Biofuels developments typically involve “two, four or more” carbon approaches (ethanol, biobutanol, or longer chain hydrocarbons in the gasoline or diesel range). Though used in biodiesel production or as an intermediate in other biofuel production processes, the one-carbon methanol is not commonly targeted as a biofuel.
Methanol has its haters, and its passionate fans. Who’s right?
A recent post by biofuels developer and commentator Robert Rapier — in his R-Squared Energy blog — re-ignited the debate last week. ” I decided to write an essay particularly devoted to methanol,” he writes.
“I was especially motivated to write this because of hypocrites who profess to be all about renewable energy and weaning the U.S. off of foreign oil – which explains their rabid support for corn ethanol – and then when the conversation turns to methanol they start to bad mouth it. When talking about methanol, hypocrites will tell you that “it is toxic.” But these people have never raised that issue over highly toxic denatured ethanol. They speculate that capital costs will be low for cellulosic ethanol but high for methanol. They complain about the lower energy density of methanol, but bring up ethanol and they will tell you all about the possibilities of designing engines to compensate for ethanol’s lower energy density relative to gasoline. Yet they don’t mention any possibility of optimizing engines for methanol. It simply has less energy. End of story.”
Although Rapier is unlikely to win any points for a kindly prose style, he hits his points hard and focuses on economics that should receive attention. “You can buy methanol today for around $1.00 per gallon. This is a big, well-established business that does not receive heavy subsidies and government support as ethanol does. On a per BTU basis, unsubsidized methanol costs $17.61 per million BTUs. You can buy ethanol today – ethanol that has received billions in taxpayer subsidies – for $1.60 per gallon. On a per BTU basis, heavily subsidized and mandated ethanol sells for $21.03 per million BTUs.”
It should be pointed out that Rapier is in the business of biofuels, not just the analysis of them, and is CTO of Merica International, a Hawaii-based holding company that consolidates the investments made by one of biofuels’ most mysterious investors, Michael Saalfeld, in companies such as Choren — and which is looking to develop a biomass-to-diesel technology in the islands. Conflict of interest? Perhaps. Inherently a refutation of methanol’s economics? In itself, no – and Rapier’s arguments should be taken on their merits. More on Merica, here.
So, what about methanol?
A lot of people refer to methanol as wood alcohol – referring to the ancient process of extracting methanol from wood, using pyrolysis. In recent years, it has been primarily extracted from methane — the primary component of natural gas, and a dangerous greenhouse gas (six times as potent, in terms of global warming, as carbon dioxide). In China, methanol is produced from coal using a BTL (biomass to liquid) technology. Biomethanol can also be made from synthesis gas (syngas), with conversion efficiencies of up to 75 percent (far more than the 25-30 percent efficiency obtained, for example, by combusting biomass for power generation). Syngas, though, is a costly technology in terms of the capital expense, and costs of $8-$10 per gallon of installed capacity are not unusual – making the financing difficult, economies of scale mandatory, and running into difficulties where biomass is costly to transport or unavailable in sufficient density within a feasible radius of the plant.
Handling/safety issues: Ingestion of 10 ml of methanol can cause permanent blindness — so handling is an issue, particularly by service station employees. It breaks down into formaldehyde and formic acid in the body, which is worse than the acetaldehyde and acetic acid formed by the breakdown of ethanol.
Performance: Methanol has cold-start problems. As an experiment some time, light a 1/4 teaspoon of gasoline and watch it combust explosively, while methanol burns far more slowly, almost difficult to ignite. It also evaporates quickly when exposed to air.
Infrastructure: Like ethanol, it is more corrosive than gasoline and requires special flex-fuel engines and parts for both cars and pumps.
Fuel economics: Though methanol is low-cost, it also has lower energy density, about 40 percent less than gasoline. So a car that travels 170 miles on straight gasoline travels 100 miles on methanol. M85 blends, or the use of methanol blends in hybrids, can mitigate.
Energy source or energy carrier: “Ulf Bossel at the European Fuel Cell Forum in Oberrohrdorf, Switzerland: “The energy carried by methanol is less than was needed to make it.”
Supporters and their perspectives
In Tennessee, Nissan has developed a methanol fuel cell pack that will be used to provide fuel for 60 tugs that transport vehicle parts at its Smyrna assembly plant. The technology provides electric power, and replaces battery chargers that used 540 MWh of electric power, generated 300 tons of CO2 emissions, and also saved 12,775 man hours used in swapping out batteries. Fuel cells can recharge a battery in one minute – compared to traditional battery charging or swapping that can take up to 20 minutes per vehicle. In a methanol fuel cell, methanol is mixed with water and fed to a fuel cell anode, where it is oxidized on a catalyst. This forms CO2, hydrogen and power. The hydrogen reacts with oxygen to produce water as an output.
In California, Nobel laureate George Olah, of the University of Southern California, has also proposed the substitution of methanol for hydrogen in fuel cell technology. He points to methanol as a proven energy carrier, compared to the “lack of an efficient way to generate and store hydrogen”.
Olah was interviewed by Technology Review on methanol’s appeal:
TR: What’s wrong with hydrogen fuel cells?
GO: Even today you could put a pump dispensing methanol at every gasoline station. You can dispense it very well without any [new] infrastructure. For hydrogen, there is no infrastructure. To establish a hydrogen infrastructure is an enormously costly and questionable thing. Hydrogen is a very volatile gas, and there is no way to store or handle it in any significant amount without going to high pressure.
TR: But methanol is a way of storing energy, not a source of energy like gasoline. Where will the energy come from?
GO: The beauty is we can take any source of energy. Whether it’s from burning fossil fuels, from atomic plants, from wind, solar, or whatever. What we are saying is it makes a lot better sense, instead of trying to store and transport energy as very volatile hydrogen gas, to convert it into a convenient liquid. And there’s a fringe benefit: you really mitigate carbon dioxide in the atmosphere.
In the UK, researchers at Oxford university have developed a low-cost method to convert CO2 to methanol — using a “frustrated Lewis base-acid” in which a pair of molecules – that would normally form a Lewis pair” in certain conditions seek out other reactions that can be utilized to produce a fuel. The conditions required by the proposed approach can be achieved on the small scale and can utilize concentrated solar technology.
In Hawaii, Professor Pat Takahashi, Director Emeritus with the Hawaii Natural Energy Institute of the University of Hawaii, wrote “Ethanol and biodiesel are dead, long live methanol!…Methanol is the only biofuel capable of being directly fed to a fuel cell. Ethanol and gasoline need to first be passed through an expensive reformer.” Intriguingly, “one gallon of methanol has more hydrogen than one gallon of liquid hydrogen” writes Takahashi in the Huffington Post.
Where is it used?
Methanol has been extensively used as a racing fuel in Indy cars.
According to the University of California at San Diego: “When used in a properly prepared engine, methanol could combust more completely than gasoline. This would result in lower levels of the exhaust emissions that contribute to urban pollution and global warming. Methanol contains no aromatic compounds and therefore produces no benzene emissions.”
In China, the national government released in December 2009 a M85 blend standard in flex-fuel vehicles and a standard for M15 in standard vehicles. Methanol is primarily used in Shanxi and Shaanxi provinces, where it is produced from coal. The country is the largest user of methanol fuels. With methanol fuel offering cost-reduction opportunities for drivers, a 2 million tonne per year illegal blending trade in the fuel has developed, according to ICIS.