Capturing innovation: carbon capture inspired by nature

by • December 14, 2012 • Clean Tech, IndustrialComments (0)2149

When it comes to developing innovative and sustainable solutions, nature can be a powerful muse. Such was the case for the Québec City-based company CO2 Solutions. An innovator in its field, the clean tech company is using an enzyme found in humans, as well as in all other living things, for carbon capture.

This enzyme, carbonic anhydrase, is a potent biocatalyst and nature’s way of efficiently managing carbon dioxide by converting it to bicarbonate. In the human body, that process happens in the blood and lungs. Inspired by this natural process, CO2 Solutions developed and commercialized this enzyme for use in a patented ‘industrial lung’ that allows for the efficient capture of carbon dioxide produced by power plants and other large stationary emitters.

Its biomimetic technology uses carbonic anhydrase in an energy-efficient solvent to scrub the carbon dioxide from industrial flue gases, such as those produced by coal-fired power plants or aluminum refineries. Once the CO2 has been separated, it can be used in other industrial processes or sequestered underground. The use of carbonic anhydrase as a biocatalyst in the process greatly reduces the capital and operational costs normally associated with carbon capture.

Through this innovative process, CO2 Solutions has succeeded in offering industry a more efficient tool for managing carbon dioxide emissions. At the helm of the company is Glenn Kelly, its president and CEO. He sees CO2 Solutions as an emerging part of the energy industry.

“I think we’re going to be adding a new stage to the energy industry, which is the management of the emissions industry produces. For me, the innovation we offer represents a logical step forward in what I believe is going to be a big part of the energy industry’s future.” – Glenn Kelly, president and CEO, CO2 Solutions

A veteran of the oil and gas industry, with a civil engineering background, Kelly joined the company as a board member in 2008 and became CEO later that year. Right from the beginning, Kelly’s interest was piqued by the company’s innovative technology and he has used his wealth of industry knowledge to guide the firm’s progress.

“I just saw that this was a great technology, it was a tiger in a cage and I thought it had tremendous potential,” says Kelly. “Carbonic anhydrase is the best catalyst or accelerator yet to be discovered for the management of CO2 conversion into other products. We’ve taken a process from nature and adapted it for large-scale carbon capture.”

The company’s breakthrough technology grew out of work done at Laval University in the late 1990s, when researchers first began to study the use of carbonic anhydrase for carbon capture. The success of that research eventually led to the founding of CO2 Solutions in 1997.

“The complete idea was to make a system where we could capture CO2, as carbonic anhydrase does in our blood.” – Sylvie Fradette, vice-president of R&D, CO2 Solutions

Sylvie Fradette worked on the initial research project while completing her PhD in chemical engineering at Laval University. One of the original developers of the technology, today Fradette is the company’s vice-president of R&D.

She looks back on how the company first developed its carbon capture technology, after validating that the enzyme could be used to remove carbon dioxide from flue gas.

“The complete idea was to make a system where we could capture CO2, as carbonic anhydrase does in our blood. Our lungs transform that captured CO2, which is in bicarbonate form, back into the gas which we exhale,” says Fradette. “In our technology, the captured carbon dioxide is either used for other industrial applications or sequestered underground.”

Developing the proprietary technology was not a simple process, in large part because the cost of carbonic anhydrase was exceptionally high.

“In the first stages of the company, in the early 2000s, carbonic anhydrase cost $250,000 a gram, which was quite expensive,” says Kelly. “We brought that cost down to about $500 a gram, and even less now, to a couple hundred dollars a gram, because we’re producing it at much larger scale.”

In the early days, the company’s researchers worked on developing their own enzyme. Starting first with human carbonic anhydrase, they synthesized the enzyme in the lab, immobilized it, and then modified it to make the enzyme more robust.

“At the beginning, when we looked at if we could purchase the enzyme, cost was a real issue,” says Fradette. “So it became important in developing this technology to immobilize or keep the enzyme captive in the system for reuse. The objective of this work was to attach the enzyme to supports located in the low temperature, absorptions part of the scrubbing process, and by doing this we were able to keep the enzyme out of the high temperature regeneration part of the process and thus make the lifetime of the enzyme longer.”

