The formal description of chemical reactions far from equilibrium is an open task. Chemical reactions are central to various phenomena in life, industry, and the environment. In this work, we use a variational principle within the framework of extended irreversible thermodynamics to obtain relaxation equations for the fast variables and close the balance equations. Our approach extends traditional local equilibrium thermodynamics by incorporating formal expressions for the unknown generalized equations of state, which we can expand in low and higher-order terms, allowing for a more comprehensive representation of non-linear and dissipative phenomena and capturing wave-like behaviours relevant to oscillatory chemical systems. The formalism aligns well with previous theoretical works and provides additional insights into the influence of diffusion fluxes on reaction rates. The resulting equations may describe velocity reactions with different relaxation times and diffusion reactions. We present a comparison of our results with experiments in the context of a particular chemical kinetics case. We emphasize the need for practical applications in areas like environmentally friendly chemical reaction systems.

中文翻译：

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超越局部平衡的化学反应的变分方法


对远离平衡的化学反应的正式描述是一项开放的任务。化学反应是生活、工业和环境各种现象的核心。在这项工作中，我们在扩展不可逆热力学框架内使用变分原理来获得快速变量的松弛方程并关闭平衡方程。我们的方法通过合并未知广义状态方程的形式表达式来扩展传统的局部平衡热力学，我们可以将其扩展为低阶和高阶项，从而更全面地表示非线性和耗散现象，并捕获与振荡化学系统相关的波状行为。这种形式主义与以前的理论工作非常吻合，并为扩散通量对反应速率的影响提供了额外的见解。所得方程可以描述具有不同弛豫时间的速度反应和扩散反应。我们将我们的结果与特定化学动力学案例中的实验进行了比较。我们强调在环保化学反应系统等领域的实际应用需求。