Energy integration issues for hydrogen and electricity co-production based on gasification process with Carbon Capture and Storage (CCS)

摘要

Integrated Gasification Combined Cycle (IGCC) is a technology for powerrnproduction in which the feedstock is partially oxidized with oxygen and steam tornproduce syngas. In a conventional IGCC design without carbon capture, the syngas isrnpurified for dust and hydrogen sulphide removal and then sent to a Combined CyclernGas Turbine (CCGT) for power production. Carbon capture technology is expected tornplay a significant role in the coming decades for curbing the greenhouse gas emissions.rnIGCC is one of the power generation technologies having the highest potentialrnto capture carbon dioxide with the low penalties in term of efficiency and cost. In arnmodified IGCC design for carbon capture, the syngas is catalytically shifted tornmaximize the hydrogen level in the syngas and to concentrate the carbon species in thernform of carbon dioxide that can be later capture in a pre-combustion arrangement. Afterrncarbon dioxide capture, the hydrogen-rich syngas can be either purified in a PressurernSwing Adsorption (PSA) unit and exported to the external customers (e.g. PEM fuelrncells) or used in a CCGT for power generation.rnThis paper investigates the most important energy integration issues forrnhydrogen and electricity co-production scheme based on coal gasification process withrncarbon capture and storage (CCS). The coal-based IGCC case study produces aroundrn400 MW net electricity and a flexible hydrogen output in the range of 0 to 200 MWrn(LHV) with 90 % carbon capture rate. The principal focus of the paper is concentratedrnon overall energy efficiency optimization by better heat and power integration of thernmain plant sub-systems (e.g. integration of steam generated in gasification island andrnsyngas treatment line into combined cycle, integration of PSA tail gas in the powerrnblock, heat and power demand for Acid Gas Removal unit, ASU – GT integration etc.).