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Methanol is a CO2 Utilization Pathway

Methanol has been largely overlooked in the biofuels debate, perhaps that is because that is because it is typically produced from coal and natural gas and is often considered a fossil fuel product. But it is more accurate to think of methanol as a synthetic fuel that can be produced from all manner of carbon based feedstock including carbon dioxide (CO2). Methanol is the simplest and cheapest synthetic fuel molecule and is known as wood alcohol because it was produced from biomass for centuries. Modern production techniques now allow us to directly utilize CO2 captured from industry in the production of methanol to create fuels that have reduced fossil carbon content, zero fossil carbon content, and plastics that offer permanent carbon sequestration.

Methanol is simply methane plus one oxygen atom. Methane is CH4 and methanol is CH4O (or more accurately, CH3OH). Methanol occurs naturally in the environment, but commercial quantities have always been produced synthetically using a wide variety of feedstocks, primarily coal and natural gas, but also wood. One of the most productive pathways is to react methane with carbon dioxide to form methanol. In other words, take the two greenhouse gasses that are of the most concern for climate change and react them together to form a stable liquid that can fuel all energy sectors, heat, power and transportation, while also providing feedstock for plastics and chemicals.

methanol

Methanol: CH3OH

 

When natural gas (methane) is used to produce methanol it is usually reacted with steam (H2O), but this process creates an excess of hydrogen (CH4 + H2O -> CH4O + H2) that is typically used for process heat. If an inexpensive source of CO2 is available it can be included in the reaction to absorb the excess hydrogen boosting yields and productivity of the overall process. Reacting carbon dioxide with methane to form methanol is already an existing commercial process.

Another pathway for producing renewable methanol (biomethanol) from carbon dioxide uses electrolysis of H2O with CO2 (CO2 + H2O + power -> CH3OH). The first commercial plant using this process was built in Iceland in 2011 by Carbon Recycling International and uses CO2 captured from a nearby power plant and geothermal energy for inexpensive electricity to drive the process. This process works well but requires a lot of heat and power and access to inexpensive renewable energy to be environmentally and commercially viable. Research is moving forward to make methanol with CO2 captured directly from the air.

Another emerging option for renewable methanol is to use biogas as a feedstock. Biogas is produced from natural anaerobic digestion of organic materials in dedicated digesters, wastewater treatment plants and landfills. Biogas is roughly a 60%-40% blend of methane and carbon dioxide which makes it an ideal feedstock for biomethanol production.

Currently the biogas industry has been focused on producing electric power or renewable natural gas products (pipeline gas, CNG, LNG). But the biogas industry has been challenged by poor economics for power production as well as spotty access to gas pipelines. Methanol is beginning to gain attention as a third option for biogas producers.

Methanol is a traditional auto fuel with wide usage in race cars and is blended with gasoline in much of the world. But methanol is also widely used as a feedstock in the chemicals industry where it is turned into plastics and a variety of other products. When biomethanol is used to produce plastics it offers a pathway for permanent carbon sequestration.

In 2006, Nobel Prize winner George Olah and co-authors G.K. Surya Prakash and Alain Goeppert published a book titled “Beyond Oil and Gas: The Methanol Economy” where they detailed a vision for renewable methanol replacing traditional fossil fuels for energy storage, transportation and power generation as well as for use as a feedstock for chemicals and plastics. In principal, methanol can serve as a feedstock for the entire spectrum of synthetic hydrocarbon products. Dr.’s Olah and Prakash direct the Loker Hydrocarbon Research Institute at the University of Southern California where they are actively developing novel techniques to recycle carbon dioxide into methanol as well as developing methanol fuel cells.

