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

点击翻译按钮获取中文摘要

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.