Cleaner chlorine production using oxygen depolarized cathodes? A life cycle assessment
Cleaner chlorine production using oxygen depolarized cathodes? A life cycle assessment
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DOI：
10.1016/j.jclepro.2014.05.086
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发表时间：
2014-10-01
影响因子：
11.1
通讯作者：
Bardow, Andre
中科院分区：
文献类型：
--
作者：
Jung, Johannes;Postels, Sarah;Bardow, Andre
氯碱电解过程中，氯和烧碱是两种不可缺少的化工产品。氯碱电解是目前清洁生产的一个目标，因为它的大电力需求造成相当大的环境影响。使用氧去极化阴极（odc）代替目前使用的标准阴极（stc），氯碱电解的电力需求可以减少30%。然而，与现有的氯碱工厂相比，ODCs需要额外的资源，并且不产生氢气。这项工作调查了电力需求的减少是否也有助于清洁生产。为此目的，将使用ODCs的氯碱电解对环境的影响与使用STCs的现有最佳氯碱工厂的影响进行比较。生命周期评估包括工厂的制造、运行和处置。为了考虑现有氯碱厂氢气的利用，研究了两种替代利用方案：通过燃烧氢气回收能量和将氢气作为化学商品使用。采用ReCiPe方法对七个环境影响类别进行了详细研究。使用ODCs的氯碱电解在多达六种环境影响类别中产生较低的环境影响。在7个影响类别中，工厂运营在6个类别中贡献最大。因此，使用ODCs进行氯碱电解有可能促进氯碱工业的清洁生产。(C) 2014 Elsevier Ltd.版权所有。
Chlorine and caustic soda are two indispensable chemical commodities co-produced in the so-called chlor-alkali electrolysis. Chlor-alkali electrolysis is today a target for cleaner production because of its large electricity demand causing considerable envitonmental impacts. The electricity demand of chloralkali electrolysis can be reduced by 30% using oxygen depolarized cathodes (ODCs) instead of the standard cathodes (STCs) used today. However, ODCs require additional resources and do not produce hydrogen in contrast to existing chlor-alkali plants. This work investigates if the reduction in electricity demand also contributes to cleaner production. For this purpose, environmental impacts from chloralkali electrolysis using ODCs are compared to the impacts from best available existing chlor-alkali plants using STCs. The life cycle assessment includes manufacturing, operation and disposal of the plants. To account for utilization of hydrogen from existing chlor-alkali plants, two alternative utilization scenarios are studied: energy recovery by combustion of hydrogen and use of hydrogen as chemical commodity. Seven environmental impact categories are studied in detail using the ReCiPe method. Chloralkali electrolysis using ODCs yields lower environmental impacts in up to six environmental impact categories. Plant operation contributes most in six out of seven impact categories. Chlor-alkali electrolysis using ODCs has thus potential to contribute to cleaner production in the chlor-alkali industry. (C) 2014 Elsevier Ltd. All rights reserved.