symposium on Ultra-Clean Transportation Fuels at American Chemical Society National Meeting in Boston,MA,during18–22August2002.
?Tel.:+1-814-863-4466;fax:+1-814-865-3248.
E-mail address:csong@https://www.sodocs.net/doc/e34430394.html,(C.Song).1.Introduction
This review discusses fuel speci?cation issues and the problems of sulfur reduction in highway and non-road fuels and presents an overview of new
0920-5861/$–see front matter?2003Elsevier B.V.All rights reserved. doi:10.1016/S0920-5861(03)00412-7
212 C.Song /Catalysis Today 86(2003)211–263
Table 1
US EPA Tier II gasoline sulfur regulations as of 2002Category
Year 1988[7]
1995[9]
2004[3]2005[3]2006[3]Re?nery average (ppmw)
1000(maximum)[7]
330(<330ppm S and
<29.2%aromatics required for national certi?cation;<850ppm S and <41.2%aromatics as national maximum)[9]
–
30
30
Corporate average (ppmw)12090–Per-gallon cap (ppmw)30030080
approaches to ultra-deep desulfurization of re?nery streams for ultra-clean (ultra-low-sulfur)gasoline,diesel fuels and jet fuels.
In the past decade,clean fuels research including desulfurization has become a more important subject of environmental catalysis studies worldwide.Tables 1and 2show the current US EPA regulations for gaso-line [1–3]and diesel fuels [3–5]including non-road diesel fuels [6],respectively,along with earlier fuel speci?cation data in the US for comparison [7–9].With the new US EPA Tier II regulations to reduce the gasoline sulfur from current maximum of 350–30ppm (re?nery average,with 80ppm as per-gallon (1US gallon =3.7854l)cap)by 2006,and to cut the high-way diesel fuel sulfur from current 500ppmw down to 15ppmw (per-gallon average)by June 2006,re?ner-ies are facing major challenges to meet the fuel sulfur speci?cation along with the required reduction of aro-matics contents.More recently,EPA has announced plan to reduce non-road diesel fuel sulfur from current average of 3400ppm down to 500ppm by 2007and further to 15ppm by 2010[6].The US Clean Air Act
Table 2
US EPA sulfur regulations for diesel and jet fuels as of April 2003Category
Year 1989[8]
1993[6]
2006[6]
2010[6]
Highway diesel (ppmw)5000(maximum for no.1D and 2D,with minimum cetane no.40)[8]500(current upper limit since 1993)
15(regulated in 2001;exclude some small re?neries)
15(regulated in 2001;apply to all US re?neries)Non-road diesel (ppmw)
20000[8]5000(current upper limit)500(proposed in 2003for 2007)
15(proposed in 2003for 2010)
Jet fuel (ppmw)
3000
3000
3000maximum?
<3000maximum?
Amendments of 1990and related new fuel regulations by the US EPA and government regulations in many countries call for the production and use of more en-vironmentally friendly transportation fuels with lower contents of sulfur and aromatics.
Table 3shows the average properties of crude oils re?ned in the US during 1981–2001along with the US and worldwide petroleum consumption dur-ing 1981–2001based on published statistical data [10–14].The demand for transportation fuels has been increasing in most countries for the past three decades.The total world petroleum consumption increased from 49.42million barrels per day (MBPD)in 1971to 77.12MBPD in 2001,representing a 56%increase [11].The total US consumption of petroleum products reached 19.59MBPD in 2001,about 39%increase from 1971(14.11MBPD)[10].Of the petroleum products consumed in US in 2001,8.59MBPD was supplied as motor gasoline,3.82MBPD as distillate fuels,including 2.56MBPD as high-way diesel fuels and 1.26MBPD as off-road fuels and industrial fu-els,1.65MBPD as jet fuel,0.93MBPD as residual
C.Song/Catalysis Today86(2003)211–263213 Table3
Average properties of crude oils re?ned in the US during1981–2001and US and world petroleum consumption during1981–2001 Property Year
198119912001 Total amounts of crude oils re?ned in US(million barrel/day)12.4713.3015.13 Average sulfur content of crude oils re?ned in US(wt.%based on sulfur)0.89 1.13 1.42 API gravity of crude oils re?ned in US(?API)33.7431.6430.49 Total petroleum products supplied in the US including imported
crude and products(million barrel/day)
16.0616.7119.59 Total worldwide petroleum consumption(million barrel/day)60.9066.7277.12
fuel oil,and1.13MBPD as lique?ed petroleum gas (LPG),and3.47MBPD for other uses in the US[10]. The problem of deep removal of sulfur has become more serious due to the lower and lower limit of sul-fur content in?nished gasoline and diesel fuel prod-ucts by regulatory speci?cations,and the higher and higher sulfur contents in the crude oils.A survey of the data on crude oil sulfur content and API grav-ity for the past two decades reveals a trend that US re?ning crude slates continue towards higher sulfur contents and heavier feeds.The average sulfur con-tents of all the crude oils re?ned in the?ve regions of the US known as?ve Petroleum Administration for Defense Districts(PADDs)increased from0.89wt.% in1981to1.42wt.%in2001,while the correspond-ing API gravity decreased from33.74?API in1981to 30.49?API in2001[12–14].In the past two decades, average sulfur contents in crude oils re?ned in the US increased by265ppm/year and API gravity decreased by0.16?API/year,while the total crude oil re?ned in the US re?neries increased from12.47MBPD in1981 (11.20MBPD in1971)to15.13MBPD in2001[10]. The crude oils re?ned in the US tend to have higher sulfur contents than those in the Western Europe.For example,the average crude oil feeds to US re?neries in2000have1.35wt.%sulfur and31.0?API gravity, whereas European re?nery feed by comparison was sweeter at1wt.%sulfur and35?API gravity[15]. The total world consumption of re?ned petroleum product in2000was76.896MBPD,in which the con-sumptions in the US and western Europe were19.701 and14.702MBPD,respectively.The problem for diesel desulfurization is also somewhat more serious in the US because a higher proportion of light cycle oil(LCO)from FCC is used in the diesel pool in the US,which has higher contents of more refractory sulfur compounds(see below).H2demand increase is another challenge to the re?nery operations.Hydro-gen de?cits are processing restraints and will impact future hydrotreating capabilities and decisions[16].
2.Reactivity of organic sulfur compounds in hydrodesulfurization(HDS)
Fig.1presents a qualitative relationship between the type and size of sulfur molecules in various distil-late fuel fractions and their relative reactivities[17]. Various re?nery streams are used to produce three major types of transportation fuels,gasoline,jet fuels and diesel fuels that differ in composition and proper-ties.The common types of sulfur compounds in liquid fuels are outlined in Table4,which corresponds to Fig.1for transportation fuels.The reactivity ranking in Fig.1is based on well-known experimental obser-vations and a large amount of literature information [18–21].For the sulfur compounds without a conju-gation structure between the lone pairs on S atom and the?-electrons on aromatic ring,including disul?des, sul?des,thiols,and tetrahydrothiophene,HDS occurs directly through hydrogenolysis pathway.These sul-fur compounds exhibit higher HDS reactivity than that of thiophene by an order of magnitude[22],be-cause they have higher the electron density on the S atom and weaker C–S bond.The reactivities of the 1-to3-ring sulfur compounds decrease in the order thiophenes>benzothiophenes>dibenzothiophenes [23–27].In naphtha,thiophene is so much less re-active than the thiols,sul?des,and disul?des that the latter can be considered to be virtually in-?nitely reactive in practical high-conversion pro-cesses[22,28].Similarly,in gas oils,the reactivities
214 C.Song/Catalysis Today86(2003)
211–263
Fig.1.Reactivity of various organic sulfur compounds in HDS versus their ring sizes and positions of alkyl substitutions on the ring[17]. of(alkyl-substituted)4-methyldibenzothiophene and
4,6-dimethyldibenzothiophene(4,6-DMDBT)are
much lower than those of other sulfur-containing
compounds[28–31].Consequently,in deep HDS,
the conversion of these key substituted dibenzothio-
phenes largely determines the required conditions.
Gates and Topsoe[28]pointed out in1997that
4-methyldibenzothiophene and4,6-DMDBT are the
most appropriate compounds for investigations of
candidate catalysts and reaction mechanisms.
Fig.2shows the sulfur compounds in the?nished
products of gasoline,jet fuel,and diesel fuel that are
representative of current commercial transportation fu-
els in the US[32,33].It can be seen that in each of
the fuels,what are left as sulfur compounds in the?n-
ished products are those that have lower reactivities
among all the sulfur compounds in the corresponding
feed shown in Fig.1,e.g.,naphtha range for gasoline,
kerosene range for jet fuel,and gas oil range for diesel
fuel.Deep desulfurization and ultra-deep desulfuriza-
C.Song /Catalysis Today 86(2003)211–263
215
Table 4
Typical sulfur compounds and corresponding re?nery streams for fuels Sulfur compounds
Re?nery streams
Corresponding fuels
Mercaptanes,RSH;sul?des,R 2S;disul?des,RSSR;thiophene (T)and its alkylated derivatives,benzothiophene
SR-naphtha;FCC naphtha;coker naphtha
Gasoline (BP range:25–225?C)Mercaptanes,RSH;benzothiophene (BT),alkylated benzothiophenes
Kerosene;heavy naphtha;middle distillate
Jet fuel (BP range:130–300?C)Alkylated benzothiophenes;dibenzothiophene (DBT);alkylated dibenzothiophenes
Middle distillate;FCC LCO;coker gas oil
Diesel fuel (BP range:160–380?C)Greater than or equal to three-ring polycyclic sulfur compounds,including DBT,benzonaphthothiophene (BNT),
phenanthro[4,5-b,c,d]thiophene (PT)and their alkylated derivatives and naphthothiophenes (NT)
Heavy gas oils;vacuum gas oil;distillation resides
Fuel oils (non-road fuel and heavy
oils)
Fig.2.Sulfur compounds in commercial gasoline,jet fuel and diesel fuel identi?ed by GC-FPD analysis coupled with GC-MS and reaction kinetic analysis [32].
216 C.Song/Catalysis Today86(2003)211–263
tion refers to processes to remove sulfur(that exists in current gasoline and diesel fuels as shown in Fig.2)to below15ppmw for diesel fuels and to below30ppmw for gasoline,respectively.
