Carbontech

Sucking carbon out of the air to make fuel is now a viable thing, and a small plant in Squamish, BC is the testing ground – but the technology is not without its critics

Gavin MacRae

Photo by Geoffrey Fairchild CC, cropped from original

The ability to cost-effectively vacuum carbon dioxide out of the air and turn it into carbon-neutral fuel went from theoretical to viable this summer. The development could lead the way to dramatic changes in the way we tackle climate change, but the technology is not without its critics.

Direct air capture (DAC) is a technology that removes carbon dioxide from the atmosphere. Carbon Engineering, a Calgary-based company, has managed a huge drop in the price of processing carbon from the air – from a previous benchmark of US$600/ton to potentially under US$100/ton. This means DAC has gone from being experimental to something that could be developed to commercial scale right now. Carbon Engineering’s founder David Keith and others documented their breakthrough in the journal Joule, garnering accolades for transparency in sharing proprietary technology.

Carbon Engineering’s small test plant in Squamish, BC, is the proving ground for the price drop. At its heart the plant is a compilation of established industrial processes borrowed from other industries. Despite using known technologies, the project took 100 person-years of work, deep collaboration with machinery vendors, and “an immense amount of development on apparently trivial items.”

Carbon Engineering believes larger plants using their technology could capture one million tons of CO2 per year, equivalent to the yearly emissions of 250,000 cars.

A second and distinct part of Carbon Engineering’s technology is the creation of carbon-neutral hydrocarbon fuels. “Carbon-neutral hydrocarbon” sounds a tad absurd, but it works like this: the CO2 emitted into the air when the fuel is burned has already been pulled from the air to make the fuel – effectively making a closed loop.

Carbon Engineering believes larger plants using their technology could capture one million tons of CO2 per year, equivalent to the yearly emissions of 250,000 cars.

For Carbon Engineering, the fuels create a market for the CO2 they pull out of the air, which would be competitive in jurisdictions with mandated low-carbon fuel standards. Made by combining the harvested CO2 and hydrogen, the fuels emulate gasoline, diesel, or aviation fuel. The key to making these fuels carbon-neutral lies in using renewable energy sources, both to power the DAC, and to create the hydrogen by water electrolysis.

It slices, it dices

So what should we use this technology for?

At first glance the answer would seem “to fill my car,” but with electrification of transport taking off, trying to keep gasoline-powered cars relevant in the years ahead could be a losing battle. Chris Goodall, an expert and author on new energy technologies, said the growth rates of electric vehicles are so high, and the commitments by manufacturers so great, electrification of ground transport is “unstoppable.” Producing carbon-neutral gasoline to fuel personal cars would mean a convoluted series of steps to get the same result as simply charging an EV from a renewable energy source.

Two obvious targets for carbon-neutral fuel are aviation and marine shipping, which have both struggled to enact meaningful carbon cuts. These are stubborn industries that require the high energy density of hydrocarbons, or have such long turnover in infrastructure that they require a “bridge” to decarbonize in the short term.

Energy carrier

Goodall also sees huge potential for Carbon Engineering’s fuel as a long-term storage medium for renewable energy.

Renewables, although still a modest percentage of total global energy supply, are growing quickly, and their cost continues to fall. Because of the intermittency of renewable energy, at times there are periods of oversupply.

Goodall believes using the surplus energy to split water molecules, and cull the freed hydrogen, is the best way to save the energy for future use. This could be done by electrolysis (inducing an electrical current into the water). The resulting hydrogen becomes an “energy carrier,” holding the energy in a stable form.

The second step would be to convert the hydrogen into hydrocarbon fuel using Carbon Engineering’s technology. When the sun isn’t shining or the wind dies, the fuel would power turbines to create electricity.

The versatility, ease of storage, and compatibility with existing infrastructure would give liquid fuels an edge over straight hydrogen or other long-term energy storage concepts.

Carbontech

Atmospheric CO2 harvested using DAC has many uses beyond carbon-neutral fuels. Building materials, chemicals, plastics, concrete, fertilizers, and even vodka could all be formed from, or made lower-carbon with, CO2 from the sky. Conceivably any product made from fossil fuel feedstocks could be fair game. This technology, using waste carbon to create products, is called carbontech.

