A Biomass Energy Process for Poultry Growing Operations

The U.S. poultry industry produces more than 45 billion pounds of poultry annually. A majority of this production is from concentrated animal feeding operations. In a modern poultry growing facility, small chicks are raised in several large “houses” that typically cover over 20,000 ft2. Starting with each grow-out period, fresh wood mulch bedding material is spread over the house floor. Over the course of the grow-out phase, the bedding material absorbs manure and provides insulation from the cold. Once the birds are mature and harvested, the bedding material is removed. This material, known as poultry litter, is considered excellent compost and is usually sold to farmers for direct application on fields. Economics limit the transport range of the poultry litter due to its relatively low nutrient density. Consequently, direct land application is usually limited to areas near the poultry operations. Repeated local application of the compost may lead to excessive phosphorus buildup in soils. Additionally, with recent concerns over avian flu, there are often problems with the public’s perception of this practice. During cold/cool weather seasons, heating with propane or natural gas can cost an average poultry farm over $100,000 per year, depending on the amount of installed insulation and the local weather conditions. Therefore, there is more incentive for finding a lower cost fuel source with today’s rising fossil fuel energy prices. Previous poultry litter utilization projects have focused on using large power stations with biomass from several area poultry producers. However, the low energy density and resulting high transportation costs have made the feasibility of this concept questionable. If the litter could be converted onsite into a viable fuel for heating or other applications, the local poultry farmer could offset a portion of his or her energy expenses and also provide a workable alternative to land disposal. In the proposed project, we intend to develop a small-scale gasifier system to convert poultry litter biomass into a clean gaseous fuel that can be used onsite. A gasifier could supply fuel to an electrical generator and existing poultry house heaters. A portion of the gasifier ash will be utilized to scrub the producer gas of trace pollutants such as HCl and H2S. The remainder of the residual ash can be marketed outside the growing area as a concentrated fertilizer. The goal is to displace a large portion of fossil fuel usage and thereby lower nonrenewable carbon dioxide emissions.