Alcohols with carbon numbers ranging from C1 to C5 were individually blended with unleaded test gasoline. All the alcohol-gasoline blends had the same oxygen mass content. The performance c...

The performance and emission characteristics of C1-C5 alcohol-gasoline blends with matched oxygen content in a single-cylinder spark ignition engine

Evaluation on toxic reduction and fuel economy of a gasoline direct injection- (GDI-) powered passenger car fueled with methanol–gasoline blends with various substitution ratios

Aldehydes and ketones in engine exhaust gases are receiving increased attention and are beginning to be subject to special legislation due to their carcinogenic and ozone formation potential. This paper gives an overview of their properties as well as of the basic chemistry and conditions of their formation in internal combustion engines. Extensive research on the effects of engine operation and fuelling parameters is reviewed with specific references to gasoline, diesel, natural gas and methanol fuelled engines. This is accompanied by the review of the studies of the performance of exhaust catalytic converters with respect to aldehydes. Aldehyde detection and measurement methods are summarized and analysed from the point of view of their applicability to exhaust gas analysis.

Aldehydes and Ketones in Engine Exhaust Emissions—a Review:

Methanol as a Fuel: A Review with Bibliography

The current understanding of the combustion chemistry of paraffin hydrocarbons is summarized Emphasis is placed on reviewing the semiempirical methods presently available for modelling alkyl hydrocarbon combustion The anomalies inherent in some of the existing models and approaches to improve both qualitative and quantitative predictive capabilities are discussed Modelling alkane combustion chemistry over extended ranges of equivalence ratio, pressure, and temperature, requires the consideration of sequential but partially overlapping processes: an initial period of induction phase chemistry; conversion of primary aliphatics to olefins, oxidation of the resulting oelfins to carbon monoxide, and simultaneous oxidation of hydrogen produced in the hydrocarbon destruction The conditions under which the induction phase chemistry can be neglected in modelling efforts is explored HO2 chemistry is found to be required in order to extend the applicability of detailed hydrogen/carbon monoxide/oxygen mechanisms to ranges of pressure and temperature normally used in practical combustion system modelling Functional quasi-global kinetic expressions for alkane oxidation are discussed and errors in some published results on overall rate coefficients are clarified Stress is given to the advantages of quasi-global kinetic modelling and the additional modifications required for these models to have greater applicability

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Combustion chemistry of chain hydrocarbons

Exhaust emission and performance characteristics of a single-cylinder engine fueled with methanol are compared to those obtained either with gasoline or a methanol-water blend. Our measurements of engine efficiency and power, and CO and NO/sub x/ emissions agree with trends established in the literature. Consequently, the emphasis is placed on organic emissions (unburned fuel including hydrocarbons, and aldehydes), an area in which there is no consensus in the literature. In all cases with methanol fueling, the unburned fuel (UBF) emissions were virtually all methanol as opposed to hydrocarbon compounds. Without special measures to overcome methanol's large heat of vaporization, UBF emissions were four times greater with methanol than those with gasoline. Similarly, aldehyde emissions were an order of magnitude greater with methanol. These high levels of organic emissions with methanol were related to inadequate fuel-air mixture preparation, which was caused by methanol's large heat of vaporization. Modifying the single-cylinder engine intake system to improve vaporization reduced UBF emissions 80 to 90% with methanol and 30 to 50% with gasoline. Aldehyde emissions were also significantly reduced by improving mixture preparation, but remained three to four times greater for methanol than for gasoline. Blending 10% water with methanol resulted in: (1) reducedmore » engine efficiency and power, (2) increased UBF emissions, (3) no measurable effect on aldehyde and CO emissions, and (4) reduced NO/sub x/ emissions. Our tests indicate that the advantages of blending water with methanol are outweighed by the disadvantages.« less

Fred B. Parks

Papers

A Single-Cylinder Engine Study of Methanol Fuel-Emphasis on Organic Emissions