Warm Gas Multi-contaminant Removal System

Gasification technologies convert coal and biomass into synthesis gas feed streams that can either be used as a fuel for highly efficient power generation cycles or converted into value-added chemicals and transportation fuels. However, coal-derived synthesis gas contains a myriad of contaminants that may be regulated in power plant emissions and act as poisons for the catalysts used in downstream chemical manufacturing processes. TDA Research, Inc. (TDA) proposes to develop a low-cost, high capacity, sorbent that can remove ammonia and hydrogen cyanide (NH3 and HCN, the acid rain precursors) and the trace metal contaminants (such as mercury, arsenic and selenium) from the synthesis gas in a single process step. Unlike the commercially available gas clean-up technologies, our multi-contaminant control system operates at 240oC (464oF), above the dew point of the synthesis gas; operating above the dewpoint improves process efficiency and reduces capital costs. In Phase I, TDA developed a new sorbent that can remove multiple contaminants from simulated synthesis gas streams with high capacity and removal efficiency. We ran the sorbent life through 50 absorption/regeneration cycles under representative conditions without any degradation in performance. In a preliminary engineering analysis, we also showed the economic viability of the new high temperature synthesis gas clean-up system against conventional low temperature scrubbers. During Phase II we will continue to improve the performance of our sorbent and scale-up its production using commercial manufacturing techniques. We will demonstrate the viability of the system in a prototype slipstream test unit using actual coal-derived synthesis gas. We will also carry out a detailed system analysis and engineering assessment to fully quantify the benefits of the new technology. Commercial Applications and Other Benefits: The use of coal-derived synthesis gas in power generation is an emerging technology with significant commercial potential, because gasification-based power cycles operates with much higher efficiency than conventional pulverized coal combustion plants.