Document zo6YJzn0VN0Y3e28BMdbKJ6kn

8002 0001A methane. Another popular process, the chemical recovery--Chem Sys erally needed, he says, is a highly Winkler route, yields some methane, tems has performed an economic anal leveraged utility-style financial pack but no liquids (Chem. Eng., July 22, ysis of chemical byproduct output age, comprised of about 75% or more 1\974, pp. 91-92). from Lurgi-type SNG plants, while debt. Such financing not only lowers Products obtained from synthesis recognizing the uncertain outlook for costs, but also spreads the risks. gas, .'besides ammonia and methanol, this manner of coal utilization. The Considering the high price tag on coal include acetic acid, ethylene and ethyl firm found that the recovery of gasification projects--an estimated 32 ene glycol. Monsanto and BASF have benzene, toluene and xylenes from the billion for Exxon's East Texas com both operated commercial acetic-acid crude gas-naphtha stream of Montana plex, for example--risk reduction is venture^ feeding on a methanol/car sub-bituminous and Illinois bitumi especially important. bon monoxide feedstock. Ethylene can nous appears economic. Sulfur and H. James Michaels and Howard F. be worked up from synthesis gas via a ammonia, while not profitable, would Leonard, of Koppers Co.'s Engineer number of schemes, including-Fischer-' usually be recovered also, in order to ing & Construction Div. (which builds Tropsch synthesis, methanol homolo meet environmental constraints. Re K-T units)--in a paper presented at gation to ethanol, followed by dehy covery of anything else appears margi-. last June's 85th national meeting of dration, dimethyl ether cracking, and nal for chemicals, more likely for fuel. AIChE, in Philadelphia--call the direct synthesis from CO/H2, and Whatever the degree of chemicals financing method the "largest single possibly someday via the Mobil route. recovery, substances obtafbed this way tactor," at least when it comes to deter Chem Systems Inc. (New York City) would barely denjr U.&. supply mining the cost of hydrogen made by has identified methanol homologation needs--filling no rtiore than' 7% of coal gasification. as the ethylene route with the "best demand in the yea/2000, assuming 25 C. Edward Lorenz, director of the potential," though the method nev coal-based SNG plants, 75% of which feedstocks division of Du Pont's Cen ertheless rates poorly against conven would employ the Lurgi process. tral Research & Development Dept., tional steam cracking of naphtha or For chemicals obtained not as direct observes that in order to put together Oil. byproducts but by processing synthesis projects of this sort, clear policy deci But that's not all. Old-timers- like' gas, Chem/ Systems believes that sions are also needed from the federal Du Pont's Carnell (he joined the firm 'ammonia and methanol- produced via government. Whether Du Pont would in 1942) remember that before World "second-generation" gasifiers, such as want to get involved in a utility-style War II the world chemical industry thb. Texaco and slagging Lurgi ver project, presumably tied in with an was largely coal-based. Even Du sions now! being investigated with doe assortment of credit guarantees and Pont's first polyethylene was made support, /could compete with steam- regulatory restrictions, poses a "legal from ethylene derived from coke-oven methane/ reforming in the 1980s. muddle" that cannot b'e answered gas (though the process would hardly HoweverMhe success of this competi today, Lorenz states. be worthwhile at today's production tion depends, on a trade-off between Whatever the financial arrange scale). Du Pont products based on coal's lower raw material cost, and. a ment, the concept of a centralized ammonia and methanol at that time coal-based planrs higher capital risk. medium-Btu-gas facility, as embodied are listed in the table. Synthfesis-gas-baseikethylene glycol, in Exxon's East Texas project, fits the When coal gasification attracted for example, is not now competitive organizational pattern of a utility. renewed attention a few years ago, with- either conventional., ethylene- At the Fifth Annual International initial thinking centered on the large oxidje-derived glycol, or that obtained Conference on Coal Gasification, Li "first-generation" plant providing from the newer acetoxylation route, quefaction and Conversion to Electric pipeline-quality gas for fuel use only. though the picture might change if. ity, held at the University of Pitts Since "first-generation" meant Lurgi ethylene prices take off, Chem Systems burgh, Aug. 1-3, Carter Oil's John P. in many cases, some chemical byprod indicates. And ethylene synthesis itself, Racz described the thinking that went ucts were also foreseen, though much as already noted, cannot yet compete into the plan, starting in 1974. of these byproducts are considered with steam cracking of naphtha or gas The company placed its highest plant fuel. oil. priority on an assured outlet for prod A number of such substitute natural In the area of coal liquefaction, ucts. Some of the other chief criteria: a gas plants were announced earlier this Chem Systems points out that even if low-cost, reliable and suitable source decade, though only one seems still 25 plants rated at 100,000. bbl/d of coal, proven technology, favorable alive today, and barely alive at that. capacity were to come onstream by the public attitudes at chosen sites for such This is American Natural Resources' year 2000, the contribution to U.S. facilities, and fairly close proximity of North Dakota lignite gasifier, recently feedstocks supply would be small. mine and gasification plant to markets. reorganized under the name Great Benzene production could meet only Carter Oil has made lignite discoveries Plains Gasification Associates, a con 9% of projected demand. The C2/C4 in Texas that meet these criteria. sortium including American Natural feedstocks obtainable for ethylene pro Realizing that industrial natural gas and four other utilities. However, last duction could meet only 15% of esti users would be the first affected by month the Federal Energy Regulatory mated demand for the olefin. shortages, and that a good many of Commission declined to certify con financing--Joseph P. Leonard, of these users are concentrated in the struction of a 137.5-million-Btu/d Chem Systems, points out that financ Gulf Coast area, Exxon's thinking unit, arguing that no five firms alone ing methods are one of the greatest gravitated naturally to the medium- should bear the heavy financial risk determinants of economic viability of Btu utility-style project. involved. coal conversion projects. What's gen John C. Davis CHEMICAL ENGINEERING NOVEMBER 6. 1978 75 HFM- 003709