Biochar as a quality recycling-product from organic waste fractions.

RenCARBio aims to address the knowledge-gap regarding the quality of recycled-fertiliser products from waste streams, contributing to a safer and sustainable circular economy. If not sustainably handled, the increase in the amount of organic waste streams generated by the modern society, such as municipal sludge, animal and fish-farming wastes; will impact greatly the environment. The project consortium involves municipalities, waste and wastewater treatment facilities that are actively seeking solutions to this problematic. Engineering quality products from waste fractions will allow for an improved recycling of their inherent nutrient and energy value while obtaining safer and easy to handle fertilisers. For such, process technologies that reduces the volume of the waste while converting it into valuable by-products are thus, appealing. RenCARBio will research the combination of biogas production and pyrolysis processes as a symbiosis to maximise energy efficiency while producing biochar from available Norwegian organic wastes. The pilot-scale research will be assessed via LCA for a complete overview of the energy and resources needs, environmental impact and economy feasibility. The biochar produced will be assessed for its quality as a fertilizer in terms of nutrient availability to plants, content of heavy metals, pharmaceuticals and organic pollutants. In particular, development of an appropriate method for the quantification of plant-available phosphorus in biochar and investigation of selected contaminants of emerging concern (CEC), as PFAS and PCBs, will be pursued.

Today's bio-economy demands research regarding the engineering of quality recycled products from waste fractions, that will allow for a secure and hygienic recycling of their inherent nutrient and energy value without harming the environment. This project focus on typical Norwegian organic waste streams and on how to maximize their value in the transition to the bio-economy. The increase in the amount of these waste streams will impact greatly the environment, if not properly handled. Methods that can offer a reduction of the waste volume while also providing valuable by-products are appealing. Biomass conversion methods as anaerobic digestion (AD) and pyrolysis are examples. This last one needs a "dry" input feedstock, so the coupling of AD of "wet" waste feedstocks to pyrolysis, can be considered a favorable combination that also provides renewable energy in the form of methane and syngas. Such combination will be evaluated through a life cycle assessment, for an overview of the energy and resources demand, environmental footprint and feasibility of such concept. With upcoming stricter regulations regarding the quality of organic fertilizers from secondary sources, assessing the quality of the pyrolysis product to be employed as such is crucial. The effects of biochar on plant-available phosphorus (P) in soils have not been consistent. Analysis methods for plant-available P have been developed for mineral soils and do not necessarily give adequate results for organic materials. Thus, this project will develop an appropriate method by testing and/or modifying existing methods for estimating plant-available P in biochar. Research on the effects that the pyrolysis treatment of wastes may have on the biochar's pollutants content is very limited. The project will analyse the content of trace metals and selected contaminants of emerging concern (CEC) in the biochars obtained, in order to help assess their impact on the environment and humans.