Anaerobic co-fermentation of molasses and oil with straw pellets

ArticleThe average grain and straw production in Latvia is increasing in last decade. Straw is not always managed properly and its utilisation in biogas plants can be considered as an alternative. Straw is not the best feedstock for methane production, because it has high C/N ratio. Co - fermentation with other biomass with higher N content can improve the methane production. Purpose of investigation is to evaluate the wheat straw pellets biomass suitability for production of the methane and effect of its co - fermentatio n with molasses, fried sunflower oil and catalyst Metaferm. The anaerobic digestion process for biogas production was investigated in 0.75 L digesters, operated in batch mode at temperature 38 ± 1.0°C. The average biogas yield per unit of dry organic matte r added from digestion of wheat straw pellets was 0.540 L g - 1 DOM and methane yield was 0.285 L g - 1 DOM . Average biogas yield from co - fermentation of wheat straw pellets and molasses was 0.777 L g - 1 DOM and methane yield was 0.408 L g - 1 DOM . Average biogas yie ld from fermentation of wheat straw pellets with 1ml Metaferm was 0.692 L g - 1 DOM and methane yield was 0.349 L g - 1 DOM . Average biogas yield from co - fermentation of wheat straw pellets and sunflowers oil was 1.041 L g - 1 DOM and methane yield was 0.639 L g - 1 DOM . All investigated biomasses can be used for methane production

Use of ethanol production and stillage processing residues for biogas production

ArticleIn Latvia, ethanol is produced mainly from wheat grains. The production process involves the formation of the by-products of wheat bran, grains residues and stillage. By-products from production of alcohol distilling dregs (stillage) contain much organic matter therefore could be useful for the production of the biogas The product with high protein content usable for feed can be produced from the stillage too. A liquid residue is formed during the production process. Purpose of study is the assessment of the methane volume obtainable from the stillage processing residue mixed with wheat brans and grains residues in anaerobic fermentation process and from wheat brans and grains residues mixed only with inoculum. Investigation was provided in 16 bioreactors operated in batch mode at 38°C. Stillage processing residues mixed with the wheat brans and inoculum were filled into 4 bioreactors, mixed with grains residues were filled into 4 bioreactors and only inoculum was filled into two bioreactors for control. Wheat brans with inoculum were filled into 3 bioreactors. Into others 3 bioreactors were filled grains residues with inoculum. The yield of biogas from wheat brans was 1.151 L g -1 DOM and methane 0.593 L g -1 DOM after 30 days of anaerobic digestion. The yield of biogas from wheat brans with stillage processing residue was 1.098 L g -1 DOM and methane 0.600 L g -1 DOM. The yield of biogas from grains residues was 0.915 L g -1 DOM and methane 0.451 L g -1 DOM. The yield of biogas from grains residues with stillage processing residue was 1.01 L g -1 DOM and methane 0.523 L g -1 DOM. The study demonstrates that the investigated products are very good raw material for the production of methane. Stillage processing residue acted as a catalyst for the process

The production of methane from the straw pellets with addition of enzymes

ArticleBiogas production requires much cheaper raw materials. The use of straw, as not always the full use of agricultural residues, increases the methane yield in pelletised form compared to non-pelletised straw. Lack is the high ratio of carbon to nitrogen content of straw, which leads to a slow and incomplete breakdown of the matter, and less producing substances from which bacteria produce methane.Variety of additives can be used to improve anaerobic digestion process. This article shows the results of the study, where the enzymes alpha amylase and xylanase and catalysts Metaferm and Melafen mixture are used for the digestion process echancement. Investigation was provided in 16 bioreactors operated in batch mode at 38 °C. Additives were filled into 14 bioreactors and only inoculum were filled into two bioreactors for control. The yield of biogas from straw pellets without additives was 0.655 L g -1 DOM and methane 0.301 L g -1 DOM after 34 days of anaerobic digestion. The yield of biogas from straw pellets with added alpha amylase was 0.652 L g -1 DOM and methane 0.318 L g -1 DOM. The yield of biogas from straw pellets with added xylanase was 0.689 L g -1 DOM and methane 0.347 L g -1 DOM. The yield of biogas from straw pellets with added Metaferm and Melafen mixture was 0.638 L g -1 DOM and methane 0.254 L g -1 DOM. The study demonstrates that the adding of enzymes increases the production of methane

Suitability of Common nettle (Urticadioica) and Canadian goldenrod (Solidagocanadensis) for methane production

ArticleSupport for biogas production in Latvia was decreased. There is an urgent need to i nvestigate the suitability of various inexpensive renewable biomass resources for energy production. Also, itis necessary to explore the possibilities to improve the anaerobic fermentation process with the help of various catalysts. Biocatalyst Metaferm pr oduced in Latvia was used in previous studies with other biomass and showed increase in biogas and methane production. The article shows the results of studies on biogas (methane) production from chopped fresh Common nettle ( Urtica dioica ) and Canadian gol denrod ( Solidago canadensis ) biomass and effect of catalyst Metaferm in anaerobic fermentation process. The anaerobic digestion process was performed in 0.75 L laboratory digesters, operated in batch mode (38 ± 1.0 °C, 35 days). The average specific biogas or methane production per unit of dry organic matter added (DOM) from Common nettle was 0.709 L g - 1 DOM or was 0.324 L g - 1 DOM respectively. Average specific biogas or methane volume produced from chopped Canadian goldenrod in anaerobic fermentation was 0.54 8 L g - 1 DOM or 0.267 L g - 1 DOM respectively. Average biogas or methane yield from digestion of chopped Common nettle with 1 mL Metaferm was 0.752 L g - 1 DOM or 0.328 L g - 1 DOM respectively. Average specific biogas or methane yield from anaerobic fermentation of c hopped Canadian goldenrod with 1 mL Metaferm was 0.624 L g - 1 DOM or 0.276 L g - 1 DOM respectively. Adding of catalyst Metaferm increases methane yield from chopped nettle or Canadian goldenrod by 1.2% or 3.4% respectively. All investigated biomass resources c an be used for methane production