化工專業(yè)英語

1、Coal consists primarily of carbon, hydrogen, and oxygen, and contains lesser amounts of nitrogen and sulfur and varying amounts of moisture and mineral matter. The mode of formation of coal, the variation in plant composition, the microstructure, and the variety of mineral matter indicate that there

2、 is a mixture of materials in coal. The nature of the organic species present depends on the degree of biochemical change of the original plant material, on the historic pressures and temperatures after the initial biochemical degradation, and on the finely divided mineral matter deposited either at

3、 the same time as the plant material or later. 煤主要由碳、氫、氧組成并含有少量的氮、硫及含量不一的水份和礦物質(zhì)。煤的構(gòu)成方式、成煤煤主要由碳、氫、氧組成并含有少量的氮、硫及含量不一的水份和礦物質(zhì)。煤的構(gòu)成方式、成煤植物成分的變化、微觀結(jié)構(gòu)以及所含礦物質(zhì)的多樣性均說明煤是由多種物質(zhì)組成的混合體。各種植物成分的變化、微觀結(jié)構(gòu)以及所含礦物質(zhì)的多樣性均說明煤是由多種物質(zhì)組成的混合體。各種有機(jī)物質(zhì)的性質(zhì)取決于最初植物成分生化變化的程度、最初生物降解后長(zhǎng)期各種壓力和溫度的影有機(jī)物質(zhì)的性質(zhì)取決于最初植物成分生化變化的程度、最初生物降解后長(zhǎng)期各種壓力和溫度的影響

4、、與植物成分同期沉積或后期沉積的細(xì)微的礦物質(zhì)的作用。響、與植物成分同期沉積或后期沉積的細(xì)微的礦物質(zhì)的作用。Deposition 沉積物沉積物 sedimentThe principal types of organic compounds have resulted from the formation and condensation of polynuclear and heterocyclic ring compounds containing carbon, hydrogen, nitrogen, oxygen, and sulfur. The fraction of carbon i

5、n aromatic ring structures increases with rank.主要類型的有機(jī)化合物是含碳、氫、氮、氧和硫的多核化合物與雜環(huán)化合物構(gòu)成主要類型的有機(jī)化合物是含碳、氫、氮、氧和硫的多核化合物與雜環(huán)化合物構(gòu)成與縮合的產(chǎn)物。芳環(huán)結(jié)構(gòu)中碳的含量隨著煤化程度的增加而增加。與縮合的產(chǎn)物。芳環(huán)結(jié)構(gòu)中碳的含量隨著煤化程度的增加而增加。Polynuclear Aromatic Hydrocarbons （PAH）多環(huán)芳烴）多環(huán)芳烴polycyclic aromatic hydrocarbonsMonocyclicBicyclic Nearly all coal is used in

6、 combustion and coking. At least 80% is burned directly in boilers for generation of electricity or steam for industrial purposes. Small amounts are used for transportation, space heating, firing of ceramic products, etc. The rest is essentially pyrolyzed to produce coke, coal gas, ammonia, coal tar

7、, and light oil products from which many chemicals are produced. Combustible gases and chemical intermediates are also produced by the gasification of coal, and different carbon products are produced by various heat treatments. A small amount of coal is used in miscellaneous各種各種各樣的各樣的applications su

8、ch as fillers, pigments, foundry material, and water filtration.幾乎所有的煤都用于燃燒和煉焦。至少幾乎所有的煤都用于燃燒和煉焦。至少80%的煤直接在鍋爐中燃燒用于工業(yè)發(fā)電或產(chǎn)生蒸汽。少的煤直接在鍋爐中燃燒用于工業(yè)發(fā)電或產(chǎn)生蒸汽。少量的煤用于運(yùn)輸、供熱和燒制陶器。其余基本通過熱裂解產(chǎn)生焦碳、煤氣、氨、煤焦油和輕油等量的煤用于運(yùn)輸、供熱和燒制陶器。其余基本通過熱裂解產(chǎn)生焦碳、煤氣、氨、煤焦油和輕油等產(chǎn)品由此可生成其他很多化工產(chǎn)品。煤氣化過程產(chǎn)生許多可燃?xì)怏w和化學(xué)中間體不同的熱處理會(huì)產(chǎn)品由此可生成其他很多化工產(chǎn)品。煤氣化過程產(chǎn)生許多可燃

