Gasification for Biofuels

The project has addressed the entire value chain of forestry biomass fractions towards advanced (2nd generation) biofuels, with technology development and techno-economic case studies as the two solid research pillars where most of the research (and economic resources) has been focused on. In terms of technology development most of the efforts have been concentrated on getting a better insight into the formation and conversion of carbon-rich species (tars, soot) that are unconverted (heating value is reduced) and lead to operational problems during biomass gasification. For this purpose, several experimental investigations including kinetic studies on high heating rate gasification as well as fluidized bed and entrained flow gasification experiments of biomass and chars have been conducted. In general terms it can be concluded that production of biofuels should be carried out at atmospheric pressures, in presence of dolomite and using pretreated torrefied biomass, with low grade forest residues being a promising feedstock. The PhD candidate in GasBio developed a CFD tool that has shown the ability to simulate the gasification of biomass in several types of lab-scale gasifiers. This is the first step in the development of a tool for studying issues related to scale-up of gasifiers. Additionally, GasBio has addressed industrially relevant challenges. Ash-related challenges during biomass combustion through applying thermodynamic equilibrium modelling on ash chemistry. As a general rule of thumb, higher temperature combined with higher concentrations of both Chlorine and alkali will lead to more corrosion. Another industrially relevant aspect has been the economy of liquid biofuels production from woody biomass for plant capacities in the range of 150 to 600 MW biomass input. A value chain approach including decentralized utilization of woody biomass for the production of higher energy density crude (biocrude) through high temperature gasification with further upgrading of the biocrude to biodiesel at existing petrochemical facilities has been the selected case study. The optimal economic performance of biocrude production in Norway is achieved when combining the use of torrefaction for biomass pretreatment with utilization of 100% of the heat recovered for district heating. When looking particularly at biofuels for aviation, gasification-FT is the most promising technology, leading to the most economic production of biojetfuel, with market prices in the range 1.35-1.48 $/liter as compared to the nearly doubled prices (2.34-2.61 $/liter) associated with the Alcohol-to-Jet process. A direct comparison with the current price of the fossil-derived jetfuel (0.81 $/liter) shows that the gasification-FT based jetfuel is a promising sustainable alternative.

Future production of Second Generation Biofuels in Norway requires building of long term competence in thermochemical biomass conversion (i.e. gasification). GasBio aims to fulfil this national need. This project adresses key elements of processes for la rge scale production of synthetic diesel from wood and forest resources, as well as processes for smaller scale production of biofuels from forest, household and industrial waste fractions. The proposed project is backed by the most central Norwegian ind ustrial enterprises planning to establish future liquid biofuels production plants in Norway, and will be carried out in close cooperation with these. The research group behind the proposal has a solid track record in research on related issued with focus on combustion of biomass, including the leadership of NextGenBioWaste, EUs largest biomass research project ever, as well as the leadership of the recently established National Bioenergy Innovation Centre - CenBio.