The primary objective of the project is the design, construction, testing and evaluation of a pilot plant to hydrotreat fast pyrolysis bio-oils for the production of hydrocarbon fuels. Complementary objectives include an assessment of the performance and production cost of robinia and sweet sorghum, evaluation of zeolites as an alternative upgrading route, gas turbine testing on crude bio-oils and an evaluation of the recovery of high value chemicals.
Sweet sorghum and sorghum bagasse are particularly interesting feedstocks for flash pyrolysis to bio-oil as the productivity is very high and cultivation requirements are relatively low. While the resultant bio-oil has been successfully combusted in a boiler and furnace, it is not known whether the rigorous thermal and physio-chemical demands of a gas turbine combustor can be satisfied without upgrading the crude bio-oil to a higher specification hydrocarbon fuel. The primary approach to upgrading is by hydrotreatment which is being actively investigated by several members of the consortium. The project includes a comparison with zeolite cracking and an evaluation of the direct firing of crude bio-oil in a gas turbine.
A brief summary of the main experimental contributions follows:
ESAU have tested a new planting technique for robinia with around 10.000 plants in a plot of 1 ha and also implemented a nursery of about 600 m2 for production of seedlings. Different cultivars of sweet sorghum are being tested under a range of growing conditions, together with analyses of soils, fibre and dry matter production by non-destructive testing.
ENEL are undertaking characterisation of crude bio-oil for basic properties and combustion characteristics. A contract has been placed with Ensyn for a 650 kg/h demonstration flash pyrolysis for delivery in Summer 1995.
Fochi S.E.T. are proceeding with the detailed design and costing of two sizes of hydrotreating pilot plant.
Union Fenosa are continuing to develop their fast pyrolysis pilot plant to improve oil collection efficiency and product quality and are continuing to supply bio-oil samples to R&D organisations in Europe and North America.
Aston University have collated data on chemical products of pyrolysis and are establishing production schemes. Specification and assessment of integrated chemicals and fuels production processes will follow.
UCL have studied different hydrotreating catalysts and found the alumina support to be the most significant coking agent. Alternative supports are being investigated including carbon and silica. Modification of alumina by lithium is giving very interesting results.
Funding SchemeCSC - Cost-sharing contracts