Why Not Ethanol from Natural Gas, Instead of from Corn?


This year's serious drought gives rise to new questions about the practicality of ethanol from corn. At the same time, the U.S. is experiencing a natural gas boom that has brought with it low prices that are predicted to last long term. Given these concurrent situations, how about ethanol from natural gas instead? It seems like an ideal time for the government to change current legislation regarding feedstocks for the production of ethanol that is blended into motor fuel.

Corn as an ethanol feedstock

Readers will recall that the government passed the Renewable Fuels Act that led to the construction of a large number of so-called Gasohol plants that produce ethanol from corn and up to last year received a subsidy to make this production economically feasible. The background was an EPA finding that blending ethanol or other alcohols into gasoline produced a cleaner-burning fuel that reduced the production of smog caused by the emission of unburned or partially burned gasoline.

The use of corn became a boon to farmers who now had another outlet for their crop and the ethanol mandate led to the construction of a whole new industry to turn corn into a motor fuel. The downside was and is that corn is a food product so that using it to make a fuel, with government subsidies, is arguably a negative for the global food supply and has the effect of raising the price of corn. For this reason, the government has encouraged - in fact mandated - that refiners use increasing amounts of ethanol and other fuel products made from cellulosic materials (switchgrass, corn stalks, wood chips, etc.) for gasoline blending. However, no such material is commercially available as yet since the technology is still under development and its future uncertain. Meanwhile, the amount of produced ethanol (all from corn) will increase every year through 2015.

The leap from corn to natural gas

There is an obvious step to take. We should amend the current legislation to allow the production of ethanol from natural gas. A technology for this was actually used in the 1960s by US Industrial Chemicals Corporation and by Shell and is still in use in Saudi Arabia today. A new, quite different technology has recently been developed by Celanese Corporation and will be installed in a very large ethanol plant in China.


Source: Celanese

The illustrated comparison of this technology with corn-based ethanol on a Middle East basis is difficult to analyze since no feedstock prices are provided, but U.S. petrochemical feedstock prices are now in close parity with the Middle East. It is clear that ethanol can today be produced in the U.S. from natural gas at a lower cost than from corn. But this will not happen unless the government allows at least some production of fuel ethanol from gas, which is not a "renewable" fuel and therefore not currently eligible as an ethanol feedstock.. Building a few ethanol-from-natural gas plants will still keep most of the corn-based industry in operation, given the huge amount of corn-based ethanol now being produced. But there would be a beneficial effect on corn prices as less of this material is used to make a fuel. A subsidy should remain in place for cellulosic ethanol, since it is in our interest to use waste organic materials to make a needed product.

Balancing objectives for optimal outcome

If the government allows some gas-based ethanol to be produced, there will be a hue and cry from the corn-based ethanol producers (and their congressmen) who will feel their industry threatened. So, the government must balance the objectives. What the government might do is to allow a certain amount of gas-based ethanol to be produced by selling licenses to do so. The government must then balance the market-based incentive for petrochemical producers to make ethanol from gas against the effect of its policy on corn price, on the corn-based ethanol producers who established an entire industry as a result of government actions, and on the price of fuel ethanol. This can be made to work, in my opinion.

Peter Spitz is a recent addition to the ChEnected blogging team. He has spent his entire career in the chemical and energy industries, working for a large oil company, for a research and engineering company in petrochemicals, and as a consultant to the global chemical industry. He was also the founder and president of a respected international consulting firm, Chem Systems Inc., which was acquired by IBM in 1998.To learn more about him, read his complete bio. You can also visit his personal blog at chemengineeringposts.com.

What's your opinion on corn and natural gas as ethanol feedstocks?

Images: corn, jster91

Comments

Robert S's picture

I have heard arguments that ethanol in gasoline isn't beneficial - higher vapor pressure, lower energy value. If we are discussing taking corn out of the equation based on food supply arguments (a perfectly valid reason in my opinion) would we better off just taking ethanol out of the formulation entirely? Or do you think there is benefit from a little diversity in our gasoline sourcing?

Peter Spitz's picture

As far as I know, the benefits of adding alcohol to naphtha fuels to improve combustion have not been seriously questioned. The rationale for making "gasohol" from corn as a renewable fuel to reduce dependency on oil will come into question as the U.S. keeps increasing its production of oil and perhaps starts to use natural gas-derived ethanol.

