Principal studies on soil application of ashes from low temperature biomass gasification of different feedstock

Project: Research

Project Details


A low-temperature fluidised bed gasifier (LT-CFB) technology is developed that can convert low cost biomass and waste fractions into a combustible gas that can be used to replace fossil fuels such as coal and natural gas. The technology is considered to be the most advanced method for thermochemical conversion of various biomass fuels to energy. However, some common biofuels contain high amounts of alkali, chlorine and silica, which is an important obstacle for efficient gasification, since it can cause severe slagging, fouling and corrosion at elevated temperatures. However, the LT-CFB gasification concept is able to deal with some of the problems associated with difficult biomass fuels producing in addition a fine, dry powder with a high concentration of phosphorus (P), potassium and magnesium and should therefore be very suitable as a fertilizer. The successful utilization of such ash residues on arable land will be a way to add economic value to the process and is furthermore a step towards enhanced nutrient cycling, which is especially important taking the decreasing global availability of non-renewable P sources into account.
Hypothesis: The ash fraction resulting from thermal gasification can be developed into an attractive soil amendment for agricultural purposes by adjusting the thermal processes in a way that results in a product providing the optimal amount of plant nutrients (P, K, Mg, microelements) in an available form, with a simultaneously low content of heavy metals and other potentially toxic components (e.g. PAHs).
DTU Chemical Engineering: Dorette Müller-Stöver, Jesper Ahrenfeldt og Ulrik Birk Henriksen
DONG Energy: Jens Kai Holm
Effective start/end date01/03/201001/03/2012