Using the byproducts of Smithfield Foods Inc., the world’s largest pork processing plant, Duke Energy and biofuel specialist OptimaBio LLC have cooked up a recipe for renewable natural gas (RNG) that recently began production.
With the $14 million project, more than 2,000 homes and businesses are to receive power supplies generated from the RNG produced at the Tar Heel, NC, facility. It is the latest project by Smithfield’s renewable energy unit, which plans by 2025 to reduce greenhouse gas emissions by 25%.
The Smithfield unit aims to produce roughly 140,000 Dth/year of RNG for use in natural gas plants and to generate electricity. Smithfield on the East Coast also operates farms using manure as a source for RNG that is injected into local gas utility distribution systems, including Duke’s Piedmont Natural Gas system.
During the coming decade, Smithfield plans to implement additional manure-to-energy projects in Arizona, California, Missouri, North Carolina, Utah and Virginia. The renewable unit also operates wastewater-to-energy projects in Kentucky, Missouri and South Dakota, with the gas produced used to power onsite modified steam boilers.
Smithfield CEO Kenneth Sullivan said the North Carolina project is the company’s first to use RNG to help power nearby communities. “With the help of our partners, we are producing additional value for our company and our neighbors,” he said.
Meanwhile, on the West Coast, Calgren Dairy Fuels and Southern California Gas Co. (SoCalGas) have added four more Central California dairies to a network producing methane from cow manure that is turned into RNG at a Calgren plant in Pixley, CA. Last year the companies tied together a dozen dairies in Tulare County for the project. SoCalGas has a goal to make RNG 5% of overall gas supply by 2022, increasing it to 20% by 2030.
“We’re looking to build on that success by delivering more renewable energy options to our customers, including RNG produced at farms, hydrogen made from surplus solar energy, and advanced fuel cell systems that can provide energy in extreme weather events,” said SoCalGas’ Sharon Tomkins, chief environmental officer.
California has calculated that more than 80% of its methane emissions are from organic sources that include wastewater treatment, landfills, food and green waste processing, as well as farms.
University of California, Davis scientists have estimated that existing waste in the state could produce enough RNG to fuel the needs of 2.3 million homes.