9、氣體和化學(xué)中間體不同的熱處理會(huì)生成不同的含碳產(chǎn)品。也有少部分的煤被廣泛用作填料、顏料、鑄造材料和水過濾材料等方面。生成不同的含碳產(chǎn)品。也有少部分的煤被廣泛用作填料、顏料、鑄造材料和水過濾材料等方面。 There is no doubt about the switch from oil to coal as a source of organic chemicals; the only uncertainty concerns the time-scale and rate at which it happens. Coal-conversion processes under develop

10、ment are directed towards producing either gaseous or liquid feedstocks which approximate in composition to petroleum-derived feedstocks. They can then be utilized directly in existing petrochemical plants and processes. 從以石油作為有機(jī)化學(xué)品的來源到以煤為有機(jī)化學(xué)品的來源這種轉(zhuǎn)變是無可置疑從以石油作為有機(jī)化學(xué)品的來源到以煤為有機(jī)化學(xué)品的來源這種轉(zhuǎn)變是無可置疑的。但是唯一無法確

11、定的是這種轉(zhuǎn)變需要的時(shí)間與發(fā)生的速度。的。但是唯一無法確定的是這種轉(zhuǎn)變需要的時(shí)間與發(fā)生的速度。 研制中的煤轉(zhuǎn)化工藝目的是為了生產(chǎn)出氣體原料或液體原料。這些原料與石油衍研制中的煤轉(zhuǎn)化工藝目的是為了生產(chǎn)出氣體原料或液體原料。這些原料與石油衍生物原料的成分近似可直接應(yīng)用于當(dāng)今的石化工廠及其工藝中。生物原料的成分近似可直接應(yīng)用于當(dāng)今的石化工廠及其工藝中。Gaseous product 氣體產(chǎn)物氣體產(chǎn)物To achieve this, however, two problems must be overcome, which are a consequence of the differing natu

12、res of coal and oil. Firstly, the H:C ratios are different for coal and for petroleum-derived liquid feedstocks. Secondly, significant amounts of heteroatoms are present in coal, particularly sulphur which may reach levels as high as 3%. The sulphur has to be removed for two reasons: ()on combustion

13、 it will form the atmospheric(大大氣的氣的) pollutant SO2, and ()it is a potent（強(qiáng)烈的）（強(qiáng)烈的） catalyst poison, and most of the downstream petrochemical processes are catalytic. However, its removal from coal is difficult and it is therefore removed from the conversion products in stead.但由于煤和石油性質(zhì)不同但由于煤和石油性質(zhì)不同，

14、為達(dá)到這個(gè)目的有兩個(gè)問題必須解決。首先為達(dá)到這個(gè)目的有兩個(gè)問題必須解決。首先煤和從石油中提取的液煤和從石油中提取的液態(tài)原料中的氫態(tài)原料中的氫/碳比不同。其次煤包含眾多的雜環(huán)原子尤其是硫原子比例高達(dá)碳比不同。其次煤包含眾多的雜環(huán)原子尤其是硫原子比例高達(dá)3%?；谝韵聝煞健；谝韵聝煞矫嬖蛎罕仨毭摿蛎嬖蛎罕仨毭摿?1: 燃燒時(shí)會(huì)生成大氣污染物燃燒時(shí)會(huì)生成大氣污染物SO2；2：它是一種很強(qiáng)的催化劑毒物而大部分下它是一種很強(qiáng)的催化劑毒物而大部分下游石油化工工藝都需用催化劑。但從煤中脫硫很困難，因此需要從煤轉(zhuǎn)化產(chǎn)品中脫硫。游石油化工工藝都需用催化劑。但從煤中脫硫很困難，因此需要從煤轉(zhuǎn)化產(chǎn)品中脫硫。C

15、oal Processing to Synthetic Fuels and Other Products The primary approaches to coal processing or coal conversion are thermal decomposition, including pyrolysis or carbonization, gasification, and liquefaction by hydrogenation. The hydrogenation of coal is not currently practiced commercially. High

16、Temperature Carbonization. High temperatures and long processing times are used in carbonizing coking coals in coke ovens or gas retorts. Besides metallurgical（冶金的）（冶金的） or gas coke the products include fuel gas, crude tar, light oils(benzene, toluene and xylene, referred to as BTX, and solvent naph

