A Course on Synthetic Fuels Howard S. Kimmel and Reginald P. T. Tomkins '~~ Department of Chemical Engineering and Chemistry, New Jersey Institute of Technology, ~ e w a r k ,07102 The problem of desienine suitahle technical elective courses for chemistry and chemica'l engineering majors is often adifficult one. An important criterion in such a course is that it should have some relevance to thecorporate environment in which most of the students will find themselves and, at the same time, introduce some new ideas, concepts, and problem areas where the students can apply some of their previously gained knowledge. Several years ago, a senior elective course was developed on svnthetic fuels for our chemical eneineerine and chemistrv majors. Since its inception, it has proved to be the most popular elective offered hv the department with class registration ranging from 20-30 &dents per offering. C o m e prerequisites include physical chemistry and organic chemistry. The key synthetic fuel processes that are discussed are the conversion of coal to substitute natural gas, methanol, gasoline and other liquid fuels, and petrochemicals by a variety of routes; the use of oil shale and tar sands as a source of liquid and gaseous fuels; the conversion of biomass and municipal and industrial wastes to SNG and liquid fuels and some related technologies including fuel cells, magnetohydrodynamics, and combustion processes. From the outset i t is recognized that a topic such as synthetic fuels is a problem that must he looked at in a mnltidisci~linlinarvwav as it involves concewts of science. eneineerine. economics; andsocio~ogy.The inst;uctors for thk c o k e haye focused mainlv on the scientific and engineering factors eoverning synthetic fuel production whereas some of the &onomic and political features have been addressed by guest lecturers from industry. Fundamental principles of organic chemistry, thermodvnamics, and reaction kinetics were incorporatid throughout the course. For example, some time was devoted to the structure of coal: this included a review of fused aromatic and hydroaromatic ring structures and heterocyclic compounds. Thermodynamic calculstions were made on the various stews of the coal easification Drocess to establish the most suitabli operating Gnditions or temperature and Dressure for the overall reaction. The kinetics of the easification processes were discussed in terms of catalyst~electivity. In addition to the chemical principles, calculations involving both mass balances and heat balances were made for a variety of synthetic fuel routes and types of gasifiers. Overall efficiency of processes was a key element of discussions. Further topics that received attention were reactor design, selection of materials in terms of mechanical strength and corrosion, and the control of environmental pollutants.
A major problem encountered in teaching a course on synthetic fuels is the lack of a suitable textbook. Most textbooks dealing with alternative energy sources are not appropriate for acourse for chemists and chemical eneineers. Other text" books deal specifically with one topic, such as coal conversion (1.2). . . In addition. textbooks dealing with a changing . . technology are somewhat outdated and should he used wtth caus has tion. A recent hnok hv H. F. I'robstein and H. E. H ~ r k (3) proved to be most appropriate for our purposes. However, a large need still exists for supplemental information in journals and magazines such as Chem Tech, Chemical Engineering, Chemical Engineering Progress, and Chemical and Engineering News. Course material was also developed from a variety of publications and news items from government agency reports, industrial technical bulletins, and newspaper articles. Course Content A list of topics covered in the course is shown in Table 1. After a general overview of the energy situation using slides and the Energy-Environment Simulator ( 4 ) , the next three weeks of the course were devoted to the chemical and physical fundamentals of synthetic fuel production using the various equations in coal conversion to illustrate principles of thermodynamics and kinetics. The idea of optimum conditions
Table 1. Course Outllne
Twic
NO. Of Weeks Allocated 13 hr ~ lweek) r
Energy-An Overview with emphasls on Synthetic Fuels Chemical and Physical Fundamentals of Synthetic Fuels: Thermodynamics. Kinetics. Organic Chemistry. Gasifiers Oil Shale and Tar Sands Characteristicsof Coal a d Environmental impact Coal Gasification Coal Liquefaction Direct Use of Coal and MHD Biomass and Waste Noncombustion Processes Repom on Student hojects T i m allocated depends on number of studems In olars.
