Commercial gasification systems

This process produces low or medium Btu gases from wood and wood wastes, agricultural residues and MSW. Processing these synthetic gases with water can produce ammonia, methanol, or hydrogen. Commercial gasification systems exist, but their widespread use has been limited by hauling distances for the feedstock. 

Table 2.11 provides a summary of the commercial and semicommercial experiences for gasification systems. 

The key to successful commercialization of gasification systems devoted to power production rests both on maintaining the government R D focused on industry needs and ensuring that the proper key technical issues are being addressed. The sidebar discussion summarizes those factors that have an impact on the future development of the technologies described here. 

This work shows that oxygen-free sulfite in lime/limestone slurries, exposed to sulfur dioxide, slowly decomposes under process conditions. In fact, auto-redox reactions of sulfur oxyacids can occur in all coal desulfurization systems, including coal-gasification systems and impurities present in commercial flue gas systems are capable of catalyzing the reaction under process conditions. Our experiments indicate that any large-scale coal utilization will depend on appropriate control of the autoredox reactions of sulfur species. 

Off gases are generated from both the Fischer Tropsch and reforming steps. Quality is very high (600-2500 Btu/SCF) with a heavy concentration of low molecular weight paraffins. On a commercial scale, these gases would be recycled back to the gasification system. 

Tasks underway at the research scale include alternate feedstock studies, gasification system optimization, waste stream characterization, and liquid fuels tailoring. A pilot scale facility (10 tons/day) is contemplated with eventual commercialization dependent on results at this stage. 

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