Anaerobic co-fermentation of molasses and oil with straw pellets
Latvia University of Life Sciences and Technologies, Faculty of Engineering, Institute of Energetics, Cakstes blvd. 5, LV3001 Jelgava, Latvia
The 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-fermentation 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 matter added from digestion of wheat straw pellets was 0.540 L g-1DOM and methane yield was 0.285 L g-1DOM. Average biogas yield from co-fermentation of wheat straw pellets and molasses was 0.777 L g-1DOM and methane yield was 0.408 L g-1DOM. Average biogas yield from fermentation of wheat straw pellets with 1ml Metaferm was 0.692 L g-1DOM and methane yield was 0.349 L g-1DOM. Average biogas yield from co-fermentation of wheat straw pellets and sunflowers oil was 1.041 L g-1DOM and methane yield was 0.639 L g-1DOM. All investigated biomasses can be used for methane production.