SustainabilityEnvironmentTurning Potatoes into Biogas

Turning Potatoes into Biogas


[deck]B.C.-based Heppell’s Potato Corp. finds creative use for waste materials.[/deck]

Since its formation more than 90 years ago, one of the guiding principles of Surrey, B.C.-based Heppell’s Potato Corp. and its owners has been the fundamental belief that there is always a better way of doing things.

So it was only natural three years ago that when partners Pete Schouten and Wes Heppell began looking for solutions to one of their biggest challenges — acquiring more agricultural land in British Columbia’s fertile Fraser Valley. They settled on a unique approach.

The duo bought up a struggling biogas plant in nearby Abbottsford that had been previously owned by a company Schouten was a minor investor in. Their thinking was that by obtaining the biogas plant, dairy and poultry farmers in the region could ship their organic waste there and wouldn’t need as much land to dispose of it. That, plus goodwill generated by the biogas business, might mean they’d be willing to lease a portion of their land to Schouten and Heppell.

While their idea hasn’t quite panned out the way they wanted — they haven’t yet been able to acquire as much land as hoped — it has been an overwhelming success by most accounts.

Fraser Valley Biogas, a division of Heppell’s Potato Corp., now operates the plant, which Schouten says was the first operation of its kind in Canada to recapture renewable natural gas from farm and agricultural waste. It now produces about tens of thousands of gigajoules of renewable natural gas a year, which is enough to heat in excess of 1,000 homes. It’s fueled by more than 120 tons of cow and chicken manure and off-grade potatoes and squash received from Heppell’s and other neighbouring farms each day, as well as other organic wastes.

“You can trace it back to what Dave Heppell (one of the original founders of Heppell’s) used to always tell us. There is a better way,” says Schouten, who is CEO and co-owner of Heppell’s.

The process of converting organic waste into biogas, or renewable natural gas as it is also known, is relatively simple. Manure is used as the soup stock to which vegetable waste is then added in the form of everything from off-grade potatoes to potato and squash peels, as well as other organic wastes, which are then ground up and placed in a machine “that’s kind of like a stomach,” according to Schouten.

The contents will then remain in the container for about 56 days where they will mingle with microorganisms. The tiny bugs in this anaerobic digestion system will eat the material, which causes them to produce methane gas during those eight weeks.

There’s no [waste]. We divert a lot of organic product that would normally goes to a waste water treatment plants or a landfill.

– Pete Schouten

The gas rises up to the top of the tank where there is an expandable liner. When the tension on that liner reaches a certain level, an exhaust fan kicks in and extracts the gas.

The gas then goes through a non-chemical scrubbing process in which water at 7 C is pushed down and the gas bubbles up, which strips away all of the noxious components and leaves behind only the methane. The methane is then compressed and piped to the purchaser, FortisBC, which is an investor-owned utility company in British Columbia. Approximately 100,000 kilograms of waste material will produce 7,250 cubic metres of renewable gas at the Abbotsford plant.

The beauty of the system is that it completely eliminates waste, according to Schouten. “Any of the material left behind in one of two half-million-gallon storage containers is pumped out and then utilized as a nutrient rich fertilizer on our cropland,” he says.

“All the weeds and pathogens have been killed and we’re left with a really nutrient-rich product we call digestate,” Schouten says. “There’s no [waste]. We divert a lot of organic product that would normally goes to a waste water treatment plant or a landfill.”

Schouten says off-grade potatoes and potato waste make ideal ingredients since both are starchy and produce “a decent amount of gas.” He adds the biggest challenge is coming up with the right mix of ingredients that allows everything to work efficiently together.

Off-grade potatoes form part of the raw product that is processed into renewable natural gas at Fraser Valley Biogas. Photo: Heppell’s Potato Corp.
Off-grade potatoes form part of the raw product that is processed into renewable natural gas at Fraser Valley Biogas. Photo: Heppell’s Potato Corp.

“It’s not a case of just throwing everything in. It’s a stomach and if you throw just anything into your stomach you’re going to get sick. We’re very particular about what goes in and how much. You’ve got to be really on top of it,” he says.

One of the early problems the company struggled with was fluctuating levels of gas production. Production could peak one day and then drop to almost nothing the next. While it still occasionally happens, it now occurs far less frequently.

“We can usually trace it back. Now we just have to worry about day-to-day management of it and procuring the right feedstocks,” Schouten says.

Thirst for Renewable Gas

All of the gas produced at Fraser Valley Biogas is sold to FortisBC, which distributes natural gas and electricity to more than one million customers across the province.

FortisBC spokesperson Grace Pickell says the private utility was eager to do business with Schouten and his company. Its customers can request that a percentage of their energy needs come from renewable natural gas and demand has exploded since the program was first offered in 2011.

“Basically we were responding to what we were hearing from our customers in the province. People were looking for another option beyond just conventional natural gas,” says Pickell, adding the utility has sold more than 225,000 gigajoules of renewable natural gas since the program was implemented four years ago.

“We started doing the investigation to see who across B.C. could supply us with this and that’s how we got into business with Pete’s company,” says Pickell. “It is a carbon-neutral product … so it’s a really great alternative for customers who are looking to have a locally-made natural gas resource.”

The success of Fraser Valley Biogas has not gone unnoticed. Staff regularly field calls from other North American biogas plants inquiring about the work they are doing.

“We ask them questions and try to give them as much knowledge as we can,” Schouten says. That interest hasn’t been limited to those working in the industry. Fraser Valley Biogas conducts regular tours of its plant for members of the general public.

Schouten says he hopes the work his company is doing in Abbotsford inspires people in other parts of the country to be responsible stewards of the environment.

“If everybody makes a small effort at their own house by separating their organic wastes and getting it to the right spot, they can make a huge difference in the future,” he says.


Cavendish Farms in Biogas Business

B.C.’s Fraser Valley isn’t the only region in the country where potato waste is being converted into biogas.

Cavendish Farms, one of North America’s leading producers of frozen potato products, opened its own biogas plant in New Annan, P.E.I. in 2009. According to the company, the Cavendish Bio-Gas Facility has helped the company reduce greenhouse gas production at its two P.E.I. processing plants by 35 per cent since then.

It has also helped significantly reduce the company’s reliance on fossil fuels to run the boilers at its processing plants and has eliminated the need to truck waste 1,600 kilometres to an offsite location each day, Cavendish says.

According to the company, all of the renewable natural gas produced at the biogas facility through an anaerobic digestion process is used at the Cavendish processing plants. Any remaining material left over after the process is complete is used as an organic fertilizer.


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