Termotehnika

Ligno-cellulosic biomass such as agricultural and forestry waste streams can be converted decentralized into pyrolysis oils and transport to a mineral oil refinery for co-refining to biomass derived liquid transportation fuel components. Due to the different composition of pyrolysis oil compared to mineral oils (such as a much higher oxygen content) direct co-refining by simple mixing is not recommended. It is shown that mild hydrotreating produces a feedstock that can be mixed with the regular cat cracker feed up to 20%. The resulting liquid product, after cracking of the mixture in a FCC-unit facility of Shell, is free of oxygen probably due to hydrogen transfer from the mineral oil. The product slate is essentially the same as for the mineral oil only. The required hydrogen could also be produced from the pyrolysis oil (e. g. by gasification). It is shown here that hydrogen or synthesis gas (e. g. for alcohol or Fischer-Tropsch fuels) can preferably be produced by catalytic steam reforming of pyrolysis oil in a special reactor unit, in the form of a stand alone unit or in combination with an existing reformer (e. g. running on refinery gas).