From Scott Carlberg

WTE is the acronym for Waste-to-Energy, when a waste product finds its final use in making energy of some sort. An entrepreneur is doing just that in eastern NC.

Rich Deming is CEO of Power Resource Group: “North Carolina enjoys the economic benefits of an extensive agricultural infrastructure. That also means there is animal waste, an unavoidable byproduct. This waste, even when re-used as fertilizer, finds its way into waterways, rivers, and sounds, producing massive chemical overloads and posing numerous environmental and health hazards.”

Deming’s company uses that waste. In Farmville, NC, a biomass facility is fueled by used poultry litter. The plant consumes more than 200 tons per day of fuel and generates 1.7 Megawatts of electricity, 72,000 pounds per hour of steam, and about 20 tons of ash per day. The project produces thermal energy for use by industry, electricity which is put on the grid, and ash which is used fertilizer.

In the fuel hall

A series of buildings are at the site: A fuel hall for receiving feedstock that is approximately 11,500 square feet; a boiler hall, control room for electrical gear and water treatment, two smaller buildings house the three steam turbines for electricity generation, and a place to store ash residue. Two concrete pads have tanks for emissions injections, and three emissions devices and heat exchange equipment help make the steam energy useful to this co-located industrial facility. It is on 3.5 acres.

Here’s how the project works.

Boiler

Three 750 HP solid fuel biomass boilers are the energy island. Feedstock goes in, changed to steam, hot water, ash, and electricity comes out. The boilers receive continuous feedstock from the fuel hall and send steam through a common header to three turbines to make power. After the turbines, a reduced-pressure steam heats water in two heat exchangers.

Heat exchangers

The heat exchangers serve two purposes: First, to continuously use water from an adjacent pond and reduce the heat of the power plant. Second, the heat exchanger heats 80 gallons per minute of water which is used by the adjacent industry for sterilization and the processing of animal food products.

Ash from the boilers is sent to the ash-house via conveyors, and emissions from the boilers is sent to the baghouses where it is filtered, treated, and reduced to meet minor source (the lowest available) air permitting standards.

Generators/turbines

A power facility of 1.7 Megawatts is a small power facility. The energy environment is changing, however. Large facilities that can make hundreds of megawatts have been the backbone of power generation. They will still be very important. The future of electric power will also now include numerous, smaller power generators that are aggregated to make, for all purposes, one large plant. As these smaller facilities use resources once considered a problem, like poultry waste, that helps all of us.

 

Read more about the project at the Power Resource Group website.