Development of green corrosion inhibitors for absorption-based CO2 capture processes

在使用烷醇胺水溶液吸收二氧化碳(CO2)的过程中，腐蚀是最严重的操作问题之一，特别是当碳钢用于工厂建设时。为了将这种严重的腐蚀抑制到可接受的水平，缓蚀剂被广泛地应用于这一过程。然而，目前的缓蚀剂都是重金属，具有固有的毒性，可能对人类健康和环境造成不利影响。由于化学品使用和处置的环境法规，此类有毒缓蚀剂的处理和工艺废物的处理受到限制，而且成本高昂。现在必须发现环境上可以接受的新的缓蚀剂，以提供工业的替代品。因此，这项拟议研究的最终目标是开发具有成本效益的绿色缓蚀剂，并建立有效应用所开发的绿色缓蚀剂的最佳做法或战略。本研究分为三个主要任务：1)潜在绿色缓蚀剂的理论筛选和配方；2)配方缓蚀剂的性能评价；3)建立绿色缓蚀剂体系的预测和机理腐蚀模型。开发的绿色缓蚀剂以及有效应用缓蚀剂的战略将随时可用，以响应环境法规和工业需求。这些缓蚀剂有望取代目前的重金属缓蚀剂，从而降低废物处理成本和健康风险。这将为加拿大在绿色化学品使用领域发挥领导作用提供机会。此外，从业者，特别是工艺工程师，将能够将开发的绿色缓蚀剂纳入其二氧化碳捕集工艺的设计和操作策略中，以降低能耗和工艺设备的溶液循环速度或尺寸。这将大大节省二氧化碳捕集的资本和运营成本，否则这些成本会受到腐蚀问题的限制。这将使二氧化碳捕获更经济、更环保。

Corrosion is one of the most severe operational problems in the carbon dioxide (CO2) absorption process using aqueous solutions of alkanolamines, especially when carbon steel is used for plant construction. To suppress such severe corrosion to an acceptable level, corrosion inhibitors are widely applied to this process. However, current corrosion inhibitors are heavy metals that are inherently toxic and potentially pose adverse impacts on human health and the environment. Due to the environmental regulations on the chemical use and disposal, handling of such toxic corrosion inhibitors and disposal of the process waste are restricted and costly. New corrosion inhibitors which are environmentally acceptable must now be discovered to provide alternatives to industry. The ultimate objectives of this proposed research are therefore to develop cost-effective green corrosion inhibitors and establish best practices or strategy for an effective application of the developed green corrosion inhibitors. The proposed research is divided into three main tasks: 1) theoretical screening and formulations of potential green corrosion inhibitors, 2) performance evaluation of the formulated inhibitors, and 3) development of a predictive and mechanistic corrosion model for the green inhibitor system. The developed green corrosion inhibitors together with the strategy for effective inhibitor application will be readily available in response to environmental regulations and industrial needs. These inhibitors are expected to replace current heavy metal inhibitors, thus reducing cost of waste disposal and health risk. This would present an opportunity for Canada to take a leadership role in the area of green chemical use. In addition, practitioners, especially process engineers, would be able to factor in the developed green corrosion inhibitors in their strategy for the design and operation of CO2 capture processes to reduce energy consumption and solution circulating rate or size of process equipment. This would lead to significant savings in both capital and operating costs for CO2 capture, which are otherwise limited by corrosion problems. This would make CO2 capture more economical and environmentally favorable.