Science journalism sometimes make me sigh out loud, and if you caught me reading it, you might see me visibly deflate, sinking into my padded commuter train seat with a look of anger-changes-nothing what’s-the-point despair painted across my empty sadface.
This time the source of my resignation and defeat is the magazine. I present you an article from issue 2894 of 10 December 2012, written by Bob Holmes, cleverly entitled “Less Than Zero”, with part of the O in Zero rubbed out as a design device to catch the eye (it does). The online version has the headline “Biofuel that’s better than carbon neutral”, with the subhead, “The race is on to create a biofuel that sucks carbon out of the sky and locks it away where it can’t warm the planet”
Why should the prospect of carbon-sequestrating vehicle fuel leave me so unexcited and underwhelmed ? Because of the fudges.
Fudge #1 : Carbon dioxide concentration levels
“The green sludge burbles away quietly in its tangle of tubes in the Spanish desert. Soaking up sunshine and carbon dioxide from a nearby factory, it grows quickly. Every day, workers skim off some sludge and take it away to be transformed into oil…”
This first paragraph is about algae being grown using concentrated industrial carbon dioxide from a nearby cement factory. The second paragraph confuses algae oil production using high levels of carbon dioxide with growing biomass in normal air with normal levels of carbon dioxide :-
“Indeed, this is no ordinary oil. It belongs to a magical class of “carbon negative” fuels, ones that take carbon out of the atmosphere and lock it away for good. The basic idea is fairly simple. You grow plants, in this case algae, which naturally draw CO2 from the atmosphere. After you extract the oil, you’re left with a residue that holds a substantial portion of the carbon…”
Let’s get this straight – the algal oil production of the first paragraph does not belong to “a magical class of “carbon negative” fuels…that naturally draw CO2 from the atmosphere.” In the first paragraph, the algae is being grown using industrial concentrations of carbon dioxide, not atmospheric concentrations of carbon dioxide.
Fudge #2 : Net carbon dioxide emissions
The algal biodiesel oil being produced in the first paragraph depends for its growth on carbon dioxide that would have been vented to the atmosphere from a “carbon positive” process – in other words, from a process that is a source of net greenhouse gas emissions to air. The algae grown using this diverted carbon dioxide will only temporarily capture this carbon dioxide – as (most of it) will be released again when it’s burned as fuel.
There is no way that the algal biodiesel oil mentioned in the first paragraph can be “carbon negative”.
Confirmation of this comes later on in the article, when actual representative numbers are used :-
“…Bio Fuel Systems, (BFS) a small company in Alicante, Spain, that uses cyanobacteria to make its “Blue Petroleum”…The numbers given to New Scientist by BFS president Bernard Stroiazzo illustrate the fraction of carbon that can be trapped by the process. To make a single barrel of oil, the algae suck a little over 2 tonnes of CO2 from the smokestack of the cement works. Not all of that stays out of the atmosphere, though. The algal cultures need regular mixing, which takes energy, as does supplying fertiliser and creating the oil through a patented process involving high heat and pressure. All the fossil fuels needed for these processes release about 700 kilogrammes of CO2. Burning the oil itself – in car engines, say – emits another 450 kg. The rest of the carbon – the equivalent of about 900 kg of CO2 – stays in the leftovers, an inorganic carbonate sludge that can be buried or mixed into concrete. “That will never go back in the atmosphere,” says Stroiazzo…”
So, let’s unpack that.
a. The cement works emits 2,000 kilograms of carbon dioxide that is captured for the algae growing process. These would have been direct greenhouse gas emissions to air had they not been diverted. So at this point we are 2,000 kg “carbon negative”.
b. Supplying fertiliser (which may or may not include accounting for manufacturing and transporting fertiliser) and making the oil through their patented pyrolysis (high heat and pressure) technique, causes 700 kg of carbon dioxide emissions (not to mention the carbon embedded in the equipment required). The numbers do not specify whether other kinds of greenhouse gas emissions are implicated, so let’s just stick with carbon dioxide. Subtacting this from the previous number makes us 1,300 kg “carbon negative”.
c. Burning the oil in engines releases another 450 kg of carbon dioxide. That makes us 850 kg “carbon negative”. Apparently this is “the equivalent of about 900 kg of CO2”, which is in the “leftovers”, which can be buried or used in hardcore or surfacing material.
So, a total of 2,000 + 700 + 450 = 3,150 kg of carbon dioxide is emitted, and only, say, 900 kg of carbon dioxide is sequestered. That’s around 29% of the total of the emissions, and at first glance, that looks rather good, but it disguises something. The 700 kg of emissions that were caused by the processing of the algal biofuel were unnecessary, and only 900 kg of the carbon dioxide is left sequestered at the end. That’s not a very good trade-off. In fact, that’s a very poor efficiency of overall carbon capture.
Fudge #3 : Dependency on industrial sources of concentrated carbon emissions and heat
And none of this would work without a source of concentrated carbon dioxide. “A few companies are developing technologies to extract and concentrate CO2 from the air. Global Thermostat, based in New York, has patented a process that uses chemicals and low-temperature waste heat – about 90 °C – to capture CO2 from a stream of air. Its pilot plant has been operating near San Francisco for more than a year, and a second is on the way, says co-founder Graciela Chichilnisky. The company has already signed an agreement to supply its technology to Algae Systems and is in talks with several other algal biofuel companies, she says.”
From the Global Thermostat website, under the heading “Exclusive Benefits”, “Highly flexible location – GT technology can be located anywhere – the only inputs needed are heat and air”. What this actually means is that the DAC (direct air capture) system being developed can only operate on the back end of an industrial facility. So this “GT technology” is only parasitical.
Fudge #4 : Not addressing the problem at the source
In the final paragraph of this article, Bob Holmes writes, “Since we can’t seem to keep the CO2 from entering the atmosphere, we’re left with only two ways to avoid trouble. We could embark on grand geoengineering schemes to cool the planet, all of which bring huge risks of unintended consequences (New Scientist, 22 September, p 30). Or we could try to pull some of the CO2 back out of the atmosphere, one car trip at a time…”
I would challenge him on that statement “…we can’t seem to keep the CO2 from entering the atmosphere…”. The alternatives are rather poor in terms of efficiency and potential harmful side effects. In all of this article there is no attempt to address whether all the carbon dioxide and heat coming from the industrial facility, and the transportation that requires low carbon fuels, are “necessary” in the first place – if consumer demand, globalised trading patterns and industrial processes were streamlined, the global economy could reduce its greenhouse gas emissions and waste heat output without the need for inefficient tinkering.
Fudge #5 : Progress is not as good as it seems
“…To date, the research facility has produced only a few thousand litres of fuel. However, a pilot plant – bankrolled by investors including Google, BP and GE – will start operation near Los Angeles this month… Cool Planet’s results are encouraging…”Even if carbon-negative biofuels turns out to be just a bit player, they will have done at least a little to reduced carbon emissions.”…”
Ah…BP. The oil and gas giant that distracted us away from their highly polluting hydrocarbon fuel production by setting up a solar power business.
It’s just more greenwash.