Hot-gas cleanup—sulfur recovery technical, environmental, and economic issues

Advanced high-efficiency integrated gasification combined cycle (IGCC) power systems employing hot-gas cleanup are being developed to produce electric power from coal. Hot-gas cleanup consists of hot particulate removal and hot-gas desulfurization (HGD) technologies that match or nearly match the temperature and pressure of the gasifier and turbine generator. HGD is carried out using solid regenerable metal oxide sorbents that can remove the sulfur down to low parts per million and can be regenerated with air for multicycle operation. Economic studies have shown that HGD results in lower capital and operating costs than conventional cold gas desulfurization. Development of efficient sorbent desulfurization-regeneration reactor and tailgas treatment subsystems properly integrated with the overall IGCC systems is a key requirement for successful commercialization of HGD.