Hybrid thermochemical and biochemical conversion of biomass for renewable fuels and products

全球煤炭和液体燃料的日消费量分别为1,500万吨和9,000万桶。可再生燃料在液体燃料需求中所占比例不到0.1%。加拿大运输业产生的温室气体(GHG)占该国总量的40%以上。自2014年起，安大略省已停止在其热电厂使用煤炭。加拿大还在2010年实施了5%乙醇混合的联邦规定。在世界范围内，没有商业上可行的替代可再生燃料生产，对这种工艺的需求是巨大的。目前的乙醇生产使用粮食作物中的糖和淀粉，这些作物与粮食生产争夺土地。从木质纤维素生物质中提取的第二代液体生物燃料，包括农业残渣、林业废弃物、草和树木生物质，可以成为化石石油的可持续替代品。然而，原料成本占乙醇生产总成本的60%-75%。因此，根据以往的经验和记录，拟议的研究方案旨在开发一种综合生物精炼方法，采用一系列创新技术来转化湿生物质和低价值生物质原料(农业废物、温室藤本植物、市政绿箱收集、动物粪便等)。生物碳(潜在的煤炭替代品)、可再生液体燃料乙醇(潜在的石油替代品)和其他附加值产品。这种新的方法从每个副产品中回收价值，包括：(A)水热碳化(HTC)用于生产固体生物碳，HTC工艺水(PW)作为湿生物质的联产产品；(B)化学循环气化(CLG)用于富氢合成气的生产，并使用HTC生物碳在过程中捕获二氧化碳；(C)厌氧消化(AD)然后干法重整(DRM)从PW生产合成气；(D)超临界水气化(SCWG)从PW生产合成气；以及(E)将工艺(B)、(C)和(D)产生的合成气转化为液体燃料(乙醇)和其他增值生物产品的发酵工艺。这些目标将通过开展新的项目来解决特定于技术的实际问题来实现，并通过让研究生参与来推进最先进的技术。具体的技术贡献包括：(I)用于开发连续流动HTC反应堆的创新生物质进料系统；(Ii)利用AD系统集成HTC PW氧化开发自热HTC反应器和PW生物降解的方法；(Iii)HTC过程中碳产量的两步动力学建模；(Iv)集成和测试水合系统，并使用HTC生物碳作为燃料，研究新型5千瓦中试CLG系统中的吸附剂(CaO)特性；以及(Iv)通过开发创新的供气和乙醇提取系统，增强合成气体在水溶液中的传质。

The daily global coal and liquid fuel consumption are 15 million tonnes and 90 million barrels, respectively. Renewable fuels account for less than 0.1% of the liquid fuel demand. The Canadian transportation sector produces more than 40% of the country's greenhouse gases (GHG). Ontario has discontinued coal usage in its thermal power plants as of 2014. Canada has also implemented a federal mandate of 5% ethanol blending in 2010. Worldwide, there is no commercially viable drop-in renewable fuel production and the demand for such a process is immense. Current ethanol production uses sugars and starches from food crops which compete for land with food production. Second-generation liquid biofuels derived from lignocellulose biomass including agricultural residues, forestry waste, grasses and tree biomass can be a sustainable alternative to fossil oil. However, feedstock costs are 60-75% of the overall ethanol production cost. Therefore, building on previous experience and track record, the proposed research program aims at developing an integrated bio-refinery approach that employs an array of innovative technologies to convert wet and low-value biomass feedstocks (agricultural wastes, greenhouse vines, municipal green bin collections, animal manure, etc.) into biocarbon (potential substitute for coal), renewable liquid fuel ethanol (potential substitute for petroleum) and other value added products. This novel approach, where value is recovered from every co-product, integrates: (a) Hydrothermal carbonization (HTC) for solid bio-carbon production and HTC process water (PW) as co-product from wet biomass; (b) Chemical looping gasification (CLG) for H2-enriched syngas production with in-process CO2 capture using the HTC bio-carbon; (c) Anaerobic digestion (AD) followed by dry reforming (DRM) to produce syngas from PW; (d) Supercritical water gasification (SCWG) to produce syngas from PW; and (e) Fermentation process that converts the syngas produced from processes (b), (c), and (d) into liquid fuel (ethanol) and other value-added bio-products. These objectives will be achieved by undertaking new projects to resolve a technology-specific practical problem, and advances the state-of-the-art by involving graduate students. The technology-specific contributions are: (i) An innovative biomass feeding system for development of a continuous flow HTC reactor; (ii) An approach to integrating HTC PW oxidation for development of an autothermal HTC reactor and biological degradation of PW using an AD system; (iii) Two-step kinetic modeling on carbon yield in HTC processing; (iv) Integration and testing of a hydration system and the use of HTC biocarbon as the fuel to study sorbent (CaO) characteristics in a novel 5 kW-Pilot CLG system; and (iv) Mass transfer enhancement of syngas in aqueous solution by developing innovative gas supply and ethanol extraction systems.