Biogas production from fresh and old sawdust litter with chicken manure

Abstract

In Latvia, forest products are widely used for heat production by direct incineration. As it causes air pollution, especially in cities, other technologies are being considered. One of them is anaerobic digestion of biomass or biogas (methane) production. Biofuels and biogas are playing a key role in the decarbonisation of the transport sector and will contribute in the future to a fuel switch in combination with electrification, for example in hybrid cars. In sectors which are difficult to decarbonize, such as heavy-duty vehicles, ships and airplanes, biofuels often represent the only technically and economically viable solution. The European Biogas Association estimates that by 2030 overall annual potential for biogas will be at least 50 billion m3. In Latvia, there is a lot of timber processing and there is a lot of sawdust. They are also used as bedding in poultry farms. Bird droppings could improve their utility for biogas production. This article shows the results about anaerobic digestion of fresh and old sawdust and sawdust litter with chicken manure and slaughterhouse waste. Fresh and old sawdust and sawdust litter with chicken manure and slaughterhouse waste were digested in 6 l digesters at temperature 38 oC in batch mode process. Average specific biogas or methane yield from anaerobic fermentation of fresh sawdust was 0.407 L·g-1DOM or 0.175 L·g-1DOM respectively. Average specific biogas or methane yield from anaerobic fermentation of old sawdust was 0.369 L·g-1DOM or 0.153 L·g-1DOM respectively. Average specific biogas or methane yield from anaerobic fermentation of sawdust litter with chicken manure and slaughterhouse waste was 0.554 L·g-1DOM or 0.335 L·g-1DOM respectively.