METHANOL IS MORE THAN A FLEX FUEL

Methanol synthesis from natural gas is one of the most efficient, most environmentally benign industrial processes in existence. Modern natural gas to methanol plants can exceed 71 per cent thermal efficiency and are nearly self-sufficient. They are so clean that one process vendor explains that most of its air emissions come from gasoline and diesel transport trucks and utility vehicles in support of the plant, rather than the plant itself. Additionally, properly-configured methanol plants can actually benefit by consuming carbon dioxide from other sources, which should legitimately enhance their acceptability to the environmentalist community.Methanol is the second most important chemical intermediate (after ethane/ethylene). Its importance has increased in recent years because of changes in refinery configuration as worldwide crude oil feedstocks gradually but inevitably grow heavier. Methanol as a chemical feedstock is very important, but its application as a motor fuel is yet far more promising.

In this article, we dispatch two methanol-as-motor-fuel myths: 1) that methanol has higher toxicity than other motor fuels, and 2) that methanol lower energy density poses a significant problem.

Health, Safety, and Environmental (superiority of methanol)

Some experts have singled out methanol as a neurotoxin, but in fact, ethanol is also a well known neurotoxin, as are several of the substances normally found in gasoline. Many will be surprised (as we were) to learn that both ethanol and gasoline are generally fatal at lower doses than methanol. Further, methanol is generally superior in all other health, safety and environmental aspects. In groundwater, it has a half-life of 1-7 days, 10 to 100 times shorter than some substances found in gasoline.

Methanol fuels were adopted on the racing circuit mostly for greater safety; their superior performance was only an added bonus. Methanol burns at one-fifth the rate of gasoline and is much more easily extinguished. The EPA has estimated that a 95 per cent reduction in vehicle fire fatalities would result from methanol usage.

Lower combustion temperature methanol fuel vehicles emit slightly less carbon dioxide, considerably less hydrocarbons, and much less NOx compared to their gasoline counterparts. This is particularly interesting since NOx has been the most stubborn criteria pollutant to curtail. Methanol fuel could render the clunky, urea-consuming selective catalytic reduction systems now being added to diesel engines superfluous.

Energy density 

Another oft-heard canard is that methanol's lower energy density dooms it to inferior status among potential motor fuels. While it is true that methanol finishes second from the bottom, above compressed natural gas (CNG) on this overrated statistic, it is fallacious to equate energy density with expected fuel mileage from an internal combustion engine. 

Even vehicles designed for gasoline or flex fuel vehicles (which, by design, are not optimal for anything!) should be partially able to take advantage of methanol's superior octane rating and achieve mileage up greater than expected from energy content only. One plucky guy converted his vehicle to 100 per cent methanol by adjusting the engine control software and replacing a 41 cent fuel seal. His horsepower increased 10 per cent, and fuel economy in dollars per mile improved by 40% over gasoline. Fit-for-purpose (i.e., not flex-fuel, or converted conventional fuel) vehicles should be able to do far better.

Some long-haul truckers are retro-fitting their rigs with methanol-water injection systems in otherwise unmodified diesel engines and experiencing a boost in economy of 20 to 30 per cent (over diesel!) a considerable sum for vehicles that consume 20,000 gallons of fuel per year. Measured horsepower increased by up to 75 per cent and torque by 65 per cent: truly eye popping numbers.

Dedicated methanol (i.e. not flex-fuel) vehicles can operate at 25-30 per cent higher efficiency than conventional gasoline engines, about the same efficiency as diesel engines. Current methanol prices assuming energy parity are equivalent to $2.60/gallon wholesale gasoline. But if methanol is 25 per cent more efficient than gasoline, the corresponding wholesale gasoline equivalent price of methanol is $2.09. As of this writing, the gasoline wholesale price is $3.10. But how does methanol stack up against competitive fuels?

Methanol vs. CNG

CNG can no doubt power vehicles, but in the case of consumer passenger vehicles, at a price of greater weight, lower range, longer refueling times, and reduced cargo capacity, considerably greater vehicle cost and a major rework and investment required of the refueling infrastructure. The cost adding CNG capability to a passenger car is probably about thirty or forty times that of adding methanol capability. The only commercially available CNG passenger vehicle, the Honda Civic GX, sells at a $7500 premium over a similarly equipped gasoline Civic. CNG stations cost about twice as much as liquid refueling stations.

Methanol vs. Ethanol

Ethanol is comparable to methanol in consumer vehicle performance, but there is no proven gas-to-ethanol route of comparable efficiency to gas-to-methanol. Certainly, both public enthusiasm and government subsidies for corn-based ethanol are expiring. 

Celanese has announced a technology that promises gas-to-ethanol efficiencies comparable to existing gas-to-methanol technologies. But it remains unproven at the commercial scale and is a proprietary technology. Meanwhile, highly efficient gas-to-methanol technology is available from multiple providers and is decades-long proven at commercial scale.

