COGAS process

Based on the title of this symposium the objective of this paper is to discuss some dilemmas facing synthetic fuel process developers. The COGAS Process under development by the COGAS Development Company is a combined liquefaction and gasification process. Development has been conducted since mid-1972 when the joint venture company was formed. We face two types of dilemmas. 

Before discussing these two problems, the COGAS Process will be briefly described. If further detail is desired, CDC has available a number of papers. 

Continued development of the COGAS Process promises to help make our nation self-sufficient in meeting its needs for liquid and gaseous fuels. The process can handle all ranks of coals, ranging from lignite through high-volatile A bituminous coal. 

The COGAS Process promises to become an important means for this country to supplement its diminishing petroleum and natural gas supplies by the conversion of coal to clean-energy-fuels. Depending on continuing technical success, and a receptive economic climate, this promise should be achieved in the late 19801s. 

I would like to cite a few specifics of the situation today. Using the COGAS Process as an example, the most recent estimate of the total plant investment cost of the commercial COGAS plant is 1.4 billion in mid-1978 dollars (4). In addition, there will be costs for land, adminstration during construction, start-up, working capital requirement to 1.5 billion exclusive of interest during construction before the plant produces at design capacity. 

The COGAS Process (4) was presented by the senior author from the Illinois Coal Gasification Group, the prime contractor for the DOE demonstration plant program. Economics for the conceptual commercial plant were presented in mid-1978 dollars. 

Eby, R. J., McClintock, N., Bloom, R. Jr., "The Illinois Coal Gasification Group Project - COGAS Process", 10th Synthetic Pipeline Gas Symposium, October, 1978. 

The COGAS process involves the gasification of the COED char to produce a synthesis gas composed of carbon monoxide and hydrogen. The heat for the char gasification reaction is provided by the combustion of part of the char. 

A condensation process such as that represented in Eq. (1) is strongly endothermica However, the reaction is possible due to the formation of COgas which results in a high increase in entropy (the available data indicate that the magnitude of the net term TAS0 is ca. 7—8 kcal per mol of CO evolved). 

Certainly, there are not many corporations today that could afford - even if they had the assets - to put up their assets for such a plant. Financing would be a substantial problem because of the enormous investments, particularly for a process which has not previously been practiced commercially. Of course, we expect that operation of the COGAS Demonstration Plant will develop the confidence in the process that will be required for financing a commercial plant. 

Plant investment was prepared by the Dravo Corp. Gas price was presented on the basis of "a typical utilities guidelines which differed in many details from the utility financing method of C. F. Braun. In the case of COGAS, liquid product credit has a substantial effect on the gas price. In the paper this credit was at current market prices of 15.40/bbl for No. 4 fuel oil and 16.80 for naphtha. The resulting plant tailgate gas price on a 20-year operating time DCF basis was 5.08/MMBtu. However, if the liquids and gas are priced on an equivalent Btu basis, the fuel oil would be 25/bbl, the naphtha 27/bbl and the gas 4.10/MMBtu. These latter liquid prices are in the range of those estimated for liquids from coal by other processes. 

So synthetic fuel process developers have the two dilemmas discussed herein - when will there be a commercial synthetic fuesl industry and is the process under development going to be competitive. Hopefully, the Government will make the moves necessary to produce the investments in commercial-scale plants soon. COGAS Development Company feels it has the competitive process. 

The following sequence of an oscillatory cycle has been proposed (i) Os b formation takes place only on the Oads-covered palladium surface, accompanied by a decrease of the sticking coefficient for the oxygen adsorption So (ii) the formation of COads layer is a result of the fast reaction COgas + Oads With the formation of CO2 molecules and their desorption (iii) the elevated concentration of the empty active sites appears either due to reverse diffusion process O ub Oads with subsequent removal of Oads in the reaction with COads, or due to slow reaction Osub with COads to form CO2 (iv) the transition to the initial oxygen layer proceeds from S(02) increase due to the decrease of Osub concentration. 

The other processes under development, the main ones being Hygas, C02 Acceptor, Synthane, Bi-Gas, COED, COGAS, Atgas-Patgas, Molten Salt, B W, and Exxon Catalytic, are designed with three main objectives in mind ... 

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