17、tha), and ammonia gas. 煤制備合成燃料及其它產(chǎn)品煤制備合成燃料及其它產(chǎn)品 煤加工轉(zhuǎn)化的主要方法是熱分解，包括高溫分解或干餾、氣化及加氫液化。煤的加氫目前煤加工轉(zhuǎn)化的主要方法是熱分解，包括高溫分解或干餾、氣化及加氫液化。煤的加氫目前還沒有實(shí)現(xiàn)商業(yè)化。還沒有實(shí)現(xiàn)商業(yè)化。高溫碳化。高溫碳化。 在焦?fàn)t或干餾爐中在高溫下長(zhǎng)時(shí)間進(jìn)行煤的碳化和焦化。除了冶金焦炭和氣化在焦?fàn)t或干餾爐中在高溫下長(zhǎng)時(shí)間進(jìn)行煤的碳化和焦化。除了冶金焦炭和氣化焦之外，焦化的主要產(chǎn)品包括燃料氣、粗焦油、輕油（苯、甲苯、二甲苯，也就是焦之外，焦化的主要產(chǎn)品包括燃料氣、粗焦油、輕油（苯、甲苯、二甲苯，也就是BTX，和

18、溶劑，和溶劑石腦油和氨氣）石腦油和氨氣）Metallurgy 冶金冶金Most coal chemicals are obtained from high temperature tar with an average yield over 5% of the coal which is carbonized. The yields in coking are about 70% of the weight of feed coal. Tars obtained from vertical gas retorts have a much more uniform chemical compos

19、ition than those from coke ovens. Two or more coals are usually blended（配煤）（配煤）. The conditions of carbonization vary depending on the coals used and affect the tar composition. Coal-tar chemicals include phenols, cresols, xylenes, benzene, toluene, naphthanlene, and anthracene.大部分煤基化學(xué)品是從高溫煤焦油中獲取，碳化

20、過程中平均大部分煤基化學(xué)品是從高溫煤焦油中獲取，碳化過程中平均5%的煤生成焦油。焦的產(chǎn)率大約是的煤生成焦油。焦的產(chǎn)率大約是進(jìn)料煤的進(jìn)料煤的70%。從立式干餾爐制備的焦油比焦?fàn)t中的焦油有更均勻的化學(xué)成分。通常兩種或更多。從立式干餾爐制備的焦油比焦?fàn)t中的焦油有更均勻的化學(xué)成分。通常兩種或更多中的煤配合使用。碳化的條件因煤種而異，因此焦油的組成也不同。煤焦油化學(xué)品包括苯酚、甲中的煤配合使用。碳化的條件因煤種而異，因此焦油的組成也不同。煤焦油化學(xué)品包括苯酚、甲酚、苯、甲苯、二甲苯、萘和蒽。酚、苯、甲苯、二甲苯、萘和蒽。vertical 豎直的豎直的 horizontal 水平的水平的 The larg

21、est consumer of coke is the iron and steel industry. Coke is also used to make calcium carbide, from which acetylene乙炔乙炔 is made. Synthesis gas for methanol and ammonia production is also made from gasification of coke. Low Temperature Carbonization. Lower temperature carbonization of lump coal at c

22、a 700 primarily used for production of solid smokeless fuel, gives a quantitatively and qualitatively different yield of solid, liquid, and gaseous products than does the high temperature processes. Although a number of low temperature processes have been studied, only a few have been used commercia

23、lly. These have been limited in the types of coal that are acceptable, and the by-products are less valuable than those obtained from high temperature processing. 焦化的最大消費(fèi)者是煉鐵和煉鋼工業(yè)。焦還沒用于制造電石用于制備乙炔。焦的氣化所得合成氣焦化的最大消費(fèi)者是煉鐵和煉鋼工業(yè)。焦還沒用于制造電石用于制備乙炔。焦的氣化所得合成氣可用于制備甲醇和合成氨?？捎糜谥苽浼状己秃铣砂?。低溫碳化低溫碳化 在大約在大約700度下低溫碳化塊煤主要用

