Partner: WSP

“We’re really at the beginning of seeing the potential of what can be done with trash,” says Andrea Redford. She is the chief business development officer for Canadian biofuel manufacturing technology company Enerkem.

The circular economy is increasingly being realised in many sectors and finding ways to take waste carbon and put it back, efficiently, into useable products is becoming a reality.

“Ten years, 20 years into the future, I really see a world where the carbon will be in a loop,” says Redford. “And we will be taking waste carbon into products again, it doesn’t necessarily have to be a coffee cup becomes a coffee cup, but what it becomes is about is about the molecules from the feedstock that we have available in a mixed pool of hydrocarbons.”

In this article, we explore a revolutionary technology that is turning non-recyclable waste that is being dumped in landfills all over the world, into sustainable biofuels, chemicals and products that could support a wide range of industries in lowering their carbon emissions.

Enerkem has developed a gasification technology, which produces advanced biofuels and circular chemicals from non-recyclable waste. Materials are basically fed into a high temperature and pressure vessel where oxygen and steam are applied causing a series of chemical reactions that convert the waste into a gaseous form of the most basic molecules. These new gases are carbon monoxide and hydrogen, better known as syngas.

“So essentially what we do is we want to turn that syngas into products which are drop in and able to directly replace products which are currently used in the industry in fuels and chemicals,” says Redford.

The company takes the syngas and converts that into molecules, such as simple alcohols like methanol, which can be used for fuels, or chemical applications. This could be converted into more complicated ethanol, or take the same gas along other pathways to make other chemicals, or via technology, such as Fischer Tropsch technology, to make synthetic aviation fuel.

Varennes Carbon Recycling Plant

Enerkem’s gasification technology is being deployed on its largest project to date – the Varennes Carbon Recycling Plant in Quebec, Canada. Where it will take 200,000 tonnes per year of non-recyclable and forestry waste. And turn it into around 125 million litres per year of biofuels, equivalent to 50 Olympic sized swimming pools. Construction is about to begin and WSP is responsible for detailed engineering design and procurement so that this technology becomes a real piece of critical infrastructure.

There are two main obstacles that the team really faced when taking on this project. Gasification is not new but the scale of this brings its own challenges from both a physical infrastructure perspective and ensuring that there is a market for the products.

Ali Ashraf, Project Manager – Engineering for WSP says, “So when Enerkem first started with a lab concept about 20 years ago, they were able to come up with a pilot plant in Westbury, Quebec. The first commercialisation occurred in Edmonton about five to six years ago.

“There we take the Municipal Solid Waste which would be the landfill portion from the sorting facility that the city of Edmonton runs. So this is the heterogeneous mix reject from the Material Recovering Facility in Edmonton.”

This is processed in the commercial gasifier that Enerkem is implementing across all of its projects.

Redford adds, “But to get to that point, was a long road of measured scale up steps all the way through our R&D facilities, our innovation centre pilot scale facilities, which are located in Westbury in in Quebec, to that that full size gasifier that we operate. So this is really just something which truly has been the work of decades to get us to this point.”

The Varennes project might have the same commercial size gasifier but the scale of the complex is much larger, which was a key challenge for Ashraf and the team.

Aside from the scale, the other challenge is tied to technology. Because unlike previous gasifiers Enerkem have made major progress in terms of the ability of their technology to work with a very mixed waste feedstock to create a consistent end product. And that is very difficult, so difficult that no one else has done this yet.

Ashraf explains, “Essentially, we have to have a plant that’s able to take vast and large amounts of very variable feedstock and convert it into very fixed and very high quality products that are sold back into the market. And so the challenge with that is to have a plant that is able to be variable and can adjust and adapt to the various inputs and produce a very fixed output at a scale that makes it commercially viable, while also being flexible enough to adapt to various products that were coming in and treating and handling.”

Process-driven design

The gasifier complex will look more like a petrochemical refinery that a waste processing site. But it is the process that drives the design, and there is a feeding system, the gasification, the syngas production… and then the “methanol island”. But it all begins with the waste.

“So the first step is, is the feedstock preparation and receiving,” says Ashraf. “And what that involves is, essentially, waste handling material handling. We sort it, shred it, dry it. And we have essentially a feeding system that goes then into the gasification portion of the plant, which is the proprietary technology, where we essentially convert these carbon rich residues or waste products into synthetic gas.”

There are different types of gasifiers and Enerkem uses what is known as fluidised bed reactors where the gasification medium is supplied through the base of the reactor and can be operated at lower temperatures than some of the other technologies.

Redford adds, “We do run a relatively low severity process compared to some other gasification technologies which are out there.  This is an aspect of our process which delivers increased efficiency compared to some of the alternatives.”

