TECHNOLOGY OPTIONS FOR CLEAN COAL POWER GENERATION WITH CO_2 CAPTURE

摘要

Coal contributes to about forty percent of the electricity generation in the world today and is expected to maintain its dominant share in the foreseeable future. The state-of-the-art coal-fired power plant today with 600°C steam temperature is about 20% more efficient than the average operating power plants, and can reduce emissions such as SO_2, NO_x, and mercury to ultra-low levels. Hitachi is developing a full portfolio of new clean coal technologies aimed at further efficiency improvement, 90% CO_2 reduction, and near-zero emissions of other pollutants. The technologies under development include 700°C next generation ultrasupercritical boilers and steam turbines, post-combustion CO_2 absorption, oxyfuel combustion, and IGCC with CO_2 capture. This paper provides an overview of the development status of the technologies and discusses their expected performance and economic impacts, with special focus on post-combustion absorption and oxyfuel combustion which are promising near-term solutions of CO_2 capture for new and existing power plants.