Compared to gasoline methanol is lower energy density but higher in octane allowing higher compression and more efficient engines with very clean emissions. Methanol is considered to be safer than gasoline and was the preferred fuel in IndyCar racing for decades due to improved safety over gasoline.  A dramatic crash at the 1964 Indianapolis 500 led to the switch to methanol after some gasoline fueled race cars caught fire creating a thick cloud of black smoke that blocked the view of oncoming cars leading to additional crashes. One of the cars that caught fire was running on methanol and the fire was noticeably smaller without the heavy smoke and this encouraged race officials to mandate methanol as the standard fuel until 2007 when it was replaced by corn ethanol. Methanol actually burns so clean it is virtually invisible under bright sunlight which is good for the environment but represents a safety concern for firefighters. The use of additives or methanol fuel blends can address the invisible fire concern.

Mario Andretti, winner of the 1969 Indianapolis 500 in his methanol fueled race car.

Mario Andretti, winner of the 1969 Indianapolis 500 in his methanol fueled race car.

 

Methanol has been validated by Siemens and GE as a high quality fuel for gas turbines and suitable for electric power production. Methanol can also be used in fuel cells with advantages over hydrogen due to the ease of storage (hydrogen is stored in expensive tanks under high pressure). Methanol has been positively evaluated as a marine fuel to potentially replace traditional dirty bunker fuels that have been banned from the US and Europe. Methanol can be converted into gasoline using the ExxonMobil MTG process (methanol to gasoline).

DME, Dimethyl Ether, is a simple derivative of methanol that serves as a replacement for both diesel and propane. DME stores like propane in simple steel tanks under slight pressure and be directly blended with propane and LPG as a cooking and heating gas and is widely used in China. But DME can also fuel heavy duty diesel engines with only slight modifications to the fuel system. DME is non-toxic and non-corrosive and can be safely handled. Volvo and Mack Trucks are champions of DME in heavy trucking due to its excellent engine performance and extremely clean emissions. DME has very interesting chemistry, it is CH3OCH3, and the two carbon atoms are not bound to each other which means that when DME is burned no soot is produced. DME is one of the cleanest vehicle fuels available and in heavy trucks it would allow for the elimination of the diesel particulate filters that are an expensive annoyance to truck owners and mechanics.

The traditional criticisms of methanol are that it is caustic and toxic to humans, but as a practical matter it is no more toxic than gasoline. Methanol is also corrosive to certain materials, but flex-fuel vehicles that can tolerate ethanol can generally tolerate methanol as well, and we have been designing vehicles for decades that run on methanol so the engineering issues are well understood. Methanol is a huge international industry today and is transported via container ships, rail cars, and trucks and distributed down to the retail level. This broad infrastructure and experience with methanol are strengths that can be leveraged to grow the industry.

Methanol is historically cheap and the commodity pricing today is under $1 a gallon without any kind of subsidies or mandates. The methanol lobby is fairly limited, largely because the industry is pretty successful on its merits without requiring government support. Typically it is the industries that are least economic on their own that lobby the hardest for public support.

But biomethanol does require some public support and policy is needed. Methanol could readily be blended with gasoline but currently it is not allowed in the US. The DME market is also restricted for lack of policy, standards need to be introduced for propane blending as well for the technical specifications for tanks and distribution equipment. DME was just recently legalized as a transport fuel in California. Biomethanol is not included under the renewable fuels standard and there is no way to earn valuable RINs except when biomethanol is used for producing biodiesel which does allow for fractional RIN’s to go to the biomethanol producer. BioDME can earn RINs in California but currently there are almost no DME trucks on the road.

Small scale methanol production technology has greatly improved in recent years and we now have the option to take the two greenhouse gasses that are of the most concern for global warming, methane and carbon dioxide, and react them together to form methanol, a liquid fuel that can provide energy storage and fuel all energy sectors while replacing fossil fuels for the production of chemicals, plastics and synthetics. When biomethanol is used to produce plastics and building materials it offers permanent carbon sequestration.

We are overdue for a serious policy discussion on biomethanol and the central role it can play in a clean energy economy.

Content Discussion

Bob Meinetz's picture
Bob Meinetz on June 21, 2016

That’s interesting Ed, I look at methanol as a potent public relations pathway for the fossil fuel industry to paint another pretty face on pulling carbon from the ground.

