Environmental Assessment of Dimethyl Carbonate Production: Comparison of a Novel Electrosynthesis Route Utilizing CO2 with a Commercial Oxidative Carbonylation Process
Environmental Assessment of Dimethyl Carbonate Production: Comparison of a Novel Electrosynthesis Route Utilizing CO2 with a Commercial Oxidative Carbonylation Process
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DOI：
10.1021/acssuschemeng.5b01515
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发表时间：
2016-04-01
影响因子：
8.4
通讯作者：
Azapagic, Adisa
中科院分区：
文献类型：
--
作者：
Garcia-Herrero, Isabel;Cuellar-Franca, Rosa Marisa;Azapagic, Adisa
采用生命周期评价（LCA）方法，对由废二氧化碳合成碳酸二甲酯（DMC）新工艺的环境可持续性进行了评价。该方法涉及在甲醇钾和离子液体1-丁基-3-甲基咪唑溴化物存在下CO2和甲醇的电化学反应以产生DMC。实验数据和工艺模拟相结合，以估计环境影响，并将其与传统的基于甲醇氧化羰基化的商业“埃尼”工艺进行比较。从“摇篮到大门”共评估了11个环境影响类别，包括全球升温潜能值（GWP）、潜在毒性和资源消耗。例如，在电化学过程中产生的DMC的GWP范围为63.3至94.5kg CO2当量/当量。kg DMC，取决于工艺配置。这比本研究中估计的商业工艺的全球升温潜能值（3.2千克CO2当量/吨）高出约25倍。kg DMC。这是因为在电化学方法的当前设计中实现的低转化率（0.7%），在分离过程中需要高能量消耗。结果表明，工艺产率必须增加到至少20%，以将GWP降低到与商业工艺相当的水平。在这个产量下，电化学过程也变得比商业系统更具可持续性，因为考虑了大多数其他影响。该研究展示了LCA如何在技术开发的早期阶段通过将实验数据和过程模拟相结合，在设计过程中开发环境更可持续的过程中发挥关键作用。
Life cycle assessment (LCA) has been used at an early design stage to evaluate the environmental sustainability of a novel process for synthesizing dimethyl carbonate (DMC) from waste CO2. The process involves an electrochemical reaction of CO2 and methanol in the presence of potassium methoxide and the ionic liquid 1-butyl-3-methylimidazolium bromide to produce DMC. Experimental data and process simulation have been combined to estimate the environmental impacts and compare them to the conventional commercial "Eni" process based on oxidative carbonylation of methanol. Eleven environmental impact categories have been assessed from "cradle to gate", including global warming potential (GWP), toxicity potentials, and resource depletion. For example, GWP of DMC produced in the electrochemical process ranges from 63.3 to 94.5 kg CO2 eq./kg DMC, depending on a process configuration. This is around 25 times higher than GWP of the commercial process estimated in this study at 3.2 kg CO2 eq./kg DMC. This is because of the low conversion achieved in the current design of the electrochemical process (0.7%), requiring high energy consumption in the separation process. The results suggest that the process yield must be increased to at least 20% to reduce the GWP to a level comparable with the commercial process. At this yield, the electrochemical process also becomes more sustainable than the commercial system for most other impacts considered. The study demonstrates how LCA can play a key role in the development of environmentally more sustainable processes during design by combining experimental data and process simulation at an early stage of technology development.