FITEC ENVIRONMENTAL TECHNOLOGIES: PIONEERING A NOVEL APPROACH TO AD

Passion. Vision. Technology. These are three of the main drivers behind the terrific success of Tom Ferencevic, B.Sc., founder and owner of Fitec Environmental Technologies. Based out of Welland, Ontario (near Niagara Falls), Ferencevic is an environmental scientist and agronomist by trade, who over the past two decades, has greatly contributed to the growth of the biogas industry in North America. 

Currently, Fitec has designed and built five anaerobic digester (AD) plants in Canada, with one under construction in Mexico, and has a pipeline of 14 projects underway that extend from Alberta to Quebec, and into the United States and Mexico. The existing facilities co-digest a mix of source separated organics (SSO), Industrial, Commercial and Institutional (IC&I) and agricultural organic waste (including manure), totaling greater than 100,000 tonnes per year, and combined, output approximately 1,600 m3 of biogas per hour. The project in Mexico alone will produce 625 m3 per hour when it is commissioned near the end of 2022. 

Over the past five years, the company has developed an innovative system for AD that uses a self-cleaning mechanical arm technology to continuously remove both sinking and floating contaminants and requires very little, if any, process water at the front end. The result is a robust and resource-efficient system with a low operating cost, and one that produces a clean digestate.

The value of digestate

The AD process creates two valuable outputs: biogas and digestate, the latter being the residual organic matter left over from the process. According to Ferencevic, while the value of biogas produced by anaerobic digestion as a sustainable, flexible, clean fuel or source of electricity is well understood, digestate still has little perceived value to the marketplace in North America. He says it is widely considered to be a cost item on a business plan. To most, it costs for trucking material and managing it, and it costs to clean digesters. 

Now, this perception is starting to turn, whereby industry, government regulators and other stakeholders are understanding more and more that digestate is a very valuable material. 

“Quality digestate is ideal as a liquid or solid fertilizer or soil amendment, or for direct application to land in the agricultural, landscaping and other sectors,” Ferencevic explains. He says digestate is a lower cost, sustainable, effective replacement for peat-based and chemical fertilizers, which have risen significantly in cost, especially over the last several years. 

“Many farmers are realizing that quality digestate is even better than straight manure on their land, for example, because of the very high levels of organic matter it contains – as well as NPK and micronutrients, which are very valuable in terms of soil health.” 

A unique approach to AD

Organic waste materials contain a wide range of contaminants including plastic, sand, grit and stones. To remove these kinds of contaminants, Ferencevic says the traditional AD method uses liquid separation. At the front end, solids are liquified and reduced, making everything very watery. This process separates the solid, floating material and the sinking fraction, but to do this requires a tremendous amount of fresh water. 

“We, on the other hand, allow all kinds of residual contaminants to remain in the input feedstock, and it goes into our digester,” explains Ferencevic. “It can handle it because of our process, and our self-cleaning digester technology. Our method relies on the naturally occurring bacteria in the digester. As bacteria breaks organics down over time, water is released from the material. You get this natural liquefying effect as part of the digestion process, and this causes contaminants to settle out either at the surface or at the bottom of the tank, based on their density. 

“We skim out the floating contaminants with our skimming system and sweep out the sinking ones with our automated floor sweeper and grit separation technology. We also use specialized piston-driven pumps to feed material in. They work more slowly, and they cost a bit more in capital, but they're significantly cheaper to operate over time and they don’t need to be replaced as frequently.”

Designed by Germany-based engineering firm, Finsterwalder Umwelttechnik, the digester tank self-cleaning technology used by Fitec in their AD plants has now proven its effectiveness in over 20 operations around the world, some running for over 18 years without any shutdowns for digester cleaning. The technology employs a slow-moving mechanical arm at the bottom of the tank that pushes settling material to a drain. This material is then pumped to a grit separator that allows clean digestate to be returned to the digester and the relatively dry contaminant load to be disposed of. This technology is fully automated and functions continuously to prevent build-up in the digester tank. 

“Our self-cleaning digester technology is key to preventing tank buildup, which significantly lowers costs of running these plants,” Ferencevic explains. “They don’t need to be shut down regularly for extensive cleaning. But more importantly, it allows us to produce clean digestate. All of the digested feedstock in our systems passes through a 1-mm screen. This means that no piece of plastic or other non-digestible contaminant larger than 1 mm is present in our digestate. This has been repeatedly verified by independent, third-party testing. We've been doing this now for two decades in Europe, and the system has exceeded expectations for many years. It all comes down to our holistic approach, and our dedication to efficiency and conservation.” 