3.Catalysts for hydrotreating/HDS
3.1.Catalyst formulations
The formulations of modern hydroprocessing cata-lysts originated from early research in catalytic coal liquefaction and coal liquids upgrading to automo-tive fuels in the1920s and the1930s in Germany which led to catalysts based on molybdenum and tung-sten with nickel or cobalt promoters[34–36].The basic compositions of current hydrotreating catalysts are represented by molybdenum sul?de promoted by cobalt or nickel and supported on porous?-alumina, Co–Mo/Al2O3,Ni–Mo/Al2O3,with various modi?ca-tions by using additives(e.g.,boron or phosphorus or silica)or more promoters(e.g.,Ni–Co–Mo/Al2O3)or improved preparation methods.The activity and se-lectivity of the hydrotreating catalysts have been im-proved signi?cantly as a result of continuous research and development in research institutions and catalysts, and petroleum companies worldwide.
An excellent review has been published by Topsoe et al.[37]on chemistry and catalysis by metal sul-?des.Design approaches for developing more active catalysts are based on the ideas to tailor the active sites for desired reactions.The exact nature of ac-tive sites in Co–Mo or Ni–Mo catalysts is still a sub-ject of debate,but the Co–Mo–S model(or Ni–Mo–S model for Ni–Mo catalysts)is currently the one most widely accepted[37,38].According to the model,the Co–Mo–S structure or Ni–Mo–S structure is respon-sible for the catalytic activity of the Co-promoted or Ni-promoted MoS2catalyst,although the model does not specify whether the catalytic activity arises from Mo promoted by Co or from cobalt promoted by molybdenum.Density-functional theory(DFT)calcu-lations show that addition of Co–MoS2structure low-ers the sulfur binding energy at the edges and thereby provides more active sites[39].Recently,the forma-tion of sulfur vacancy in MoS2under H2atmosphere has been observed directly for the?rst time by scan-ning tunneling microscope(STM)[40].Comparison of STM images for Mo sul?de-based particles with and without cobalt promoter atoms shows that with-out cobalt,the MoS2particles assume a neat triangu-lar shape.Once cobalt enters the crystals,the particles become truncated hexagons–triangles with clipped-off vertices[41].These new?ndings from experimental STM observations are consistent also with the FT-IR studies for NO chemisorption on Co–Mo catalysts. Co–Mo catalysts with more Co sites exposed(Co edge sites)tend to have higher activity for HDS[37],and this trend has been observed also for Co–Mo/MCM-41 and Co–Mo/Al2O3catalysts based on DBT HDS and FT-IR of chemisorbed NO[20].
Among the Co–Mo–S structures for alumina-supported catalysts,the intrinsically more active phase was referred to as type II(Co–Mo–S II),and the less active phase as type I(Co–Mo–S I);type I structure is assumed to be bonded to support through Mo–O–Al linkages and has less stacking,whereas type II struc-ture has higher stacking and few linkages with support [38].For steric reasons,catalyst–support linkages in Co–Mo–S I probably hinder reactant molecules from approaching the catalytically active sites,and thus Co–Mo–S II is more active than Co–Mo–S I although Mossbauer and EXAFS signals of types I and II structures are the same.Daage and Chianelli [42]reported that the top and bottom layers(rim)of unsupported MoS2stacks(slabs)have a much higher activity than the surface of intermediate layers(edge) for hydrogenation of DBT,while the hydrogenolysis of the C–S bond in DBT occurs equally well on all MoS2layers.They proposed a rim-edge model,and explained that the?at?-adsorption on MoS2surface results in hydrogenation of DBT which can take place on rim sites but this adsorption is more dif?cult on edge sites,whereas vertical adsorption of sulfur is as-sumed to be necessary for C–S bond hydrogenolysis which can take place on surface Mo sites of all layers (both rim and edge).The Co–Mo–S model makes no distinction between rim and edge,but Co–Mo–S II would seem to have relatively more rim sites that are not likely to be in?uenced by steric hindrance of reactant adsorption.Consequently,more Co–Mo–S II structures can lead to more active catalysts for desulfurization of polycyclic sulfur compounds. Table5shows typical hydroprocessing conditions used in industry[43].The choice of commercial hy-drotreating catalysts,represented by Co–Mo,Ni–Mo
C.Song /Catalysis Today 86(2003)211–263
217
Table 5
Typical hydroprocessing conditions used in industry [43]Fuel type and historical conditions
Pressure (MPa)LHSV (h ?1)Temperature (?C)Recent history
Naphtha (gasoline) 1.38–3.452–8290–370Kerosene/gas oil (jet/diesel fuels) 3.45–8.272–4315–400FCC feed pretreat 5.17–13.80 1.0–3.0370–425Current trends
Naphtha (gasoline) 1.38–5.172–6290–370Kerosene/gas oil (jet/diesel fuels) 3.45–10.300.5–3.0315–400FCC feed pretreat
6.90–20.70
0.5–2.0
370–425
and Ni–Co–Mo usually supported on alumina with or without modi?ers,depends also on the capability of reactor equipments,operating conditions (pressure,temperature),feedstock type and sulfur contents,and desired level of sulfur reduction.Increasingly more se-vere conditions and more active catalysts are used to-day for hydroprocessing.In general,for low-pressure and high-temperature desulfurization of distillate fuels,Co–Mo catalysts may be better than Ni–Mo catalysts.For high-pressure and low-temperature con-ditions,Ni–Mo catalysts perform better than Co–Mo catalysts.Ni–Mo catalysts generally have higher hy-
Table 6
Worldwide re?nery catalysts markets [44–46]Category
Year 1992[46]
1997[44]
2001[44,45]2005[45]Total catalyst market
US$7.40billion [47]US$10.16billion Total re?nery catalyst market US$2.2billion US$2.07billion US$2.32billion US$2.68billion By sector in re?nery
Hydrotreating/desulfurization US$265million (12%)US$723million (34%)US$789million (34%)US$965million (36%)Catalytic cracking/FCC US$900million (41%)US$944million (45%)US$696million (30%)US$804million (30%)Naphtha reforming US$90million (4%)US$124million (6%)US$139million (6%)US$134million (5%)Hydrocracking US$200million (9%)
US$155million (7%)US$116million (5%)US$134million (5%)Others a 34%
US$
125
million
(6%)
US$580
million
(25%)
US$643
million
(24%)
By region for re?nery North America (%)4038Western Europe (%)2019Asia/Paci?c (%)1920Rest of world (%)b
21
23
a Include isomerization,alkylation,etheri?cation,polymerization,lubes,sulfur recovery,hydrogen,and puri?cation catalysts.b
Includes Eastern Europe,Mid-East,and South America.
drogenating ability than Co–Mo counterparts,and higher H 2pressure and lower temperature favor the hydrogenation reactions and thus facilitate HDS by hydrogenation pathway.The trimetallic Ni–Co–Mo catalysts can combine the features of Co–Mo and Ni–Mo,and this new formulation feature is being used in some recent commercial catalysts.3.2.Global catalyst markets
Table 6shows the global merchant re?nery catalyst market distribution during 1997–2001with a projec-tion to 2005[44–47],together with the data for 1992[46]for comparison.The largest volume gain in re-?ning catalysts was in hydrotreating/HDS catalysts.In fact,HDS catalysts recently overtook FCC as the largest market for re?nery catalyst makers.HDS cata-lysts are playing an increasingly more important role in re?neries today for producing clean fuels that meet the regulatory sulfur requirements.A 1999report puts the 1997global merchant catalyst market at US$7.4billion,with the following distribution:28%re?nery,27%chemical,23%polymerization,and 22%envi-ronmental,in which the environmental part excludes the value of the precious metals and substrate used and includes only manufacturing fees [47].According to a study reported in 2000,the global merchant catalyst
218 C.Song /Catalysis Today 86(2003)211–263
market is about US$10billion/year,with the captive market worth an additional US$2billion to US$3billion and total market growth approaching 10%per year [48].It is clear from these studies that re?ning catalysts,particularly desulfurization catalysts,repre-sent an important category of growth areas due to the needs for producing cleaner transportation fuels.In addition,some new approaches and new technologies that do not use hydrotreating are also emerging in the past several years [17,21,49].
4.Deep desulfurization of naphtha for ultra-clean gasoline
4.1.Gasoline pool and sources of sulfur
Table 7shows the typical gasoline pool composi-tions in the US [50]and in the western Europe [51].It is well known that naphtha from FCC makes up about 25–40%(average of 36%in the US)of gasoline blend stocks,but accounts for over 90%of the sulfur (up to 90–98%)and essentially all of the ole?ns in the entire gasoline pool.Therefore,the key to deep desulfuriza-tion of gasoline is sulfur removal from FCC naphtha.It is well known that sulfur removal from FCC naph-tha can be achieved by catalytic HDS,but the accom-panying decrease of octane number is a signi?cant loss due to the saturation of ole?ns.Fig.3shows the re-lationship between HDS and octane loss for conven-tional hydrotreating,in which the plot is made based on data from industrial sources [52].Because FCC naphtha also has a high content of ole?ns (e.g.,20%)
Table 7
Typical gasoline pool composition in US and western Europe Gasoline blend stocks Percentage of gasoline pool volume in US Percentage of gasoline pool sulfur in US Percentage of gasoline pool volume in western Europe FCC naphtha
369827Naphtha reformate 34–40Alkylate
12–9Light straight-run naphtha 317.5Coker naphtha
11～0Hydrocracked naphtha 2–～0Isomerate 5–10Butanes 5– 5.5MTBE 2– 1.0Total (%)
100
100
100
which have higher octane number,selective sulfur re-moval without loss of octane number (or without loss of ole?ns)is desirable.Hydrotreating of FCC naphtha is an attractive process alternative,provided that oc-tane losses are minimized by either minimizing ole?n saturation during HDS or restoring the octane number after the HDS.
FCC naphtha can be divided (in a fractionator or splitter)into light cat naphtha (LCN,IBP:140?F or 60?C),medium (or intermediate)cat naphtha (MCN or ICN)cut,and heavy cat naphtha (HCN)cuts.To-tally debutanized FCC naphtha distills between 80and 430?F (27–221?C)boiling range [53].A MCN or ICN cut is de?ned by an initial boiling point that should in-clude thiophene (183?F,85?C)but thiophene begins to distill with C6hydrocarbons boiling above 140?F (60?C)and below 200?F (93?C)which makes the better fractionation more important for MCN [53].The ?nal boiling point of MCN is ?exible between 270and 360?F (132and 182?C)[54].
