摘要
回顾了世界各国煤炭地下气化的发展状况，提出了地下气化必须解决的问题，展望了地下气化的发展前景。
Present situation,some unsolved questions and future development of underground gasification were discussed.
关键词
煤
地下气化
气化炉
长通道
双火源
underground gasification,gasifier,long passage,double fire resources,double stage
