Technology Meets the Farm Biogas Supply in MissouriCovering hog lagoons has been a practice at some Smithfield-owned farms in Missouri for over 10 years, as the industry has evolved to mitigate rainfall water from manure containment facilities, says Blake Boxley, Smithfield Hog Farms’ director of environmental sustainability. “We get a lot of rainfall in northern Missouri and rainfall impacts our business. Whatever goes into our lagoons, we have to land-apply back out,” he says. In a wet year, some farms in the state could get up to 70” of rain. The solution at the time was large high-density polyethylene (HDPE) lagoon covers with clean and dirty water separation. It also helped create an opportunity for biogas capture. Initially, the gases captured were burned off, but bioenergy technology has quickly caught up. In 2014, Smithfield partnered with Rudi Roeslein, founder of Roeslein Alternative Energy to create renewable energy projects from the biogas trapped under the covers. “Generating energy from manure, prairie or other biomass is pretty simple,” Roeslein says. “In an anaerobic digester or a covered lagoon, where anaerobic digestion takes place, solids are broken down to release methane gas that is transported to a central processing facility to be converted into RNG.”
How Biogas Capture WorksOn farms in Missouri, biogas is pulled from covered lagoons and pumped or “blown” into a central cleaning station on the farm. The methane gas is cleaned, separating methane from other elements to meet Department of Energy specifications. At three sites, it is injected directly into a natural gas pipeline. At farms farther from the pipeline and those waiting for transfer lines to be installed, the gas is hauled by trailer. Since the RAE project began, Smithfield has installed biogas capture equipment on about half of their 88
grow-finish hog lagoon sites in the state. Plans for the remaining sites will be completed within the next two years.