Sulfur species change from primarily mercaptans in the low boiling IBP:140?F (60?C)LCN to thio-phenes and substituted thiophenic sulfur compounds in 140–390?F (MCN +HCN ),and benzothiophenes and substituted benzothiophenes in the 390–430?F (bot-tom part of HCN).Above 390?F (199?C),total sulfur increases rapidly with boiling point [53].In general,LCN has most of the ole?ns and the sulfur in mercap-tan form;caustic treatment is used for LCN treatment to remove mercaptans.Thiophene cannot be extracted by caustic treatment and that is why fractionation of FCC naphtha is important.HCN contains much less ole?ns and most of the thiophenic sulfur,and thus
C.Song /Catalysis Today 86(2003)211–263219
10152025303540455010
100100010000
Sulfur level, ppm
O l e f i n c o n t e n t , %
10
100
1000
10000
Sulfur level, ppm
R O N (G C )
Fig.3.Relationship between desulfurization and ole?n content (top)and octane number of FCC naphtha (plot by Ma et al.based on data from Desai et al.[52]).
can be desulfurized in a hydrotreater.MCN or ICN is the lowest-octane portion of FCC naphtha,and can be desulfurized deeply to produce a blend stock or re-former feedstock [54].
4.2.Approaches to gasoline sulfur removal Table 8outlines the catalytic and non-catalytic ap-proaches to gasoline deep desulfurization with general remarks on their features based on published infor-mation in the open literature [17,55–57].Approaches to reducing sulfur content in FCC naphtha include:(1)post-treating product to remove sulfur from FCC naphtha [55,56];(2)pretreating the FCC feed to re-move sulfur [50];(3)increasing sulfur conversion in situ to hydrogen sul?de during the FCC operation [56].The principles of these methods are based on one or more of the following processes:catalytic HDS,selective HDS,reactive adsorption using solid sorbent and H 2at elevated temperature,selective adsorption without using H 2at ambient temperature,distilla-tion or extraction coupled with HDS,membrane,and
220 C.Song/Catalysis Today86(2003)211–263
Table8
Approaches to deep desulfurization of naphtha for cleaner gasoline
Category Description and representative process Remarks
(I)Post-FCC sulfur removal Conventional HDS process without special ole?n
preservation(many companies)
HDS
Convert organic sulfur to H2S by selective HDS while
preserving ole?ns(ExxonMobil’s SCAN?ning;IFP
Prime G+)
Selective HDS
Hydrodesulfurize organic sulfur,saturate ole?ns but
convert paraf?ns for octane gain(ExxonMobil
OCTGain125;UOP-INTEVEP’s ISAL)
HDS plus octane recovery
Reactive adsorption and capture of sulfur by solid adsorbent at elevated temperatures under low H2 pressure(Phillips Petroleum S-Zorb Gasoline)Non-HDS;stoichiometric H2 consumption
Sulfur adsorption and capture by solid metal oxide
adsorbent at high temperatures(RTI TReND)
Non-HDS;use H2atmosphere
Polar adsorption by using solid adsorbent based on
alumina(Black and Veatch Prichard IRV AD)
Polar adsorption
Selective adsorption for removing sulfur(SARS)as organic compounds by solid adsorbent at ambient temperature without using H2(Pennsylvania State University,PSU-SARS)S adsorption,no H2;can reach<1ppm S for fuel cells
Integrated adsorption and hydrotreating of
concentrated sulfur from adsorption(Pennsylvania
State University,PSU-SARS-HDSCS)
S adsorption coupled with HDS
Drop the organic sulfur to heavier fraction by
alkylation of thiophenes(BPs OATS process)
Alkylation and boiling point shift
Remove the organic sulfur by using caustic treatment (Merichem’s THIOLEX/REGEN process;Exomer by Merichem and ExxonMobil)or extraction(GTC Technology’s GT-DeSulf)Extraction of sulfur in light fraction of naphtha
Remove the organic sulfur by using membrane
?ltration(Grace’s S-Brane TM Process)
Membrane separation of light naphtha
(II)Pre-FCC sulfur removal Deep HDS of feed before catalytic cracking in FCC
reactor,which greatly reduces sulfur in FCC naphtha
and in LCO(Akzo Nobel,IFP,UOP,etc.)
HDS at higher H2pressure
Physico-chemical treatment such as adsorption or
extraction to remove sulfur(concept suggested here as
a possible approach based on PSU-SARS)
Adsorption without H2
(III)In situ FCC sulfur removal Convert more organic sulfur into H2S during FCC
operation,which can reduce organic sulfur in liquid
products(Akzo Nobel’s Resolve;Grace Davison’s
Saturn(GSR-6.1))
Sulfur conversion in FCC
Capture organic sulfur using metal species to retain
sulfur as sulfur oxide,and regenerate it in the
regenerator(concept suggested here as a possible
approach based on reactive adsorption using sorbent)
Sulfur capture in FCC
C.Song /Catalysis Today 86(2003)211–263221
biochemical processes.Due to limitation of space and scope,only some of the approaches and processes re-lated to catalysis and adsorption are further elaborated below.
Compared to the diesel sulfur problem,it is not very dif?cult to remove sulfur from gasoline by HDS.The challenges to the re?nery for gasoline deep desulfu-rization are to meet the new EPA Tier II regulations on sulfur contents (2006–2010)and aromatic contents and still produce high-octane gasoline in a pro?table manner.As can be seen from Fig.3,the increasing extent of sulfur removal by conventional HDS of FCC naphtha also translates into decreasing octane number due to saturation of ole?ns [52].
4.2.1.Selective HDS of FCC naphtha
Selective HDS could be achieved by designing cat-alysts that promote thiophene HDS but do not saturate ole?ns,or by passivating ole?n hydrogenation sites on the catalysts.Some reports indicate that there exist dif-ferent active sites on hydrotreating catalysts (such as sul?ded Co–Mo/Al 2O 3)for thiophene desulfurization and for ole?n hydrogenation [57–63].On the other hand,a recent report suggests that selective HDS of FCC naphtha may be due to competitive adsorption of sulfur compounds that inhibit adsorption and satura-tion of ole?ns in naphtha [64].ExxonMobil’s SCAN-?ning [65]and IFP’s Prime G +are two representa-tive new processes for gasoline desulfurization based on selective HDS in which organic sulfur is converted
Fig. 4.ExxonMobil’s SCAN?ning process for selective naphtha HDS from Halbert et al.[65];see also ExxonMobil web site:https://www.sodocs.net/doc/e34430394.html,/re?ningtechnologies/[66].
to H 2S but ole?nic species are largely preserved for preventing octane loss.
Fig.4shows the scheme of SCAN?ning (Selective Cat Naphtha hydro?ning),?rst developed by Exxon (now ExxonMobil).It is a catalytic HDS process that is based on a proprietary catalyst called RT-225[65,66].The process ?ow can be described as follows.The feed is mixed with recycle hydrogen,heated with re-actor ef?uent and passed through the pretreat reac-tor for diole?n saturation.After further heat exchange with reactor ef?uent and preheat using a utility,the hydrocarbon/hydrogen mixture enters the HDS reac-tor containing proprietary RT-225catalyst.In the re-actor,the sulfur is converted to H 2S under conditions which strongly favor HDS while minimizing ole?n saturation.The RT-225catalyst system was jointly de-veloped by ExxonMobil and Akzo Nobel speci?cally for selective removal of sulfur from FCC naphtha by HDS with minimum hydrogenation of ole?ns,thus preserving octane.Fig.5illustrates the performance of SCAN?ning catalyst for naphtha HDS and ole?n hydrogenation [62].The SCAN?ning could be used for wide-cut naphtha and the catalyst causes very little yield loss.Therefore,SCAN?ning offers the ability to eliminate FCC naphtha product splitting towers and to reduce hydrogen consumption to 30–50%less than in conventional hydro?nishing,resulting in signi?cant investment and operating cost savings.SCAN?ning can be retro?tted using existing equipment,however,there are multiple con?gurations that can best adapt
222 C.Song /Catalysis Today 86(2003)211–263
10095
90
85
800
20
40
60
80100
% Olefin Saturation
% H y d r o d e s u l f u r i z a t i o n
Fig.5.Relative activities of SCAN?ning catalyst for selective cat naphtha HDS [62].
OLEFIN + H 2R-S-R′ + H 2
RIM SITES RIM + EDGE SITES
ALKANE (LOWER OCT ANE)RH + H 2S
Fig.6.Catalytic sites on HDS catalysts for naphtha [62].
the process to site-speci?c conditions.Related to cat-alyst for SCAN?ning,Fig.6shows a concept to con-trol the catalytically active sites on sul?de catalysts for conversion
of sulfur compounds (rim sites and edge sites)and for hydrogenation of ole?ns (rim sites)[62].Fig.7.Prime G +process developed by IFP [67,68].
Fig.7shows the scheme of Prime G +desulfurization process,which was developed by IFP (Intitute Fran-cais du Petrole),and largely preserves ole?ns as its strategy for diminishing octane loss [67–69].Prime G +is based on a combination of a selective
C.Song /Catalysis Today 86(2003)211–263
223
Fig.8.General performance of Prime G +process developed by IFP [67,68].
hydrogenation unit which removes diole?ns and light mercaptans,a splitter,and a selective HDS of mid-and HCN cut through a dual catalytic system.It is designed for FCC naphtha ultra-deep desulfurization with minimal octane penalty.FCC debutanizer bot-toms are fed directly to the ?rst reactor,where under mild conditions diole?ns are selectively hydrogenated and mercaptans are converted to heavier sulfur species.The selective hydrogenation reactor ef?uent is then usually split to produce a LCN and a HCN cut.The LCN stream is mercaptan free with a low-sulfur and diole?n concentration enabling further processing in an etheri?cation or an alkylation unit.The HCN then enters the main Prime G +section,where it undergoes a deep HDS in a dual catalyst system with very lim-ited ole?ns saturation and no aromatic losses to pro-duce an ultra-low-sulfur gasoline,as shown in Fig.
8
Fig.9.ExxonMobil’s OCTGain process for selective naphtha HDS [66,71].
