Mike Watt, vice president of operations, Walker Environmental Group

In a Canadian province that exports 3.5 million tons of waste each year into the United States, and where landfill space is at a premium, Niagara Falls, Ontario-based Walker Environmental Group (WEG) has figured out how to make the most out of a nontraditional asset.

Taking in more than 1.1 million tons of waste per year at its 1,200-acre site, the company, a division of Walker Industries, has been turning valuable methane gas into energy on a massive scale for 15 years and providing it to a customer hungry for the energy—a nearby paper plant owned by Montreal-based Resolute Forest Products. The paper facility, located in Thorold, Ontario, produces newsprint from 100 percent recycled content and is one of the largest energy consumers in the region. It is located about 2.5 miles from WEG’s landfill space.

Built in 2002, the landfill gas project was considered quite an achievement. Today, the system continues to be one of the largest landfill-gas-to-energy (LFGE) projects in North America, providing 50,000 to 70,000 gigajoules of energy each month to the Resolute production plant, offsetting about 60 percent of the plant’s natural gas needs.

Mike Watt, WEG executive vice president, and Gord Cole, vice president of operations at Resolute, worked on the initial contract for the project all those years ago and have continued to see success and expansion with the landfill gas capabilities ever since. In March 2015, the companies announced the project had achieved a milestone, eliminating the need for more than 200 million cubic meters of natural gas throughout the project’s lifetime.

PROJECT HISTORY

“In 2002, we commissioned the first of our pipelines to the plant and began supplying alternative fuel for [Resolute’s] boilers,” Watt recalls. “It took a couple of years to work through all the contractual issues and figure out where to build the pipeline.”

The system performed better than expected. Three years after the initial pipeline was installed, WEG decided to build another pipeline along the same route. The pipelines are owned by the Alberta-based energy utility company, Embridge.

Cole recalls that back in about 2000, WEG’s landfill had been increasing in size and began flaring off gas. At the same time, he says, “We burned natural gas and light oil for our steam plant which generated steam to help dry our paper.”

Cole says the paper company places an emphasis on energy efficiency. Energy accounts for 23 percent of Resolute’s paper production costs. In a 2014 report, the company notes it generated 72 percent of its total energy needs across its operations from renewable sources and 76 percent of its fuel energy usage came from biomass. Landfill gas only makes up a small portion of the renewable fuel energy Resolute consumes. Paper making is an energy-intensive process, though, and the landfill gas the Thorold production facility uses is equivalent to the natural gas used to power 80,000 homes.

Using the renewable gas in Resolute’s processes certainly embodies the sustainable principals of the company and its forward-thinking approach to the environment. “I think it speaks to the beliefs of our company and of our desire to decrease landfill gas emissions,” Cole says. “Back in 2000 when we started doing this, I don’t know anyone else burning landfill gas at such a capacity. At our company it was an inaugural move.”

WEG and Resolute spent time together in those early years discussing whether the paper plant could burn the landfill gas or if there would be too many impurities. They also worked to determine how the boilers might accept the gas. “We found a way to inject it into our boilers to offset extensive natural gas and light fuel oil with renewable energy,” says Cole.

The boilers have since been upgraded, and because the landfill gas goes directly into two boilers it does not require much cleanup, according to Watt. “The boilers don’t really care what they are seeing, there’s energy value there.”

Watt notes that direct-use projects such as Resolute’s are more economic than injecting the landfill gas into an engine. “If you put landfill gas into an engine, it really needs to be cleaned up,” he says. Contaminants from landfill gas include particulates, oxygen and nitrogen. While that extra stuff can’t go into an engine, Watt says it can go into a boiler quite easily. “In terms of gas upgrading here, all we do is take care of the moisture because you don’t want water in the pipeline,” he says.

MORE TO GO AROUND

WEG produces 6,000 cubic feet per minute of landfill gas or about 1.6 million gigajoules per year at its Niagara Falls site. Only a portion is sent to Resolute, as the facility doesn’t have use for all of the gas. “Right now we don’t take it all because we don’t have the capacity to burn it all,” says Cole. “We are looking at different projects to utilize landfill gas to generate electricity.”

The landfill gas also powers a 1-megawatt (MW) engine at WEG, which sends energy back to the grid. The remaining gas is flared. The landfill gas is generated from two side-by-side landfills—an older landfill, which is now mostly closed, and a newer landfill that has been operating for the last six years. “We are drawing gas from both,” says Watt. He explains that landfill gas quantities rise steadily through the life of the landfill until closure. Shortly after closure, the methogenic bacteria starts to decline as the organic material gets eaten up.

“The old site is declining already and the new site is increasing,” says Watt. “Overall landfill gas is still rising.”

While WEG’s landfill gas is rising, Resolute’s usage has declined as demand for newsprint has declined.

“Our peak gas burning was in 2009. Then in 2010, we idled one of our paper machines,” says Cole. “We cut the capacity of the plant in half. At the same time Walker has more and more gas, which is why we have been working on another project.”

Cole says Resolute is considering a 5-megawatt project with WEG for electricity. “We are looking at the economics now and it will be tied to what we end up doing with the plant,” he says.

