5.1 Phuong Thuy Vu – University of Copenhagen

ReUseWaste > Thesis abstracts > 5.1 Phuong Thuy Vu

Development of anaerobic digestion methods for optimal energy yield and P recovery from animal manure production, Phuong Thuy Vu, WUR

The overall goal of this project was to develop new knowledge and technology for economically feasible operation of manure-based biogas plants and minimize the problem of nutrients surplus on farms. The concept is based on the combination of optimizing biogas yield of anaerobic digesters, and nutrient utilization, focusing on the segregated faeces of pig waste from the V-belt system as input for digestion.

Various factors of the husbandry system of animals, like diet, type and age of pigs, housing system, bedding material, water intake, manure conveyance and storage, and environmental conditions have large impact on the manure production and manure characteristics and consequently on the biogas production potential in AD systems. Treatment of seperated anure will lead to more effective and economical feasible manure-based biogas plant. Biogas production of the segregated faeces will be equal or higher than from that same amount of slurry (without urine separation). The research addressed questions such as how the source separation of manure influences manure composition as input for anaerobic digestion and how does pre-treatment methods of the solid fractions influence the biogas production and nutrient speciation in AD system.

A central study compared the performance of a novel source segregation method for fattening pig excreta to conventional separation methods for pig slurry (screw press, centrifugation, flocculation). For the source segregation system, a larger amount of organic matter accumulated in the solid fraction (96%) than for conventional separation systems (34-93%). Also the dry matter content, nutrient content (total N and P), and methane production of this solid was higher than for the other systems. Furthermore the volumetric methane yield was much higher than for the solid fraction from the other separation systems (1.6 vs 0.8-1.0 m3 CH4/m3 reactor/day for a CSTR). Due to the high methane yield, digestion of the solid from source segregation is expected to require a considerable
smaller reactor than for slurry digestion, which would increase the economic feasibility of mono-digestion systems for animal manure.

  • Composition and biogas yield of a novel source segregation system vs conventionally separated pig excreta. Article submitted. 

 

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