[67–69].Catalysts used in this HDS section are a com-bination of HR-806and HR-841catalysts developed by IFP and commercialized by Axens,where HR-806achieves the bulk of desulfurization,and HR-841is a polishing catalyst which reduces sulfur and mercap-tans with no activity for ole?n hydrogenation [70].Prime G +is less severe and has been commercially demonstrated for over 7years in two US re?neries,and in an Asian re?nery [1].There are over 10Prime G +units,and the economics are estimated to be as follows:capital investment,US$600–800/bpsd;com-bined utilities,US$0.32/bbl;H2,US$0.28/bbl;cata-lyst,US$0.03/bbl [68].
4.2.2.Deep HDS combined with octane recovery processing
Another hydrotreating approach is to carry out deep HDS of organic sulfur and saturate ole?ns,then convert low-octane components such as paraf?ns to high-octane components for octane gain by isomer-ization and alkylation.Two representative industrial processes in this category are ExxonMobil’s OCT-Gain and UOP-INTEVEP’s ISAL.
The OCTGain process was ?rst developed and ini-tially commercialized in 1991by Mobil (now Exxon-Mobil).Fig.9shows the scheme of OCTGain process [66,71].The process,now in its third generation,uses a ?xed-bed reactor to desulfurize FCC naphtha while maintaining octane.The process ?rst totally removes sulfur and saturates ole?ns,and then restores the oc-tane to economically needed levels,thus variation in
224 C.Song/Catalysis Today86(2003)211–263
feed sulfur content does not impact product sulfur and
treated products typically contain<5ppm sulfur and <1%ole?ns[72].The basic?ow scheme is similar to that of a conventional naphtha hydrotreater.Feed
and recycle hydrogen mix is preheated in feed/ef?uent
exchangers and a?red heater then introduced into a
?xed-bed reactor.Over the?rst catalyst bed,the sulfur
in the feed is converted to hydrogen sul?de with near
complete ole?n saturation.In the second bed,over a
different catalyst,octane is recovered by cracking and
isomerization reactions.The reactor ef?uent is cooled
and the liquid product separated from the recycle gas
using high-and low-temperature separators.The va-
por from the separators is combined with makeup gas,
compressed and recycled.The liquid from the sepa-
rators is sent to the product stripper where the light
ends are recovered overhead and desulfurized naph-
tha from the bottoms.The product sulfur level can be
as low https://www.sodocs.net/doc/e34430394.html,pared to ExxonMobil’s SCAN-
?ning,the OCTGain process is run at more severe
conditions for it to recover octane,so this process is
more appropriate for re?ners with higher sulfur lev-
els which requires severe hydrotreating to reach the
sulfur target[1].While octane loss can be eliminated
with the proper operating conditions,some yield loss
may result[1].
OCTGain has been commercially demonstrated at
ExxonMobil’s re?nery in Joliet,IL[1].More recently,
OCTGain process has been demonstrated for deep
desulfurization and octane enhancement of heavy
cracked naphtha feeds in its?rst commercial grass-
roots application in the Qatar Petroleum OCTGain
unit[73].On the actual re?nery feed,an ultra-low-
sulfur(<1ppm),low ole?ns gasoline is produced,
while process?exibility allows the adjustment of oc-
tane number between?2and+2RON of the feed,
as re?nery economics dictate.Naphtha yield loss and
hydrogen consumption were much less than design
allowances.The desulfurized gasoline is low in mer-
captans and has suitable vapor pressure for direct
blending into the re?nery’s gasoline pool[73].
ISAL process,jointly developed by INTEVEP,SA
and UOP,is designed as a low-pressure?xed-bed hy-
droprocessing technology for desulfurizing gasoline-
range feedstocks and selectively recon?gures lower
octane components to restore product octane number.
Its?ow scheme is very similar to that of a conven-
tional hydrotreating process,but a major feature of this process is the catalyst formulation,typically a combi-nation of a HDS catalyst such as Co–Mo–P/Al2O3and octane-enhancing catalyst such as Ga–Cr/H-ZSM-5 catalysts in two beds[49,74].The naphtha feed is mixed with H2-rich recycle gas and processed across ?xed catalyst beds at moderate temperatures and pressures.Following heat exchange and separation, the reactor ef?uent is stabilized.The similarity of an ISAL unit to a conventional naphtha hydrotreat-ing unit makes implementation of ISAL simple and straightforward[75].There are several revamp and several new units based on ISAL process[75]. Researchers from UOP and INTEVEP have dis-cussed the technical aspects of the process and catalyst chemistries leading to these desirable results[76,77]. The ISAL process reduces the naphtha sulfur and ni-trogen content,reduces the naphtha ole?n content, does not increase the aromatics content,and can main-tain or increase the naphtha octane[78].The ability of the ISAL process to provide both desulfurization and octane?exibility is the result of a development pro-gram that was begun by INTEVEP in the early1990s for possible improvements in?xed-bed isomerization and alkylation technologies.One result of this program was the discovery of a new catalyst system that could increase octane by isomerization of its gasoline-range feedstock[77].An interesting feature of this system was that an octane boost occurred despite the oc-currence of signi?cant ole?n saturation[77].There-fore,INTEVEP and UOP teamed up to develop the ISAL process to enable re?ners to hydrotreat highly ole?nic feedstocks,such as coker and FCC naphtha, while controlling both the sulfur content and the oc-tane of its product.This?exibility is achieved by the use of a catalyst system that promotes an array of octane-enhancing reactions,including isomerization, conversion,dealkylation,and molecular-weight reduc-tion.The ability of the ISAL process to operate within a wide range of desulfurization and product octane combinations allows the re?ner to tailor the unit’s op-eration to the speci?c processing needs of the re?nery. In addition,recent improvements to the ISAL cata-lyst system and the process con?guration allow these tighter gasoline sulfur speci?cations to be achieved at higher yield and lower capital cost.Its products can meet the most stringent speci?cations of gasoline sul-fur and ole?n content.Because the?ow scheme and processing conditions of an ISAL unit are similar to
C.Song/Catalysis Today86(2003)211–263225
a conventional naphtha hydrotreating unit,the process can be implemented as either a new grassroots unit or as a revamp of an existing hydrotreater[77].The tech-nology is based on typical hydrotreating?ow schemes, which imply ease of operation and reliability as a re-?nery process.The upgraded FCC naphtha from the ISAL process is speci?cally suited to meet reformu-lated gasoline speci?cations in global market[78]. What are the differences between UOP-INTER-VEP’s ISAL process and ExxonMobil’s OCTGain process?The two processes are similar in terms of process design concept and processing schemes,but the catalysts and processing conditions are different. What are the differences between ExxonMobile’s SCAN?ning and OCTGain processes?SCAN?ning is used for selective HDS(to<30ppm sulfur)and has a high content of ole?ns in the product with little reduction in octane number.It was developed by ExxonMobil and Akzo Nobel Catalysts to reduce hydrogen consumption over a low-temperature and a low-pressure?xed-bed reactor.When the new Ex-omer process(caustic extraction of sulfur)is added to this,the desulfurization capability is extended fur-ther to10ppm[79].The Exomer process has been developed by ExxonMobil and Merichem to extract all the mercaptans from the fuel,and provide catalyst stability.The process does not involve the use of a catalytic naphtha splitter,which reduces the capital and operating costs of the motor gasoline desulfuriza-tion unit.OCTGain technology is used for deep HDS and the product has little ole?ns but a high-octane value due to isomerization of paraf?ns(alkanes)in the process,where the octane gain is at the expense of some yield loss to LPG.The technology can be used to vary product octane on a day-to-day basis, while keeping almost100%desulfurization. Isomerization of alkanes in naphtha cuts,as in-volved in OCTGain and ISAL processes,can be achieved by using catalysts to improve the octane num-ber of gasoline.For example,Jao et al.[80]reported on naphtha isomerization over mordenite-supported Pt catalysts.Their results demonstrated that catalyst performance was determined by Pt dispersion when using pure feed,whereas it was determined by both Pt dispersion and Pt cluster stability for feed containing 500ppm sulfur.Highest Pt dispersion and,thus,best performance with pure feed was obtained with a cat-alyst prepared by the ion exchange and pretreated at a low-temperature ramping rate(0.5?C/min)during calcination and reduction.In addition,this catalyst was pretreated by calcination at450?C,followed by reduction at450?C.In contrast,the catalyst having the best performance with feed containing500ppm sulfur was pretreated by calcination at450?C,followed by reduction at530?C.The authors suggested that the superior performance may result from a compromise between metal dispersion and metal cluster stability. As but one example of bimetallic catalysts,Lee and Rhee[81]prepared a series of bifunctional bimetallic M–Pt/H-Beta(M=Cu,Ga,Ni,and Pd)catalysts and examined them for the isomerization of n-hexane.The sulfur-containing feed was prepared by addition of thiophene in pure n-hexane to have500ppmw sulfur. Sulfur in the feed brought about a substantial decrease in the catalyst performance and the sulfur deactivation of bifunctional Pt/H-Beta turned out to be a two-step irreversible process caused by metal poisoning fol-lowed by coking.To test their effect on the sulfur tolerance,various second metals(Cu,Ga,Ni,and Pd)were added to monometallic Pt/H-Beta catalysts. Unfortunately,all of these,except for Pd,greatly de-creased the sulfur tolerance of the original Pt/H-Beta catalyst.Regardless of the preparation method or the Pd/Pt atomic ratio of the bimetallic Pd–Pt series,all the bimetallic catalysts showed high sulfur tolerance, in comparison to the monometallic Pt/H-Beta and Pd/H-Beta[81].The metal dispersion and the hydro-genation activity decreased in the Pd–Pt series com-pared to Pt/H-Beta.However,the amounts of sulfur adsorbed and coke deposited on the sulfur-deactivated Pd–Pt/H-Beta were much lower than those on Pt/H-Beta,Pd/H-Beta,and the other M–Pt/H-Beta cat-alysts.The authors suggested that the Pd–Pt bimetallic interaction in Pd–Pt/H-Beta increased the amount of electron de?cient metal sites,and that Pd–Pt bimetal-lic interaction inhibits irreversible sulfur adsorption and thereby reduces sulfur-induced coke formation [81].This is why the Pd–Pt series maintained high activity under sulfur deactivation conditions.