Once the researchers had successfully produced and immobilized the synthetic carbonic anhydrase, cost came down and larger scale testing began. From 2003 to 2005, the company ran proof-of-concept testing at the Alcoa aluminum smelter, in Québec, as well as at the Québec City waste incinerator.

“In both cases we were able to show that the enzyme was working quite well. It was successful in capturing CO2 on a significant scale at both facilities,” says Kelly.

After establishing the enzyme’s large-scale potential for carbon capture, the next major milestone for the company was in 2009, when CO2 Solutions signed a development agreement with Codexis Inc., a Silicon Valley company that enhances naturally occurring enzymes.

“They worked with us to produce some super enzymes that survive at much higher temperatures and in much harsher conditions than anything we’ll find in nature,” says Kelly. “We were also able to do away with the support system and blend this more robust enzyme directly into the solvent.”

The cost for producing this improved enzyme, says Kelly, is in the range of $10 to $100 per kilogram—a striking drop from the initial cost of $250,000 per gram.

With the stronger, cheaper enzyme from Codexis, the company would go on to further collaborate with aluminum producer Alcoa Inc. in 2011, to capture carbon dioxide emissions from aluminum production, and to neutralize some of Alcoa’s industrial wastes using the CO2 byproduct.

CO2 Solutions also improved its technology, making the entire process more efficient. In its new platform (Figure 1: for larger image, click on picture), flue gas flows into the absorber column on the left. This column contains the solvent infused with the super enzyme. The flue gas rises up the column, bubbling through the solvent which scrubs it of CO2. The super enzyme works like soap does in water, accelerating the purification process and increasing carbon capture by 50 to 70 times. The carbon dioxide-free gas then leaves at the top of the column.

Meanwhile, the CO2 rich solvent flows through a filtration system, which captures the enzyme and channels it back into the absorber column for reuse. The solvent then flows on into the second column, the stripper column, where it is heated to extract the carbon dioxide from the liquid. The pure CO2 is channeled out the top of the second column for compression and storage or for reuse.

“The big costs that industry faces relative to CO2 capture are the capital costs of hardware and, more importantly, the operational costs associated with the energy required to boil off the pure CO2,” says Kelly. “Without carbonic anhydrase and even with certain energy efficient solvents, the scrubber column in this model would need to be 600 metres tall, whereas ours is only 30 metres. The enzyme reduces the size of the structure required, so your capital costs come down significantly. The introduction of the enzyme allows for the use of far less solvent, requiring less energy to regenerate, so operational cost drops by as much as 40 per cent. Overall, these factors bring carbon capture well within an affordable range.”

In November 2012, the clean tech company was awarded $500,000 in funding from Alberta’s Climate Change and Emissions Corporation (CCEMC) for pilot testing in the Alberta Oil Sands.

The 12-month project will see CO2 Solutions’ technology adapted for the efficient capture of carbon dioxide emissions from oil sands production, the fastest growing source of carbon emissions in Canada.

“The reason CCEMC was put into place was to advance technologies that will allow industry to reduce its costs for carbon management and carbon capture. That’s exactly our mission in life,” says Kelly. “So for us, it’s a very strong validation of the potential of our technology.”

In terms of other future projects, Kelly sees the company’s technology being applied to more conventional, non-regulatory driven industries such as natural gas sweetening, chemical and ammonia production, and other smaller economically driven applications.

As for policy-driven large-scale emitters, in the future Kelly anticipates more regulation for emissions, with 2015 as the tipping point where industry will start installing the equipment to manage their carbon dioxide emissions.

“In Canada we have pretty ambitious federal government targets, to reduce emissions 17 per cent by 2020,” says Kelly. “To get there, we’ll need regulation. If we’re ever going to meet those targets, we’re going to have to start managing our emissions on a much larger scale than we’re doing now.”

Whether we hit this target or not, only time will tell. But CO2 Solutions is certainly poised to be a big part of the effort.

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