煤的气化Coal gasification

煤先受热脱挥发分，剩下的焦炭再与气化剂反应。碳与氧的部分燃烧放热，为强吸热的碳-水蒸气反应 C + H₂O → CO + H₂ 供能。通过调节氧气与水蒸气的比例来控制温度和煤气组成。主要炉型有固定床（鲁奇炉）、流化床（温克勒炉）和气流床（德士古、壳牌、GE 炉），气流床温度可达 1300–1600 °C。

Coal first releases its volatiles on heating, and the remaining char reacts with the gasifying agent. Partial combustion of carbon with oxygen releases heat that drives the strongly endothermic carbon–steam reaction C + H₂O → CO + H₂. The oxygen-to-steam ratio sets the temperature and gas composition. Main reactor types are fixed bed (Lurgi), fluidised bed (Winkler) and entrained flow (Texaco, Shell, GE), the last running at 1300–1600 °C.

18 世纪末默多克用煤干馏得到的煤气照明，19 世纪城市普遍使用煤气灯。1920 年代温克勒发明流化床气化炉，1930 年代鲁奇公司开发加压固定床气化炉。二战期间德国、南非（萨索尔，1955 年起）依靠煤气化和费托合成生产液体燃料。中国是当今煤化工规模最大的国家。

In the late eighteenth century Murdoch lit buildings with gas from heated coal, and city gaslighting spread in the nineteenth. Winkler invented the fluidised-bed gasifier in the 1920s, and Lurgi developed the pressurised fixed-bed gasifier in the 1930s. Germany in the Second World War, and South Africa's Sasol from 1955, produced liquid fuels by gasification and Fischer–Tropsch synthesis. China now has the world's largest coal-chemical industry.

煤气化是整体煤气化联合循环发电（IGCC）、煤制甲醇、煤制烯烃和煤制天然气的龙头工艺。与直接燃烧相比，它便于在燃烧前脱硫并集中捕集 CO₂，但整个产业链的碳排放和耗水量都较高。

Gasification is the front end of integrated gasification combined cycle (IGCC) power, coal-to-methanol, coal-to-olefins and synthetic natural gas. Compared with direct combustion it makes pre-combustion sulfur removal and concentrated CO₂ capture easier, but the whole chain has high carbon emissions and water use.