4.2.3.Catalytic distillation for desulfurization
The catalytic distillation desulfurization process developed by CDTech is signi?cantly different from conventional hydrotreating[82,83].The most im-portant portion of the CDTech desulfurization pro-cess is a set of two distillation columns loaded with
226 C.Song/Catalysis Today86(2003)
211–263
Fig.10.Flow scheme of CDTech’s CDHydro+CDHDS for naphtha desulfurization[82].
desulfurization catalyst in a packed structure.In this process,the LCN,MCN,HCN are treated separately, under optimal conditions for each.The?rst column, called CDHydro,treats the lighter compounds of FCC gasoline and separates the heavier portion of the FCC gasoline for treatment in the second column.The sec-ond column,called CDHDS,removes the sulfur from the heavier compounds of FCC gasoline.
Fig.10shows the?ow scheme of the process [82,84].The full-range FCC naphtha is fed to the CDHydro column and the desulfurization begins with fractionation of the light naphtha overhead in CDHy-dro column.Mercaptan sulfur reacts quantitatively with excess diole?ns to product heavier sulfur com-pounds,and the remaining diole?ns are partially sat-urated to ole?ns by reaction with hydrogen.Bottoms from the CDHydro column,containing the reacted mercaptans,are fed to the CDHDS column where the MCN and HCN are catalytically desulfurized in two separate zones.HDS conditions are optimized for each fraction to achieve the desired sulfur reduction with minimal ole?n saturation.Ole?ns are concen-trated at the top of the column,where conditions are mild,while sulfur is concentrated at the bottom where the conditions result in very high levels of HDS. The temperature and pressure of the CDTech process columns are lower than?xed-bed hydrotreating pro-cesses,particularly in the upper section of the distil-lation column,which is where most of the ole?ns are located.These operating conditions minimize yield and octane loss.
While the CDTech process is very different from conventional hydrotreating,the catalyst used for re-moving the sulfur compounds is the same[1].CD-Hydro combines fractionation and hydrogenation and it is designed to selectively hydrogenate diole?ns in the top section of a hydrocarbon distillation column. Conventional hydrotreating requires a distillation col-umn after?xed-bed hydrogenation unit,while CD-Hydro eliminates the?xed-bed unit by incorporating catalyst in the column.Proprietary devices containing catalysts are installed in the fractionation column’s top section,and hydrogen is introduced beneath the cata-lyst zone.Fractionation carries the light components into the catalyst zone where reaction with H2occurs. Fractionation also sends the heavy materials to the bot-tom.This prevents foulants and heavy catalyst poisons in the feed from contacting the catalyst.In addition, the clean hydrogenated re?ux continuously washes the catalyst zone.These factors combine to give a longer catalyst life.In the bottom of catalyst zone,mercap-tans react with diole?ns to form heavy,thermally sta-ble sul?des.These sul?des have higher boiling points than the C5fraction and are easily fractionated to the bottom product[83].This can eliminate a separate mercaptan removal step[82].There are over14com-mercial CDHydro units in operation for C4,C5,C6 and benzene hydrogenation applications[82]. CDHDS is used in combination with CDHyrdro to selectively desulfurize gasoline with minimum oc-tane loss.Bottoms of CDHydro column,containing the reacted mercaptans,are fed to the CDHDS column
C.Song /Catalysis Today 86(2003)211–263227
where the MCN and HCN are catalytically desulfur-ized in two separate zones.HDS conditions are opti-mized for each fraction to achieve the desired sulfur reduction with minimal ole?n saturation.Ole?ns are concentrated at the top of the column,where condi-tions are mild,while sulfur is concentrated at the bot-tom,where the conditions results in very high levels of HDS [82].
Catalytic distillation essentially eliminates catalyst fouling because the fractionation removes heavy coke precursors from the catalyst zone before coke can form and foul the catalyst bed.The estimated ISBL capital cost for 35,000bpd CDHydro/CDHDS unit with 92%desulfurization is US$25million,and the direct oper-ating cost including utilities,catalyst,hydrogen,and octane replacement are estimated to be US$0.03/gal of full-range FCC naphtha [82].A recent article dis-cusses the CDHDS technology from CDTech for re-liable HDS operation,where the catalyst cycle length for CDTech catalytic distillation technologies can be aligned with the 5-year FCC operating cycles [8]
.Flow Scheme of S Zorb Gasoline
Principle of S Zorb process
ET
Fig.11.ConocoPhillips’s S-Zorb sulfur removal process based on solid adsorbent and its continuous regeneration [85,86].
4.2.4.Reactive adsorption for sulfur capture at elevated temperatures
Reactive adsorption refers to the processes using metal-based sorbent for sulfur capture to form metal sul?de.Phillips Petroleum (now ConocoPhillips)de-veloped a new process called S-Zorb that can be used for making low-sulfur gasoline [85].Fig.11shows the scheme of S-Zorb Gasoline process along with the principle of S-Zorb process [85,86].The sulfur atom of the sulfur-containing compounds adsorbs onto the sorbent and reacts with the sorbent.Phillips Petroleum uses a proprietary sorbent that attracts sulfur-containing molecules and removes the sulfur atom from the molecule.The sulfur atom is retained on the sorbent while the hydrocarbon portion of the molecule is released back into the process stream.Hydrogen sul?de is not released into the product stream and therefore prevents recombination reactions of hydrogen sul?de and ole?ns to make mercaptans,which could otherwise increase the ef?uent sulfur concentration.Based on the principle,it appears that
228 C.Song/Catalysis Today86(2003)211–263
the sorbent is based on reduced metal that reacts with sulfur to become metal sul?de.
The spent sorbent is continuously withdrawn from the reactor and transferred to the regenerator section. In a separate regeneration vessel,the sulfur is burned off of the sorbent and SO2is sent to the sulfur plant. The cleansed sorbent is further reduced by hydrogen and the regenerated sorbent is then recycled back to the reactor for removing more sulfur.The rate of sor-bent circulation is controlled to help maintain the de-sired sulfur concentration in the product.Because the sorbent is continuously regenerated,Phillips estimates that the unit will be able to operate4–5years between shutdowns[4].
Table9shows the performance of S-Zorb pro-cess for naphtha under the following general oper-ating conditions:reactor temperature,650–775?F (343–413?C);reactor pressure,100–300psig(7–21atm);space velocity,4–10WHSV;H2gas pu-rity,>50%[86].ConocoPhillips’s?rst commercial S-Zorb Gasoline unit began operations successfully Table9
Performance of S-Zorb process for FCC naphtha[86]
Case1a Case2a Feed properties
Unit capacity(bpd)3500035000 Sulfur(ppmw)3001500 Product properties
Sulfur(ppmw)1010
V olume yield(%)>99.9>99.9
RVP change None None
(R+M)/2loss<0.3<1.0 Utilities
Chemical hydrogen
consumption(ft3/bbl)
2570
Fuel(btu/bbl)3300033000 Electricity(kW/bbl)0.8 1.1 Cooling water(gal/bbl)115115 Steam,MP(lb/bbl)1212 Nitrogen(ft3/bbl416 Economics
Capital cost(ISBL)US$800/bbl US$900/bbl Operating cost(cent/gal)b0.9 1.2
a S-Zor
b SRT when processing full-range FCC naphtha(re-actor temperature:650–775?F(343–413?C);reactor pressure: 100–300psig(7–21atm);space velocity:4–10WHSV;H2gas purity:>50%).
b Includes utilities,4%per year maintenance and sorbent costs.in its Borger re?nery in Texas,USA,in early2001, for processing6000barrels of gasoline feed per day to produce gasoline with10ppmw sulfur[86].A second S-Zorb Gasoline unit at25,000barrels per day is scheduled to be started in late2003at the ConocoPhillips re?nery in Ferndale,W A[87]. Research Triangle Institute(RTI)is developing another reactive adsorption process called TReND (transport reactor for naphtha desulfurization)which is based on metal oxide sorbent.The feature of TReND process is that supported metal oxide-based regenerable sorbent is used to capture the sulfur in a transport reactor which is similar to FCC reactor[88]. RTI has conducted extensive studies on desulfuriza-tion of synthesis gas from coal gasi?cation[89],and recently applied their expertise in H2S removal using metal oxide to organi
c sulfur removal from liqui
d fu-els at800–1000?F(426–535?C)with or without th
e presence o
f H2gas feed in the TReND process[90]. Fig.12shows the scheme of the transport reactor for TReND process,and Table10shows the results for naphtha desulfurization with RTIs pilot test reactor [91,92].Mercaptan type sulfur is captured completely without H2,but thiophenic sulfur capture seems to
be Fig.12.RTIs transport reactor for naphtha desulfurization (TReND)process[91].
C.Song /Catalysis Today 86(2003)211–263
229
Table 10
PONA and octane analysis for FCC naphtha testing in RTIs PTR [91]
Feed
Product PONA analysis (%)Paraf?ns 41.4540.9Ole?ns
19.722.1Monocycloparaf?ns 12.8411.1Dicycloparaf?ns 0.850.3Alkylbenzenes 22.3819.6Indanes/tetralins 2.28 2.4Naphthalenes 0.50.5Octane number Research 91.090.8Motor
80.8
81.5
better in the presence of H 2[90].The octane number is preserved in general in naphtha desulfurization.RTI has also conducted pilot plant test with an engineering company.
Tawara et al.[93–95]reported their study on us-ing Ni/ZnO catalyst as sorbent for adsorptive HDS of kerosene for fuel-cell applications,where Ni reacts with sulfur under H 2to form NiS which then pass the sulfur to ZnO to form ZnS and regenerate Ni.The more recent paper describes Ni/ZnO as an autoregen-erative nickel catalyst for adsorptive HDS [95].Based on the work of Tawara et al.,Babich and Moulijn [49]discussed the mechanism of reactive adsorption using Ni/ZnO shown in Fig.13.This may provide some fun-damental understanding regarding what may happen under reactive adsorption using metal or metal
oxide
Fig.13.Mechanism of reactive adsorption desulfurization [49].
under H 2atmosphere,such as the S-Zorb and TReND process.
4.2.