24、于制備固體無煙燃料，得到了與高溫加工量和性質(zhì)度下低溫碳化塊煤主要用于制備固體無煙燃料，得到了與高溫加工量和性質(zhì)截然不同的固體、液體和氣體產(chǎn)物。截然不同的固體、液體和氣體產(chǎn)物。雖然研究了很多低溫碳化過程，但是僅有很少的實(shí)現(xiàn)商業(yè)化。由于可接受的煤種很有限，同時(shí)副雖然研究了很多低溫碳化過程，但是僅有很少的實(shí)現(xiàn)商業(yè)化。由于可接受的煤種很有限，同時(shí)副產(chǎn)物沒有高溫碳化產(chǎn)物的價(jià)值高。產(chǎn)物沒有高溫碳化產(chǎn)物的價(jià)值高。Liquefaction of coal, via hydrogenation, is quite an old process which was operated commercially in

25、 Germany during World War II when external fuel supplies were cut off. Tens of millions of tonnes of gasoline were produced in this way during this period. Interestingly, Germany is today playing a leading part Interestingly, Germany is today playing a leading part in the development of more in the

26、development of more efficientefficient processes. For the processes. For the resulting liquids to be suitable chemical feedstock the H:C resulting liquids to be suitable chemical feedstock the H:C ratio must be improved in favor of more hydrogen. Clearly ratio must be improved in favor of more hydro

27、gen. Clearly this can be achieved in two wayseither by adding this can be achieved in two wayseither by adding hydrogen or by removing hydrogen or by removing carbon.carbon.液化。煤的加氫液化是一個(gè)非常古老的工藝，早在第二次世界大戰(zhàn)期間，德國(guó)由于缺乏外液化。煤的加氫液化是一個(gè)非常古老的工藝，早在第二次世界大戰(zhàn)期間，德國(guó)由于缺乏外部的燃料供給，就已經(jīng)進(jìn)行商業(yè)化操作了。在這個(gè)時(shí)期，約通過該法生產(chǎn)了幾千萬噸汽油。部的燃料供給，就已

28、經(jīng)進(jìn)行商業(yè)化操作了。在這個(gè)時(shí)期，約通過該法生產(chǎn)了幾千萬噸汽油。有趣的是現(xiàn)在德國(guó)在開發(fā)更有效的工藝上走在了前列。對(duì)于生成的液體可以作為合適的化有趣的是現(xiàn)在德國(guó)在開發(fā)更有效的工藝上走在了前列。對(duì)于生成的液體可以作為合適的化學(xué)品原料的話，學(xué)品原料的話，H H：C C比必須改善以有更多的氫。很明顯這個(gè)可以通過加氫或脫炭實(shí)現(xiàn)。比必須改善以有更多的氫。很明顯這個(gè)可以通過加氫或脫炭實(shí)現(xiàn)。LiquefactionAlthough many of the new processes are only at the pilot-plant stage（中試階段）of development, their supe

29、riority over the old methods is due to increased sophistication of the chemical engineering employed plus improvements in the catalysts available.The basic problems, however, remain the samepoor selectivity in producing the desired fractions and a relatively high rate of consumption of hydrogen.雖然很多

30、新工藝仍處于發(fā)展的初級(jí)階段，但是，同老方法相比，它們由于提高可用催化劑雖然很多新工藝仍處于發(fā)展的初級(jí)階段，但是，同老方法相比，它們由于提高可用催化劑的性能和增加了所用化工工程的精確性，因而這種方法更具優(yōu)勢(shì)。的性能和增加了所用化工工程的精確性，因而這種方法更具優(yōu)勢(shì)。但是基本問題仍然是一樣的但是基本問題仍然是一樣的對(duì)生產(chǎn)目標(biāo)產(chǎn)品的選擇性較低，而氫的用量相對(duì)較高。對(duì)生產(chǎn)目標(biāo)產(chǎn)品的選擇性較低，而氫的用量相對(duì)較高。The fundamental processes involved are pyrolysis, solvent extraction and hydrogenation. Differen

31、ces between the techniques being developed lie in how these fundamental processes are combined. Note that in the above processes the main product is a highly carbonaceous （含碳的）solid material known as char. This is either burnt to provide process heat or reacted with water and oxygen to produce hydro

