In U.S. Patent 7,648,566, General Electric (GE) reveals a integrated gasification combined cycle (IGCC) coal to syngas plant that also captures CO2 gas while producing hydrogen at a lower costs.
The GE reactor system is based on high-temperature membrane separation of carbon dioxide from syngas. It offers many advantages for an integrated coal-to-H2 and electricity polygeneration process. The integrated concept allows for a reduced energy cost for CO2 capture, lower capital cost, and a smaller overall footprint for the reactor and the plant.
Furthermore, the integrated approach leverages synergies between water-gas shift reactions and the need for CO2 removal. The use of membranes for H2S removal eliminates the need for energy-intensive absorption and solvent regeneration.
The economic benefits of the module will facilitate commercialization of IGCC electricity generation plants or IGCC polygeneration plants with CO2 separation. The elimination of two processes (solvent regeneration and PSA) and the consolidation of four others (HTS, LTS, H2S removal, CO2 removal) into an integrated module will significantly reduce capital costs which will have a significant impact on the economic feasibility of coal-based H2 production technologies.
GE’s integrated syngas clean-up reactor has numerous advantages over non-integrated reactors, such as a reduced volume of steam in the stream (thereby reducing the energy consumption required for the steam generation), optional elimination of a heat exchanger in the reactor, improved efficiency (e.g., higher carbon monoxide conversion and lower hydrogen loss), and optionally, maintenance of a substantially constant pressure through the reactor.
GE’s integrated syngas clean-up reactor has numerous advantages over non-integrated reactors, such as a reduced volume of steam in the stream (thereby reducing the energy consumption required for the steam generation), optional elimination of a heat exchanger in the reactor, improved efficiency (e.g., higher carbon monoxide conversion and lower hydrogen loss), and optionally, maintenance of a substantially constant pressure through the reactor.
An additional advantage of this reactor is the decoupling of the membrane section(s) and the catalyst sections. This decoupling enables each portion to operate at a more preferable temperature for that portion (e.g., a catalyst and/or membrane keyed to the temperature at that point in the reactor can be employed).
For example, specific catalysts can be chosen for each catalyst section (e.g., catalysts that exhibit enhanced performance at the operating temperature of that particular portion), and specific membrane materials can be chosen for each membrane section to also optimize performance and/or to reduce cost. Further advantages of the decoupling include the enablement of individual replacement of a portion if damaged or otherwise malfunctioning, and the broadening of design specifications for each portion.
The first conversion-removal portion comprises a first catalyst section configured to convert CO in the stream to CO2, and a first membrane section located downstream of and in flow communication with the first catalyst section. The second conversion-removal comprises a second catalyst section configured to convert CO in the stream to CO2 and a second membrane section located downstream of and in flow communication with the second catalyst section. The second membrane section is configured to selectively remove the CO2 from the stream and to be in flow communication with a second sweep gas.
