DataSheet1_Assessment of electrified ethylene production via biomass gasification and electrochemical CO reduction.docx

The chemical industry needs new methods for sourcing carbon-containing feedstocks from renewable sources to decrease CO2 emissions and reduce reliance on fossil fuels. Ethylene, a crucial base chemical used for making polymers and ethylene oxide, is primarily produced through steam cracking of fossil feedstocks. However, an evolving technology is the electrochemical reduction of CO2 or CO to produce ethylene. The study assesses the environmental, economic and energetic performance of a new biomass-based process that produces ethylene based on the electrochemical reduction of CO. The results are based on mass and energy balances from process simulation. The CO is produced by either gasification of biomass or combustion of biomass with CO2 capture and CO2 electrolysis. Besides ethylene, the process produces acetic acid, ethanol, oxygen and hydrogen as by-products which are purified and sold. The annual output varies between 36 and 68 kt ethylene with a biomass input of 157 kt. The levelized cost of ethylene ranges from 3,920 to 7,163 €/t with the gasification routes being the most cost-effective. The ethylene price is heavily dependent on electricity price, current density, operating voltage, and by-product prices. The carbon efficiency of the gasification-based routes is lower (64%) than the combustion-based routes (85%–86%). However, the energy efficiency is higher for the gasification-based routes (42%) compared to the combustion-based routes (28%). Conversion of ethanol to ethylene increases the ethylene yield with minimal impacts on the ethylene price. In terms of CO2 emissions, the gasification-based routes show lower emissions. Scenarios using wind power show a significant emission reduction potential compared to fossil products.化工行业亟需开发全新方法，从可再生资源中获取含碳原料，以降低二氧化碳（CO₂）排放并减少对化石燃料的依赖。乙烯（Ethylene）是制备聚合物与环氧乙烷的关键基础化工原料，目前主要通过化石原料的蒸汽裂解工艺生产。不过，新兴的电化学还原技术可通过二氧化碳（CO₂）或一氧化碳（CO）还原制备乙烯，该技术正逐步发展完善。本研究针对一种基于一氧化碳（CO）电化学还原的新型生物质基乙烯生产工艺，评估其环境、经济与能量性能。研究结果基于流程模拟得到的物料与能量衡算数据。该工艺所需的一氧化碳（CO）可通过两条路径制取：一是生物质气化，二是生物质燃烧结合二氧化碳（CO₂）捕集与CO₂电解。除乙烯外，该工艺还会副产乙酸、乙醇、氧气与氢气，这些副产物经提纯后可对外销售。当生物质投料量为157 kt时，乙烯年产量介于36~68 kt之间。乙烯的平准化成本介于3920至7163 €/t，其中生物质气化路径的成本效益最优。乙烯售价主要受电价、电流密度、操作电压以及副产物售价的影响。气化路径的碳效率为64%，低于燃烧路径的85%~86%。但气化路径的能量效率为42%，高于燃烧路径的28%。将乙醇转化为乙烯可提升乙烯收率，且对乙烯售价的影响极小。在二氧化碳（CO₂）排放方面，气化路径的排放量更低。相较于化石原料生产的乙烯，采用风电的工艺场景具备显著的减排潜力。