Farming is the main economic activity in North Carolina. According to the state’s Commissioner of Agriculture and Consumer Services, it brings in 84 billion dollars each year. In 2017, North Carolina even became the leading state for poultry and egg production in the United States, representing 4.8 billion dollars in revenue. However, poultry generates huge amounts of litter. Mat Ware, Vice President, Operations (Energy sector) for Veolia in North America, explains that when poultry farms were still few in number, all the used litter could be utilized as soil fertilizer. However, there are so many henhouses nowadays that farming land is not enough to absorb the droppings. Professionals are also worried about the consequences of spreading this waste in overly large quantities, especially in terms of polluting the region’s rivers, lakes and groundwater resources.
Biomass as a solution
Back in 2007, the North Carolina Utilities Commission decided to develop energy production using this waste and required a certain percentage of the energy sold by the local public services to come from poultry waste. Several poultry litter-fueled power plants were thus created, such as the Lumberton facility, a former coal-fired power station converted by Georgia Renewable Power (GRP) into a biomass plant, which treats poultry waste and recovers some of it, mixing it with wood chips to produce electricity.
Since May 2017, Veolia has been running and managing the Lumberton site on behalf of GRP, supplying electricity to the Duke Energy grid. While the plant previously only recovered around 10% of the poultry waste – the rest of the energy coming from wood chip recovery – Veolia has succeeded in increasing the share of poultry waste recovered to over 30%. “We worked flat out to optimize the plant’s efficiency,” states Mat Ware. “The owners are planning to replace the boilers, which would allow us to reach 100% poultry waste recovered.” Nowadays, the plant treats up to 285,000 metric tons of poultry waste each year and produces 25 MW of energy per hour.
A contractual clause paired with a financial incentive encourages the facility to recover as much litter as possible. This is a beneficial challenge in more ways than one: first of all, the ash from the plant, which still contains the nutrients from the litter decomposition, can be used either as a green fertilizer or for land restoration. Then, the heat given off by the recovery process is used to dry the wood chips destined for export that will power biomass plants in the United Kingdom, Europe and Asia.
In Morocco, the first carbon-neutral automotive plant in the world thanks to olive stones
Far from the United States, other countries are using original biomass fuels as an energy source. In Morocco, for instance, Veolia has joined forces with the car manufacturer Renault on its Dacia site in Tangier. Tariq Bensaid, Director of Operations for Veolia Industries in Morocco, explains how olive residues are used in the car manufacturing process.
“Morocco is the fourth largest olive producer in the world. We therefore have a huge amount of olive stones and pulp from olive groves and oil mills. At the automobile plant in Tangier, we power our biomass boilers with a mix made up of 80% olive residues and 20% ground wood pallets. In total, 23,000 metric tons of olive residues are treated each year by these biomass boilers to produce heat. We have two boilers with a capacity of 6 MW, which produce hot water at 90°C, and a 6.5-MW boiler for the production of superheated water at 220°C at 36 bar pressure. This heat supplies the hot water required for the manufacturing processes. The extra thermal energy is used in other processes, such as operating the ovens for drying the car paint. This initiative has enabled the plant to obtain the European Union’s eco-label for its sustainable production methods.
“These chips generally have a moisture content of 30%,” adds Mat Ware. “By drying them to lower this content to 6 or 7%, we obtain a better fuel while reducing the volume of water to be transported.”
For Georgia Renewable Power, the partnership with Veolia has borne fruit, as Ciaran McManus, GRP’s Director of Assets and Operations, explains: “We are delighted to partner with Veolia in this pioneering project. Burning chicken droppings for fuel is highly complex and has certainly put the expertise and skills of both companies to the test. We really had to work together to ensure this project’s success.”
Thanks to Veolia’s engagement and the visionary choice made by GRP to convert the facility, North Carolina has found a twofold solution to its problem: treating and recovering chicken droppings, as well as producing renewable electricity for individuals and industry. This collective effort has delivered a solution to everyone’s benefit.
• 285,000 metric tons of poultry waste treated each year in North Carolina
• 25 MW of energy produced per year, enough to power some 18,750 households in the region
• 23,000 metric tons of olive residues recovered in Tangier
• 76 GWh of heat produced, used to manufacture cars at Renault’s Moroccan plant