Conceptual Design and Energy Analysis of Integrated Combined Cycle Gasification System

In this paper, an integrated gasification combined cycle conceptual design that achieves optimum energy efficiency and 82.9% heat integration between hot and cold utilities is illustrated. The integrated combined gasification cycle (IGCC) is also modeled and evaluated for the co-production of electricity, ammonia and methane for 543.13 kilo tonne per annum (KTA) of municipal solid waste (MSW). The final products are 1284.89 MW, 8731.07 kg/h of liquid ammonia at 8 degrees C and 32,468 kg/h of methane gas at 271 degrees C. The conceptual design includes advanced heat integration between syngas and hot and cold streams in all process units. The water gas shift (WGS) unit includes integration between equilibrium reactors and cold streams. The air separation unit (ASU) includes four air compressors followed by a pressure swing adsorber (PSA), which separates oxygen and nitrogen gases into separate streams. Both O-2 and N-2 gases are compressed and sent to gasifier and syngas cleaning unit, respectively. The overall design shows reliability and solved steady state equations for all process units with improvements in thermal efficiency in comparison with single cycle gasification plants. The environmental emissions for GHGs such CO2 and SO2 are lower due to higher overall energy efficiency.