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首页> 外文期刊>Recent Patents on Chemical Engineering >Mathematical Simulation of Kinetics of Radiation-Induced Free-Radical Oxidation by Nonbranched-Chain Mechanism
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Mathematical Simulation of Kinetics of Radiation-Induced Free-Radical Oxidation by Nonbranched-Chain Mechanism

机译：非支链机理的辐射诱导自由基氧化动力学的数学模拟

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New reaction scheme is suggested for the initiated nonbranched-chain addition of free radicals to the multiple bond of the molecular oxygen. The scheme includes the addition reaction of the peroxyl free radical to the oxygen molecule to form the tetraoxyl free radical. This reaction competes with chain propagation reactions through a reactive free radical. The chain evolution stage in this scheme involves a few of free radicals, one of which (tetraoxyl) is relatively low-reactive and inhibits the chain process by shortening of the kinetic chain length. Based on the proposed scheme rate equations (containing one to three parameters to be determined directly) are deduced using quasi-steady-state treatment. The kinetic description with use the obtained rate equations is applied to the y-induced nonbranched-chain processes of the free-radical oxidation of liquid o-xylene at 373 K and hydrogen dissolved in water containing different amounts of oxygen at 296 K. The ratios of rate constants of competing reactions and rate constants of addition reactions to the molecular oxygen are defined. In these processes the oxygen with the increase of its concentration begins to act as an oxidation au-toingibitor (or an antioxidant), and the rate of peroxide formation as a function of the dissolved oxygen concentration has a maximum. From the energetic standpoint possible nonchain pathways of the free-radical oxidation of hydrogen and the routes of ozone decay via the reaction with the hydroxyl free radical in the upper atmosphere (including the addition yielding the hydrotetraoxyl free radical, which can be an intermediate in the sequence of conversions of biologically hazardous UV radiation energy) were examined. The energetics of the key radical-molecule gas-phase reactions is considered.
机译：提出了一种新的反应方案，用于将自由基引发的非支链加成到分子氧的多重键上。该方案包括过氧自由基与氧分子的加成反应以形成四氧自由基。该反应通过反应性自由基与链增长反应竞争。该方案的链发展阶段涉及一些自由基，其中一个自由基（四氧基）相对较低的反应性，并通过缩短动力学链长来抑制链化过程。基于拟议的方案，使用准稳态处理推导了速率方程（包含一到三个要直接确定的参数）。使用获得的速率方程的动力学描述适用于y诱导的非支链过程，该过程由液态邻二甲苯在373 K自由基和溶解在含有不同量氧气的水中以296 K的自由基进行自由基氧化。定义了竞争反应的速率常数和加成反应对分子氧的速率常数。在这些过程中，浓度增加的氧气开始起氧化自发剂（或抗氧化剂）的作用，并且过氧化物的生成速率随溶解氧浓度的变化而最大。从能量的观点来看，氢的自由基氧化的可能的非链途径和通过与高层大气中的羟基自由基反应（包括产生氢四氧基自由基的加成反应的臭氧衰减途径）的臭氧衰减的途径，可以是氢四氧基自由基的中间体。检查了对生物有害的紫外线辐射能量的转化顺序）。考虑了关键自由基分子气相反应的能量。

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