Matt Lucas, Associate director of the Center for Carbon Removal (now Carbon180), sees carbontech as the key to unlock a paradigm shift in how we think of and use carbon, and a way to revitalize manufacturing that is both profitable and climate conscious.

The potential market for carbontech has been estimated at around one trillion dollars, and vast untapped profits mean DAC and carbontech could enjoy widespread political support. “We need to talk about carbon as an economic opportunity,” said Lucas, “not just as a liability and a thing to be mitigated, the way we’ve been talking about it thus far.”

Negative emissions technologies

DAC can also be used for carbon capture and storage, without creating fuels or other products with the carbon. In this scenario the carbon is sequestered in depleted oil or gas wells, or underground aquifers. Using DAC this way would make it a negative emission technology.

With the window quickly closing to meet Paris Agreement targets, it’s looking very likely we will not only have to stop dumping carbon into the atmosphere, but we are also going to have to start taking it out. This is what negative emissions technologies (NETs) do.

NETs can be conceptually very different from each other, but they all have the end result of taking carbon out of the atmosphere or the oceans and locking it away in the earth. The Intergovernmental Panel on Climate Change have many modeled pathways to meeting Paris goals which rely on negative emissions – according to critics a little too much.

Is there a catch?

Some observers have reservations about negative emissions. An article in Science by research scientists Kevin Anderson and Glen Peters typifies the rationale. Anderson and Peters argue relying on unproven negative emissions technologies in the future allows policymakers to avoid politically and economically tough climate policy in the present. This reliance on a techno-fix down the road constitutes a “moral hazard” and an “unjust and high-stakes gamble.” Critics also note that negative emissions are more expensive, ton-for-ton of carbon, than reducing emissions.

In a written rebuttal, scientist Klaus Lackner and 45 other signatories argue that the critics provide no evidence that negative emissions technologies are having any effect on the pace of climate mitigation efforts or the failure of countries to cut emissions. Shelving negative emissions technologies, they wrote, would remove “important options for mitigating and ameliorating climate change.”

“Even if you magically flipped a switch and turned off all the emissions today, we’ve emitted so much carbon into the atmosphere, and locked in so much climate change, that we’re going to need to do negative emissions anyhow.”

DAC is able to sidestep much of the controversy since it doesn’t use large areas of land, require sustainable biomass, or have potential impacts on biodiversity, as bio-energy with carbon capture and storage does (where biomass is grown to burn for energy and the carbon released  is then captured and stored).

Goodall and Lucas are both well-acquainted with the arguments for and against negative emissions.

Goodall said he’s pessimistic about the world solving climate change unless decarbonizing technologies harness capitalism. “I believe that self-restraint, tough measures to reduce carbon emissions per se are actually less effective than pushing the technology as hard as you can to make it economically viable, make it economically beneficial to use zero carbon technologies for the creation of fuels.”

Lucas explains DAC is part of a suite of necessary measures regardless of ideological arguments. “Even if you magically flipped a switch and turned off all the emissions today, we’ve emitted so much carbon into the atmosphere, and locked in so much climate change, that we’re going to need to do negative emissions anyhow.”

“I would never advocate for slowing down decarbonization because we have negative emissions,” Lucas adds, “but I think the bigger concern is that the [climate] models say that we need negative emissions, and nobody’s working on it.”

Both camps in the negative emissions debate agree on one point: NETs should be used as an adjunct to decarbonization. Used this way, DAC could make a versatile compliment to aggressive carbon cuts, a sort of plucky sidekick used to solve tough-to-decarbonize trouble spots and undo the damage we’ve already done – as long as our main focus is kicking fossil fuels to the curb.

If, however, the public or policymakers believe negative emissions technology can be used as a brute-force tool to “reverse” climate change without decarbonizing, the critics will be proven right.


Gavin MacRae is a writer suffering mild eco-anxiety as a side effect of recent fatherhood. He is also WS’ new editorial assistant, and lives in the Comox Valley.

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