By Bryce Gray, St. Louis Post-Dispatch.

Beginning next month, the manure of northern Missouri pigs will provide energy to far-flung power users connected to a national pipeline system for natural gas.

The biogas project — which relies on anaerobic digestion of animal waste to produce methane — is the culmination of a five-year partnership between St. Louis-based Roeslein Alternative Energy and Smithfield Hog Production, the state’s largest owner of pig farms.

But the gas production facility poised to come online next month at Ruckman Farm near Albany, Mo., is only the start of what is intended to be a much broader marriage of renewable energy and agribusiness. Plans are in place to gradually apply the same technology to Smithfield’s nine hog-finishing farms across northern Missouri — a $120 million endeavor that will eventually harness the waste of approximately 2 million pigs and is projected to be the largest biogas project in North America.