Volume 62 Number 3 March 1985
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Table 2. Coal Gaslllcatlon Reactions and Values of Standard Free Energy Changes at Various Temperatures ( 1 ) AGO (Kcailmol)
Reaction
298 K
500 K
IOOOK
of temnerature and Dressure. heat and mass transfer, and reactor'de~i~n were ~ m p h a a i z ~Typical d. equations usid for the thermodynamic study are given in Table 2, together with values of standard free energy changes. This is a particularly good exampli: to show the need for trade off in looking at a sequence of reactions where high temperatures favor one reaction, whereas lower temperatures favor another reaction in the sequence. The effectad pressure on equilihrium compositions were also examined. As the strurture of the raw materials such as coal and oil shale are a reflection of the product fuels, environmental pollution, and upgrading or refining steps, a fairly detailed discussion was devoted to this topic and supplemented by the class attending a seminar to hear recent developments in structural aspects of coal given by a scientist from a local petroleum company. As catalysts are used in almost all of the Drocesses at some stage. - some attention was given to the nature 01 catalysis, including poisoning and enhancement. The selection of a suitable catalvst was considered. The methanol to gasoline (MTG) prockss was used as an examde. A week was spent on discussion of oil shale and tar sands, supplemented by readings in the literature (5-7). The next six weeks were devoted t o coal conversion processes, including methane production, synthesis gas, water gas shift, the Fischer-Tropsrh process, and the Mobil M process. A discussion of coal combustion inrhded tluidized-bed combustion and the problems associated with raking and swelline of coals. Some details of vnrious "drv hottom" and "slaggiug" gasifiers were provided and an evaluation of the merits of different gasifiers in terms of efficiencies. costs. and complexity followe&.Design considerations and requirements were also discussed. These topics were supplemented by two guest lecturers from industrv both of whom had been involved with coal conversion processes. One focused on the economics of coal conversion by combined cycle power plants using coal gasification. The oiher focused on a donor solvent coaliiquefaction process, covering several problems encountered in scale-up and the approach to their solution. A field trip to a synthetic gas reduction plant operated by the local utility followed the lectures on coal gasification. Although the topics of coal combustion and coal conversion are discussed in some detail in the textbook (3), additional background material was also found useful (8-15). A discussion of magnetohydrodynamics, MHD, (16)was included in the consideration of the direct use of coal as an energy soure. The final series of lectures focused on biomass and waste, and noncombustiou Drocesses (such as batteries and fuel cells) of importunre t o chemists and chemical engineers. Further readines were suggested rl7-191. The discussion of biomass and wastes emphasized the processes for conversion to synthetic fuels. The objectives and nature of the course did not permit indepth consideration of the subject matter. This was a major factor in requiring the students to prepare a formal report on an aspect of synthetic fuels. In keeping with departmental prartice, we provided the students with an exercise in creative thinking that required the use of writwn and oral communication skills. For this independent project, the students selected a topic
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250
Journal of Chemical Education
Table 3. To~lcs01 Student Prolects 011 Shale Tar Sands
Synthetic Fuels from Coal Coal Conversion Coal and Energy Some Environmental Effects of Increased Coal Utilization Flue Gas Desuifurization Coal combustion in Fluidized Beds Peat Municipal Solid Waste as an Alternate Fuel Use of Catalysis in Solvent Refined Coal Liquefaction Generation of Methane in Sanitary Landfills Densified Biomass Fuel Cells Conversion of Waste Palypmpylene to Fuel Oil Fuel Farming Energy from Biomass Fuel horn Wastes Energy horn Solid Waste via Incineration Gasohol Residium Conversion based on one of the subjects of the course and presented an oral d i i s i o n of the paper to the class and a written summary of the paper to the instructor. The paper was not intended to be an exhaustive literature survey, although a bibliography was required. The student was to describe the topic as a problem and provide an assessment of various aspects of the problem, i.e., technological, economic, political, social, etc., as the selected prohlem warranted. The purpose of the paper wan not onlv 6 e x n o s e the students to new material but also to give them the oiportunity to question the soundness of the various aspects of the problem. In discussing the assignment with the students, creativity on their part was stressed, and they were encouraged to organize and substantiate their own ideas on the subject in the formulation of an original and personal position. The controversial aspects of several current and future enerev sources aooeared to nrovide a natural hasis for this typeof project a.nd many students responded accordingly. Tahle 3 Dresents some of the tooicr wlected bv the students for thei;projects. Chemists and chemical engineers should have a technical understanding of our presentiy existing energy situation, the current energy sources, as well as future energy sources with emphasis on synthetic and alternative fuels, and the development of new nonpetroleum, transportable energy storage forms. This paper has described one approach to provide this training. Literature Cited (1) Wen. C. Y.. and LOB.E. S.,Editon, "Coal CMveraion Technology." Addison-Wesley Publishing Co., Reading. MA, 1979. (2) Anderson, L. L.. and Tiilman. D. A,, "Synthetic Fuels f r w CMI: Overview and Assessment;'Jahn Wiley & Sons, Inc., Nev York, 1979. (3) Pmbetpm,R F..and Hi&. R.E.."SlmthcticFuela"Mffiraw.HiUBmkCo.,NewYork, 1982. (4) Kimmei, H., Gmw, J. M. and Tomkins, R. P. T.. J. Educ TechnoL System. L O,67 i1881182). Haking, M. B., J. CReM. EDUC., 51,725(1977). Aibuieseu, P., Heel Engin.,68 (January-March1978). Ailen,A.R.,Chem Tech,6,384 11978). Batie, W. W., Punevani, D. V., and Mensinger, M. C.. C h m Toch.8,559 (1978). Verms, A., Chom Tech, 8,372 (1978). Verms, A,. Chem Tech, 8,626 (1978). MaeNeh,A. J.,Chem.Engin.Pw,71.51 (1975). Gatos,B.C.,Chem Tech,9,97 11979). Harju, J. B.,Poll.Engin, 12.53 (Me,", 1980). Highley, J., Environ. Sci Technoi., 14.270 (1980). Meise1.S. L., McCuilough. J. P..Leehthsier,C. H.. and Weiar,P. B..Chem Tech, 6, RR 119761.
(19)
(1981). Camcron,D..Chsm Tech. 9,633 (1979)