Because the landfills are generating so much gas, Watt says the company is trying to find other projects and build additional pipelines to supply other industries in the area. “Because we have an old site and a new site, we’ve got 30 years of landfill gas supply at least.”

The landfill gas system includes 160 wells. Watt describes the process of collection as relatively simple. Each well has a slight vacuum on it to suck the methane. It all goes into a collection head and back to a processing plant where filters remove the particulate. Moisture also is removed at this stage. A simple blower compresses the gas and sends it down the pipeline. “Methane finds the path of least resistance, so it is very easy to collect,” says Watt. He acknowledges, “There is a little bit of an art to it because you don’t want to suck oxygen or air from the atmosphere into the pipeline.”

Meters measure the purity of the methane, which typically ranges from 52 to 56 percent. Watt says it is important to maintain that ratio so you know if you are sucking air into the system.

WEG also composts food, leaf and yard waste at its Niagara Falls facility. Approximately 20 percent of the organics WEG receives is going into what Watt describes as alternative processing such as aerobic composting. Watt doesn’t see organics diversion programs as having a major effect on the LFGE project. “We do expect that in the longer term we are going to see less organic material in the landfills, and that will result in less landfill gas. But for now, I don’t see any big swing.”

WEG also operates a biosolids treatment facility at the Niagara Falls site. The biosolids are mixed with cement kiln dust and dried into a stabilized, granulated material for use by farmers.

MAKING IT WORK

Watt says one of the secrets to success in the landfill gas business is scale. “If you have a really large landfill, you can afford to do a bunch of other things with respect to landfill gas collection. Small sites just aren’t economic. These kinds of projects just don’t work there.”

WEG has six facilities across Canada. Four are considered large-scale energy production facilities. In addition to the Niagara Falls LFGE facility, they include a 5.2-MW system in Mississauga, Ontario; a 5.2-MW system in Montreal; and a 6-MW plant in Ottawa, Ontario.

“We have many more [landfill gas] collection facilities installed. Most are just flaring because there is no utilization opportunity,” says Watt. He adds, “The problem with landfills is they tend to be fairly remote, so connection to the grid for renewable gas purposes tends to be a bit problematic.”

A large system the company installed a few years ago in the urban setting of Winnipeg, Manitoba, could hold potential for a utilization project. “That will be our next target,” he says.

Canada offers some green energy incentives for producing power for the grid, which has been a big driver on some renewable energy projects, according to Watt. The project with Resolute did not rely on government incentives, however. He says it was a “straight commercial decision.”

“The large-scale direct use projects do work in many cases without incentives, but when you are producing green power [for the grid], it is not so much that it is tougher, but there is a lot more technology involved,” explains Watt. Along with the additional technology comes a higher price tag. Watt estimates each megawatt can cost $2 million dollars, so a 5-MW plant can be a $10 million investment. Getting a return on that investment with standard utility rates is difficult, but WEG has been able to make it work.

“What we are doing is not different than anyone else, we’ve just been very successful at it,” says Watt. “I think there has been a lot of barriers over the years, and we’ve got four good-sized plants that are all cash flow positive.”

Watt advises being able to accurately measure the capital expenditures of a project and delivering that project on budget is the one area of a project developers can control. “You know how much gas you are getting and you know how much money you are getting from the power. The one big vehicle can be controlling the cost of the plant.” He adds, “If you screw that up, you are going to be in trouble.”

Maintenance costs are another important factor in a successful LFGE project, according to Watt. “You’ve got to pick the right equipment, specifically the engine parts. We consistently use Jenbaucher GE engines, not because we like them better than the others, but it just gives us consistency across all our plants.”

Watt adds that selecting the proper equipment is critical and maintaining it properly is essential. “Failures I have seen usually have been badly maintained facilities,” he says.

Aside from maintenance and equipment, Watt says a successful facility is mostly about being able to get good quality gas, and the key to that is having a qualified operator. “You can get a lot from technical papers, but somebody that knows how to run a well field is a really critical part of these operations,” he says.

POWER IN PARTNERSHIPS

Another key to success is having the right partners. The partnership with Resolute has certainly worked out all these years. From Resolute’s perspective, Cole says, “The relationship between the companies has been really good. We’re supportive of each other’s business challenges and have always found ways to have meaningful discussions to help move each other forward.”

Another partnership WEG has developed has been on the LFGE operations. WEG is a 50-50 partner with Cambridge, Ontario-based Comcore Environmental on its LFG projects. Comcore is responsible for all the permitting and much of the maintenance on all the LFG sites.

The 15-year partnership with Comcore has been vital to the operations since it began, according to Watt. “I believe in solid partnerships and making sure you have the right skill sets at the table.”

As world leaders begin to tackle climate change on a major scale, Watt says LFGE is a major component of reducing greenhouse gas (GHG) emissions. “The whole methane collection business can play a critical role in meeting GHG commitments. There is going to be a need for these types of projects that can really destroy methane in some way, shape or fashion so it is not vented into the atmosphere, even if it is only flared. It is our part in terms of climate change control.”

The author is editor of Renewable Energy from Waste and can be reached at ksmith@gie.net.