32、gen.液化液化所涉及的基本所涉及的基本過程有過程有熱解，溶劑萃取和加氫。熱解，溶劑萃取和加氫。研發(fā)的各種工藝研發(fā)的各種工藝間的差間的差異在于這些基本過程異在于這些基本過程的的結(jié)合結(jié)合方式方式。請(qǐng)注意，在上述過程中的主要產(chǎn)品是一種。請(qǐng)注意，在上述過程中的主要產(chǎn)品是一種高高含碳含碳的的固體固體材料，即焦炭材料，即焦炭。焦炭可以用于燃燒來提供熱量焦炭可以用于燃燒來提供熱量，或與水和氧反應(yīng)產(chǎn)，或與水和氧反應(yīng)產(chǎn)生氫氣生氫氣。The liquids produced by coal liquefaction are similar to fractions obtained by distillatio

33、n of crude oil (although they are much richer in aromatics), and therefore require further treatment, e.g. cracking, before being used for synthesis.煤液化的液相產(chǎn)品與粗油蒸餾獲得的產(chǎn)品組分相似（盡管其芳香族化合物的含量煤液化的液相產(chǎn)品與粗油蒸餾獲得的產(chǎn)品組分相似（盡管其芳香族化合物的含量更高），因此，在其用于合成前，必須經(jīng)過進(jìn)一步處理，即裂解。更高），因此，在其用于合成前，必須經(jīng)過進(jìn)一步處理，即裂解。A number of gasifiers a

34、re either available commercially or in various stages of development. These are described as fixed bed, fluidized bed, and entrained or rotating bed. 氣化。氣化爐較多，有的已經(jīng)商業(yè)化，有的還處于研發(fā)的不同階段。這些氣氣化。氣化爐較多，有的已經(jīng)商業(yè)化，有的還處于研發(fā)的不同階段。這些氣化爐可分為固定床、流化床和夾帶床或旋轉(zhuǎn)床?；癄t可分為固定床、流化床和夾帶床或旋轉(zhuǎn)床。The fixed bed involves an upward flow of r

35、eaction gas through a relatively stationary bed of hot coal. The gas velocity is slow enough to avoid blowing the coal out of the bed. The fluidized bed operate at higher gas velocities than the fixed bed and utilizes somewhat smaller particles.固定床是讓一股向上流動(dòng)的反應(yīng)氣流經(jīng)一個(gè)相對(duì)固定的熱煤床層。氣體流速很固定床是讓一股向上流動(dòng)的反應(yīng)氣流經(jīng)一個(gè)相對(duì)

36、固定的熱煤床層。氣體流速很慢從而避免將煤帶出床層。流化床則在一個(gè)氣速比固定床高的操作條件下進(jìn)行，并慢從而避免將煤帶出床層。流化床則在一個(gè)氣速比固定床高的操作條件下進(jìn)行，并且使用較細(xì)顆粒的物料。且使用較細(xì)顆粒的物料。Gasification. The entrained bed operates with parallel flows of reaction gas and finely pulverized coal particles to minimize reaction time and maximize throughput of product. 夾帶床采用反應(yīng)氣和細(xì)粉煤顆粒并行流

37、動(dòng)的操作方式，從而獲得最小的反夾帶床采用反應(yīng)氣和細(xì)粉煤顆粒并行流動(dòng)的操作方式，從而獲得最小的反應(yīng)時(shí)間和最大的產(chǎn)品吞吐量。應(yīng)時(shí)間和最大的產(chǎn)品吞吐量。The rotating bed is similar to a kiln, which operates with the coal entering at the upper part of the inclined kiln. Rotation avoids clinking and exposes fresh surfaces to enhance completion of the reaction.旋轉(zhuǎn)床則類似于一個(gè)窯，煤從這個(gè)傾斜的窯的

38、上部進(jìn)入。旋轉(zhuǎn)避免了碎裂旋轉(zhuǎn)床則類似于一個(gè)窯，煤從這個(gè)傾斜的窯的上部進(jìn)入。旋轉(zhuǎn)避免了碎裂和新鮮表面的暴露，從而強(qiáng)化了熱解反應(yīng)的完成。和新鮮表面的暴露，從而強(qiáng)化了熱解反應(yīng)的完成。Surface Gasification technology. Gasification of coal for fuel gas and chemical intermediate production has been developed commercially and improvements in technology are being studied in a number of facilities.I

39、n the United States, the purpose of a number of programs has shifted from production of a substitute natural gas (methane) to electric power generation through the integrated gasification-combined-cycle (IGCC) plants. The interest in this use of coal results from the low emission levels that can be

