The race to capture, use and monetize waste CO2

March 5, 2014 |

Badger-State-Ethanol.1Reduce carbon? Rid the world of excess CO2? Not so fast, buster. 

A new generation of technologies has come along that capture, re-purpose and monetize CO2 emissions. 

Will they realize their promise? As Liquid Light steps out of stealth and into the light, the state of the art is looking pretty good.

If you have watched the debate over carbon emissions for a reasonable length of time, you may have asked yourself why technologists and governments are so intent on preventing carbon emissions by transitioning away from fossil fuels, when they might just capture any CO2 at the point of release and do something useful with it, or simply store it.

The short answer to your question is that technologist are working on it — furiously. Venture capital has been funding efforts, and research labs have been hard at work as well.

Many technologies that have emerged have been biobased — using the CO2 fixing capability of plants and microbes. We’ve closely followed, for example, the story of a slew of algae tecnologies, plus more exotic technologies such as Proterro and Joule Unlimited, which use CO2, water and sunlight to directly build alkenes and alcohols (in the case of Joule), and sugars (in the case of Proterro). LanzaTech, which uses carbon monoxide in its process, is also hard at work for breakthroughs using CO2.

The limitation? There’s only so much CO2 that a plant or microbe needs (or can take), and the acreage needed for systems can be daunting, and exposes companies that need to get rid of CO2 into a complex supply chain.

And so we enter the world of two less-familiar acronyms — carbon capture and storage (CCS) and carbon capture and usage (CCU). Capture is not much of a problem any more. The problems with technology developed to date are: for the former, the storage is impractical and unaffordable; with the latter, the reactivity rates have been too low to make any conversion technology viable.

The trouble with carbon dioxide

The trouble with CO2 is that, at the end of the day, it is as (chemically) dull as a stump — about as reactive as a Pet Rock. You see, if we happened to be emitting hydrogen like crazy, it naturally binds itself (cost free) into a range of molecules depending on what’s around (no free hydrogen floating around, which is another topic for another day). Carbon monoxide is also highly reactive — and that’s why most modern automotive tailpipe systems have a built in catalytic converter that alters poisonous carbon monoxide into CO2.

But getting the reactivity out of CO2 is like keeping Grandpa awake during a piano recital.

Addressing the problem with new catalysts

This week, in Nature Chemistry, a team out of Stanford reported the development of new catalysts for converting CO2 (and hydrogen, possibly green hydrogen) into methanol. Scientists from Stanford University, SLAC National Accelerator Laboratory and the Technical University of Denmark combined theory and experimentation to identify a new nickel-gallium catalyst that converts hydrogen and carbon dioxide into methanol with fewer side-products than the conventional catalyst.

“Methanol is processed in huge factories at very high pressures using hydrogen, carbon dioxide and carbon monoxide from natural gas,” said study lead author Felix Studt, a staff scientist at SLAC. “We are looking for materials than can make methanol from clean sources, such as sunshine, under low-pressure conditions, while generating low amounts of carbon monoxide.”

Who’s in the lead? Consider the case of Liquid Light

And even more interesting, a small company funded by BP Ventures, Redpoint, Osage University, VantagePoint and Chrysalix is coming out of stealth after six years of developing a technology to convert CO2 into an array of speciality chemicals at reactivity rates — and thereby costs — that not only make it attractive as a carbon remediation, but in this case actually lower the cost of carbon compared to using fossil oil & gas in the first place.

The company? Liquid Light, which is just now emerging out of stealth mode.

The goal? Create a (licensable) chemical process that can utilize carbon emissions that actually come from the chemical plant itself — and make an array of chemicals through electrochemical processes and catalysis.

“One of the most expensive inputs for chemical companies,” said Liquid Light CEO Kyle Teamey, in speaking with the Digest, “whether they are getting it from oil, gas or biomass. So, why not repurpose a waste source of carbon, where you get large economic and environmental advantages?”

“Plus, those sources are difficult to hedge and unpredictable. By using local emissions, the customer owns that CO2 and controls the cost of carbon.”

