Reaction pathways in the supercritical water oxidation of typical alcohols
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摘要: 采用自主设计的连续流动气封壁超临界水氧化反应装置,研究了典型醇类物质甲醇、乙醇和异丙醇在超临界水中氧化的反应途径,并归纳了醇类物质超临界水氧化反应的规律及特点。研究结果表明,甲醇超临界水氧化反应的主要中间产物为甲醛,同样条件下转化率较乙醇和异丙醇低;乙醇和异丙醇超临界水氧化反应的主要中间产物为丙酮、乙酸、乙醛和甲醇等。三种醇超临界水氧化过程中均涉及到大量活性自由基的相互作用,表现为脱氢、裂解和聚合等反应形式;产物包括碳链增长、不变、降低三种类型。总体来看,醇类物质超临界水氧化反应的趋势是向碳链降低的方向进行,即通过一系列中间产物最后生成CO2和水。Abstract: Supercritical water oxidation (SCWO) experiments of typical alcohols such as methanol, ethanol, isopropanol were carried out by using an innovatively designed lab scale, continuous flow gas sealed wall reactor (GSWR) to explore the reaction pathways and generalities of simple alcohols. The investigation indicates that during the supercritical water oxidation reactions, methanol has a lower conversion than ethanol and isopropanol, and with the main intermediate of formaldehyde. However, the important intermediates for SCWO of ethanol and isopropanol include acetone, acetic acid, acetaldehyde and methanol. Dehydrogenation, decomposition and polymerization reactions associated with many free radicals are involved in the supercritical water oxidation processes of all three alcohols, and three kinds of products produced, which include chemicals with the increased, unaltered and decreased carbon chain compared with the reactants, but generally speaking, the tendency of decreased carbon chain orientation dominates for the SCWO reactions of alcohols, and has the terminal products of carbon dioxide and water.
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Key words:
- supercritical water /
- oxidation /
- alcohol /
- reaction pathway /
- intermediates
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