40、achieved and the potential for higher power generation efficiency.表面氣化技術(shù)。煤氣化用于燃料氣和化學(xué)品中間體的生產(chǎn)已經(jīng)商業(yè)化，且很多機(jī)表面氣化技術(shù)。煤氣化用于燃料氣和化學(xué)品中間體的生產(chǎn)已經(jīng)商業(yè)化，且很多機(jī)構(gòu)正在進(jìn)行技術(shù)改進(jìn)的研究。構(gòu)正在進(jìn)行技術(shù)改進(jìn)的研究。在美國(guó)，一些項(xiàng)目的目標(biāo)從代用天然氣（甲烷）的生產(chǎn)向利用整體煤氣化聯(lián)合循在美國(guó)，一些項(xiàng)目的目標(biāo)從代用天然氣（甲烷）的生產(chǎn)向利用整體煤氣化聯(lián)合循環(huán)（環(huán)（IGCCIGCC）技術(shù)發(fā)電轉(zhuǎn)移。）技術(shù)發(fā)電轉(zhuǎn)移。人們之所以對(duì)這種煤炭利用技術(shù)感興趣，是因?yàn)樗嬖诘团欧潘胶透甙l(fā)電效率人們之所以

41、對(duì)這種煤炭利用技術(shù)感興趣，是因?yàn)樗嬖诘团欧潘胶透甙l(fā)電效率的潛力。的潛力。Future large gasification plants, intended to produce ca 7X106 m3 standard of methane per day are expected to be sited near a coal field having an adequate water supply. It is cheaper to transport energy in the form of gas through a pipeline than coal by either

42、rail or pipeline. The process chosen is expected to utilize available coal in the most economical manner.未來可日產(chǎn)未來可日產(chǎn)7X10 6 m3 7X10 6 m3 標(biāo)準(zhǔn)甲烷的大型氣化廠，其理想的位置是在具有充標(biāo)準(zhǔn)甲烷的大型氣化廠，其理想的位置是在具有充足水源的煤田附近。能源通過管道以氣相形式輸送要比通過鐵路或管線輸送煤足水源的煤田附近。能源通過管道以氣相形式輸送要比通過鐵路或管線輸送煤要便宜要便宜。選擇的工藝最好是采用最經(jīng)濟(jì)的方式利用不同的煤選擇的工藝最好是采用最經(jīng)濟(jì)的方式利用不同的煤。U

43、nderground Coal Gasification (UCG). Underground coal gasification is intended to gasify a coal seam in situ, converting the coal into gas and leaving the ash underground. This approach avoids the need for mining and reactors gasification. UCG is presently considered most interesting for deep coal or

44、 steeply sloping seams. This approach involves drilling holes to provide air or oxygen for gasification and removal of product gases and liquids.地下煤氣化（地下煤氣化（UCGUCG）。地下煤氣化是為了在原位將煤層氣化，使煤轉(zhuǎn)化為氣，）。地下煤氣化是為了在原位將煤層氣化，使煤轉(zhuǎn)化為氣，同時(shí)將灰留于地下。這種方法無需開采和反應(yīng)器氣化。同時(shí)將灰留于地下。這種方法無需開采和反應(yīng)器氣化。對(duì)深層煤和極度傾斜煤層，對(duì)深層煤和極度傾斜煤層，UCGUCG是目前人們最感

45、興趣的技術(shù)是目前人們最感興趣的技術(shù)。這種方法需要鉆這種方法需要鉆孔以輸入氣化所需的空氣或氧氣并輸出生成的氣體和液體產(chǎn)品?？滓暂斎霘饣璧目諝饣蜓鯕獠⑤敵錾傻臍怏w和液體產(chǎn)品。A low calorific value gas, which includes nitrogen from air, could be produced for boiler or turbine use in electric power production, or an intermediate calorific value gas containing no nitrogen for an industri

46、al fuel gas, or syntheses gas for chemical and methane production could be provided. This approach is still noncommercial in part because it is not economically competitive.地下煤氣化可以產(chǎn)出供鍋爐和發(fā)電的汽輪機(jī)所用的含有氮?dú)獾模ㄔ醋钥諝獾叵旅簹饣梢援a(chǎn)出供鍋爐和發(fā)電的汽輪機(jī)所用的含有氮?dú)獾模ㄔ醋钥諝猓┑蜔嶂禋怏w，也可以生產(chǎn)供工業(yè)燃料氣所需的不含氮的中等熱值的氣體，或）低熱值氣體，也可以生產(chǎn)供工業(yè)燃料氣所需的不含氮的中等熱值