Targeting monoethylene glycol (MEG) to start

Liquid Light’s first process is for the production of ethylene glycol (MEG), with a $27 billion annual market, which is used to make a wide range of consumer products such as plastic bottles, antifreeze and polyester clothing. Liquid Light’s technology can be used to produce more than 60 chemicals with large existing markets, including propylene, isopropanol, methyl-methacrylate and acetic acid.

For example, this process requires $125 or less of CO2 to make a ton of MEG (based on a CO2 cost of $75-$80 per ton) Other processes require an estimated $617 – $1,113 of feedstocks derived from oil, natural gas or corn. These differences are especially significant as MEG sells for $700 – $1,400 per metric ton. Source of the hydrogen in this case varies — organic molecules can be used, or water.

Based on lab data, the company is projecting that a 400kT per year Liquid Light MEG plant would offer more than $250 million in added project value as compared to a plant built using the best currently available process technology. A 625kTa plant would have a 15 year net present value of over $850 million to a licensee.

The Liquid Light prototype reactor cell

The Liquid Light prototype reactor cell

The core technology

Liquid Light’s core technology, developed initially based on licensed processes from Princeton and substantially enhanced since then, is centered on low-energy catalytic electrochemistry to convert CO2 to chemicals, combined with hydrogenation and purification operations. By adjusting the design of the catalyst, Liquid Light can produce a range of commercially important multi-carbon chemicals. Additionally, by using ‘co-feedstocks’ along with CO2, a plant built with Liquid Light’s technology may produce multiple products simultaneously.

The company’s technology is not aimed at capture — it would work with any existing carbon capture strategy. It’s goal is to be logistically simple and low cost — a drop-in complement acquired on-site and used on-site, at a relatively low cost.

The carbon cycle

Liquid Light’s process can sequester carbon – meaning it is a net reducer of carbon in the environment – when using energy sources like solar, hydro, wind or nuclear power. To further demonstrate this potential benefit, the company also showed the process can be powered by intermittently-available renewable energy sources like solar and wind. The result is that chemicals can be made directly from renewable energy sources and CO2.

Working with carbon sources

“Depending on the goals of the customers, in this portfolio of technologies, some processes can work with pretty impure CO2,” noted Teamey. “The lowest we’ve seen so far is 20%. Some require more pure CO2, but in general we are using pipeline purity levels of CO2 rather than lab grade purity.

The secret sauce

Is it in the process or in the catalysts? “We can’t have one without the other,” Teamey told the Digest. “But the catalyst piece is probably more fundamental, allowing us to make multiple carbon chemicals.

Timeline to scale and commercialization

Think 2017-2018 for the company to be ready for deployment of large-scale systems. The company is at lab-stage and completed a commercial prototype — now it will be proceeding to build its pilot reactor and then a demonstration of the complete reactor cell and all components.

One item to note — as has been a trend in recent years, this is a modular design where multiple reactor cell units are stacked together — so scale-up has far less risky steps (as in the case of fermentation technologies, where there is the step-up to larger and larger fermenters).

The biobased companies have, in some cases, a time advantage in that they are already at pilot, demonstration or commercial scale. This technology has some distinct advantages for chemical companies in being a chemical process (no need to learn to deal with biology, onsite) and currently targets one of the largest markets in the chemicals business in MEG. SABIC is the world-leader on this one, but BASF, Shell, and Dow are just a few of the world leaders active in this molecule.

A cautionary note

In traditional processes. MEG is generally made from ethylene oxide, made itself from ethylene and ultimately from ethane (or naphtha). Which puts this technology squarely in the middle of the shale gas revolution. To the extent that companies like Dow are investing in ethane crackers aimed at utilizing shale gas feedstock, we may find, in the North American markets, less interest in MEG production from CO2. But control of the feedstock from end to end — well, that’s a goal, too, and companies like Toyota Tshosho have been pursuing a MEG strategy around that very idea.

Plus, there are all those ripe Asian markets where low-cost gas (and thereby carbon) has not yet found its way.

Not to mention that the world is just leetle bit short of hydrogen.

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