262 - Turning CO₂ back into fuel

This is what plants do, right? They take in carbon dioxide, add a load of sunlight, move the carbon back into their structure, output oxygen. If we waited long enough, we’d get coal, oil and gas. That is why we talk about the need to plant trees so as to reduce the levels of CO₂ and hence reduce the move towards significant climate change.

But, if we look at what it is that is most blamed for climate change then we come up with a list that includes PFCs, NO₂, CH₄ and CO₂. There are three big factors: variations in what the sun puts out, well beyond our control; changes in reflectivity of the planet—atmosphere and surface—which we have been affecting, perhaps most by reducing the areas of ice; and the greenhouse effect, for which we blame water vapour, carbon dioxide and methane, or in short form H₂O(v), CO₂, CH₄.  We are generally bothered—and aware— that being warmer tends to make processes go faster, so whatever we have out of kilter gets worse faster as things warm up. Some of the results produce negative feedback and some positive, which serves to add to the confusion in this social climate where there is so much shouting and so little thinking. For example, if we cause there to be more cloud, this generally increases reflectivity and so has a cooling effect (a negative in this context), while adding water vapour has the opposite effect. [1] is readable and sensible.

There’s a lot of fuss about atmospheric CO₂ and I’m going to direct my attention to that in this piece¹. The reason for that is demonstrated in the pie chart adjacent  (EPA, [10], with background and links). We release some 30 billion tons per year into the atmosphere through human activity. I don’t think it matters whether the unit is ton or tonne, here, since we’re at only one significant figure. What matters is the magnitude, not the precision. The accompanying graph (top, red jagged line) shows that this seems to be having a direct effect on measurable CO₂, and that goes some way towards explaining why we should be looking to do carbon capture. I’ve covered aspects of this in earlier essays.  [links at foot of page]. What is understood is that we would like to move carbon into land or ocean, so as to balance the output of gaseous carbon with a matching uptake of ‘fixed’ carbon. 

Planting trees is a good example of this, but the need is for something equivalent to the whole of the Brazilian rainforest. Quick solution? Lose a lot of human population without making the gas position worse, so a pandemic would be good, globally. Politically and socially unacceptable, though, so let’s confine this to what is feasible, non-terrorist style.

Reading The Atlantic this week—which seems to produce a lengthy article I appreciate about once per month and seems far too North America-centric for its title—I read [2], which shares news of a way of copying the plant process of moving CO₂ into hydrocarbons, possibly allowing us to make fuel from the air. The how is exciting and important, but I’m going to point you at links because I think the situation will change. There are several viable projects that have reached the prototype scale. [2], [3], [4] will set you on a browsing route.

What is relevant here is that the testing so far is has reached industrial trials and we’re looking at a cost of between $1 and $2.50 per gallon of car fuel burned to recover that same amount of CO₂, in some sense rendering that fuel carbon neutral. The magic is that this process is likely to create fuel that could go back into a combustion engine. The way the press is reporting this, the impression is left that the CO₂ is captured and new fuel is created from this at the price I just quoted, This cannot be so for several reasons I don’t think I can be bothered to enumerate but which basically condense to giving us something for nothing; my last tank fill cost me £6 per gallon². Yes, a lot of this is tax; a quick google says that ‘regular gas’ is $2.54 this week—and I’ve set up that link so you can see what it is when you read this—which is so much the same as the figure for removing the CO₂ from the atmosphere, I don’t believe they’re measuring the same thing at all. If we instead read that as the extra cost to add, then we’re looking at ‘gas’ moving to $3.50 to $5, or in the UK up to between £7 and £8 per gallon, without changing the tax structure, all of which fits well with my image of how our energy costs are spiralling¹.

What these several processes are offering is a way to reduce the output to the atmosphere of CO₂, if we can site such plant where it is that we most generate the gas. Side issue here, what are those processes?³  Some of the processes for the clean-up are being envisaged, impractically, as giant sucking machines cleaning up the air and creating, by applied magic, burnable hydrocarbons. I suggest that any practical application is going to be sited where the clean(er) result has value – a large closed space not used for growing plants. Possibly a shopping mall but more likely sited at a manufacturing facility where such gases are already produced in volume. I tried to discover useful content about what is done already about that: [8] describes possible action within the lime industry. What I learned from this was that there is a need to add value to the CO₂, such as making it a useful product for other purposes and processes; we need for the greenhouse gases to be given a value, even if that is a false one. Such a false value would be by accruing some sort of subsidy from the state by, in effect, the state buying the recovered gas or the result of any recovery process, whether that carbon capture result in storage or utilisation (CCS & CCU, in the trade jargon).  Recovery of CO₂ from fossil fuel power plants is discussed in [9], which you might afford where I won’t. 