Even assuming producers were using expensive “biogas”, along with atmospheric CO2 it would have to be compressed to 5–10 MPa (50–100 atm) and raised to a temperature of 250°C to create methanol – where does that energy come from? And let’s be honest – if producers combined a little biogas with inexpensive fossil methane and called it all “biogas”, who’s gonna know?

I know toxicity is relative, but come on:

“Methanol has a high toxicity in humans. As little as 10 mL of pure methanol…can cause permanent blindness by destruction of the optic nerve. 30 mL is potentially fatal, although the median lethal dose is typically 100 mL (3.4 fl oz)…”

A possible pathway for bio-rat poison, with questionable economics.

Nathan Wilson's picture
Nathan Wilson on June 21, 2016

A fundamental problem with all hydrocarbon synfuels is that they are easiest to make from fossil fuel. If we are going to do power-to-fuel, why not start with a carbon-free fuel? That way, even if the fossil fuel industry can’t be kept completely out of the market, then at least they can use CC&S to control emissions.

Hydrogen is of course the simplest carbon-free fuel, but ammonia (NH3 – see https://nh3fuelassociation.org/) is easier/cheaper to store and transport (with triple the energy density of 5000 psi H2). Ammonia has almost as much energy density as methanol, and is also toxic. But ammonia is much less flammable than methanol, plus it evaporates quickly at room temperature, so it may have a safety advantage.

In either case though, it is important to remember that in a very low CO2-emitting energy system, hydrocarbon fuel must be replaced in nearly all cases with other energy carriers (e.g. electricity, district heat, or carbon-free fuel). There is simply not enough biomass to replace most of our fossil fuel use, and trying to push that limit would be very destructive to ecosystems. What little bioenergy is available should be reserved for making aviation fuel (perhaps biomethane or FT diesel).

Roger Arnold's picture
Roger Arnold on June 21, 2016

As Ed notes, methanol can be made various ways. The most common commercial approach reacts methane from natural gas with a controlled mix of steam and CO2 in the presence of a suitable catalyst. It’s a surprisingly efficient process, provided one has access to a handy source of reasonably pure CO2.

Ed talks about using biogas as the source for both methane and CO2, which certainly works. To the extent that biogas is available, it’s a cheaper feedstock for synthesis of methanol than pipeline grade natural gas with added CO2. Ironically, most natural gas as it comes from the well contains ample CO2 for making methanol. Most of the CO2 is removed by amine scrubbing before the gas enters the distribution pipeline.

Making methanol the conventional way and then claiming it was made from biogas might be a way to avoid taxes, if and when we manage to implement a national carbon tax. But it would be a stupid risk for any large supplier to take. It would be a clear case of fraud, and obvious in any financial audit..

One point of possible confusion to be aware of: the “renewable methanol” produced at that pilot plant in Iceland is not the same as “biomethanol” and should not be confused with it. It’s synthesized from CO2 and hydrogen and doesn’t involve methane — except as an “accidental” co-product of the synthesis reaction. That’s the process that George Olah advocated for the methanol economy. It’s not constrained by the limited capacity for producing biogas — though it requires very cheap electricity for producing hydrogen before it can compete on a straight cost basis with regular methanol. Iceland happens to have that.

Rick Engebretson's picture
Rick Engebretson on June 22, 2016

Excellent summary of methanol (and DME) fuel history, production, economics, properties, and markets.

Another issue worth considering is National Energy Security. Talk of environmental “sustainability” must recognize we are currently witness to historic refugee flow and military build-up in localized oil regions. The CIA director recently broke with Pres. Obama and openly advised the world in a Congressional hearing of his concerns for such instability. Endless oil war is not sustainable, even with batteries.

You understate, “We are overdue for a serious policy discussion on biomethanol and the central role it can play in a clean energy economy.”

