Coalcon Process

In this process, hot, oxygen-free flue gas is employed to heat the coal to approximately 325°C (615°F) and also to carry the coal to a feed hopper where it is pressurized and fed (by gravity) to the reactor. In the reactor, the coal is fluidized (with hydrogen at a pressure some 250 psi above the reactor pressure) whereupon the high temperature and pressure (I60°C [I040°F] 555 psi) brings about conversion of the coal. 

A fractionator is employed to subdivide the overhead stream into (1) gases, hydrogen, carbon monoxide, carbon dioxide, and methane (2) light oil (3) heavy oil and (4) water. Most of the char is removed from the base of the reactor, quenched with water, and cooled. The char can then be used as a feed to a Koppers-Totzek gasifier and reacted with oxygen and steam to produce hydrogen for the process. 

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The available information leads one to believe that the maximum production of liquids with no net hydrogen consumption and the low-temperature catalytic hydrocarbonization/gasification are alternatives which appear to have great merit. The former of these, when applied to western coals, appears to be technically ready for commercial application and economically competitive with alternative coal liquefaction processes. Advantages of the flash hydropyrolysis processes over the Coalcon process are difficult to perceive. 

The thing I cannot comment on is what he was referring to with regard to the proprietary developments from Carbide. They apparently did some work in the course of the Coalcon process. 

The Coalcon process (Figure 19.7) differs from other processes insofar as it involves the use of a dry, noncatalytic fluidized bed of coal particles suspended in hydrogen gas instead of a fixed-bed or liquid phase system (Nowacki, 1979). The process also converts organic sulfur in the coal to hydrogen sulfide. 

Coalcon A coal gasification process using a fluidized bed operated with hydrogen. Developed by Union Carbide Corporation and the Chemical Construction Company, based on work on liquid-phase hydrogenation completed by Union Carbide in the 1950s. A 20-ton per day pilot plant was operated in the 1960s, but a planned larger demonstration plant was abandoned because of cost. 

Handling of caking coals has proved to be a serious obstacle to the development of hydrocarbonization processes and was, in fact, one of the principal factors contributing to the failure of the Coalcon project. However, a number of technologically successful approaches to handling of caking coals have now been demonstrated. The most common approach is through special reactor... 

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