Will replacing ethanol with methanol decrease the predicted increase in ozone?

Question

There has been a study which predicts a dangerous increase in ozone pollutant if more ethanol is blended into diesel and biodiesel. The un combusted ethanol will decompose into acetaldehyde which will react with oxygen to form ozone. If methanol instead of ethanol is used to blend in with diesel, can we expect similar decomposition with methanol, i.e. methanol to formaldehyde to ozone?

Answer 1

Sorry, don't know the organic chem enough to answer except that they are different alcohols and therefore might affect the ozone production.  Bigger question: Is blending methanol a viable alternative? Is methanol production through fermentation as easy as ethanol? I doubt it.....otherwise why is ethanol production so common and methanol not?

Why blend it with diesel? I thought the main use of EtOH blending was with gasoline (as is now used in CA and E85 other places).

Answer 2

The short answer is we can expect decomposition but it's not at the same rate.  Here are three studies that address this issue:

AQIRP (Auto/Oil Air Quality Improvement Research Program). 1993a. Reactivity Estimates for Reformulated Gasolines and Methanol/Gasoline Mixtures. Technical Bulletin No. 12, pp. 6-12a. Coordinating Research Council, Atlanta, GA.

AQIRP (Auto/Oil Air Quality Improvement Research Program). 1993b. Reactivity Estimates for Reformulated Gasolines and Methanol/Gasoline Blends in Prototype Flexible/Variable Fuel Vehicles. Technical Bulletin No. 7, Coordinating Research Council, Atlanta, GA.

AQIRP (Auto/Oil Air Quality Improvement Research Program). 1995. Gasoline Reformulation and Vehicle Technology Effects on Exhaust Emissions. Technical Bulletin No. 17. Coordinating Research Council, Atlanta, GA.

and 4 more that look a little more useful with links on the second link:

Reactivity Assessment

Carter W. P.L. "Development and application of improved methods for measurements of ozone formation potentials of volatile organic compounds," $300,000, 4/1998-5/2002 (final report, 1.4 MB).

Carter W. P. L. "Evaluation of atmospheric impacts of selected coatings VOC emissions," $300,000, 7/2001-6/2004.

Harley H., J. Milford, and A. Russell "Development of reactivity scales via 3-D grid modeling of California ozone episodes," $240,000, 2/1999-5/2002 (final report, 0.6 MB).

Russell A. "Assessment of the ozone and aerosol forming potentials (reactivities) of organic compounds over the Eastern United States," $15,000, 5/2001-8/2002 (final report, 6.8 MB).

Emission Inventory

Censullo A., D. Jones, and M. Wills "Investigation of low reactivity solvents for use in consumer products," $85,000, 2/1999-5/2002 (final report, 0.4 MB).

Answer 3

methanol probably will not. it is less energy dense, and will burn more efficiently than etanol, so you will leave almost none unburned to add into the atmosphere. Of course keep in mind that, as bad as ethanol is, it is still much better than gasoline.

Answer 4

To answer the above user's question, ethanol is produced by fermentation of sugar in feedstocks; methanol can't be produced as easily by a simple process.