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At least 19 records

Evaluation of dissociated and steam-reformed methanol as automotive engine fuels

Dissociated and steam reformed methanol were evaluated as automotive engine fuels. Advantages and disadvantages in using methanol in the reformed rather than liquid state were discussed. Engine dynamometer tests were conducted with a four cylinder, 2.3 liter, spark ignition automotive engine to determine performance and emission characteristics operating on simulated dissociated and steam reformed methanol (2H2 + CO and 3H2 + CO2 respectively), and liquid methanol. Results are presented for engine performance and emissions as functions of equivalence ratio, at various throttle settings and engine speeds. Operation on dissociated and steam reformed methanol was characterized by flashback (violent propagation of a flame into the intake manifold) which limited operation to lower power output than was obtainable using liquid methanol. It was concluded that: an automobile could not be operated solely on dissociated or steam reformed methanol over the entire required power range - a supplementary fuel system or power source would be necessary to attain higher powers; the use of reformed mechanol, compared to liquid methanol, may result in a small improvement in thermal efficiency in the low power range; dissociated methanol is a better fuel than steam reformed methanol for use in a spark ignition engine; and use of dissociated or steam reformed methanol may result in lower exhaust emissions compared to liquid methanol.

Lalk, T. R.

California methanol assessment. Volume 2: Technical report

Energy feedstock sources for methanol; methanol and other synfuels; transport, storage, and distribution; air quality impact of methanol use in vehicles, chemical methanol production and use; methanol utilization in vehicles; methanol utilization in stationary applications; and environmental and regulatory constraints are discussed.

Otoole, R.

Predicted exhaust emissions from a methanol and jet fueled gas turbine combustor

A computer model of a gas turbine combustor has been used to predict the kinetic combustion and pollutant formation processes for methanol and simulated jet fuel. Use of the kinetic reaction mechanisms has also allowed a study of ignition delay and flammability limit of these two fuels. The NOX emissions for methanol were predicted to be from 69 to 92% lower than those for jet fuel at the same equivalence ratio which is in agreement with experimentally observed results. The high heat of vaporization of methanol lowers both the combustor inlet mixture temperatures and the final combustion temperatures. The lower combustion temperatures lead to low NOX emissions while the lower inlet mixture temperatures increase methanol's ignition delay. This increase in ignition delay dictates the lean flammability limit of methanol to be 0.8, while jet fuel is shown to combust at 0.4.

Adelman, H. G.

Detection of solid methanol toward W33A

A recently detected absorption feature at 3.53 microns in the spectrum of W33A has been assigned to methanol (CH3OH). Its optical depth implies that methanol is the second most abundant molecule (7 percent relative to H2O) in the grain mantles in the line of sight toward W33A observed to date. Laboratory experiments have shown that the implied abundance is difficult to explain by UV irradiation of the dust grains alone. Grain surface reactions or condensation directly out of the gas phase must also play roles, but the relative contributions of the various processes are difficult to estimate. The optical depth of the 3.53-micron feature constrains the contribution of methanol to the 6.8-micron feature in W33A to be 10 percent or less, requiring the contribution of at least one other compound to this feature, while the estimated contribution to the 4.9-micron absorption band is even smaller. Only a small contribution of formaldehyde (H2CO) is consistent with the observed 3.53-micron band profile. In contrast to methanol, formaldehyde can be produced readily by photochemical reactions within the ice mantle.

Grim, R. J. A.

Methanol in the sky with diamonds

The present of gas phase methanol in dense interstellar molecular clouds was established by radio detection of its rotational emission lines. However, the position, width, and profile of a absorption band near 1470 cm(exp -1) in the IR spectra of many dense molecular clouds strongly suggests that solid methanol is an important component of interstellar ices. In an attempt to better constrain the identification of 1470 cm(exp -1) feature, we began a program to search for other characteristic absorption bands of solid state methanol in the spectra of objects known to produce this band. One such feature is now identified in the spectra of several dense molecular clouds and its position, width, and profile fit well with those of laboratory H2O:CH3OH ices. Thus, the presence of methanol-bearing ices in space is confirmed.

Allamandola, L. J.