5.Polar adsorption using alumina-based adsorbents
The IRV AD process by Black and Veatch Pritchard and Alcoa Industrial Chemicals is claimed to be a low-cost process for making low-sulfur gasoline [96–98].The process uses an alumina-based adsor-bent to counter-currently contact liquid hydrocarbon in a multistage adsorber.The adsorbent is regenerated in a continuous cross-?ow reactivator using heated reactivation gas.The process operates at lower pres-sure,does not consume hydrogen or saturate ole?ns.The adsorption mechanism is based on the polarity of sulfur,and nitrogen compounds in gasoline range.The adsorbent is ?uidized and continuously removed and regenerated,using hydrogen,in a second col-umn.The regenerated adsorbent is then recycled back into the reactor vessel at the rate which it is being removed.In the regeneration column,the adsorbed heteroatom containing petroleum compounds,which is about 4%of the re?nery stream being treated,are removed from the adsorbent [1].However,since it is based on polarity,it is not expected to be very selec-tive towards sulfur compounds in liquid fuels such as gasoline,diesel fuels and jet fuels.Work on the IRV AD process is currently discontinued [49].4.2.6.Selective adsorption for removing sulfur
Pennsylvania State University is exploring a new desulfurization process by selective adsorption for
230 C.Song /Catalysis Today 86(2003)211–263
removing sulfur (PSU-SARS)at ambient tempera-ture without using hydrogen or any other reactive gas [21].In general,adsorption of sulfur compounds has been studied and reported in both open literature and patent literature for many years,but not successfully developed for liquid fuels because there are major problems with selectivity towards sulfur compounds in the presence of many other compounds such as aromatics and polar species in re?nery streams.In developing the PSU-SARS concept,the key consider-ation is to design the adsorbent materials to selectively interact with sulfur in the presence of large excess of aromatic compounds,which exist in concentrations of >20%in comparison with less than 1wt.%sulfur compounds [32,33,99].
The scienti?c basis behind the experimental ap-proach for PSU-SARS is that there exists site-speci?c interactions between sulfur and metal species that are known to be possible with some organometal-lic complexes [32,33].Penn State is preparing and examining various new adsorbent materials for selec-tive adsorption desulfurization process concept based on sulfur-selective adsorption of liquid hydrocarbon fuels (gasoline,diesel fuel and jet fuel)for produc-ing ultra-clean transportation fuels and for fuel-cell applications.There are several recent reports on PSU-SARS for deep desulfurization of distillate fuels (diesel,gasoline and jet fuels)based on selective ad-sorption for removal of sulfur compounds at
ambient Fig.14.Known coordination geometries of thiophene in organometallic complexes,indicating likely adsorption con?gurations of thiophenic compounds on the surface of adsorbents [32].
conditions without using H 2[21,32,33,99–102].Am-bient temperatures for various application environ-ments range from room temperature to about 250?C.Fig.14illustrates the known coordination geome-tries of thiophene in organometallic complexes,which indicate likely adsorption con?gurations of thiophenic compounds on the surface of adsorbents [32].Both thiophenic compounds and non-sulfur aromatic com-pounds can interact with metal species by ?-electrons.However,in Fig.14only two types of interaction of thiophene with metal involve sulfur atom in thiophene,the ?1-S bonding interaction between the sulfur atom and one metal atom,and the S-?3bonding interaction between the sulfur atom and two metal atoms.Several adsorbents based on transition metal complexes sup-ported on porous materials,zeolites,supported tran-sition metals,mixed metal oxides,activated carbon,etc.have been developed and used for selective ad-sorption desulfurization of diesel fuel,gasoline and jet fuel at ambient temperatures.The results from testing various liquid fuels show that selective adsorption of sulfur compounds can be achieved using PSU-SARS process in laboratory scale [17,21,32,33,99–102].Fig.15shows the breakthrough curves for the ad-sorptive desulfurization of commercial real gasoline containing about 210ppmw of sulfur over Ni-based supported adsorbents,PSU A-2at room temperature (30?C)and PSU A-5at different temperatures [101].Fig.16shows the sulfur-selective GC-pulsed ?ame
常用介词的用法
分考点1 表示时间的介词 Point 1 at, in, on 的用法 （1）at 的用法 At 表示时间点，用于具体的时刻（几点，正午，午夜，黎明，拂晓，日出，日落等），或把某一时间看作某一时刻的词之前以及某些节假日的词之前。 at 6：00 在6点钟 At noon 在中午 At daybreak 在拂晓 At down 在黎明 At Christmas 在圣诞节 【特别注意】在以下的时间短语中，at 表示时间段。 At dinner time 在（吃）晚饭时 At weekends/ the weekend 在周末 （2）in 的用法 ①表示时间段，与表示较长一段时间的词搭配，如年份，月份，季节，世纪，朝代，还可以用于泛指的上午、下午、傍晚等时间段的词前。 In 2009 在2009年 In April 在四月 In the 1990s 在20世纪90年代 In Tang Dynasty 在唐朝 In the morning在上午 ②后接时间段，用于将来时，表示“在一段时间之后”。 The film will begin in an hour. 电影将于一个小时之后开始。 【特别注意】当时间名词前有this，that，last，next，every，each，some等词修饰时，通常不用任何介词。 This morning 今天上午last year 去年 （3）on 的用法 ①表示在特定的日子、具体的日期、星期几、具体的某一天或某些日子。 On September the first 在9月1号 On National Day 在国庆节 We left the dock on a beautiful afternoon. 我们在一个明媚的下午离开了码头。 ②表示在具体的某一天的上午、下午或晚上（常有前置定语或后置定语修饰）。 On Sunday morning 在星期日的早上 On the night of October 1 在10月1号的晚上 【特别注意】“on +名词或动名词”表示“一...就...”. On my arrival home/ arriving home, I discovered they had gone. 我一到家就发现他们已经离开了。 Point 2 in，after 的用法 In 和after都可以接时间段，表示“在...之后”，但in 常与将来时连用，after 常与过去时连用。 We will meet again in two weeks.
英语介词用法大全
英语介词用法大全 TTA standardization office【TTA 5AB- TTAK 08- TTA 2C】
介词（The Preposition）又叫做前置词，通常置于名词之前。它是一种虚词，不需要重读，在句中不单独作任何句子成分，只表示其后的名词或相当于名词的词语与其他句子成分的关系。中国学生在使用英语进行书面或口头表达时，往往会出现遗漏介词或误用介词的错误，因此各类考试语法的结构部分均有这方面的测试内容。 1. 介词的种类 英语中最常用的介词，按照不同的分类标准可分为以下几类： (1). 简单介词、复合介词和短语介词 ①.简单介词是指单一介词。如： at , in ,of ,by , about , for, from , except , since, near, with 等。②. 复合介词是指由两个简单介词组成的介词。如： Inside, outside , onto, into , throughout, without , as to as for , unpon, except for 等。 ③. 短语介词是指由短语构成的介词。如： In front of , by means o f, on behalf of, in spite of , by way of , in favor of , in regard to 等。 (2). 按词义分类 {1} 表地点（包括动向）的介词。如： About ,above, across, after, along , among, around , at, before, behind, below, beneath, beside, between , beyond ,by, down, from, in, into , near, off, on, over, through, throught, to, towards,, under, up, unpon, with, within , without 等。 {2} 表时间的介词。如： About, after, around , as , at, before , behind , between , by, during, for, from, in, into, of, on, over, past, since, through, throughout, till(until) , to, towards , within 等。 {3} 表除去的介词。如： beside , but, except等。 {4} 表比较的介词。如： As, like, above, over等。 {5} 表反对的介词。如： againt ,with 等。 {6} 表原因、目的的介词。如： for, with, from 等。 {7} 表结果的介词。如： to, with , without 等。 {8} 表手段、方式的介词。如： by, in ,with 等。 {9} 表所属的介词。如： of , with 等。 {10} 表条件的介词。如：
英语介词用法详解
英语常用介词用法与辨析 ■表示方位的介词：in, to, on 1. in 表示在某地范围之内。如： Shanghai is/lies in the east of China. 上海在中国的东部。 2. to 表示在某地范围之外。如： Japan is/lies to the east of China. 日本位于中国的东面。 3. on 表示与某地相邻或接壤。如： Mongolia is/lies on the north of China. 蒙古国位于中国北边。 ■表示计量的介词：at, for, by 1. at表示“以……速度”“以……价格”。如： It flies at about 900 kilometers a hour. 它以每小时900公里的速度飞行。 I sold my car at a high price. 我以高价出售了我的汽车。 2. for表示“用……交换，以……为代价”。如： He sold his car for 500 dollars. 他以五百元把车卖了。 注意：at表示单价(price) ，for表示总钱数。 3. by表示“以……计”，后跟度量单位。如： They paid him by the month. 他们按月给他计酬。 Here eggs are sold by weight. 在这里鸡蛋是按重量卖的。 ■表示材料的介词：of, from, in 1. of成品仍可看出原料。如： This box is made of paper. 这个盒子是纸做的。 2. from成品已看不出原料。如： Wine is made from grapes. 葡萄酒是葡萄酿成的。 3. in表示用某种材料或语言。如： Please fill in the form in pencil first. 请先用铅笔填写这个表格。 They talk in English. 他们用英语交谈(from 。 注意：in指用材料，不用冠词；而with指用工具，要用冠词。请比较：draw in penc il/draw with a pencil。 ■表示工具或手段的介词：by, with, on 1. by用某种方式，多用于交通。如by bus乘公共汽车，by e-mail. 通过电子邮件。
with的用法大全
with的用法大全----四级专项训练with结构是许多英语复合结构中最常用的一种。学好它对学好复合宾语结构、不定式复合结构、动名词复合结构和独立主格结构均能起很重要的作用。本文就此的构成、特点及用法等作一较全面阐述，以帮助同学们掌握这一重要的语法知识。 一、 with结构的构成 它是由介词with或without+复合结构构成，复合结构作介词with或without的复合宾语，复合宾语中第一部分宾语由名词或代词充当，第二部分补足语由形容词、副词、介词短语、动词不定式或分词充当，分词可以是现在分词，也可以是过去分词。With结构构成方式如下： 1. with或without-名词/代词+形容词; 2. with或without-名词/代词+副词; 3. with或without-名词/代词+介词短语; 4. with或without-名词/代词+动词不定式; 5. with或without-名词/代词+分词。 下面分别举例：
1、 She came into the room，with her nose red because of cold.(with+名词+形容词，作伴随状语) 2、 With the meal over ， we all went home.(with+名词+副词，作时间状语) 3、The master was walking up and down with the ruler under his arm。(with+名词+介词短语，作伴随状语。) The teacher entered the classroom with a book in his hand. 4、He lay in the dark empty house，with not a man ，woman or child to say he was kind to me.(with+名词+不定式，作伴随状语) He could not finish it without me to help him.(without+代词 +不定式，作条件状语) 5、She fell asleep with the light burning.(with+名词+现在分词，作伴随状语) 6、Without anything left in the cupboard， she went out to get something to eat.(without+代词+过去分词，作为原因状语) 二、with结构的用法 在句子中with结构多数充当状语，表示行为方式，伴随情况、时间、原因或条件(详见上述例句)。
高中英语45个介词的基本用法
——45个基本介词的用法 1、about 【原始含义】 a-b-out “A在B外面” 【引申含义】 [prep] （1）在…到处，在…各处here and there eg: We wandered about the town for an hour or so. He looked about the room. （2）在…附近next to a place eg. She lives about the office. （3）关于in connection with eg: a book about English study I don’t know what you are talking about. [adv] （1）大约close to eg: We left there about 10 o’clock. It costs about 500 dollars. （2）到处，各处 eg: The children were rushing about in the garden. （3）在附近 eg : There is no food about. 【常见搭配】 作介词时的搭配: 一.动词+(about+名词) （1）arrange (about sth) 安排关于某事（2）argue (about sth) 讨论某事 （3）ask (about sth) 询问关于某事（4）boast (about sb/sth) 吹嘘... （5）care (about sb/sth)关心…,对…感兴趣（6）chat(about sth) 谈论某事（7）complain(about sb/sth) 抱怨… （8）dream (about sb/sth) 梦见某人/某物（9）go (about sth) 着手做...；从事...
