Abstract:

As a potential energy source that can partially replace fossil fuels, biofuels have the advantages of green, renewable, and sulfur-free, but their production costs are generally higher. The co-processing of bio-oil and vacuum gas oil in a fluid catalytic cracker (FCC) can effectively reduce the investment cost of a bio-refinery and the production cost of bio-fuels by utilizing the existing equipment in a refinery. To obtain the optimal biomass raw material and bio-oil production technology, Eco-indicator 99 was used to quantify the environmental impacts of the co-processing process, and a multi-objective optimization model was proposed to simultaneously reduce the economic costs and the environmental impacts. The results showed that catalytic pyrolysis was superior to fast pyrolysis in both reducing economic costs and environmental impacts; the different optimal biomasses were obtained under different objectives; biomass cost accounted for the largest proportion of costs and environmental impacts. Therefore, when optimizing the co-processing process, the environmental impact of the process should be considered. Reducing the biomass consumption is the most effective way to reduce both the costs and environmental impacts of the co-processing process.

Key words: biomass, pyrolysis, vacuum gas oil, co-process, FCC, multi-objective optimization, optimal design

摘要：

生物燃料作为一种可部分代替化石燃料的潜在能源具有绿色、可再生、无硫等优势，但其生产成本一般较高。生物质油与蜡油在催化裂化装置中的共炼通过利用炼厂已有设备可有效降低生物炼厂的投资费用进而降低生物燃料的生产成本。为同时降低共炼过程的经济费用和环境影响以筛选最优的生物质原料和生物质油制备技术，采用Eco-indicator 99方法量化共炼过程的环境影响，提出了针对该过程的多目标优化模型。结果表明：无论是降低经济费用还是减少环境影响，采用催化热解技术制备生物质油优于快速热解；不同目标下所获得的最优生物质原料不同；生物质原料在费用和环境影响中占比最大。因此，在对共炼过程进行优化时，需要考虑过程对环境的影响，而降低生物质原料的消耗对共炼过程费用和环境影响的降低最为有效。

关键词: 生物质, 热解, 蜡油, 共炼过程, FCC, 多目标优化, 优化设计