Methanol vs. Conventional Motor Fuels

The remaining question is whether methanol can compete with conventional gasoline and diesel. At current conditions, the answer is an unqualified yes. Modern interest in methanol began in 1976 as a replacement for lead as an octane booster, one spinoff of which was California's M85 (85 per cent methanol, 15 per cent additive, usually gasoline) methanol vehicle program that ran from 1982 to 2005. In the beginning, these were dedicated methanol (not flex fuel) vehicles, running the gamut from cars to vans to busses. 

Rigorous maintenance was performed and records kept on both the methanol vehicles and gasoline vehicle control group. Methanol mileage was lower, but emissions were as good or better for the methanol vehicles. 

Methanol emissions were found to be less conducive to ozone formation. Methanol vehicles' 0-100 km/hr acceleration was about one second faster than gasoline vehicles, a significant improvement.

The program was terminated in 2005. Some have cited the discontinuation of California's program as evidence of methanol's unsuitability as a motor fuel, but in fact, vehicle owners were well satisfied with the performance of their cars. Their chief objection was to the scarcity of refueling stations - only 100 were available in the entire state. As a result, the program switched to M85 flex-fuel vehicles in 1992. No doubt it was difficult to build support for the program during a period when oil prices were declining or low. Perhaps methanol's lack of a natural constituency comparable to corn-based ethanol is, most significant of all. In 1989, EPA put methanol at considerable disadvantage by waiving ethanol's vapor emissions, but not methanol's. There is no known physical justification for this action.

Technically, methanol can be used up to 15 per cent in gasoline without any modifications and up to 100% at an estimated cost of only $210 per for new, flex-fuel, vehicles (although as mentioned previously, individuals are doing the same for far less). This modest cost would likely become negligible with mass production of methanol vehicles. Since methanol is a liquid like current fuels, existing refueling infrastructure can be converted to methanol with modest modifications. New methanol refueling stations are likely to be only a small fraction more expensive than conventional refueling stations.

While this article is focused on passenger vehicles, where methanol is a clear winner over alternatives and at least competitive with conventional fuels, it has been proposed that methanol spark ignited engines can replace heavy-duty diesel engines. Methanol's extremely high effective octane rating could give engines of half the displacement equivalent output to today's diesel behemoths, saving weight and achieving on the road efficiency gains of 4 to 9 per cent.

USA and China

At present, U.S. methanol production is ramping up. It is true that since the natural gas price spikes of the 2000's that the once world-class U.S. methanol industry now imports about 80% of domestic demand. But now with the lowest natural gas prices outside of the Middle East, the U.S. will once again become a major producer. Two plants have been restarted, one is being moved from Chile, and one major methanol consumer has announced a new plant. 

By 2015, the U.S. should be close to supplying its own demand. More new plant announcements are likely in the coming months which could result in the U.S. once again producing a surplus of methanol for export.

While the U.S. continues to bog down in its self-inflicted corn ethanol debacle, China is moving forward on methanol motor fuels at their usual manic pace. Methanol blends ranging from M5 to M100 are available, with M15 being the most popular. In 2007, there were 770 methanol refueling stations; the current figure is probably multiples of this number. Growth is driven by small and regional companies; PetroChina and Sinopec have shown little interest due to their surplus of refining capacity. But actual volumes are believed to be well in excess of official methanol motor fuel demand, because the economics of methanol fuel blends are so compelling. It's nice to know that the free market is alive and well in China. Not so nice that in the U.S., methanol is stymied by favoritism to ethanol and needless stumbling blocks for methanol. In spite of tepid, or possibly hostile, interest on the part of the major Chinese companies, M15 and M85 standards have been implemented for all of China, the fastest growing motor fuels market in the world.

Other benefits. The future

What is the potential for natural gas derived methanol to make a substantial dent in the U.S. importation of liquid hydrocarbons? By increasing or applying 17 per cent of current natural gas production to methanol production, 10 per cent of U.S. liquids imports could be displaced. This would require construction of 43 current scale methanol plants at a cost of about 53 billion dollars. The U.S. refining industry capital investment budget over the years 2005-2010 was, guess what, $53 billion. But unlike renewables or CNG vehicles, there is no need to ask for subsidy or handouts, at current prices for gasoline, methanol, and natural gas, the plants can payout in 3 to 5 years, continuing to earn a handsome return over their expected 30 year lives. And that is without considering all of the attendant costs of relying heavily on Middle Eastern oil production.

Methanol motor fuel from natural gas is the here and now, but looking to the more distant future, methanol has a couple more tricks. Methanol is mostly produced from natural gas, but may also be produced from biomass vastly more efficiently than ethanol. Methanol from biomass is estimated to have one-tenth the carbon footprint of corn ethanol. Fuel cell powered vehicles were recently believed to be the savior of the motor fuels market. 

But it has widely been appreciated that the biggest challenge to fuel cell powered cars is the very difficult and troublesome transition to a hydrogen refueling infrastructure. But methanol is an excellent energy carrier for fuel cells and its refueling infrastructure is vastly more achievable than hydrogen. Maybe the fuel cell fueled future is not so far off after all, but methanol from natural gas is here today.

Source: Houston Business Journal