Industry accounts for about 40% of the world’s greenhouse gas emissions. The chemicals industry, with 6-7% of greenhouse gas emissions, is the dirtiest industry.  A startup called Solugen has discovered new processes using biocatalysis that eliminate emissions.

Part of the chemical industry’s problem is the process of manufacturing chemicals. It releases the potent greenhouse gases methane and oxides of nitrogen. Also, chemical manufacturing plants produce their products far from the end users. So transportation and the supply chain add even more emissions.

Basically, chemical companies buy feedstock and run it through some kind of process to make a product. Perhaps they start with some kind of fossil fuel as a feedstock. Their processes operate at high heat and pressure to produce the intended product and a lot of unintended wastes.

But perhaps they start with, say, corn and ferment it to make, say, ethanol. Only half of the corn becomes ethanol. The rest becomes carbon dioxide.

What is biocatalysis?

Catalysts matter in manufacturing. About 90% of chemical products rely on using catalysts in some part of the manufacturing process.

Biological processes within cells likewise rely on catalysts. And like everything else natural, biological catalysis works more efficiently and less wastefully than human chemical imitations. Biocatalysis, then, is the attempt to put these natural processes to work in manufacturing.

In the body, proteins act as enzymes, which are catalysts. That is, enzymes have two basic properties: They speed up chemical processes without being consumed in the reaction and also without changing the equilibrium between the reactants and what they produce.

The molecule an enzyme acts on is called the substrate. The enzyme bonds to the substrate, and something happens to the substrate but not to the enzyme. It can be reused to speed up other reactions of the same kind.

Enzymatic activities are not constant. The body regulates them so that they function appropriately to meet whatever needs arise during the life of the cell. Manufacturing using enzymatic catalysis operates similarly both in producing new compounds and breaking down compounds no longer needed.

Molecular biology and biotechnology have advanced enough over the past two decades to produce biocatalytic reactions that have not been observed in nature. With protein engineering, one of several kinds of biological catalysis, scientists define parameters and develop enzymatic transformations to fit them.

Using a natural process to produce something not existing in nature does not waste anything. It eliminates waste products. After all, nature uses everything it produces. Biocatalysis, with its engineered enzymes, is therefore a green and sustainable technology. It has also proven cost effective. It is now widely applied to making pharmaceuticals, as well as some commodity chemicals.

Biocatalysis and traditional metal catalysts are not alternatives. They can work together.

What is Solugen?

Sean Hunt, a chemical engineering student at MIT, and Gaurab Chakrabarti, a medical/PhD student studying pancreatic cancer at the University of Texas Southwestern Medical Center played poker regularly while Hunt dated Chakrabarti’s lab partner.  As they got to know each other, they decided to try to combine their two approaches.

Hunt and Chakrabarti started Solugen in 2016 upon winning a $10,000 grant from MIT. Using PVC pipes and other off-the-shelf supplies, they started making hydrogen peroxide.

The owner of a float spa business heard their pitch to MIT and wanted to buy their product to sanitize water more sustainably. He posted it to a Facebook group that other float spa operators belong to. Solugen therefore made its first money in this niche market.

A float spa is a dark and soundproof tank of warm water with a high concentration of Epsom salt. The salt makes it easy for people to float on their backs. It also helps dull pain and relieve stress. The absence of sight and sound encourages a quiet, meditative state. The experience, which is both pleasurable and therapeutic, lasts about an hour. The float spa operator must then treat the water to make it safe for the next customer.

As academics, Hunt and Chakrabarti could have come up with all kinds of neat ideas that would remain buried in academia and never become commercially successful. But they took their ideas to Y Combinator, a technology startup accelerator.

As Hunt described it, the accelerator “beat the overly academic side out of us.” In consulting with the founders of other Clean Tech 1.0 companies, they concluded that building a good distribution network mattered as much as inventing a good process.

Building a viable biocatalysis business

Solugen’s chemienzytmatic processes combine chemistry with synthetic biology. From chemistry, they use metal catalysts. From synthetic biology, they use engineered enzymes.

The chemical industry relies on four basic reactions. One, called carboxylation, subjects natural gas to carbon monoxide at 100 times atmospheric pressure. It accounts for about 25% of consumer products. Nature’s comparable and more efficient process use carbon dioxide.

The other reactions are oxidation, reduction, and dehydration. So far, all of Solugen’s products rely on oxidation. The company intends to fully exploit their potential before exploring how to use other reactions.

