基于Zn/ZnO的新型近零排放洁净煤能源利用系统

A Novel System of Near Zero Emission Clean Coal Energy Utilization Based on Zn/ZnO

以基于Zn/ZnO的两步式煤气化技术为基础构建了一种新型的近零排放洁净煤能源利用系统.在气化反应器中,煤在高温下与ZnO反应,生成CO气体和锌蒸汽,然后经冷凝分离出来的锌被送入水解反应器中生成氢气和固体ZnO;最后ZnO又被回收到气化反应器中.气化反应器的加热系统考虑了3种加热方式(碳内热式、碳外热式以及太阳能加热方式),对这3种系统方案的理论能效和清洁性能进行了评估.结果显示:在不考虑CO2处理能耗的情况下,碳内热式方案可获得最高热电效率,达到65%左右;太阳能加热方案的清洁性能最佳,其单位产电所需处理的CO2量比其余2种方案均降低了一半以上.

Based on the Zn/ZnO two-step coal gasification technology, a novel system of near zero emission clean coal energy utilization is constructed. Coal is gasified with ZnO （s） in a gasifier under high temperature, producing CO and Zn（g）. After separation by partial condensation, Zn（1） reacts with H20 （g） in a hydrolysis reactor, producing H2 and ZnO（s）. The produced ZnO is recycled into the gasifier after separation from H2. Three types of gasifier heating systems are considered, carbon heating inside, carbon heating outside and solar heating system. New energy utilization systems based on these three different heating methods are evaluated and compared. Results show that, the new energy utilization system can attain a thermal electric efficiency as high as 65% when equipped with carbon heating inside system, ignoring energy penalty of CO2 sequestration. On the other hand, solar heating system is more environmentally friendly than the other two systems, and its CO2 emission that needs to be sequestrated per unit produced electricity is only half of the other ones.