This efficiently produced syngas then has to be cleaned, in the next portion of the plant which involves scrubbing towers, water treatment, and a separation of residues.

“What’s interesting is that the gasification cleaning condition are first of their kind,” says Ashraf. “They involve equipment that doesn’t exist anywhere else. In designing this equipment, we had to approach vendors with requirements and design criteria they had not seen before.”

This is mainly related to the challenge mentioned already – scale

Ashraf adds, “Some of the process requirements and mechanical requirements, and loads that we’re designing to are really at the limit of what conventional products technologies and manufacturers can provide.”

The next step of the plant then is to take that syngas that is produced and go through a process of synthesis and product purification to ultimately convert that syngas which is composed of primarily hydrogen, carbon monoxide and other carbon gases and clean it to the point where we’re able to essentially produce methanol, ethanol and other by-products for the biofuels in chemical industry.

“The methanol product will be destined for fuel applications,” says Redford. “There’s obviously quite high demand for low carbon methanol. there’s a lot of a lot of buzz right now around methanol for marine fuel. And a lot of demand for this.”

The consortium that raised the CA$875M project investment consists of Shell, Suncor and Proman with each partner bringing their expertise in traditional energy sectors and petrochemicals to the bio-fuels space.

But before processing can begin Ashraf and his team have to design and deliver the facility, which will sit on a footprint of around 500,000 square feet or 46,000 square metres and also includes a one of the world’s largest electrolysers for making green hydrogen using the plentiful supply of hydropower that Canada has an abundance of.

Most of the buildings are industrial process plant with the associated pipework as well as the tall thin distillation columns

“The interesting part about the visible visual profile of this plant is that it’s, it’s very much a little bit like a Lego structure,” says Ashraf “The unique design challenge we have here is that we were designing everything in modular structures. So everything may look a little like a little Lego brick that stacked on one on one of each, in order to have an ultra-modular design that allows us to have various flexibility and expansion as well as overall construction opportunities.”

Breaking ground at Varennes

Sitting on the banks of the St Lawrence River, Varennes is around 30 minutes south east of Montreal, which will enable components and construction materials to be floated along to site, reducing road traffic.

But as any experienced civil engineer will tell you, the success of a project starts with understanding the ground that it is being constructed in, and when Enerkem approached WSP with an early geotechnical study, Ashraf recommended additional investigations. The findings showed that the ground conditions were much worse than anyone had predicted.

“What we have here is a very silty clay, it’s a bit like Swiss cheese,” says Ashraf.

Silty clay has larger particles and larger spaces between them than a more uniform clay, which massively affects the ground’s performance and how it reacts to the structures that are placed in it. This silty clay is basically not as strong for day-to-day pressures or in the event of something much less common like an earthquake.

Ashraf explains, “Less overall bearing capacity and more subject to amplification following seismic conditions and so you can imagine a world where if you’ve got a very clay like structure or subsurface condition with a lot of piles following an earthquake or seismic event, there’s the risk of essentially a liquefaction of that of that soil.”

So designing piles and saying foundation systems that can resist these potential conditions becomes more challenging in terms of the size and spacing of piles their depth and how to optimise the structures above ground to ultimately ensure that the design is safe.

And safety is the number one priority, ahead of cost or anything else, so it was important that the design is conservative enough to ensure the building would be safe and operable, but also aggressive enough to manage the capital cost of development and construction.

In this case the solution was to create a bespoke web of foundation types and depths depending on the loads, location and ground conditions. In many cases this meant switching from a simple concrete pad to installing deep reinforced concrete piles.

“We’ve got specific parts of the facility where we had more traditional conventional, you know, concrete foundations that go anywhere from two to three metres deep,” says Ashraf. “And now we have piles that have to go century to refusal, which are anywhere about 30 metres deep.

Refusal means all the way down to the bedrock, which is quite low as this is close to the water. There is also a sloping profile across the site, so the area closer to the water is lower. The design had to evolve as it progresses from one side of the facility to another.

What is more the team will keep on testing as they go so that if they find that the clay is more dense and less silty in certain locations they can reduce the depth of piles, saving money where they can.

Where local leads the world

The team were particularly eager to make sure the project was a success, as a local company is producing an important, world-beating technology.

“This was very exciting, because it was part of the energy transition that we all heard up and it was real, it was happening,” says Richard Fecteau, Senior Vice President for Energy Resources in Industry, WSP Canada. “The capital was invested. And it was in our backyard.”

He says that when they were putting the proposal together to bid for the project there was a lot of excitement among local engineers who, like Ashraf, want to play a role in a transition towards greener energy systems.

