An $80 million hog-manure-to-energy project is under construction in Northern Missouri, developed and constructed by Roeslein Alternative Energy (RAE) in collaboration with Murphy-Brown of Missouri (MBM) the livestock production subsidiary of Smithfield Foods.
Crews are installing impermeable covers on 88 existing lagoons to harvest biogas, also called renewable natural gas, from MBM hog finishing farms using anaerobic digestion technology developed and installed by RAE. The companies say the waste-to-energy project is the largest of its kind, utilizing manure from one of the biggest concentrations of finishing hogs in the Midwest to create several hundred million cubic feet of renewable natural gas annually for regional distribution.
The project will demonstrate the environmental and economic benefits of using manure in a different way, says Rudi Roeslein, RAE president and CEO of Roeslein & Associates, a systems integration firm specializing in modular construction.
Impermeable synthetic covers will be placed on existing nutrient treatment lagoons where barn scraper technology will deliver raw nutrients of livestock manure to covered lagoons (pictured). The covers turn the lagoons into anaerobic digesters, where naturally occurring microorganisms decompose the manure in an oxygen free environment. Biogas rises to the top where it will be collected and cleaned of impurities.
What remains is more than 98 percent methane with about the same chemical composition as natural gas that can be used for vehicle fuel or injected into the natural gas grid system. The undigesteable solid residue can be used by local farmers as a natural fertilizer and the water can be used for irrigation.
The companies expect renewable natural gas production to begin in late 2014.
In addition to using hog manure, RAE ultimately intends to produce renewable natural gas from cover crops harvested between growing seasons on prime agriculture land and grasses harvested from highly erodible farm ground converted to native grasslands.
In North Carolina, a 600 kW Storms Hog Power facility — the state’s largest swine-waste-to-energy system — came on line in October 2013, and sustained peak or near peak output since April.