基于脱氧-脱硫协调机制的生物质油和直馏蜡油混炼过程的过程集成和分析评价

The co-processing of bio-oil and vacuum gas oil (VGO) and its process integration and optimization are proposed to deal with the seasonal change of biomass supply and the high price of bio-fuels based on the coordination of desulfurization of the VGO and deoxygenation of the bio-oil. A superstructure model is built based on the co-processing reaction kinetics, then a multi-objective design and optimization is proposed to evaluate the economic and environmental effects of the process. Due to the changes of biomass and crude oil supply and the product consumption, and the high contents of sulfides and oxides in the mixed oil, a multi-period model is proposed by integrating the competition between the desulfurization and the deoxygenation. Furthermore, a multi-period stochastic programming of the co-processing supply chain is presented as the uncertainties are contained in the process. Based on the integration results, an operational optimization model is further presented to obtain a molecular-level optimization scheme for the co-processing process with the consideration of removal differences among different sulfides and oxides. The techno-economic analysis and the life cycle assessment are adopt to discuss the mechanism of the co-processing parameters on the product prices and environmental impacts. The project results can not only deal with the change of biomass supply and the high cost of bio-fuels, but also provide a comprehensive theoretical guidance from economic, environmental, temporal, spatial and molecular perspectives for the co-processing of bio-oil and VGO. And the methodologies proposed in this project have important theoretical significances and broad prospect of engineering applications for the utilization of bioenergy.

本项目提出生物质油和直馏蜡油的混炼及其过程的集成和优化，以解决生物质供应季节性变化和生物汽柴油生产成本高等问题。以协调生物质油脱氧和直馏蜡油脱硫的关系为基础，建立耦合过程反应动力学的混炼过程超结构模型，进而建立基于LCA方法的混炼过程多目标设计优化模型；考虑到生物质和原油供给及产品消纳的变化以及混合油硫氧化物含量高等问题，构建耦合脱硫和脱氧竞争关系的混炼过程多周期优化模型，并进一步建立考虑不确定因素的混炼过程多周期供应链随机规划模型；基于以上优化结果，提出考虑不同硫氧化合物脱除难度不同的混炼过程操作优化模型；最后采用TEA和LCA方法阐明混炼过程中相关因素对产品价格和环境的影响机制。项目的研究成果不仅可解决生物质供应和成本高等问题，还可为混炼过程从经济和环境方面、时间和空间尺度以及分子级角度提供全方位的基本理论指导，同时所提的方法对于生物质能源的利用具有重要的理论意义和广阔的工程前景。

生物质能源作为唯一含碳的可再生能源，其高效利用对于降低原油依赖度并缓解温室效应具有重要意义。然而，由于生物炼厂较高的投资成本造成生物燃料的生产成本过高。考虑到生物炼厂和传统炼厂均包含裂化装置和加氢装置，为降低生物燃料的生产成本，本项目提出将生物质与原油在已有炼厂共炼以生产包含生物碳的汽柴油。由于生物质油与蜡油具有相似的馏程和粘度，生物质油一般与蜡油在炼厂催化裂化装置中共炼。针对生物质油和蜡油在催化裂化装置的共炼过程，项目组通过协调生物质油脱氧和蜡油脱硫的竞争关系，提出耦合过程反应动力学的超结构模型以获得最优的生物质原料和热解技术以及共炼过程的最优集成方案；基于全生命周期思想，建立多目标优化模型获得共炼过程在经济和环境两方面的最优设计方案；考虑到生物质和原油供给对于共炼过程的重要性，提出耦合生物质供给季节波动和产地分布的多周期供应链集成模型，以获得时间和空间尺度下的共炼过程生物质和原油供给的最佳集成方案；为进一步降低共炼过程的操作成本，建立耦合分子级硫氧化物脱除的共炼过程操作优化模型，以从分子角度协调脱硫和脱氧竞争关系；最后，采用技术经济分析方法和全生命周期评价方法对共炼过程进行分析和评价，以获得共炼产品的最低售价和环境优势，结果表明共炼主要产品汽油的最低售价仅为7.0元/升，同时可降低CO2排放量6.8%以上。具有与石油基汽油的竞争潜力。因此，通过本项目的研究，为共炼过程从经济和环境方面、时间和空间尺度以及分子角度提供了全方位的设计和优化思路，为共炼技术的进一步应用和推广提供了全方位的指导。