Chakrabarti found an enzyme in pancreatic cancer cells that produces hydrogen peroxide when he was in medical school. He persuaded Hunt to explore how enzymatic catalysis could improve chemical manufacturing.

So Solugen’s first product was hydrogen peroxide. The ordinary way of making this very simple chemical is convoluted, flammable, and highly toxic. Transporting it likewise has a huge carbon footprint.

By 2019, Solugen’s plant in Houston made 10 tons of hydrogen peroxide every day, with useful organic acids as a byproduct. It has since enlarged its plant, which Hunt and Chakrabarti call a Bioforge. It is built on the site of a former petrochemical plant that had exploded and burned for seven hours.

The Bioforge runs on wind energy. It has no emissions and no wastewater discharge. In only five years, Solugen has scaled up its factory to produce 10,000 tons of hydrogen peroxide per year with biocatalysis. The next fastest plant to scale up to that size took 15 years.

Where most plants with Solugen’s output occupy about 20 acres of land, the Houston Bioforge occupies less than half an acre. It will be able to build additional Bioforges much closer to their customers than other chemical companies can. Such proximity minimizes transportation and supply chain issues.

A new unicorn

In September 2021, Solugen became a Climate Tech unicorn. That is, it is a privately held startup worth more than a billion dollars (unicorn) in the green space. It achieved that status by raising $350 million in new funding. It aims to become the world’s first carbon negative chemical company.

Solugen makes end products manufacturers can use, not just ingredients for other chemical companies. It has achieved unicorn status only by extracting as much value as possible from one set of molecules rather than simply hand them off to someone else. And these products are actually less expensive to make than comparable products made from fossil fuels.

Concentrating on scaling up one biocatalyhtic process and selling one product made them profitable early on. Too many other startups try to take on too much at once. One profitable product makes it easier to expand to others a few at a time. The first new products use the same basic process. A successful product line makes it easier to expand to other processes.

From water treatment, Solugen has expanded to agriculture, cement, energy, and food and beverages. Its sales teams first market to small and medium-sized companies. Success there catches the attention of Fortune 500 companies. Also, they market based on performance, price, and safety. Sustainability claims for biocatalysis come only after they can prove them based on their customers’ experience.

Solugen claims to be carbon negative in the water and concrete industries and carbon neutral in others. For example, it sequesters 1.5 pounds of carbon dioxide for every pound of glucose it makes.

A full life cycle assessment of their first Bioforge, in Houston, shows that in making 10,000 tons of products every year, it offsets or sequesters 30,000 tons of carbon dioxide equivalents. (Measurement of the effect of all greenhouse gases involves mathematically converting each one to the effect of carbon dioxide.) The company plans to add another 100 Bioforges worldwide in the near future.

But nothing’s perfect

Solugen’s feedstock, corn syrup, is an agricultural product. Agriculture has its own environmental problems in growing crops and distributing them. What’s more, the syrup comes from a crop that could otherwise feed people or farm animals.

Ideally, usable sugars would come from cellulose. Cellulose can come from non-food crops such as switchgrass, which grows on land unsuitable for food crops. Or it can come agricultural waste Some research labs can already make glucose from agricultural waste way less expensively than they can buy it. But, of course, they don’t operate at industrial scale.

Someone, maybe even Solugen, will eventually find an economical way to derive sugars and alcohols from cellulose. But maybe not anytime soon. Once Solugen and biocatalysis come to the attention of the general public, I wouldn’t be surprised if some of the more mindlessly anti-corporate environmentalists turn up their noses at agricultural processes and accuse Solugen of greenwashing.

Humans have yet to make anything that has no downside. In the meantime, if sugars can replace fossil fuels as feedstock for chemicals, it will make the chemical industries much less bad than they are now.

Sources:

The central role of enzymes as biological catalysts / in The Cell: A Molecular Approach, 2nd ed, by Geoffrey M. Cooper, 2000
Cleaning up hydrogen peroxide production / Zach Winn, Chemical Online. September 5, 2019
Climate Tech’s newest unicorn makes chemicals from sugar, not fossil fuels / Adele Peters, Fast Company. December 10, 2021
Role of biocatalysis in sustainable chemistry (abstract) / Roger A. Sheldon and John M. Woodley, Chemical Review. September 6, 2017
Solugen, Climate Tech’s newest unicorn / Climate Tech VC, September 10, 2021
Solugen raises $357 million for its ‘chemienzymatic’ approach / Michael McCoy, Chemical & Engineering News. September 10, 2021