Methane Gas from High Solids Digestion of Poultry Manure and Wheat Straw

Abstract

An investigation was conducted for 15 months to assess the potential for methane production from high solids slurries consisting of manure from laying chickens combined with 0, 20, 40, and 60% by volatile solids (VS) weight chopped wheat straw. Two pilot scale digesters, each with an operating volume of 100 liters, were fed on alternate days at loading rates of 6 kg VS/m 3 -day. Retention times were held constant at 15 days, and the temperatures were maintained at 35 C. The methanogenic bacteria appeared to acclimate successfully to high concentrations of ammonia nitrogen (4.5 g/liter). Greatest gas production and volatile solids breakdown were observed for the digester fed 100% chicken manure (2.95 v/v gas/digester per day and 57.4%, respectively). Although addition of wheat straw provided a more stable environment for the methanogenic bacteria, gas production decreased with increasing amounts of straw (1.75 v/v gas/digester per day for 40% manure plus 60% straw). (

Chicken Manure Methanogenesis.

“…The respective compositions of broiler litter, fresh layer manure collected from local chicken houses, and cow manure are shown in Table 1. The results are essentially similar to those reported for manure collected in other countries (Shin and Huang, 1980;Huang and Shih, 1981;Hills and Ravishanker, 1984). However, in the case of layer manure we found less organic material, and in the case of broiler litter less lignin compared with those amounts reported in the literature, due to the very small amount of wood shavings used locally relative to US standard growth techniques.…”

“…However, in this work, methane concentration in the biogas was relatively low (42 to 55%) and VFA concentrations were not reported. Hills (1982) and Hills and Ravishanker (1984) reported for layer chicken and turkey manures greater VS degradation (55% at somewhat lower organic loads) then found by Shih and Huang. However, VFA concentration in their work was still relatively high (70 mM).…”

Characterization of Poultry Litter for Storage and Process Design

“…Poultry litter can also be used to make energy by converting it into methane, which is a gas that can be used as a fuel. Putting poultry litter through an anaerobic digester in order to form methane gas has been a well established process (Hills and Ravishanker, 1984;. Kinetic models have been created for this process relating gas yield to influent concentration and retention time of the digester (Webb and Hawkes, 1985).…”

“…Western Australia, Ireland, Britain) and in the U.S. to build large scale powerstations that use poultry litter as its feedstock (http://www.eprl.co.uk/profile; http://www.fibrowattusa.com). Poultry litter also has the potential to be used for the production of methane and the production of activated carbon for water purification purposes (Hills and Ravishanker, 1984;.…”

Optimal Loading Rates and Economic Analyses for Anaerobic Digestion of Poultry Waste

“…Prior research has demonstrated the technical feasibility of anaerobic digestion of animal wastes, including poultry waste. 3,4 Operational parameters have been established to provide for optimal production. 5 However, the economic feasibility of digestion using poultry litter has not been favorable.…”