化工过程熵增指数及其在磷复肥清洁生产评价中的应用

从热力学第二定律出发， 指出清洁生产的热力学本质是控制物质由有序结构向无序转化并从中获取最大效益， 其优劣可由过程熵增反映。 引用复杂体系非平衡定态过程最小熵产生原理，推导出依据与外界交换的物流和热流信息定量计算化工复杂系统过程熵增的方法， 并定义过程熵增指数ζ 。 评价了化工过程对环境热力学状态的综合影响。选择以硫和以氨为载能原料的磷复肥工艺为例进行了计算和对比，其过程熵增指数分别为6.753和4.571，反映出载能原料硫作为废物排放对环境热力学状态产生更大的影响。

Indicator of Entropy Production in Chemical Processes and Application to the Analysis of Cleaner Production of Phosphate Compound Fertilizer

Based on the second law of thermodynamics, it was stated in this paper that the thermodynamic essential of cleaner production is to control the conversion of matters from order to random in the most beneficial way. The efficiency can be indicated by the entropy production in the process. Adopting the principle of minimum entropy production in a steady process of a complex system, a simplified methodology was deduced to calculate the entropy production for complex chemical processes based on the information of mass and heat flux exchanged between the system and environment. A indicator of entropy production was proposed to evaluate the thermodynamic impact of a process by the ratio of total process entropy production to the entropy contained in the valid products. A pair of practical processes of phosphate compound fertilizer, in which sulfur and ammonia are used as energy carrier respectively, were chosen to be calculated and compared. The indicator of entropy production is 6.753 for the sulfur route and 4.571 for the ammonia route. It becomes clearer that the sulfur route makes more thermodynamic impacts to the environment because the matter of sulfur is discharged as waste while the matter of ammonia conversed to the valid products of compound fertilizer.