High entrained-flow processes

The existence of unsaturated hydrocarbons in the raw synthesis gas varies widely. In low temperature processes, there will, in general, be significant quantities of aromatics and other unsaturates in the volatiles and tars, though the exact amount also will depend heavily on the feedstock. For high-temperature-entrained flow processes including oil gasification, the presence of any hydrocarbon other than methane, whether saturated or unsaturated, is minimal. 

If high cold gas efficiency is desired, the potential of all single-stage entrained-flow processes is limited by the ash fusion behavior, whereas gasifiers with nonslagging outlet conditions show the potential to achieve the global maximum. 

The Koppers-Totzek process was first commercialized in 1952 and, by 1984, was used in 19 plants in 17 different countries [27]. The process uses powdered coal at atmospheric pressures in a parallel flow of 02 and H20 at temperatures of 1400-2000°C. The high process temperatures eliminate the formation of hydrocarbons and produce a gas containing 85—90% syngas (CO and H2). A process schematic is shown in Figure 2.26 [37]. Recent process developments include the Pressurized Entrained Flow Gasification (PRENFLO) with operating pressures being increased to 40 bars. 

Many similar types of gasifier process effluents and coal tar have been studied from a variety of coal gasifiers. The composition of organic extracts of scrubber water particulate matter from a high pressure, entrained flow gasifier has been reported... 

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