GM’s Focus on Electricity; Expanded Hybrid Offerings and a 2-Mode Hybrid Plug-in VUE Under Development (corrected)
AGCO Approves Biodiesel Blends up to B100 for SisuDiesel Engines

Improving Combustion and Reducing Emissions with Methanol/Gasoline Blends

Researchers at Xi’an Jiaotong University (XJTU) in China have quantified the improvement of combustion and reduction in emissions with the use of gasoline-methanol blends of up to 30% (M30) in spark-injection engines.

Increasing the methanol fraction of the blend shortens the flame developing period and the fast burning period, and the indicated mean effective pressures become higher during the first 50 cycles.

The team also developed a new quasi-instantaneous measurement system to measure emissions. With the increase of the methanol fraction up to 30%, the unburned hydrocarbon and carbon monoxide (CO) decrease.

Measured results show that the hydrocarbon emissions are reduced about 40% at 5° C and 30% at 15° C during the cold-start and warm-up period; CO is reduced nearly 70% when the engine is fueled with M30, and a higher difference in the exhaust gas temperature of about 140° C is achieved at 200 s after starting compared to gasoline.

Earlier, other researchers at XJTU had investigated the effect of methanol/gasoline blends on the combustion and emissions characteristics of cold starts. They found that moderate methanol addition can slightly improve the combustion performance at low temperatures, compared to that of pure gasoline fuel, because methanol addition into gasoline results in the improvement of blend evaporation.

This group found that emissions of HC during the rich fuel/air mixture combustion at relatively low temperatures increase with the increasing addition of methanol into gasoline, because of the enhanced evaporation of blended fuel, compared to gasoline. They also pointed out that HC and CO emissions can be reduced when moderate addition is used, because a leaner mixture has been supplied to realize rapid combustion for blended fuels.

Methanol—the simplest alcohol, and sometimes called wood alcohol due to earlier production processes—has been considered as a gasoline substitute at various times reaching back to the 1920s. During the oil crises of the 1970s, research into methanol/gasoline blends accelerated once again.

Now, the prospect of producing methanol as a fuel substitute from coal or from biomass is re-stimulating interest in its use and associated impacts.

However, methanol’s energy density is about half that of gasoline, with the result that vehicle’s would experienced reduced range when using higher methanol fractions in vehicles—a situation similar to current flex-fuel vehicles focused on using ethanol. But also like ethanol, methanol also offers the potential for optimized engine design.



Rafael Seidl

The results are in line with earlier research and experience on using methanol neat or in a blend. Range is only reduced if the fuel tank volume is unchanged. With over 100 domestic carmakers, many in JVs with foreign companies, there is currently an explosion of new models and knock-offs in China, so increasing the tank volume over time would be doable. Comparisons of fuel economy per unit of volume are meaningless for different fuel grades; you need to compare $/mile (or RMB/km) driven, including the amortization costs of any upgrades required to use the alternate fuel grade.

The real question is how do you produce the fuel in the first place. If China is willing to substitute petroleum imports with biomethanol, reducing its CO2 footprint in the process, that's a good thing in my book. Conversely, producing methanol from coal would be a rather idea thing in environmental terms.

Mark R. W. Jr.

But isn't methanol more corrosive? Some automakers warn against using methanol blends in fuel for that reason.

Max Reid

Methanol is Methane in liquid form, how does it compare with LNG in terms of efficiency, vehicle usage and so on.

Hardly there are 1000 vehicles running on Methanol worldwide, but 5 million vehicles are running on CNG and LNG is gaining acceptance.


LNG has boil off problems and CNG has tank size problems. Methanol can be made from biomass or coal rather than NG. I think that it costs about $300 more per car for the makers to produce an FFV that could run M85/E85. If we are to get beyond M5/E10, then we will need those cars soon. In fact, to get beyone E10 it will require them in great numbers. I don't think that we will get to E85 nation wide in the U.S., but to get more than E10 we will need FFVs.


Methanol is not the same as methane.

One is CH4 the other is CH3OH


Just to get to E10 The US would have to increase prodution by 300%

tom deplume

Research in the 1970s showed that up to about M30 that fuel mileage increased even though the mixture had a lower energy density. Might have had something to do with the inefficiency of carburators back then. Wonder if the same would hold true with modern lean burn EFI?


If we get to E10, we can go no further without FFVs. If we do not start making FFVs now, there will not be a sufficient number of vehicles on the road to create a market. If we had been making FFVs all along, there would be a large number of these vehicles of the road today and a ready market for the E10+ product, whenever we are ready to supply it.


Interesting. The methanol apparently increases the flame speed, meaning that it is more knock/detonation resistant than normal gasoline. This means that timings can be brought closer to TDC and that the AF can be leaned. This would allow a vehicle to essentially make more power, or the same power at lower RPMs. This would help negate the lower fuel density of the gasoline/methanol blend.

The problem is that the engine cannot sense the fuel blend and adjust itself to take advantage of these properties. Manufacturers would only alter the ECU of existing/production vehicles if such a blend became standard. Chicken+egg...

Does anyone know if methanol can be made from rice/rice waste? If so, China could probably support domestic production of methanol and increase revenues to farmers in the process.

Paul Dietz

Does anyone know if methanol can be made from rice/rice waste?

Methanol can be made from any source of synthesis gas (CO + H2), which includes biomass.


Rice straw can be gasified and synthesized into methanol. The FFVs that I advocate have sensors to detect the percentage of methanol in the fuel and adjust timing accordingly. Since the cost per car is so low for FFV, I recommend that we mandate all cars sold be FFV by 2010.

Cheryl Ho

There are developments in DME/Methanol in China today:
Access to methanol, a key primary input, to manufacture DME , Xinao recognise this and JV with Methanex to grow the DME Business. While there are several technology developments recently for selective production of olefins, especially propylene either from methanol or from DME. UOP and Lurgi are fairly advanced in the technology. In fact Lurgi AG, will be sharing their experience at upcoming North Asia DME / Methanol conference in Beijing, 27-28 June 2007, St Regis Hotel. The conference covers key areas which include:

DME productivity can be much higher especially if
country energy policies makes an effort comparable to
that invested in increasing supply.
National Development Reform Commission NDRC
Ministry of Energy for Mongolia

Production of DME/ Methanol through biomass
gasification could potentially be commercialized
Shandong University completed Pilot plant in Jinan and
will be sharing their experience.

Advances in conversion technologies are readily
available and offer exciting potential of DME as a
chemical feedstock
By: Kogas, Lurgi and Haldor Topsoe

Available project finance supports the investments
that DME/ Methanol can play a large energy supply role
By: International Finance Corporation

For more information:

The comments to this entry are closed.