You need JavaScript to view this

Co-digestion of ley crop silage, straw and manure

Abstract

Anaerobic co-digestion of ley crop silage, wheat straw and liquid manure with liquid recirculation was investigated in laboratory- and pilot scale. An organic loading rate of 6.0 g Vs L{sup -1} d{sup -1} was obtained when 20% of liquid manure (TS-basis) was added, whereas an organic loading rate of 2.5 g VS L{sup -1} d{sup -1} was obtained when the manure was replaced with a trace element solution. The methane yield varied between 0.28 and 0.32 L g VS{sup -1}, with the value being lowest for a mixture containing 60% silage, 20% straw and 20% manure (TS-basis), and highest for 100% ley crop silage. The concentration of ammonia-N was maintained at ca 2 g L{sup -1} by adjusting the C:N-ratio with straw. To achieve good mixing characteristics with a reasonable energy input at TS-concentrations around 10%, the particle sizes of straw and silage had to be reduced with a meat mincer. The digester effluent was dewatered, resulting in a solid phase that could be composted without having to add amendments or bulking agents, and a liquid phase containing 7-8% TS (mainly soluble and suspended solids). The liquid phase, which should be used as an organic fertilizer, contained up to 90%  More>>
Authors:
Nordberg, Aa; Edstroem, M [1] 
  1. Swedish Inst. of Agricultural Engineering, Uppsala (Sweden)
Publication Date:
Aug 01, 1997
Product Type:
Conference
Report Number:
NEI-DK-3077; CONF-9709214-
Reference Number:
SCA: 090900; PA: DK-98:001101; EDB-98:031713; SN: 98001920986
Resource Relation:
Conference: Workshop on the future of biogas in Europe 1997, Herning (Denmark), 8-10 Sep 1997; Other Information: PBD: Aug 1997; Related Information: Is Part Of The future of biogas in Europe 1997; Holm-Nielsen, J.B. [ed.]; PB: [143] p.
Subject:
09 BIOMASS FUELS; BIOMASS PLANTATIONS; STRAW; MANURES; METHANE; MIXTURES; WASTE PROCESSING PLANTS; ANAEROBIC DIGESTION
OSTI ID:
579975
Research Organizations:
Sydjysk Univrsitetscenter, Esbjerg (Denmark). Biomasseinstituttet
Country of Origin:
Denmark
Language:
English
Other Identifying Numbers:
Other: ON: DE98736994; ISBN 87-90074-12-2; TRN: DK9801101
Availability:
OSTI as DE98736994
Submitting Site:
DK
Size:
pp. 74-81
Announcement Date:

Citation Formats

Nordberg, Aa, and Edstroem, M. Co-digestion of ley crop silage, straw and manure. Denmark: N. p., 1997. Web.
Nordberg, Aa, & Edstroem, M. Co-digestion of ley crop silage, straw and manure. Denmark.
Nordberg, Aa, and Edstroem, M. 1997. "Co-digestion of ley crop silage, straw and manure." Denmark.
@misc{etde_579975,
title = {Co-digestion of ley crop silage, straw and manure}
author = {Nordberg, Aa, and Edstroem, M}
abstractNote = {Anaerobic co-digestion of ley crop silage, wheat straw and liquid manure with liquid recirculation was investigated in laboratory- and pilot scale. An organic loading rate of 6.0 g Vs L{sup -1} d{sup -1} was obtained when 20% of liquid manure (TS-basis) was added, whereas an organic loading rate of 2.5 g VS L{sup -1} d{sup -1} was obtained when the manure was replaced with a trace element solution. The methane yield varied between 0.28 and 0.32 L g VS{sup -1}, with the value being lowest for a mixture containing 60% silage, 20% straw and 20% manure (TS-basis), and highest for 100% ley crop silage. The concentration of ammonia-N was maintained at ca 2 g L{sup -1} by adjusting the C:N-ratio with straw. To achieve good mixing characteristics with a reasonable energy input at TS-concentrations around 10%, the particle sizes of straw and silage had to be reduced with a meat mincer. The digester effluent was dewatered, resulting in a solid phase that could be composted without having to add amendments or bulking agents, and a liquid phase containing 7-8% TS (mainly soluble and suspended solids). The liquid phase, which should be used as an organic fertilizer, contained up to 90% of the N and 74% of the P present in the residues. Calculations of the costs for a full-scale plant showed that a biogas price of SEK 0.125 MJ{sup -1} (0.45 k Wh{sup -1}) is necessary to balance the costs of a 1-MW plant. An increase in plant size to 4 MW together with an increase in compost price from SEK 100 tonnes{sup -1} to SEK 370 tonnes{sup -1} and a 20% rise in the methane yield through post-digestion (20%) would decrease the price to SEK 0.061 MJ{sup -1} (0.22 kWh{sup -1}). (au) 15 refs.}
place = {Denmark}
year = {1997}
month = {Aug}
}