A comparison of electricity and hydrogen production systems with CO_2 capture and storage. Part A: Review and selection of promising conversion and capture technologies

摘要

We performed a consistent comparison of state-of-the-art and advanced electricity and hydrogen production technologies with CO_2 capture using coal and natural gas, inspired by the large number of studies, of which the results can in fact not be compared due to specific assumptions made. After literature review, a standardisation and selection exercise has been performed to get figures on conversion efficiency, energy production costs and CO_2 avoidance costs of different technologies, the main parameters for comparison. On the short term, electricity can be produced with 85-90% CO_2 capture by means of NGCC and PC with chemical absorption and IGCC with physical absorption at 4.7-6.9 ?ct/kWh, assuming a coal and natural gas price of 1.7 and 4.7 ?/GJ. CO_2 avoidance costs are between 15 and 50 ?/t CO_2 for IGCC and NGCC, respectively. On the longer term, both improvements in existing conversion and capture technologies are foreseen as well as new power cycles integrating advanced turbines, fuel cells and novel (high-temperature) separation technologies. Electricity production costs might be reduced to 4.5-5.3 ?ct/kWh with advanced technologies. However, no clear ranking can be made due to large uncertainties pertaining to investment and O&M costs. Hydrogen production is more attractive for low-cost CO_2 capture than electricity production. Costs of large-scale hydrogen production by means of steam methane reforming and coal gasification with CO_2 capture from the shifted syngas are estimated at 9.5 and 7 ?/GJ, respectively. Advanced autothermal reforming and coal gasification deploying ion transport membranes might further reduce production costs to 8.1 and 6.4 ?/GJ. Membrane reformers enable small-scale hydrogen production at nearly 17 ?/GJ with relatively low-cost CO_2 capture.