Del Monte turns pineapple waste into renewable energy
GWE installed a wastewater treatment plant at Cagayan de Oro pineapple canning factory to produce 93% organic pollution (COD) removal in its anaerobic reactors, producing enough green energy (methane rich biogas) to power two 1.4 MW electrical power generator units or gensets.
High cost of electricity
Jean-Pierre Ombregt, CEO, GWE, said the waste-to-energy pineapple operation means DMPI can replace fossil fuels with green energy, and given the high prices of electricity form the Grid and the sometimes erratic supply, the plant will get a quick ROI (return on investment).
“The DMPI plant has exceeded its high environmental goals by treating more than 13,000 cubic metres a day of wastewater, or nearly five million cubic metres a year,” he said.
“The process has led to anaerobic effluent achieving ca. 40 mg/l COD (93% removal) and final effluent achieving 70 mg/l COD, or a further 83% removal, which is remarkable given the large operation of DMPI.
“In terms of the positive environmental impact and the virtually free electricity gains going straight to the bottom line, this is an exemplary project for food, beverage and agribusiness processors worldwide.”
700,000 tons of pineapple & papaya a year
DMPI processes more than 700,000 tons of pineapple and papaya a year to produce approximately 100 food and vegetable variants.
The company is owned by Del Monte Pacific Ltd (DMPL), which owns Del Monte Foods Inc., the company that owns the Del Monte brand in the US.
DMPI is one of the largest producers, distributors and marketers of premium quality, branded food products for the US retail market through its affiliate DMFI, as well as private label products.
DMPI produces 10% of the world’s annual production of processed pineapple products.
“Biogas from waste water is an outstanding source of base load power,” added Ombregt.
“As part of a renewable energy mix – complementing wind and solar generation, for example – electricity generated with biogas is highly reliable and consistent.”
The GWE process includes:
* Pre-treatment of flume wastewater for large solids and sand removal before joining with the rest of the effluents, which pass a primary clarifier.
* Anaerobic digestion in four Anubix B (UASB type) methane reactors of a type proven globally for low-to-medium strength mainly soluble carbohydrate containing effluents, attaining outstanding COD removal efficiencies, in some cases even up to 99%
* Aerobic activated sludge type polishing treatment of the anaerobic reactor effluent (upgrade of existing facilities)
* Mechanical sludge dewatering of the aerobic excess sludge (by reuse of existing facilities)
* Biogas sweetening in a 2 step (physico-chemical followed by biological) Sulfurix, Biosulfurix process for sulphur removal, followed by Gasodrix biogas drying
* Feed of the sweetened and dried biogas to the 2 electricity generation sets
