Tailored Production and Utilisation of Sustainable Low Cost Lignocellulosic Advanced Biofuel Blends as Diesel and Petrol Substitutes: SusLABB

The project will develop methodologies for a novel, fully tailored, biofuel blend production process which optimises the blends and their production design parameters on the basis of a range of targets: performance in engines, real world emissions on blending with gasoline and diesel, overall sustainability, practical suitability for automotive use, and biofuel production costs.

The aim is to develop a process design which is able to use a variety of low grade biomass feedstocks, thus contributing to the requirements of the next phase of the EU Renewable Energy Directive (RED) for increased use of advanced biofuels. The transport sector contributes ~14% to global greenhouse gas (GHG) emissions, principally from petroleum derived liquid fuels. Transport therefore presents a key challenge in developing low carbon economies.

Due to energy density challenges in developing alternative drive trains, or propulsion systems for heavy goods, shipping and aviation sectors, societal reliance on liquid fuels is likely to continue beyond the near term. It is therefore crucial to produce liquid fuels with lower lifetime GHG emissions compared to fossil fuels. This is mandated by the EU through the RED requiring member states to source >10% of transport energy from renewables by 2020, rising to 32% by 2030.

The revised RED II requires all road transport fuels sold in the EU to include a minimum 3.5 % of "advanced biofuels" - liquid fuels derived from non-fossil feed stocks not in direct competition with food for land use; essentially stipulating the use of lignocellulose and wastes. Advanced biofuels face challenges to be cost competitive with fossil fuels, and even 1st generation biofuels, due to the inferior nature of lignocellulosic feed stocks. Methodologies with fewer processing steps offer greater potential for cost effective production are thus emphasised in this work which will develop optimal processes for the production of biofuel blends compatible with either diesel or gasoline.

The use of biofuel blends may present advantages over single component biofuels such as ethanol, as multi-component mixtures can extend blend walls and therefore potentially promote the use of larger biofuel fractions on blending with petroleum fuels, leading to the potential for greater GHG reductions. The project will develop a process for the production of biofuel blends based on alkylevulinate, ether and alcohol components via several different starting alcohol routes.

In Phase I, experimental studies will parameterise the performance of various acid hydrolysis configurations on different sugar and carbohydrate sources (e.g. model compounds, miscanthus, cellulose, algae, household wastes), using methanol, ethanol, butanol, and different acid types. The influence of temperature, pressure, and reaction time, on yields, energy requirements, process difficulty and product compatibility with existing infrastructure will be studied. In parallel, important chemical and physical properties of the biofuel blends will be determined, as well as sustainability factors, providing boundaries on feasible fractions of the different components in the blended fuel.

In Phase II detailed engine emissions and performance characteristics of the fuels on blending with diesel/gasoline will be investigated, using experimental and model simulation tools. Real world emissions factors will be established for the fuel blends based on instrumented engines and on-road vehicles. These emissions factors as well as all techno-economic factors will feed into a final lifecycle techno-economic-sustainability (TES) assessment to determine optimal blends. Both GHG and emissions of relevance to air quality will be included. This TES will be coupled to an optimisation procedure to determine process conditions suitable for the production of optimal blends. The overall output of the project will be a process design suitable for producing an optimum techno-economic & sustainable advanced biofuel.

Impact

The project will provide information on cost effective ways to produce renewable fuel blends that could begin to replace fossil fuels in the transport sector in the short to medium term. Industrial involvement in the project means that direct routes to potential utilisation will be embedded into the project. A full sustainability assessment will mean that the optimal use of waste derived biomass feedstocks will be achieved, which will overcome many of the concerns of first generation biofuels.