Carbon Reuse

A Holy Grail for many for climate-mitigation efforts is “carbon capture and sequestration” or CCS.  This offers a ‘have your cake and eat it too’ vision related to fossil fuel use.

In short, rather than eliminating the burning of fossil fuels (mainly coal in this case), lets figure out how to capture carbon dioxide (in the smokestack) and ‘sequester’ that CO2 back where we dug it up from originally.  Somewhat like fusion or hydrogen vehicles, the CCS Holy Grail is used by many as sort of a panacea. “Tomorrow’s exciting technology” to distract attention from already available opportunities to drastically change our collective emissions and climate impact profile (from energy efficiency to renewables to better land use, etc).

To be clear, we should invest in creating and developing ‘solutions’ for implementation tomorrow even as we invest in deploying things that are already available.  Thus, this brief commentary is not some Luddite manifesto objecting to fostering innovation to increase tomorrow’s toolbox of solutions but a discussion of how we can/should think about CCS in a more productive way.

With that disclaimer out of the way. CCS is not the best mental structure to apply to the challenge and opportunity of capturing carbon.  The issue is “S”: sequestration. Sequestration treats CO2 as a waste product and, just like carting trash to a landfill, will create significant cost streams (transporting CO2 to sequester locations, sequestering it, and monitoring) with significant risks (what if sequestered CO2 is released?).  High cost, high risk, and with no direct benefit streams to those paying for the costs.

But, if we change that last letter, we might have something far more interesting.  As put here in discussing some innovative technologies:

  • Hy-tek Bio captures exhaust from burning fossil fuels uses this as food for algae growing in tubes. Their system has multiple innovations that look to create viable paths toward cost-effective CCR rather than the overhyped CCS (carbon capture and reutilization vs carbon capture and sequestration).

As we invest to create tomorrow’s opportunities to mitigate (and adapt to) climate change, we should look for win-win-win solution sets.  Treating CO2 as waste is more of a win-win-loss structure: a win (reduced carbon emissions) – win (increased business throughput for some firms and increased income for some communities) – loss (increased cost per energy unit and increased risk).

Looking to that CO2 as a resource with value can shift that WWL to a WWW. What are some paths for ‘reuse’ of that CO2 which could be focused on for innovation, demonstration, and deployment support?

  • Agrichar / Biochar / Terra Preta: Very simply, we have the potential for a carbon-negative fuel that will, over time, also foster improve fertility in soil.  Very simply, gasification of biomass can be combined with agricultural practices to create energy, have the waste plowed back into the soil to improve fertility (while reducing fertilizer requirements), and have some of the carbon from each of these cycles captured in the soil.  “[T]he great advantage of biochar is that the technique can be applied world-wide on agricultural soils, and even by rural communities in the developing world because it is relatively low tech.” This is a highly promising arena that is getting attention, but perhaps not enough.  For some additional discussion, for example, see: Biochar: The New FrontierThe pay dirt of El DoradoInternational Biochar InitiativeBirth of a New Wedge; and Terra Preta for Carbon Reduction.  When it comes to CCR innovation research, could there be ways to leverage CO2 from smokestacks to enrich other soils in a biochar-like manner.
  • Liquid Fuel production:
    1. The S. Navy (Office of Naval Research) is doing work to make synthetic fuel from sea-water.  One of the prime ‘resources’ from that sea water?  Carbon from CO2.  Could this be developed in such a way to enable turning high-density CO2 streams from carbon capture in smokestacks to liquid fuels?
    2. Algae/other fuel stocks w/CO2:  A CCR Holy Grail is to have algae farms taking in CO2 from smokestack emissions as a nutrient source and then convert that CO2 to energy. (As the CSMput it a decade ago, “Algae: like a breath mint for smokestacks.)
  • Carbon-fiber / Carbon-fiber nanotubes: From bicycles to airplanes carbon-fiber is finding ever more uses across the global economy. The ‘next’ step is coming with carbon-fiber nanotubes. Carbon-fiber nanotubes have great structural strength and offer a path for extremely efficient, light-weight, and incredibly safe movement of electricity. The carbon-fiber nanotube offers the potential for combining structural strength with electricity movement. Imagine eliminating copper wiring from satellites — saving weight (just how valuable is a pound of weight in space), freeing up interior space (again, what is cubic centimeter’s value 23,000 miles above the earth’s surface?), and improving structural strength. As we learn and reduce costs, this equation moves to aircraft, to automobiles, to portable electronic devices, to our built infrastructure. The copper mining industry is a meaningful share of global emissions. Could carbon capture and reutilization to make carbon-fiber nanotubes provide a path to move the global economy away from using copper for things beyond beautiful kitchen utensils?  Every avoided ton of copper use roughly equates to five tons of avoided mining emissions.

Note that CCR does have issues. First, the above ideas and other arenas require investment to make them viable realities — they are not ‘there’ yet for serious climate mitigation benefits.  Second, to the extent that they rely on capturing emissions from smokestacks from fossil fuel burning facilities they are only ameliorating/reducing the worsening of our climate problems. These CCR methods would reduce additional emissions that reach the atmosphere — not directly reduce current levels or eliminate emissions altogether.

We cannot afford to treat resources as waste — that is what CCS does. CCR flips the equation from CCS’ high-cost and high-risk path to something that could turn out to be net positive and low risk.  Which sounds more appealing to you?

A version of this post first appeared here.

Image credit Wikimedia Commons. 


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