The DQA and working together with the composting industry

Beyond their introduction of a unique, environmentally friendly, application-flexible and low-cost process for anaerobic digestion, another way in which Fitec has contributed to the advancement of the AD-biogas industry in Canada, is with respect to the development of its quality standards. Similar to industry standards in place for finished compost, the Compost Quality Alliance (CQA), Digestate Quality Alliance (DQA) standards have been developed and produced by the Compost Council of Canada in collaboration with a wide range of stakeholders, ranging from members and scientists to international organics recycling and soil science associations, including the European Compost Network. Both programs involve a combination of established regulatory compliance with the goal of growing understanding between all stakeholders about the agronomic attributes of soil-destined products –compost and digestate – and ultimately ensuring that the right product is being used for the right soil application. 

As members of the Compost Council of Canada, Fitec has been involved with the development of Digestate Quality Alliance (DQA) standards since the beginning. 

“For me, the development and introduction of the DQA is important because we need to be producing a clean digestate that has long term sustainability,” says Ferencevic. “Unless it's clean and unless there's a quality check in place, it doesn't do anything to advance the industry or help the environment. Our clients have always demanded the highest standards in digestate quality, and we've been giving it to them for over 20 years. I've never known anyone who wanted to put dirty digestate on their land."

Key elements of the CQA/DQA programs focus on standardized product sampling, uniform laboratory testing, and establishing the right product attributes and usage guidelines. The CQA and DQA are designed to benefit consumers of compost and digestate, including the agriculture industry, with a more informed platform with which to select the right product for the right use, and be assured of product quality. The compost and anaerobic digestion industries benefit from these programs because the regulatory compliance established for all producers creates a more level competitive environment, helps enhance market development and helps build industry credibility and positive reputation.

“We can replace synthetic fertilizers with quality digestate and compost,” Ferencevic says. “It is the best way to go, hands down, from an agronomic and climate change mitigation standpoint. Really, it just needs to be regulated and the understanding needs to be built. The DQA is a really good approach, a good way of starting to boost the value of digestate. Farmers and others are starting to really understand its value as an end product.”

He continues, “There are established digestate standards in Europe and around the world, and so it was the logical next step here. It is also about levelling the competitive playing field. Having quality regulations for digestate materials shouldn't even be debatable really.” 

Ferencevic makes one last point about the opportunity created by the huge amount of food waste produced yearly in Canada, which needs to be diverted from landfill, and which can help create more valuable biogas and quality digestate. In 2022 the B.C.-based National Zero Waste Council conducted research on household food waste in Canada, and the results showed that for Canada as a whole, almost 2.3 million tonnes of edible food are wasted, sent to landfill, each year, costing Canadians in excess of $20 billion.

“What needs to happen and what is starting to happen, is to have people in the composting and biogas industries working together to turn our food waste into valuable product that can be returned to the soil,” Ferencevic says. “In collaboration with the Compost Council of Canada, we have done the testing and we have the data to support the fact that clean digestate from the biogas process is a viable alternative to chemical fertilizers, just like compost. Digestate can also be combined with compost to produce even more effective product.

“With our digestion process, we produce a number of residual streams,” he continues. “Anaerobic digesters do an excellent job at breaking down and utilizing simple sugars, such as fructose, starches, fat and protein. The same things that you and I eat are great for AD bacteria. What are not good for AD bacteria are longer chain cellulose types of materials, like straw, material with a lot of fibre. But these slowly degradable fibres – one of the residual streams from the digestion process – can be given to a composter to finish off.”

In Europe, he says he knows of many facilities that have an integrated AD-composting application. They take reject fractions from the anaerobic digestion process and clean it with composting technologies and tools such as star screens, drum screens and wind sifters. This separates out the residual waste fractions that can only go to landfill, reducing them to a very small amount, and it allows for the re-use of the bulk of the material, all of which was formerly destined for landfill. 

“There is easily enough food waste for both the compost and anaerobic digestion industries,” concludes Ferencevic. “We produce organic waste on farms and in the urban environment, at every step of the food production and consumption process. That is a problem unto itself, but the least we can do is recover as much energy as we can, and make sure these materials that have come from the soil, go back to the soil. We can absolutely work together, with the composting industry, to make this happen efficiently, sustainably and profitably.”

Author’s Bio: Keith Barker is the former Editor of Recycling Product News magazine and is now working as a freelance writer from his home on Vancouver Island.