10 micron spectra of protostars and the solid methanol abundance

A search has been made for the strong C-O stretching absorption of solid methanol near 9.8 microns toward the heavily obscured protostars AFGL 961, AFGL 2591, the BN object and Mon R2 IRS 3. There is no clear evidence for this feature in the spectra, resulting in very conservative upper limits to the methanol abundance of 6 percent to 17 percent relative to solid H2O toward these objects. This is well below previous estimates of 50-80 percent obtained toward W33 A, NGC 7538 IRS 9, AFGL 2136, and W3 IRS 5, which were based on the assignment of the interstellar 6.85 microns absorption feature to the methanol C-H bending mode. This study shows that such high methanol abundances are not a characteristic of all interstellar ices.

Schutte, W. A.

Catalytic decomposition of methanol for onboard hydrogen generation

The steam reformation of an equimolar mixture of methanol and water on a copper chromite catalyst was studied at three furnace temperatures and at feed space velocities from 800 to 2600 per hour. The hydrogen space velocity could be related to the reactor temperature by the equation Sv = A exp (-omega T), where A and omega are constants determined for each value of alpha and T is temperature. At a methanol conversion of 0.87 and a reactor temperature of 589 K, the extrapolated value of the hydrogen space velocity was 9400 per hour. This velocity was used to estimate the size of an onboard hydrogen reactor for automotive applications. Such a reactor would need only about 0.8 liter of catalyst to produce 7630 STP liters (1.5 lb) of hydrogen per hour. This quantity of catalyst would fit into nine tubes 17.8 centimeters along and 2.54 centimeters in inside diameter, which is smaller than most mufflers. The reactor products would contain 12 to 13 percent more chemical energy than the incoming methanol and water.

Brabbs, T.

Detection of the torsionally excited state of methanol in Orion A

Torsionally excited methanol has been detected in Orion A, where three emission lines observed in the region of 93-100 GHz coincide with laboratory measurements of three methanol transitions. Torsionally excited methanol may therefore be used as a novel temperature probe, since this state lies near 200 per cm above the ground state, or about 290 K. No emission was detected from the transition arising from levels near 300 per cm, or approximately 430 K above the ground state.

Lovas, F. J.

Evaluation of fuel additives for reduction of material imcompatibilities in methanol-gasoline blends

Screening tests determined the efficacy of six commercially available additives as modifiers of methanol's corrosivity toward metals and its weakening of tensile properties of nonmetals in automotive fuel systems. From the screening phase, three additives which seemed to protect some of the metals were tested in higher concentrations and binary combinations in search of optimal application conditions. Results indicate that two of the additives have protective properties and combining them increases the protection of the metals corroded by methanol-gasoline blends. Half of the metals in the tests were not corroded. Testing at recommended concentrations and then at higher concentrations and in combinations shows that the additives would have no protective or harmful effects on the nonmetals. Two additives emerged as candidates for application to the protection of metals in automotive methanol-gasoline fuel systems. The additives tested were assigned letter codes to protect their proprietary nature.

Rodriguez, C. F.

Methanol Fuel Cell

In proposed fuel-cell system, methanol converted to hydrogen in two places. External fuel processor converts only part of methanol. Remaining methanol converted in fuel cell itself, in reaction at anode. As result, size of fuel processor reduced, system efficiency increased, and cost lowered.

Voecks, G. E.

Methanol as a soot reducer in a turbulent swirling burner

The combined effect of using methanol as a fuel additive together with a prototype multifuel injector has been evaluated with regard to soot formation in a tubular laboratory burner with a turbulent swirl stabilized diffusion flame. Kerosene, ERBS fuel and Blending Stock with approximately 14,12.8 and 10.3 wt pct of hydrogen respectively were characterized in terms of soot loading at the axial positions Z/D = 2.5 and 4.0 and normalized radius r/R = + or 0.67. Mixtures of ERBS fuel and Blending Stock with 15 and 7.5 wt pct of methanol were also characterized in the same way. Measurements with the plain fuels showed a drastic reduction in soot formation, in the order of one hundred and fifty fold decrease, due to the new injector design. Further reductions by a factor of 2 and 1.5 were accomplished with the mixtures of 15 and 7.5 wt pct of methanol respectively.

Izquierdo, A. J.

