The challenge of reclaiming digestate from anaerobic digestion
Methanization, a fast-growing technology in the agri-food and waste management industries, is attracting interest for its ability to produce biogas while reducing the environmental impact of organic waste.
While biogas is often highlighted as the end product, digestate (the residue from the anaerobic digestion process) also deserves special attention! A product with high agronomic potential, it nevertheless raises complex issues in terms of treatment, recovery and environmental safety. Ovive takes a closer look at the issues involved in digestate recovery!
Understanding anaerobic digestion and the nature of digestates
Methanization is a biological process for degrading organic matter in the absence of oxygen, resulting in the production of biogas (mainly methane) and digestate. This process, applied to both industrial and agricultural sectors, is part of a strategy of energy transition and sustainable waste management.
Digestate from anaerobic digestion comes in liquid or solid form, depending on the processes used and the nature of the inputs. It is rich in nitrogen, phosphorus and potassium, making it a potential organic fertilizer. However, depending on the initial composition of the waste (livestock effluent, leachate, sewage sludge, etc.), it may also contain undesirable elements such as heavy metals. A good knowledge of the raw material is essential!
Digestate can be valorized in various ways: land application, composting, drying, biological treatment, etc. These options depend on the operator’s objectives, the regulatory context and the type of input treated. The use of anaerobic digestion additives can also play a role in optimizing yield or improving digestate quality.
Levers for value enhancement and associated constraints
Agronomic use of digestate is the most widespread: properly managed, digestate effectively replaces mineral fertilizers. However, regulations require strict traceability, in particular to guarantee the absence of contamination (drug residues, pathogens, etc.). In certain cases, such as for liquids with a high organic matter content, recovery can also be envisaged.
Finally, the methanization of leachates is the solution of choice for landfill sites. The digestate produced by this process requires considerable expertise, due to the high pollution load and the variability of the inputs. However, this option is a responsible environmental choice, reducing pollution and greenhouse gas emissions.
Why choose Ovive for methanization and digestate recovery?
For more than 25 years, Ovive has been supporting manufacturers throughout France in all stages of anaerobic digestion and digestate recovery. With expertise in biological, physico-chemical and membrane processes, Ovive designs customized, high-performance solutions in line with the needs and objectives of each customer.
Whether for liquid digestate purification, co-product quality assessment or overall optimization of anaerobic digestion facilities, Ovive mobilizes its solutions to guarantee sustainable environmental and agronomic performance.
