A critical review on livestock manure biorefinery technologies : Sustainability, challenges, and future perspectives

• An ever increasing demand for animal protein products has posed serious challenges for managing the increasingquantities of livestock manure. The choice of treatment technologies is still a complicated task and considerabledebates over this issue still continue. To build a clearer picture of manure treatment framework, this study wasconducted to review the most frequently employed manure management technologies from their state of the art,challenges, sustainability, environmental regulations and incentives, and improvement strategies perspectives.The results showed that most treatment technologies have focused on the solid fraction of manure while theliquid fraction still remains a potential environmental threat. Compared to other waste to energy solutions,anaerobic digestion is the most mature technology to upgrade manure’s organic matter into renewable energy,however the problems associated with high investment costs, operating parameters, manure collection, anddigestate management have hindered its developments in rural areas in developing countries. Bio-oil productionthrough hydrothermal liquification is also a promising solution, as it can directly convert the wet manure intobiofuel. However, lipid-poor nature of manure, operational difficulties, and the need for downstream process toremove nitrogenous compounds from the final product necessitate further research. Livestock manure management(both solid and liquid fractions) under biorefinery approach seems an inevitable solution for futuresustainable development to meet circular bioeconomy requirements. Much research is still required to establish asystematic framework based on regional requirements to develop an integrated manure nutrient recycling andmanure management planning with minimum environmental risks and maximum profit.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Naturresursteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Environmental Engineering (hsv//eng)

Nyckelord

Livestock manure

Circular bioeconomy

Anaerobic digestion

Compost

Nutrient recovery

Miljö- och energisystem

Environmental and Energy Systems

Publikations- och innehållstyp

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