合成气Syngas

不同来源的合成气 H₂/CO 比例不同：甲烷蒸汽重整约为 3，煤气化约为 0.5–1。下游用途要求特定比例，如甲醇合成和费托合成需要约 2。通过水煤气变换反应 CO + H₂O ⇌ CO₂ + H₂ 可提高氢含量，再脱除 CO₂ 和硫化物。

The H₂/CO ratio depends on the source: about 3 from steam methane reforming and about 0.5–1 from coal gasification. Downstream uses need particular ratios, such as about 2 for methanol and Fischer–Tropsch synthesis. The water–gas shift, CO + H₂O ⇌ CO₂ + H₂, raises the hydrogen content, after which CO₂ and sulfur compounds are removed.

19 世纪人们把水蒸气通过炽热焦炭得到的“水煤气”用作城市燃气。1913 年哈伯-博施法、1923 年巴斯夫高压甲醇合成和 1925 年费歇尔与托罗普施的费托合成，使合成气成为化学工业的平台原料。1938 年罗伦发现羰基合成（氢甲酰化）反应。

In the nineteenth century 'water gas', made by passing steam over glowing coke, was used as town gas. The Haber–Bosch process (1913), BASF's high-pressure methanol synthesis (1923) and Fischer and Tropsch's synthesis (1925) made syngas a platform feedstock of the chemical industry. Roelen discovered hydroformylation (the oxo process) in 1938.

合成气可制甲醇（再制甲醛、乙酸、烯烃）、液体燃料、醛和醇，也可直接作燃料发电。合成气中的 CO 无色无味且剧毒，与空气混合易爆，生产和输送必须严格密封并安装检测报警。

Syngas is converted to methanol (and from it formaldehyde, acetic acid and olefins), liquid fuels, aldehydes and alcohols, or burnt directly for power. Its CO is colourless, odourless and highly toxic, and mixtures with air are explosive, so equipment must be tightly sealed and fitted with gas detectors.