47、的氣體，或是供化學(xué)品和甲烷生產(chǎn)所需的合成氣。由于在經(jīng)濟(jì)上不具備競(jìng)爭(zhēng)力，這種方法是供化學(xué)品和甲烷生產(chǎn)所需的合成氣。由于在經(jīng)濟(jì)上不具備競(jìng)爭(zhēng)力，這種方法目前仍沒有實(shí)現(xiàn)商業(yè)化。目前仍沒有實(shí)現(xiàn)商業(yè)化。Although many environmental and safety problems can be avoided using UCG. there is some concern about groundwater contamination as a result of the process.The chemistry of underground gasification has much

48、 in common with surface gasification, however, many of the parameters參數(shù) cannot be controlled because the reaction occurs in a remote site. Heat energy to drive the gasification comes primarily from carbon combustion to produce CO and then CO2.雖然雖然UCGUCG技術(shù)可以避免許多環(huán)境和安全問題，但是該工藝對(duì)地下水的污染還是需要技術(shù)可以避免許多環(huán)境和安全問題

49、，但是該工藝對(duì)地下水的污染還是需要注意的注意的。雖然地下氣化化學(xué)和地表氣化有許多相同之處，然而，由于其反應(yīng)發(fā)生在遠(yuǎn)程地雖然地下氣化化學(xué)和地表氣化有許多相同之處，然而，由于其反應(yīng)發(fā)生在遠(yuǎn)程地點(diǎn)，因而許多參數(shù)無法控制。氣化反應(yīng)所需的熱能主要來自于碳燃燒生成點(diǎn)，因而許多參數(shù)無法控制。氣化反應(yīng)所需的熱能主要來自于碳燃燒生成COCO和和COCO2 2的的反應(yīng)。反應(yīng)。Because many coal seams are also aquifers含水層 there is a considerable amount of water intrusion, which leads to steam gene

50、ration at the expense of the reaction energy. As a result the rate of air or oxygen passage through the injection wells and seam are adjusted to maintain a low level of moisture in the product gas. The steam is beneficial for char gasification and some is consumed in the water gas shift reaction to

51、produce H2 and CO, from H20 and CO2. Some H2 reacts with C to produce CH4, which enhances the calorific value of the gas.由于許多煤層同時(shí)也是含水層，因此有大量水入侵，從而導(dǎo)致反應(yīng)熱的消耗和由于許多煤層同時(shí)也是含水層，因此有大量水入侵，從而導(dǎo)致反應(yīng)熱的消耗和蒸汽的生成。因此，必須調(diào)整空氣或氧氣通過注入井和煤層的速率，以維持產(chǎn)品氣蒸汽的生成。因此，必須調(diào)整空氣或氧氣通過注入井和煤層的速率，以維持產(chǎn)品氣中的水分在一個(gè)較低的水平。蒸汽對(duì)于焦炭的氣化是有好處的，其中部分蒸汽用于中的水

52、分在一個(gè)較低的水平。蒸汽對(duì)于焦炭的氣化是有好處的，其中部分蒸汽用于從從 H20 和和 CO2向向 H2 和和 CO 轉(zhuǎn)變的水煤氣變換反應(yīng)。一些氫氣和轉(zhuǎn)變的水煤氣變換反應(yīng)。一些氫氣和C發(fā)生反應(yīng)產(chǎn)生甲發(fā)生反應(yīng)產(chǎn)生甲烷，從而增加氣體的熱值。烷，從而增加氣體的熱值。Gasification of coal using steam and oxygen in different gasifiers provides varying proportions of CO and H2. Operations at increasing pressures increase the formation of

53、methane. Because mixtures of CO and H2 are used as the start of chemical synthesis and methane is not wanted or needed for chemical processes, the conditions favoring its formation are avoided. The product gases may then be passed over catalysts to obtain specific products. Iron-based catalysts are