Methanol in dark clouds

The first observation of methanol in cold dark clouds TMC 1, L 134 N, and B 335 is reported. In all three clouds, the relative abundance of methanol was found to be in the range of 10 to the -9th (i.e., almost an order of magnitude more abundant than acetaldehyde), with no observable variation between the clouds. Methanol emission showed a complex velocity structure; in TMC 1, clear indications of non-LTE were observed. Dimethyl ether was searched for in L 134 N; the upper limit of the column density of dimethyl ether in L 134 N was estimated to be 4 x 10 to the 12th/sq cm, assuming 5 K rotation temperature and LTE. This limit makes the abundance ratio (CH3)2O/CH3OH not higher than 1/5, indicating that dimethyl ether is not overabundant in this dark cloud.

Friberg, P.

Photoionization of methanol and formaldehyde

Photoions produced in methanol and formaldehyde by radiation in the spectral region 450-1150 A were analyzed mass spectrometrically, and their relative yields were determined as a function of wavelength. First ionization potentials were determined, and the ion yield curves were interpreted in terms of ionization processes in conjunction with other data. Fragment ions were detected on mass numbers of 31, 30, 29, 15, and 14 for methanol, and 29, 2, and 1 for formaldehyde. The associated appearance potentials were determined and were used to calculate heats of formation of the ions CH2OH(+) and HCO(+), and the radicals CH3, CH2, and HCO.

Warneck, P.

Cracking of Ti-6Al-4V in methanol solutions containing sulfates.

Whether cracking of unnotched Ti-6Al-4V specimens occurs in methanol containing H2SO4, Li2SO4, or Fe2(SO4)3 is a function of the age of the solution and the concentration of the sulfate. With H2SO4 concentrations of 0.10 N to 0.25 N, the methanol solutions lose their ability to crack the specimens with time after mixing and prior to exposure. The aging time required to inhibit the cracking varies inversely with the water content of the solution. With larger quantities of H2SO4, 0.5 N and 1 N, no cracking is observed. Interpretations of Raman spectroscopic studies of the aging solution suggests that the nature of the O-H group may play a role in the crack initiation or inhibiting mechanism.

Haney, E. G.

Two new methanol transitions in Orion A

Emission from the 11(1) - 10(2) (A-) and 5(0) - 4(1) (E) transitions of CH3OH at rest frequencies of 76,247.4 and 76,509.9 MHz, respectively, has been detected toward Orion A. The velocity widths of the two transitions are estimated to be approximately 3 km/s, which is consistent with other methanol lines in Orion. It is noted that the 117.5-kayser upper-state energy of the 11(1) - 10(2) (A-) transition is the highest yet reported for methanol in any source. The observed intensity is shown to be consistent with the 90-K thermal excitation model that seems to be appropriate for all other reported CH3OH lines in Orion A. Total column densities of 3 x 10 to the 16th per sq cm for the 11(1) - 10(2) (A-) transition and of 2 x 10 to the 16th per sq cm for the 5(0) - 4(1) (E) transition are calculated.

Jennings, D. E.

Alumina-supported Pd-Ag catalysts for low-temperature CO and methanol oxidation

Pd-Ag bimetallic catalysts, supported on gamma-Al2O3, have been evaluated as exhaust catalysts for methanol-fueled vehicles. Laboratory studies have shown that a 0.01% Pd-5% Ag catalyst has greater CO and CH3OH oxidation activity than either 0.01% Pd or 5% Ag catalysts alone. Moreover, Pd and Ag interact synergistically in the bimetallic catalyst to produce greater CO and CH3OH oxidation rates and lower yields of methanol partial oxidation products than expected from a mixture of the single-component catalysts. The Pd-Ag synergism results from Pd promoting the rate of O2 adsorption and reaction with CO and CH3OH on Ag. Rate enhancement by the bimetallic catalyst is greatest at short reactor residence times where the oxygen adsorption rate limits the overall reaction rate.

Mccabe, R. W.

The contribution of methanol to the 3.4 micron feature in comets

With the advent of improved detectors and improved moderate resolution spectrometers several interesting features have been seen in the infrared spectra of comets. In particular, an emission excess at 3.52 microns was observed in several comets, and has recently been tentatively assigned to the nu 3 band of methanol (CH3OH). Using a developed model it is possible to calculate the relative strengths of the CH3OH features. The 3.52 microns emission strengths were used in a number of comets to retrieve methanol amounts, and the model was used to predict the fraction of the 3.4 micron flux which is contributed by the species. Implications for cometary formation are discussed.

Reuter, Dennis C.