This project presents the opportunity of a high efficient biomass based heat and power generation from ash rich biogenic feeds and wastes including integrated fertilizer and CO2 recycling. The interconnection and integration of biogas, pyrolysis, gasification and algae production (used in this project) is not only CO2 neutral, furthermore it has CO2 negative impact.
The consortia aims to demonstrate this project with a plant of 10 MW input capacity. This type of integrated small to mid scale heat and power plant for ash rich biomass with high electric power output and integrated fertilizer recycling is the high end innovation at the global market.
The site used will be 18 hectares of land based in Odenwald Germany. This former military camp is in the size of about 75 hectares. Infrastructure, such as roads, electric supply and so on is existing already. The bio-thermal valorisation of biomass (BtVB) of the Odenwald district in Germany and the European Bioenergy Research Institute at Aston University, UK is upgrading biomass and ash rich residues from agriculture and forestry to heat, power, oil and fertilizer. The concept relies on the intermediates produced within the steps of processing as such and does not need adoption of biomass based intermediates like pyrolysis oil, gases, char, slag’s or biogenic residues to existing refinery concepts.
The topic regenerative energy with the main pillar biomass was established as a high priority topic of the development strategy of the Odenwald district. The Odenwald district, based on the characteristic numbers like density of population, tax income and market power, is categorized as a non urban district. Due to this characterisation, the Odenwald district is benefiting from the EU supporting programmes LEADER (ELER) and EFRE.
The core process of the project is an intermediate pyrolysis. It is converting algae, residues from biogas plants, energy grass, wood residues and other residues from agriculture and forestry into pyrolysis liquids, pyrolysis gas and pyrolysis char with typical ratio of 20 to 30 wt % of char and 15 to 25 wt % of gas. The total pyrolysis vapours (about 60-75% of the energy of the input material) now low in ash are directly passed to a gasifier and gasified. The pyrolysis char bearing all ashes will not be gasified. Concurrent reaction water is brought back to the system, so that the water loop is closed, i.e. algae production. The pyrolysis char is partly taken to fertilize the energy grass fields - a so called black earth. Bringing this black earth back to fields is not only in terms of fertilizer a positive aspect, but also it is the only way to bring carbon back to the soil and therefore sequestrate it biologically.
The exhaust gases of the engines, CO2, NOx and SO2 are taken to the algae plantation as fertilizer. No CO2 is set free, even more, as beside algae, other biomass will be pyrolysed, gasified and converted to electric power, more CO2 will be brought into the algae plantation than CO2 actually released via the converting process of algae to power. The details of the whole Integrated Process is shown in the Figure below.