with用法归纳
with用法归纳 （1）“用……”表示使用工具，手段等。例如： ①We can walk with our legs and feet. 我们用腿脚行走。 ②He writes with a pencil. 他用铅笔写。 （2）“和……在一起”，表示伴随。例如： ①Can you go to a movie with me? 你能和我一起去看电影'>电影吗？ ②He often goes to the library with Jenny. 他常和詹妮一起去图书馆。 （3）“与……”。例如： I’d like to have a talk with you. 我很想和你说句话。 （4）“关于，对于”，表示一种关系或适应范围。例如： What’s wrong with your watch? 你的手表怎么了？ （5）“带有，具有”。例如： ①He’s a tall kid with short hair. 他是个长着一头短发的高个子小孩。 ②They have no money with them. 他们没带钱。 （6）“在……方面”。例如： Kate helps me with my English. 凯特帮我学英语。 （7）“随着，与……同时”。例如： With these words, he left the room. 说完这些话，他离开了房间。 [解题过程] with结构也称为with复合结构。是由with+复合宾语组成。常在句中做状语，表示谓语动作发生的伴随情况、时间、原因、方式等。其构成有下列几种情形： 1.with+名词(或代词)+现在分词 此时，现在分词和前面的名词或代词是逻辑上的主谓关系。 例如:1)With prices going up so fast, we can't afford luxuries. 由于物价上涨很快，我们买不起高档商品。（原因状语） 2)With the crowds cheering, they drove to the palace. 在人群的欢呼声中，他们驱车来到皇宫。（伴随情况） 2.with+名词(或代词)+过去分词 此时，过去分词和前面的名词或代词是逻辑上的动宾关系。
介词with的用法大全
介词with的用法大全 With是个介词，基本的意思是“用”，但它也可以协助构成一个极为多采多姿的句型，在句子中起两种作用；副词与形容词。 with在下列结构中起副词作用： 1.“with+宾语+现在分词或短语”，如： (1) This article deals with common social ills, with particular attention being paid to vandalism. 2.“with+宾语+过去分词或短语”，如： (2) With different techniques used, different results can be obtained. (3) The TV mechanic entered the factory with tools carried in both hands. 3.“with+宾语+形容词或短语”，如： (4) With so much water vapour present in the room, some iron-made utensils have become rusty easily. (5) Every night, Helen sleeps with all the windows open. 4.“with+宾语＋介词短语”，如： (6) With the school badge on his shirt, he looks all the more serious. (7) With the security guard near the gate no bad character could do any thing illegal. 5.“with+宾语＋副词虚词”，如： (8) You cannot leave the machine there with electric power on. (9) How can you lock the door with your guests in? 上面五种“with”结构的副词功能，相当普遍，尤其是在科技英语中。 接着谈“with”结构的形容词功能，有下列五种： 一、“with+宾语+现在分词或短语”，如： (10) The body with a constant force acting on it. moves at constant pace. (11) Can you see the huge box with a long handle attaching to it ? 二、“with+宾语+过去分词或短语” (12) Throw away the container with its cover sealed. (13) Atoms with the outer layer filled with electrons do not form compounds. 三、“with+宾语+形容词或短语”，如： (14) Put the documents in the filing container with all the drawers open.
介词at的基本用法
介词at的基本用法： 一、at引导的时间短语通常可表示： 1.在几点几分，例如：at one o’clock(在一点钟) I usually make the bed at one o’clock.. 2.在用餐时间，例如：at lunchtime（在午餐时间） 3.在某个节日，例如：at Christmas 在圣诞节的时候 4.在某个年龄的时候，例如：at the age of 12。在12岁的时候 5.一天中的某段较短的时间，例如：at noon在中午at night在夜里 二、at也可引导地点短语，常用于小地点之前，例如： at the bus stop在汽车站at the butcher’s 在肉店里at school在学校里at home在家里 介词on的基本用法： 一、on可引导地点短语，表示“在…上面”，例如：on the table在桌子上 二、on也可引导时间短语，通常有以下用法： 1.用于“星期”和“月份”中的任何一天之前，例如：On Monday在星期一on April 1st. 2.用于某个“星期几”当天的某段时间，例如：on Monday morning在星期一上午 3.用于具体某一天之前，例如：on that day在那一天On my birthday在我的生日那天 On Christmas day在圣诞节那天 介词in的基本用法： 一、in可引导地点短语，常表示“在…里面”，例如：in the bag在袋子里 二、in引导的时间短于通常有以下用法： 1.在某个世纪，例如：in the 21st century在21世纪 2.在某一年，例如：in 1995在1995年 3.在某一个季节，例如：in spring在春季 4.在某一个月份，例如：in March在三月里 5.在某段时期，例如：in the holidays在假期里 6.在某个持续几天的节日里，例如：in Easter Week在复活周 7.在一天中的某段时间，例如：in the morning在上午（早晨）
初中 英语 介词“with”的用法
介词“with”的用法 1、同, 与, 和, 跟 talk with a friend 与朋友谈话 learn farming with an old peasant 跟老农学习种田 fight [quarrel, argue] with sb. 跟某人打架 [争吵, 辩论] [说明表示动作的词, 表示伴随]随着, 和...同时 change with the temperature 随着温度而变化 increase with years 逐年增加 be up with the dawn 黎明即起 W-these words he left the room. 他说完这些话便离开了房间。2 2、表示使用的工具, 手段 defend the motherland with one s life 用生命保卫祖国 dig with a pick 用镐挖掘 cut meat with a knife 用刀割肉3
3、说明名词, 表示事物的附属部分或所具有的性质]具有; 带有; 加上; 包括...在内 tea with sugar 加糖的茶水 a country with a long history 历史悠久的国家4 4、表示一致]在...一边, 与...一致; 拥护, 有利于 vote with sb. 投票赞成某人 with的复合结构作独立主格,表示伴随情况时，既可用分词的独立结构，也可用with的复合结构： with +名词(代词)+现在分词/过去分词/形容词/副词/不定式/介词短语。例如： He stood there, his hand raised. = He stood there, with his hand raise.他举手着站在那儿。 典型例题 The murderer was brought in, with his hands ___ behind his back A. being tied B. having tied C. to be tied D. tied 答案D. with +名词(代词)+分词+介词短语结构。当分词表示伴随状况时，其主语常常用
高中常见介词的基本用法
介词 介词不能单独作句子成分，而是用来表示名词或代词等和句中其他词的关系，通常放在名词或代词之前，构成介词短语。介词短语作为一个成分在句中可用作定语，表语，状语等。When shall we have the talk on the history of the Party我们何时听党史报告（定语）His elder brother is in the army.他的哥哥在部队。（表语） I went to school at half past seven yesterday.昨天我7：30 上学。（状语） 《 Will you please come along with me跟我一起走好吗（状语） ※同一个汉语词可以译成不同的英语介词。例如： 一幢石头的房子 a house of stone 这个房间的钥匙 the key to this room 明天的票 the ticket for tomorrow 《 （一）About 1．表示地点：在。。。周围；在。。。附近 We took the foreign guests about the campus. 我们带领外宾在校园里各处看看。 2．表示时间：大约。。。；近于。。。时刻前后We left there about six o’clock 我大约在六点左右离开那个地方。 3．表示客体关系：对于；关于；有关。例如：1) I must see him, I’ve heard so much about him 我必须要见他，我听到很多关于他的事情。2) What do you know about China 关于中国你知道些啥 （二）Above 表示位置，职位，数量，年龄等：在。。。上方；在。。。之上；超过。。。 1) Henry’s work is well above the average.亨利的功课大大超过一般水平。 2) A bird is flying above the woods. 一只鸟在树林上飞。 3) The portrait is above the blackboard.一幅肖像挂在黑板的上方。 4) It weighs above five tons. 这东西有5 吨多重。 （三）Across 1．表动作方向/位置：横过；穿过。（在表面）1）The boy helped the old lady across the street. 男孩扶老大娘穿过马路。2) The tree had fallen down across the railway line.树倒啦，横在铁路上。 2．表示地点：在对面；在。。。的另一边。 1）The church is across the river. 教堂在河的对面。 （四）After 1.表示时间或位置：在。。。之后。 1）Please line up one after another. 请一个挨一个排好对。 He goes on working day after day ,week after week without any change. 他继续日复一日地工作，没有丝毫改变。Shut the door after you. 随手关门！ 2．引伸意义：仿照；按照。 Please make sentences after the model. 请照示例造句。 ※（五）Against 1．表示位置：依着；紧靠；撞击；碰着。 1) He rested his bike against the wall.他把自行车靠在墙上。 2) The rain was beating against the windows. 雨敲打着窗户。 2．引伸意义：反对；禁止。 1）Are you for it or against it 你是赞成还是反对 2) Is there a law in this country against spitting right and left 你们国家有没有反对随地吐痰的规定
英语介词with的用法
英语介词with的用法 with结构是许多英语复合结构中最常用的一种。学好它对学好复合宾语结构、不定式复合结构、动名词复合结构和独立主格结构均能起很重要的作用。本文就此的构成、特点及用法等作一较全面阐述，以帮助同学们掌握这一重要的语法知识。 一、 with结构的构成 它是由介词with或without+复合结构构成，复合结构作介词with或without的复合宾语，复合宾语中第一部分宾语由名词或代词充当，第二部分补足语由形容词、副词、介词短语、动词不定式或分词充当，分词可以是现在分词，也可以是过去分词。With结构构成方式如下： 1. with或without-名词/代词+形容词； 2. with或without-名词/代词+副词； 3. with或without-名词/代词+介词短语； 4. with或without-名词/代词+动词不定式； 5. with或without-名词/代词+分词。 下面分别举例： 1、 She came into the room，with her nose red because of cold.（with+名词+形容词，作伴随状语） 2、 With the meal over ， we all went home.（with+名词+副词，作时间状语） 3、The master was walking up and down with the ruler under his arm。（with+名词+介词短语，作伴随状语。） The teacher entered the classroom with a book in his hand. 4、He lay in the dark empty house，with not a man ，woman or child to say he was kind to me.（with+名词+不定式，作伴随状语） He could not finish it without me to help him.（without+代词 +不定式，作条件状语） 5、She fell asleep with the light burning.（with+名词+现在分词，作伴随状语） 6、Without anything left in the cupboard， she went out to get something to eat.（without+代词+过去分词，作为原因状语）
介词with用法小结
with在下列结构中起副词作用： 1."with+宾语+现在分词或短语"，如： 2."with+宾语+过去分词或短语"，如： （2）With different techniques used，different results can be obtained. （3）The TV mechanic entered the factory with tools carried in both hands. 3."with+宾语+形容词或短语"，如： （5）Every night，Helen sleeps with all the windows open. 4."with+宾语＋介词短语"，如： （6）With the school badge on his shirt，he looks all the more serious. （7）Withesecurityguardnearthegatenobadcharactercoulddoanythingillegal. 5."with+宾语＋副词虚词"，如： （8）You cannot leave the machine there with electric power on. （9）How can you lock the door with your guests in？ 上面五种"with"结构的副词功能，相当普遍，尤其是在科技英语中。 接着谈"with"结构的形容词功能，有下列五种： 一、"with+宾语+现在分词或短语"，如： （10）The body with a constant force acting on it. moves at constant pace. （11）Can you see the huge box with a long handle attaching to it？二、"with+宾语+过去分词或短语" （12）Throw away the container with its cover sealed.