Ed Dodge's picture
Ed Dodge on June 22, 2016

Bob, methanol actually makes lousy rat poison. Methanol is uniquely toxic to humans and other primates but not particularly toxic at all to rats and dogs and the environment in general if spilled.

But methanol is a synthetic fuel we can manufacture cheaply in unlimited quantities, stores indefinitely, and can replace petroleum at the heart of the economy because it is a feedstock for the entire spectrum of energy services and chemical products.

Ed Dodge's picture
Ed Dodge on June 22, 2016

I have never seen a thorough analysis on the carbon emissions from methanol, and certainly not one that includes all of the pathways for producing methanol, some that include using CO2 and some that don’t.

Methanol produced from biogas would presumably qualify as completely green, as would methanol from electrolysis, but methanol produced from CO2 captured from coal power and reacted with fossil natural gas? I don’t know if CO2 venting from natural gas cleanup is included in greenhouse gas inventories, or if there would be any credit for using that CO2. The carbon accounting is an open discussion as far as I can tell.

I do know this much, we need to find value in CO2 if we have any hope in reigning in emissions, and methanol looks like a very productive pathway to at least recycle carbon and temporarily store it. And large scale methanol production would have a huge impact on breaking our nations dependence on international petroleum markets that costs us so dearly in blood, treasure, and spirit.

Bob Meinetz's picture
Bob Meinetz on June 22, 2016

Roger, irony is probably not the best way to characterize the additional CO2 found in raw methane extraction (just as “natural gas” is probably not the best way to characterize the primarily-methane hydrocarbon mix missing from climate for millions of years prior to the Anthropocene). It’s CO2 which would only make the already-substantial carbon footprint of methanol more so.

“To the extent that it’s available”, by the laws of supply and demand, makes anything scarce more expensive. So in my state, for example, attempting to procure even a few percent of California methane from biogas would be ridiculously more expensive than obtaining it from the hundreds of thousands of holes already drilled in our landscape. And business interests of all stripes – fossil, renewable, nuclear, you name it – have made an art of rendering risks less stupid when there are $billions at stake.

Your afterthought regarding the very cheap electricity Iceland uses to to produce hydrogen deserves more credit. Without it, generating carbon-neutral methanol is horribly inefficient as a substitute for merely electrifying transportation – no circuitous thermodynamic substitutions necessary.

Robert Hargraves's picture
Robert Hargraves on June 24, 2016

This article is a nice reminder of the potential for methanol. Note that the ethanol lobby successfully replaced methanol with ethanol for the Indy 500.

You write “This process works well but requires a lot of heat and power and access to inexpensive renewable energy to be environmentally and commercially viable.” and also call the result “biomethanol”, which is good marketing in this day and age. However nuclear power is an inexpensive source for the energy demanded by converting CO2 to CH4. Unless that energy cost is as low as possible, “biomethanol” will never be able to compete with petroleum fuels. I did review methanol, ammonia, and hydrogen as possible vehicle fuels in my book, THORIUM: energy cheaper than coal. I’m now part of a group developing the ThorCon hybrid thorium/uranium liquid fuel nuclear reactor, which can generate electricity at ~3 cents/kWh, close to the affordability needed to synthesize methanol.

You mention direct air capture of CO2. This, too, can be energy-expensive. The US navy has demonstrated lab scale extraction of CO2 from seawater, feeding a process to synthesize jet fuel at almost competitive costs.

Thanks reminding everyone that synthetic vehicle fuels are real options to replace petroleum fuels.

Jesper Antonsson's picture
Jesper Antonsson on June 26, 2016

To use biomass is inherently problematic from an environmental perspective.

I kindof like the Los Alamos “Green Freedom” concept, where you get hydrogen by high-temperature electrolysis using nuclear reactors. Using heat for a large part of the electrolysis’ energy needs would give nuclear an even bigger advantage than it usually has over renewables, cost-wise. Then the hydrogen is combined with CO2 scrubbed from air to get methanol.