I may have more to add as the situation develops. That is a fairly common occurrence, so if you have read this, do respond with constructive reaction and thus push me to editing and extending the content.


DJS 20181011
top pic from—among other places—hereOriginally NOAA          .
Related essays 104 on Air Quality (which might lead to 38 or 103), 106 and 177 pollution, 222 diesel is bad, 
242 revisiting plastic waste, 249 social attitudes / climate change.                I thought I’d already written at length about carbon capture but a site search (google site:scoins.net carbon capture) didn’t produce what I thought I’d written about. I may do it yet.



If you’ve heard that the fashion industry is ‘the second highest polluting industry”, this is not so and this site [7] explains how, though it is secondary reporting. More fake news at last countered. Mind, it is still a significant provider of pollution, matching, that source says the livestock industry (allegedly mostly cows farting). Which makes fashion 5th or 6th after (again, [7]) electricity and heat (24.9%), agriculture (13.8%), road transportation (10.5%), and oil and gas production (6.4%), and [..] livestock (5.4%). And fashion at 5.4% too. One can argue that fashion is already included in the previous figures. Discuss: your essay topic, not mine.

[1] https://19january2017snapshot.epa.gov/climate-change-science/causes-climate-change_.html

[2] https://www.theatlantic.com/science/archive/2018/06/its-possible-to-reverse-climate-change-suggests-major-new-study/562289/

[3] https://www.forbes.com/sites/jeffkart/2018/08/30/shine-on-dimensional-energy-turning-carbon-dioxide-into-fuel/#5da4eb2e3b5e

[4] https://www.popularmechanics.com/science/green-tech/a21251308/crazy-cheap-technology-turn-carbon-dioxide-into-fuel/

[5] https://www.theguardian.com/environment/2011/apr/28/industries-sectors-carbon-emissions

[6] http://www.ghgonline.org/co2industry.htm

[7] https://ethicalunicorn.com/2018/02/01/fashion-is-not-the-second-highest-polluting-industry-here-are-the-real-numbers/

[8] https://www.eula.eu/file/477/download?token=5izV6STs

[9] https://www.sciencedirect.com/science/article/abs/pii/S0360544296000941  Life-cycle energy balances and emissions of CO2 and other gases have been evaluated for the following systems: an LNG combined-cycle (LNG C/C), an integrated coal-gasification combined cycle (IGCC) and a molten carbonate fuel cell (MCFC) combined-cycle power-generation systems with CO2 capture and sequestration technologies.The predicted CO2 recovery and sequestration will lower the net energy ratio (which measures the total efficiency of a fossil-fuel system) by 16 to 38% for the LNG C/C system, by 21 to 57% for the IGCC system and by 17 to 56% for the MCFC system. The CO2-emission control potentials for the LNG C/C, IGCC and MCFC are in the range 64–72%, 65–76% and 57–68%, respectively. However, off-site power required for CO2 emission control increases NOx and SOx emissions by as much as a factor of 1.3 to 10.

[10]   https://www.epa.gov/ghgemissions/global-greenhouse-gas-emissions-data  supplied both pie charts copied here.  Do look, since this site goes on to show graphs of the change in GHG production (awful at 10-15% increase every year and who is doing it (China, US, all of us)



¹  So many writers on this topic use the phrase spiralling upwards; where is any circular or even cyclical element in a trend that is always upwards? I’ll agree that the atmosphere swirls around, but this is simply hyperbole.

² Brits use litres for fuel, these days, though we still, oddly, measure consumption in miles per gallon. £6.00 per gallon is £6/4.54 = £1.32 per litre, within rounding of the diesel price down at the supermarket, today.  Working that the other way, 131.9 p/litre =>£5.99 / gallon.  I also rediscovered how stupid I have been in not attending more often to tyre pressures, fixing which made an instant difference to fuel consumption—for the better. Rule of thumb: for each psi pressure below optimum, expect 0.4% worse consumption. Oh, silly me and mea culpa; clearly I have items to add to the maths extension work…

³    CO₂ is, fundamentally, produced by burning of fossil fuels. ‘Carbon’ production is covered by [5] and includes other gases. Pie chart from here. [6] points at production of cement, lime and iron & steel, which are those industries making lime and using limestone. These are certainly concentrated enough to make themselves relatively easily capable of recovering the CO₂ produced.

 However, © David Scoins 2017