Asphaltene is the compound with the most complex structure and the most difficult degradation in oily sludge, which is the key to limit the efficiency of supercritical water oxidation treatment of oily sludge. In this paper, the supercritical water oxidation process of asphaltene was investigated in terms of free radical reaction, degradation pathway, and product generation mechanism using ReaxFF molecular dynamics simulation method. The results showed that increasing temperature, increasing O, and increasing HO have different effects on HO·generation. Benzene rings undergo fusion and condensation through hydrogenation abstraction and oxygen addition reactions, subsequently breaking down into long-chain alkanes. Increasing O can effectively promote the ring-opening of nitrogen-containing heterocycles. -COOH is the most important intermediate fragment for CO and CO generation, and there is a reaction competition with -CHO and -CO. When the number of oxygen molecules increases from 300 to 700, the reaction frequency of -CHO and -CO to generate CO and CO increases by 17.14 % and 12.77 %·HO determines the production of H by controlling the number of H·radicals present. As the amount of HO increases from 500 to 1500, the product ratio of H increases from 12.73 % to 21.31 %. Asphaltene is the most structurally complex organic matter in oily sludge, and its presence makes it difficult for oily sludge to be completely degraded by conventional treatment methods such as pyrolysis and incineration. Polycyclic aromatic hydrocarbons (PAHs) represented by asphaltene increase the carcinogenicity and mutagenicity of oily sludge, and even irreversibly pollute soil and groundwater. Supercritical water oxidation, as an efficient organic waste treatment technology, can realize harmlessness in a green and efficient way. So the study on the mechanism of supercritical water oxidation of asphaltene is of great significance for environmental protection.

中文翻译：

---

超临界水中沥青质的降解途径及产物形成机制


沥青质是含油污泥中结构最复杂、最难降解的化合物，是限制超临界水氧化处理含油污泥效率的关键。本文采用ReaxFF分子动力学模拟方法，从自由基反应、降解途径和产物生成机理等方面对沥青质的超临界水氧化过程进行了研究。结果表明，升高温度、增加O、增加H2O对HO·生成有不同的影响。苯环通过加氢、氧加成反应发生融合和缩合，随后分解成长链烷烃。增加O可以有效促进含氮杂环的开环。 -COOH是CO和CO生成最重要的中间片段，与-CHO和-CO存在反应竞争。当氧分子数从300增加到700时，-CHO和-CO生成CO和CO的反应频率增加了17.14%，12.77%·H2O通过控制H·自由基的数量决定了H的产生。随着H2O的量从500增加到1500，H的产物比例从12.73%增加到21.31%。沥青质是含油污泥中结构最复杂的有机物，它的存在使得含油污泥难以通过热解、焚烧等常规处理方法完全降解。以沥青质为代表的多环芳烃(PAHs)会增加含油污泥的致癌性和致突变性，甚至不可逆地污染土壤和地下水。 超临界水氧化作为一种​​高效的有机废物处理技术，可以绿色高效地实现无害化。因此研究超临界水氧化沥青质的机理对于环境保护具有重要意义。