Engineer- Poet's picture
Engineer- Poet on June 27, 2016

I could have sworn I blogged something about Green Freedom years ago, but it’s not turning up in my default search engine.

The concept is that, if you build 1 TW(e) of nuclear power to make synfuels in lieu of the 180 GW(e) it would take to electrify most things directly, you can maintain compatibility with petroleum.  This begs the questions of why you’d want to and cui bono.

“Cui bono” is easy enough to answer:  the oil companies would still be able to sell their hydrocarbon reserves for many years, and would probably be the lowest-cost source for a long time.  Contrast this with EVs, in which every sale is 10 or more years of lost consumption.  It’s certain which one XOM would prefer.

I’ve got no problem with biomass fuels made from waste that would otherwise wind up in landfills.  There are plenty of ways to do the conversion, including plasma-torch gasification followed by whatever cleanup and chemical conversion you want to do.  This seems to run to the expensive side, so it might be easier to e.g. use subcritical hot water to hydrolyze the celluose and hemicellulose fractions of waste and let bugs do the conversion to more convenient fuels.  That subcritical hot water is at temperatures easily supplied by current nuclear reactors.

That gives a supply of liquid fuel and/or chemical feedstock.  How much of the rest can use electricity directly?  I don’t know, but probably most of it.  If you knock the requirement for chemical fuel down to what can be supplied by scrap paper, yard waste and the like, you’ve dealt with the most crucial parts and can worry about the rest at leisure.

Roger Arnold's picture
Roger Arnold on June 27, 2016

I’m probably more bullish on synthetic fuels than you are, EP. There’s a great deal of capital represented in diesel equipment that is nowhere close to its end of life. And there’s long distance air transport. There will be a large market for liquid hydrocarbons for at least several decades to come — if our world doesn’t blow up before then). It would be nice if that market could be supplied from carbon-neutral sources.

I don’t see that a push for synthetic fuels has any particular benefit for fossil fuel interests. It wouldn’t take all that much of a tax on fossil carbon to make synthetic fuels the lower cost option. That’s particularly so if cheap power from high temperature nuclear reactors becomes available. But it’s also true if the “no nukes” crowd prevails, and we have to make lemonade with intermittent renewables. In that case we’d need high capacity electrolysis units whose up-front costs were low enough that we could afford to run them on “as available” power.

I don’t believe the availability of synthesized fuels would significantly impact what I expect will be a rather bumpy migration toward electrification of transport. Electrics will fairly quickly become cheaper for city and commuter vehicles, but I don’t expect them to displace liquid hydrocarbons for heavy equipment and inter-city trucking. And certainly not long distance air transport.

But who knows? I could be surprised.

Engineer- Poet's picture
Engineer- Poet on June 27, 2016

There’s a great deal of capital represented in diesel equipment that is nowhere close to its end of life.

It’s very easily converted to natural-gas injection at the next major overhaul; Cummins-Westport has developed an injection system which handles both fuels.  Both NG and LPG can be carbureted into the intake air of a diesel engine as co-fuels, ignited with a bit of oil; I’d bet ammonia works too.

And there’s long distance air transport.

Jet fuel came to about 8% of petroleum products supplied by volume in the US in 2015.  When you get down to it, the actual need for liquid hydrocarbons is perhaps 10% of what we use today and even that fraction can be reduced by substitution.

I don’t see that a push for synthetic fuels has any particular benefit for fossil fuel interests.

The first benefit is that any impact on their sales is delayed until the synfuel systems come on-line, and that can be put off endlessly with lawsuits by “Green” front groups.  The second benefit is that their own product goes seamlessly into the system.  We can start substituting with NG, LPG and ammonia starting today, and electric systems don’t burn anything (directly).  The oilco’s are stuck in that situation; their C5+ liquids don’t go into that system.

If we’re going to turn electricity into fuels, we’re better off with electrolytic synthesis of NH3 than synthetic gasoline or diesel.