煤的气化与直接燃烧有什么本质区别？得到的合成气有哪些用途？
What is the essential difference between coal gasification and direct combustion, and what uses does the resulting syngas have?
燃烧是让煤在过量空气中完全氧化，只输出热量；气化则是高温下用不足量的氧和水蒸气使煤部分氧化，主产物为由CO和H₂组成的合成气，核心步骤是放热的碳氧反应与吸热的蒸汽碳反应（C+H₂O→CO+H₂）。合成气经水煤气变换调整氢碳比后，可用于费托合成油品、生产甲醇或合成氨，把煤从燃料升级为化工原料。
Combustion fully oxidizes coal in excess air and releases heat only; gasification partially oxidizes coal at high temperature with limited oxygen plus steam, yielding syngas of CO and H₂ through the exothermic carbon–oxygen step and the endothermic steam–carbon reaction (C + H₂O → CO + H₂). Once the water–gas shift sets the H₂/CO ratio, syngas can feed Fischer–Tropsch fuels, methanol plants, or ammonia synthesis, upgrading coal from a mere fuel into chemical feedstock.
难度 进阶 · 适合 大众
CC BY 4.0 · 来源待核验 · Source pending review
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出处备注：著录含书名，但缺版次 / 出版社 / 年份中的一部分，需编辑补全后才能做独立比对。
C. Higman、M. van der Burgt《Gasification》第2版，Gulf Professional Publishing，2008年
C. Higman & M. van der Burgt, "Gasification", 2nd ed., Gulf Professional Publishing, 2008
#煤化学 #煤气化 #合成气
煤气化炉中焦炭同时经历哪些主要的碳–氧–水反应？为什么吸热的水煤气反应必须与放热的部分氧化耦合才能连续运行？
Which major carbon–oxygen–steam reactions proceed together on the char inside a coal gasifier, and why must the endothermic water-gas reaction be coupled with exothermic oxidation for continuous operation?
气化炉中焦炭经历三个关键反应：部分氧化C + ½O₂ → CO强放热；水煤气反应C + H₂O ⇌ CO + H₂吸热约131 kJ/mol；Boudouard反应C + CO₂ ⇌ 2CO同样吸热。只通蒸汽则炉温持续下降，工业上因此交替吹入空气（或氧气）与蒸汽，以氧化热平衡气化的吸热负荷。所得CO与H₂即合成气，可供费托合成、制甲醇及合成氨使用。
Three key reactions consume the char: partial oxidation C + ½O2 → CO is strongly exothermic, the water-gas reaction C + H2O ⇌ CO + H2 absorbs about 131 kJ/mol, and the Boudouard reaction C + CO2 ⇌ 2CO is also endothermic. Steam alone would let the furnace cool steadily, so industrial units blow air or oxygen alternately with steam, balancing the endothermic gasification load against oxidation heat. The resulting CO and H2 constitute synthesis gas for Fischer-Tropsch liquids, methanol and ammonia synthesis.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-02
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D. W. van Krevelen, Coal: Typology—Chemistry—Physics—Constitution, 第3版, Elsevier, 1993。
D. W. van Krevelen, Coal: Typology — Chemistry — Physics — Constitution, 3rd ed., Elsevier, 1993.
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL3571796W：Coal--typology, physics
#煤气化 #水煤气反应 #合成气
煤间接液化是怎样借助费托合成把煤变成柴油和石脑油的？
How does Fischer-Tropsch synthesis convert coal into diesel and naphtha during indirect coal liquefaction?
先将煤与氧气、水蒸气气化为一氧化碳和氢气的混合气，调好氢碳比；合成气流经约200-350摄氏度的铁或钴催化剂时，一氧化碳在表面解离出碳原子，逐级加氢成CH2单元，再经类似聚合的链增长连成从甲烷到重蜡的烃类。蜡馏分加氢裂化后即得柴油和石脑油，南非Sasol公司据此实现大规模煤制油。
Coal is first gasified with oxygen and steam into synthesis gas, a mixture of carbon monoxide and hydrogen whose ratio is adjusted to suit the catalyst. At roughly 200-350 degrees C the syngas flows over iron or cobalt catalysts: CO dissociates on the surface and its carbon is hydrogenated stepwise into CH2 units, which couple through polymer-like chain growth into hydrocarbons ranging from methane to heavy wax. Hydrocracking the wax fraction yields diesel and naphtha; Sasol industrialised this route for large-scale coal-to-liquids production.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-04
来源 · Source
A. P. Steynberg 与 M. E. Dry 主编,《Fischer-Tropsch Technology》,Studies in Surface Science and Catalysis 第152卷, Elsevier,2004 (DOI: 10.1016/s0167-2991(04)x8456-1)
A. P. Steynberg & M. E. Dry (eds.), 'Fischer-Tropsch Technology', Studies in Surface Science and Catalysis Vol. 152, Elsevier, 2004, DOI: 10.1016/s0167-2991(04)x8456-1
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.1016/s0167-2991(04)x8456-1
#费托合成 #煤间接液化 #合成气