“If you are a professional engineer in Quebec, you all know, you know, about Enerkem because it came from the university lab, to a commercial scale. So it was very attractive for process engineers or project engineers to be part of that project. The founder, the actual founder of Enerkem was a professor at the chemical engineering faculty at the Sherbrooke University.”

A chemical engineer by the name of Dr Esteban Chornet, from the local Sherbrooke University is in Quebec.

The project has also been supported financially by the federal government the local Quebec government.

“The federal government is very aggressive in its climate change plan,” says Pierre-Olivier Pineau, a professor in energy market policy at the Business School at the University of Montreal. “And the current government, which is a Liberal government, led by Justin Trudeau is basically trying to make up for the waste of time of the previous years, and we’ve been missing all our emission reduction targets for many years now.”

Canada has benefitted from a wealth of energy supplies. It is the world’s fourth largest oil producer and fourth largest hydropower producer with 81GW of installed capacity accounting for around 60 percent of its electricity production.

Low energy costs and plentiful availability created a culture of consumption. But the climate in changing, in more ways than one.

The Clean Fuel Standard will require liquid fuel (gasoline and diesel) suppliers to gradually reduce the carbon intensity of the fuels they produce and sell for use in Canada over time, leading to a decrease of approximately 13% (below 2016 levels) in the carbon intensity of our liquid fuels used in Canada by 2030.

Against this backdrop it is not surprising that Enerkem see the transport sector as being a key market for their biofuels. Pineau agrees that they could play a significant role in decarbonising transport as part of a wider transition.

“In transportation, there’s a wide variety of options that could be pursued, you know, the one that we tend to forget the most is train for freight transportation, you know, it’s 90% less energy intensive than heavy trucks and in Canada, and that’s a different path than that what Europe has taken in Canada and North America,” explains Pineau. “Heavy trucks have been increasing by more than 150% in terms of numbers in terms of energy consumption and emissions, it is actually freight transportation is the fastest growing sector in terms of emissions in Canada.”

These trucks will need to decarbonise fast as carbon taxes increase prices year on year. Hydrogen and electrification of these vehicles are potential solutions, but require large shifts in the infrastructure designed to support them. Biofuels can be used more readily including blending them in to diesel to reduce its carbon intensity.

This brings us on to the question of the definition of a biofuel because one of the economic advantages of the Varennes project is that it can create a consistently homogenous syngas from a variety of waste products. If it contains plastics for example what does that mean for the carbon intensity?

“Depending on the jurisdiction, and the regulatory framework that exists, the biogenic portions are typically most highly valued in the fuels markets,” says Redford. “And then the circular portions are normally focused on the chemical space. And logically that means that you’re taking the residual mixed plastics, and you’re putting those back into the chemicals and plastics value chain. So the carbon then truly becomes circular and the biogenic portion and is more highly valued in the fuel space.”

So there are nuances around this.

One of the main challenges for investors in this space is the uncertainty over how fuel prices, both fossil fuels and biofuels will evolve. Redford says that this is becoming less and less of a factor as guidance and declarations become clearer, year-by-year.

Pineau explains that pricing can be a challenge in Canada because of the variations between provinces which means a lack of consistency across the country.

“Because the carbon prices that exist in Canada are not the same across provinces, due to political disagreement. In Quebec there is a carbon price which is different from the Federal price, and it does not apply equally across all sectors. Developers do not know what the exact carbon cost for fossil fuel users will be, creating uncertainty. They don’t know the price of their competitor. So they don’t know exactly how they can price their own product competitively in the future.”

“So politics are getting into the way of giving a stable economic environment for developers of such projects.”

From a waste perspective Canada has had the same lack of incentive to change as the energy sector thanks to the availability of land. Which has meant landfill was available, and the impetus for incineration and gasification has been low. But people are beginning to realise that it is not wise to simply expand the landfills indefinitely. And legislators are starting to change policy to support this

“So in Quebec the government has recently taken an in-depth look at what is happening in waste management,” says Pineau. “And they announced that they would increase disposal fees.”

Because landfill is the place of last resort for waste that can’t be recycled or turned directly into something else. Waste that actually contains carbon that we can use if we have the right technology to capture it.

“This is where Enerkem is developing a technology which is which is actually different from a really the high-level high temperature gasification that is currently being done in different countries like Japan. The Enerkem technology works at lower temperature. So it is a unique technology that doesn’t need such a high temperature to turn the feedstock into syngas and then into different types of biofuels.”

And of course the feedstock itself can be flexible

“So the viability of the feedstock that can be used to lower temperature and the different types of different types of outputs that it can provide the flexibility to do basically being able to build different fuels liquid fuels for different uses. That’s really the strength, I think, of the project.”