Rich Byrnes's picture

As a “scientist” I always get a bit suspicious when “Politics” dominate the scientific discourse. I would love to hear more about Robert’s question regarding the value of ethanol in our fuels opposite the clearly unintended negative impacts of this legislation. Peter, you didn’t mention the destruction of rainforest as another negative unintended consequence of the government’s policy to mandate the use of ethanol in fuels and to provide economic incentives to produce it from renewable sources (corn). Given the now created global economic incentives to grow corn, rainforest have been cut down in large sections to convert the land to crop production. This has had a deleterious impact on our environment. When farmers cut down rainforests, the global carbon sink is reduced, the dead trees release carbon dioxide and other greenhouse gases into the atmosphere, perhaps even offsetting any potential gains. Furthermore the destruction of rainforests displaces indigenous people and kills wildlife. Any thoughts on this aspect? I believe the natural gas route to ethanol must be added to the mix, in order to offset some of the unintended negative impacts of the current policies.

Peter Spitz's picture

I am not aware that corn destined for alsohol production is being planted in areas where rain forests are being destroyed to plan the corn. Glad you agree on use of natural gas for ethanol.

Keith Dackson's picture

I would have hoped that a MS-level engineer would have thought a bit before posing such a nonsensical question. I will answer your question with a question: Why would anyone in their right mind take a perfectly good fuel (natural gas) and develop a process to make a less efficient fuel (ethanol) when it is a simple matter to convert an internal combustion engine over to burn natural gas? Seems the love of ethanol has clouded your judgment.

Rich Byrnes's picture

The question here is "What’s your opinion on corn and natural gas as ethanol feedstocks?", not what is the best fuel source for vehicles? I would love to debate the pros and cons of Natural Gas as a potential fuel source for the more than 750 million cars in the world, however that would take this discussion off topic.

Keith Dackson's picture

OK, then let me put it bluntly: It is a stupid idea to use corn for fuel ethanol, and even stupider to convert natural gas to ethanol. The ONLY use of corn as a feedstock for ethanol should be in the beverage industry.

Rich Byrnes's picture

Given the “blunt” fact that the law requires ethanol be added to our fuel, and the government adds incentives to make the ethanol from renewable sources, which then leads us to make ethanol from corn and put it in our gas may indeed be "stupid", however under these constraints until laws are changed or natural gas cars prevail, I don't understand why using natural gas to relieve the burden on corn and reduce food prices is "stupider".

Peter Spitz's picture

My blog chemeengineeringposts.com recently had a post that discussed the issues involving natural gas as a fuel for cars. This is happening for trucks and other delivery vehicles, but very slowly for cars (you can find the tiny number of natural gas refueling stations for cars from Google - I would not buy a natural gas-fueled Honda Civic at this point. But this will improve with time.

Keith Dackson's picture

It certainly seems to be happening in China - especially in Beijing and Shanghai at least since 2005. I remember using taxis where we could not stow luggage in the trunk due to the LPG tank. As far as refueling stations - again, in China there were a lot of PPG refueling stations. Why can't we use a system similar to the propane tank exchange common for gas grills? Refuel by swapping out a used tank for a fresh and just go. Seems better than having to reengineer cars to use E10 (soon to be E15) or flex fuel vehicles to be able to use E85. In fact in NY, there are less than 10 stations that even sell E85. Remember, the demand for ethanol for vehicle fuel is driven by a government mandate that requires the use of this energy poor substitute. But I guess lower MPG translates into higher fuel tax revenues since more G are used to travel the same number of M. And you know who this hits the hardest? Anyone who commutes to work. A real winner of a policy.

Rich Byrnes's picture

The retired Fire Chief that works with us tells me many first hand horror stories regarding gas grill propane tank fires and explosions due to improper operation and hook-up. In fact he gives us an annual Safety Presentation on the topic. Strictly from a Process Safety Perspective I have some reservations about handing over 230 million Compressed Natural Gas Cylinders at 3000 - 3600 PSI to the American public and telling them here, have at it, just pop this into your car and your good to go.... I doubt the public will ever warm up to having a 3000 PSI Natural Gas "Can" sitting in their closed garages at home. Professional Industrial Mechanics managing Natural Gas Fleets like Taxis, Trucks, and Buses are one thing, asking my 18 year old daughter to pop a 3000 PSI Compressed Gas Tank into her car is an entirely different matter. Natural Gas Cars maybe in our future, however they have a long way to go to make them practical and convince the public that the safety performance will be better than gasoline powered cars once used in mass.

Peter Spitz's picture

I am all in favor of using natural gas as a fuel for cars. That is happening slowly for a number of reasons that you know, mainly distribution issues. Meanwhile, we should back out some of the corn-based alcohol with natural as-based alcohol. The two are not mutually exclusive.

Robert S's picture

I'm still not sure I see the value of transforming NG into ethanol for transportation fuel? How is the value that is lost in forcing NG into ethanol gained by putting it into gasoline? Why not just remove the ethanol, seems the simplest solution. NG in vehicles is great, but I think better to wait until the infrastructure is in place to do it correctly. There are many places (most of Asia) where compressed gas is used for cars and trucks. It is hard to find a taxi in China that doesn't have a compressed canister in the trunk.