Gasification pilot units

Recovery of a portion of the heat energy available in the hot (>2000°F) syngas stream of the 25 TPD unit is intended to improve the net thermal efficiency of the process by installing a waste heat boiler, which will produce steam for use in process heating. In a larger gasification system, additional energy recovery equipment could be installed to further improve efficiency. However, the capital costs of such equipment are not justified for a small 25 TPD pilot unit. 

The PEPS Gasification system offers the capability to convert a petroleum refinery by-product into valuable, ultra-clean liquid fuels. Alternately, the system can be modified to generate hydrogen, another valuable clean fuel. These fuels could reduce the nation s dependence on imported oil. Preliminary design for a 25 TPD Clean Fuels PEPS pilot unit has been completed, as has some risk reduction testing. Future funding for completion of the project is... 

Significant development has occurred within the industry over the last several years with respect to liquid-phase processes. One example of this process that is reasonably close to commercialization is that developed by Air Products. A pilot unit has been operated for several years at their La Porte, Texas location. The process is characterized briefly as using an inert hydrocarbon reaction medium in the liquid phase to absorb the synthesis heat of reaction conventional copper-zinc catalyst is fed to the reactor system as a slurry. This type of process appears to be particularly well suited to substoichiometric feeds (hi earbon eontent), such as those produced by partial oxidation or coal gasification. The Air Products process has been extensively deseribed in patent literature [14]. Kinetie data and liquid-phase reaetion systems have also been extensively diseussed by Lee in Methanol Synthesis Technology [15]. 

Shell Gasification Process. Shell s experience with coal gasification started with operation of a 6-ton/day pilot plant in Amsterdam. This was followed by a 150-ton/day unit in Hamburg, Germany, and a 250-400-ton/day unit in Houston, TX. This led to the successful operation of a 2000-ton/day commercial unit. 

This molten salt gasification process is the basis for the Rockwell International molten salt coal gasification process. A 900-kg-h l (1 ton/h) process development unit pilot plant has been built and is being tested under contract from the Department of Energy. This plant includes the gasifier and a complete sodium carbonate recovery and regeneration system. 

The effect of the additive upon yield of hydrogen and methane in the pilot-plant unit is shown in Figure 9. At an average gasification temperature of 914 °C, addition of 5% hydrated lime in the coal feed increased the hydrogen yield approximately 30% from 6.25 to 8.1 scf/lb of moisture-and-ash-free coal feed. A similar increase of 17% was obtained when 5% dolomite was used in the coal feed at 945 °C average gasifica-... 

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