Co-combustion and Gasification of Coal and Cattle Biomass: a Review of Research and Experimentation

Large confined animal feeding operations (CAFOs), including cattle feedlots and dairies, have been cited as major point sources for air, soil, and water pollution. Subsequent land application of manure solids and the usage of liquid manure (> 90 % moisture) as irrigation water on nearby crop fields have been sited as non-point sources for soil and water pollution, particularly with respect to phosphorus overloading in local watersheds and streams [1]. For example, annual average phosphorus concentrations in the North Bosque River Watershed, in Texas, USA are limited to between 15 and 50 μg/L [2]. American Agriculture has become an increasingly mechanized and specialized system capable of growing more food on less land. Consequently, many smaller, family oriented farms that tended to grow a variety of crops and keep a diverse population of animals have disappeared. In order to stay competitive, most farmers have had to specialize in one or two crops or keep many of one type of animal. Growing single monocultures and keeping one animal type allows farms to produce more food, more efficiently [3–5].