介词with的用法
介词with的用法 1.表示人与人的协同关系，意为“一起”“和” go with 与..一起去 play with 与...一起玩 live with 与...一起住/生活 work with 与...一起工作 make friends with 与....交朋友 talk with sb = talk to sb fight with 与...打架/战斗 cooperate with 与...一起合作 2.表示“带有”“拥有” tea with honey 加蜂蜜的茶 a man with a lot of money 一个有很多钱的人 a house with a big garden 一个带有大花园的房子 a chair with three legs 一张三条腿的椅子 a girl with golden hair 金发的女孩 3.表示“用”某种工具或手段 write with a pencil 用铅笔写字 cut the apple with a knife 用刀切苹果 4.表示“在...身边”“在...身上” I don’t have any money with me. 我身上没带钱。 Take an umbrella with you in case it rains 带把伞以防下雨。 5.表示“在...之下” With the help of sb = with one’s help 在某人的帮助下 6.表示“随着” with the development of ... 随着...的发展 float with the wind 随风飘动
7.常见带有with的动词短语 agree with sb/sth 同意某人或某事deal with sth = do with sth 处理某事 help sb with sth 在...上帮助某人 fall in love with sb/sth 爱上某人/某物 get on with sb 与某人相处 get on well with sb 与某人相处得好 have nothing to do with sb 与某人无关compare A with B 将A和B作比较communicate with sb 与某人交流 argue with sb = quarrel with sb 与某人吵架Have fun with sth 玩的开心 Get away with sth 做坏事不受惩罚 Chat with sb 跟某人闲谈 Charge sb with sth 指控某人。。。 Put up with sth 忍受 8.常见带with的形容词固定搭配 be satisfied with 对...满意 be content with sth 对...满足 be angry with sb 生某人的气 be strict with sb 对某人严格 be patient with sb 对某人有耐心 be popular with sb 受某人欢迎 be filled with sth 装满... 充满..... = be full of sth What’s wrong/the matter with sb/sth be familiar with sb/sth 熟悉某人或某物 be connected with sb/sth 与....有关 Be decorated with 被。。。装饰 Be impressed with/by
45个英语介词的用法
45个常见介词的基本用法 介词短语=介词+名词 1、about 基本含义：a-b-out “A在B外面” 引申含义：“A和B的联系” 1、在…周围：The kids are sitting about their teacher. I like the necklace about her throat. 2、环绕：The bird always flies about the forest. I plan to travel about the world. 3、关于：a book about English study They are talking about the new film. 4、[adv] 大约 固定搭配： 1、How about... 2、something+adj+about X 一些关于X的adj的事 2、above 基本含义：a-b-over “A在B上方” 引申含义： 1、在…上方:The sun rose above the horizon. 2、数目大于…/重量超过…/价格（能力、地位）高于… There is nothing in the store above 50 cents. “He who comes after me is above me ,because he was before me” 固定搭配： 1、above all: 首先（强调重要性） Above all, he was an outstanding
mathematician. 2、above all things:最最… What you need, above all things, is confidence. 3、be above oneself: 兴高采烈=high spirit When he heard the good news, he was above himself. 3、across 基本含义：a-grass “A走过一片草坪” 引申含义： 1、穿过：She walked across the road. 2、在...对面: The bar is just across the street. 3、交叉：He sat with his arms across his chest. The two lines pass across each other at right angles. 固定搭配： 1、A come across B. A偶遇B。 I came across Yu Minhong the other day. 2、A get sth across to B.A使某 物被B了解。 I want to get my theory across to all students. 4、after 基本含义：“A在B之后” （强调顺序） 引申含义： 1、在…之后（时间顺序、空间顺序） After dinner, they went out for a walk. I should after him, but he still went on. 2、照着…的样子
介词in,on.at,for.with,by,of的基本用法
介词用法知多少 介词是英语中最活跃的词类之一。同一个汉语词汇在英语中可译成不同的英语介词。例如汉语中的“用”可译成：（1）用英语（in English）；（2）用小刀（with a knife）；（3）用手工（by hand）；（4）用墨水（in ink）等。所以，千万不要以为记住介词的一两种意思就掌握了这个介词的用法，其实介词的用法非常广泛，搭配能力很强，越是常用的介词，其含义越多。下面就简单介绍几组近义介词的用法及其搭配方法。 一. in, to, on和off在方位名词前的区别 1. in表示A地在B地范围之内。如： Taiwan is in the southeast of China. 2. to表示A地在B地范围之外，即二者之间有距离间隔。如： Japan lies to the east of China. 3. on表示A地与B地接壤、毗邻。如： North Korea is on the east of China. 4. off表示“离……一些距离或离……不远的海上”。如： They arrived at a house off the main road. New Zealand lies off the eastern coast of Australia. 二. at, in, on, by和through在表示时间上的区别 1. at指时间表示： （1）时间的一点、时刻等。如： They came home at sunrise （at noon, at midnight, at ten o’clock, at daybreak, at dawn）. （2）较短暂的一段时间。可指某个节日或被认为是一年中标志大事的日子。如： He went home at Christmas （at New Y ear, at the Spring Festival, at night）. 2. in指时间表示： （1）在某个较长的时间（如世纪、朝代、年、月、季节以及泛指的上午、下午或傍晚等）内。如： in 2004, in March, in spring, in the morning, in the evening, etc （2）在一段时间之后。一般情况下，用于将来时，谓语动词为瞬间动词，意为“在……以后”。如： He will arrive in two hours. 谓语动词为延续性动词时，in意为“在……以内”。如： These products will be produced in a month. 注意：after用于将来时间也指一段时间之后，但其后的时间是“一点”，而不是“一段”。如： He will arrive after two o’clock. 3. on指时间表示： （1）具体的时日和一个特定的时间，如某日、某节日、星期几等。如： On Christmas Day（On May 4th）, there will be a celebration. （2）在某个特定的早晨、下午或晚上。如： He arrived at 10 o’clock on the night of the 5th. （3）准时，按时。如： If the train should be on time, I should reach home before dark. 4. by指时间表示： （1）不迟于，在（某时）前。如：
with的用法大全
with的用法大全 with结构是许多英语复合结构中最常用的一种。学好它对学好复合宾语结构、不定式复合结构、动名词复合结构和独立主格结构均能起很重要的作用。本文就此的构成、特点及用法等作一较全面阐述，以帮助同学们掌握这一重要的语法知识。 一、with结构的构成 它是由介词with或without+复合结构构成，复合结构作介词with或without的复合宾语，复合宾语中第一部分宾语由名词或代词充当，第二部分补足语由形容词、副词、介词短语、动词不定式或分词充当，分词可以是现在分词，也可以是过去分词。With结构构成方式如下： 1. with或without-名词/代词+形容词; 2. with或without-名词/代词+副词; 3. with或without-名词/代词+介词短语; 4. with或without-名词/代词+动词不定式; 5. with或without-名词/代词+分词。 下面分别举例： 1、She came into the room，with her nose red because of cold.(with+名词+形容词，作伴随状语) 2、With the meal over ，we all went home.(with+名词+副词，作时间状语)
3、The master was walking up and down with the ruler under his arm。(with+名词+介词短语，作伴随状语。) The teacher entered the classroom with a book in his hand. 4、He lay in the dark empty house，with not a man ，woman or child to say he was kind to me.(with+名词+不定式，作伴随状语) He could not finish it without me to help him.(without+代词+不定式，作条件状语) 5、She fell asleep with the light burning.(with+名词+现在分词，作伴随状语) 6、Without anything left in the cupboard，she went out to get something to eat.(without+代词+过去分词，作为原因状语) 二、with结构的用法 在句子中with结构多数充当状语，表示行为方式，伴随情况、时间、原因或条件(详见上述例句)。 With结构在句中也可以作定语。例如： 1.I like eating the mooncakes with eggs. 2.From space the earth looks like a huge water-covered globe with a few patches of land sticking out above the water. 3.A little boy with two of his front teeth missing ran into the house. 三、with结构的特点 1. with结构由介词with或without+复合结构构成。复合结构中第一部分与第二部分语法上是宾语和宾语补足语关系，而在逻辑上，却具有主谓关系，也就是说，可以用第一部分