Wastewater combinations profit meat producers

SOME of the world’s most environmentally efficient and profitable green energy technologies are being specifically tailored to the needs of the beef, poultry, pork, rendering and stockfeed industries. The high-temperature thermophilic anaerobic digestion technologies, typically operating at 55^oC, are part of a proven combination of processes that digest waste water’s organic content to produce green energy while achieving outstanding waste water effluent discharge qualities.

The RAPTOR™ system, from wastewater treatment and green energy authority Global Water Engineering (GWE), combines thermophilic high-rate anaerobic processes with complementary technologies including dissolved air flotation (DAF), screening and aerobic treatments.

This highly efficient combination of processes transforms food processing sludge waste and waste water from an environmental problem into profitable green energy (methane) to replace fossil fuels.  Thermophilic digestion destroys pathogens quickly, unlike lower temperature mesophilic digestion, so effluent can be used as a soil conditioner or fertilizer.

At one plant in Europe handling 6,000 pigs and 2,000 sows a week, the technology paid for itself within one year from biogas savings alone. With 20-50 tons a day of waste submitted to digestion, the GWE plant achieved the equivalent of 6300Nm³ of biogas a day, which was converted to boiler process water and 625kW of electricity (or 300 to 750kwh per ton of waste). Effluent quality was increased substantially, with a chemical oxygen demand (COD) concentration of 200mg/l achieved as specified, at which level the treated waste water was suitable for discharge.

Another plant successfully deploying anaerobic technologies for green energy and high quality waste water treatment is the COHRAL^{TM (}Covered High Rate Anaerobic Lagoon) being installed by CST Wastewater Solutions at Oakey Beef Exports on Queensland’s Darling Downs, which is owned by NH Foods Australia Pty Ltd, (formerly Nippon Meat Packers). CST Wastewater Solutions represents GWE technology in Australasia.

The COHRAL plant is expected to repay its cost of construction inside five years through gas purchase savings amounting to many millions of dollars – then continue to deliver benefits and profitability virtually in perpetuity, said Oakey Beef Exports Pty Ltd general manager Pat Gleeson.

“The Asia-Pacific one of the many regions in the world that is only just beginning to realize the potential of green energy from waste water,” said CST Wastewater Solutions managing director Michael Bambridge. “Instead of waste water being an environmental problem and as expense – a huge consumer of energy through mixers and aerators in smelly settling ponds – it becomes an asset. Instead of companies having to figure out some expensive way to dispose of it, waste water becomes a profit item.

“Biogas from waste water is an outstanding source of base load power. As part of a renewable energy mix – complementing wind and solar generation, for example – electricity generated with biogas is highly reliable and consistent.  As the major component of natural gas, methane is an environmentally attractive alternative to fossil fuels.”