54、used to produce hydrocarbons in the Fischer-Tropsch process, or zine or copper catalysts are used to make methyl alcohol.煤氣化制備液體燃料和化學(xué)品。在不同的氣化爐中采用蒸汽和氧氣進(jìn)行煤氣化煤氣化制備液體燃料和化學(xué)品。在不同的氣化爐中采用蒸汽和氧氣進(jìn)行煤氣化所產(chǎn)生的一氧化碳和氫氣的比值是不同的。操作壓力的增大可以促進(jìn)甲烷的形成。所產(chǎn)生的一氧化碳和氫氣的比值是不同的。操作壓力的增大可以促進(jìn)甲烷的形成。由于一氧化碳和氫氣的混合物才是化學(xué)合成的初始底物，而甲烷是該化學(xué)過程不需由于一

55、氧化碳和氫氣的混合物才是化學(xué)合成的初始底物，而甲烷是該化學(xué)過程不需要的，因此，需要避開有利于甲烷形成的條件。產(chǎn)品氣將被通過催化劑以生產(chǎn)特定要的，因此，需要避開有利于甲烷形成的條件。產(chǎn)品氣將被通過催化劑以生產(chǎn)特定的產(chǎn)品。在的產(chǎn)品。在FTFT工藝中用鐵基催化劑可生產(chǎn)烴類，鋅或銅催化劑則用于甲醇的生產(chǎn)。工藝中用鐵基催化劑可生產(chǎn)烴類，鋅或銅催化劑則用于甲醇的生產(chǎn)。Liquid Fuels and Chemicals from Gasification of Coal. The Fischer-Tropsch process has not been economical in competitive

56、markets. The South African Sasol plant has operated successfully using the modification of the Fischer-Tropsch process. The original plant was designed to produce 227,000 t/y of gasoline, diesel oil, solvents, and chemicals from 907,000 metric tons of noncaking high ash sub-bituminous coal. The succ

57、ess of the Sasol project is attributed to the availability of cheap coal and the reliability of the selected components.Fischer-TropschFischer-Tropsch工藝在競(jìng)爭(zhēng)市場(chǎng)中不具備經(jīng)濟(jì)優(yōu)勢(shì)。南非工藝在競(jìng)爭(zhēng)市場(chǎng)中不具備經(jīng)濟(jì)優(yōu)勢(shì)。南非SasolSasol廠應(yīng)用廠應(yīng)用改良的改良的Fischer-Tropsch Fischer-Tropsch 工藝卻取得了成功。該廠的設(shè)計(jì)生產(chǎn)能力是：每工藝卻取得了成功。該廠的設(shè)計(jì)生產(chǎn)能力是：每年利用年利用 907,000 907

58、,000 噸不粘高灰次煙煤來生產(chǎn)噸不粘高灰次煙煤來生產(chǎn)227,000 t 227,000 t 汽油、柴油、溶劑和汽油、柴油、溶劑和化學(xué)品?；瘜W(xué)品。SasolSasol項(xiàng)目的成功歸功于便宜煤的使用以及所選組分的可靠性。項(xiàng)目的成功歸功于便宜煤的使用以及所選組分的可靠性。A variety of pilot plants using fluid-bed gasifiers have been built in the United States, Germany and elsewhere. The Winkler process is the only one that has been used

59、 on a large scale. It was developed in Germany in the 1920s to make synthesis gas at atmospheric pressure. Plans were being made to develop a pressurized version.在美國(guó)、德國(guó)以及其他地方建立了各種應(yīng)用流化床氣化爐的工廠。在美國(guó)、德國(guó)以及其他地方建立了各種應(yīng)用流化床氣化爐的工廠。 Winkler Winkler 工藝是唯一以大規(guī)模進(jìn)行運(yùn)作的工藝。在常壓下進(jìn)行合成氣生產(chǎn)的工藝始于工藝是唯一以大規(guī)模進(jìn)行運(yùn)作的工藝。在常壓下進(jìn)行合成氣生產(chǎn)的工

60、藝始于1920s1920s的德國(guó)。并制訂了加壓工藝的發(fā)展計(jì)劃。的德國(guó)。并制訂了加壓工藝的發(fā)展計(jì)劃。Pressurized 加壓的加壓的Atmospheric pressure The use of biotechnology to process coal to make gaseous and liquid fuels is an emerging field. Bacteria and enzymes have been studied to establish the technical feasibility of conversion.The earliest work was do