Acceptor gasification process

The COt Acceptor Gasification Process is discussed in light of the required properties of the CaO acceptor. Equilibrium data for reactions involving the CO% and sulfur acceptance and for sulfur rejection jit the process requirements. The kinetics of the reactions are also sufficiently rapid. Phase equilibrium data in the binary systems CaO-Ca(OH)t and Ca(OH)jr-CaCOs show the presence of low melting eutectics, which establish operability limits for the process. Data were obtained in a continuous unit which duplicates process conditions which show adequate acceptor life. Physical strength of many acceptors is adequate, and life is limited by chemical deactivation. Contrary to earlier findings both limestones and dolomites are equally usable in the process. Melts in the Ca(OH)2-CaC03 system are used to reactivate spent acceptors. 

This reaction is the basis of Consolidation Coal Co/s carbon dioxide acceptor gasification process (13,17,18), which eliminates need for oxygen to provide heat to the steam-carbon reaction. The process could be modified for recovering elemental sulfur by incorporating a step using Reaction 1. 

C02 Acceptor A fluidized bed coal gasification process in which the heat is provided by the exothermic reaction of carbon dioxide with calcium oxide. Developed by the Conoco Coal Development Company in the 1970s. 

Some of these processes which are in the stage of pilot plants or design of demonstration plants are the HYGAS, BI-GAS, GO2 Acceptor, Synthane, and Self-Agglomerating Ash gasification processes (5). These processes are designed to fill the pipeline distribution systems and to mix... 

The experimental work described here deals exclusively with the properties of the acceptor as dictated by the needs of the process. Data on kinetics of the gasification reactions, for example, will not be presented at this time. 

Table II notes that in the process two important equilibria in acceptor reactions are involved. These were checked experimentally since the literature data are contradictory. No data at all were available on the H2S acceptor reaction, which is important in the gasification step, and the equilibrium was also determined for Reaction 5.

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