Methanol as a fuel

Methanol is being considered as a replacement for gasoline, especially in urban areas that have extremely high levels of air pollution caused by motor vehicles. For example. Southern California has been testing methanol-powered cars since 1981. About half of these cars use 100% methanol (MlOO). The other half are flexible-fueled vehicles (FFVs) that use either M85, a blend of 

85% methanol and 15% gasoline, or gasoline. Although methanol fuels M85 and Ml00 have received more attention than corresponding ethanol fuels E85 and El 00, EEVs are being built to test the use of both M85 and E85. 

What are the advantages and disadvantages of switching to methanol-powered vehicles Methanol burns more cleanly than gasoline, and levels of troublesome pollutants such as carbon monoxide, unreacted hydrocarbons, nitrogen oxides, and ozone are reduced (Chapter 4). However, there is concern about the higher exhaust emissions of carcinogenic formaldehyde from methanol-powered vehicles. Since the number of methanol-powered vehicles is limited, it is still difficult to assess the extent to which these formaldehyde emissions will contribute to the total aldehyde levels from other sources. 

Another option is to use methanol to make gasoline. Mobil Oil Company has developed a methanol-to-gasoline process although it is currently not competitive with refined gasoline prices in the United States. 

Unlike gasoline fires, methanol fires and ethanol fires may be extinguished using water. 

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For last few years, extensive studies have been carried out on proton conducting inorganic/organic hybrid membranes prepared by sol-gel process for PEMFC operating with either hydrogen or methanol as a fuel [23]. A major motivation for this intense interest on hybrid membranes is high cost, limitation in cell operation temperature, and methanol cross-... 

One of the considerations regarding the use of methanol as a fuel is that it emits higher amounts of formaldehyde, which is a contributor to ozone formation and a suspected carcinogen, compared to gasoline. Proponents of methanol dispute this, saying that one-third of the formaldehyde from vehicle emissions actually comes from the tailpipe, with the other two-thirds forming photochemically, once the emissions have escaped. They state that pure methanol vehicles produce only one tenth as much of the hydrocarbons that are photochemically converted to formaldehyde as do gasoline automobiles. 

Fuel cells typically use hydrogen directly, mostly as compressed gas, possibly also as liquid hydrogen stored on board. Even though the C02-equivalent emissions were assessed to be low, methanol from farmed wood as a fuel for fuel cells turned out to be no optimum solution. The reason is not revealed by the WTW graph. Industry has decided against methanol as a fuel-cell fuel for two reasons ... 

An important process for production of synthetic protein uses methanol ns feedstock. The use of methanol as a fuel, either as pure melhanol. as a mixture (approximately I5 4) with gasoline, or as a feedstock for synthetic gasoline is envisaged for possible large-scale application as well as use in gas turbines lor electricity generation. See also Wastes as Energy Sources. 

At present oil prices, around US 30/Bbl, the Cm values are between US 114 and 177. As oil prices tend to rise and methanol costs remain practically fixed, methanol as a fuel becomes an economically feasible alternative under Brazilian conditions and its feasibility tends to improve as oil becomes more and more expensive and difficult to obtain. 

Gasoline substitution. Two General Motors vehicles are operating in their normal work, using methanol as a fuel. One has a 6 cylinder engine, the other a 4 cylinder engine. Modifications were ... 

It is not the purpose of this paper to evaluate the suitability of methanol as a fuel for gas turbines. Consequently, no attention will be given to such factors as the cost of methanol fuel, safety considerations of exchanging heat between hot exhaust gases and fuel, and the dynamics of the complex cycle with recuperative chemical reactions. The purpose of this paper is to outline the thermodynamic Implications of chemical recuperation using methanol fuel as an example. 

New Zealand also has no significant oil reserves but large natural gas and coal deposits. The New Zealand government has committed the country to the use of methanol as a fuel supplement. This methanol will be manufactured from natural gas reserves and perhaps, in the long term, from coal. 

Methanol a Versitile Fuel. Thus there is no doubt that methanol will assume a significant role as an automotive fuel. At present its application is limited to situations where local conditions fit the advantages of methanol as a fuel, in any of its guises. 

For fuel cell vehicles carrying reformers and using methanol as a fuel, additional life-cycle impacts from the methanol life-cycle have to be considered. A few of these have been analysed, e.g., by Pehnt (2003). 

Major end uses for methanol are for the production of formaldehyde, about 30%, which is used for the preparation of phenol-formaldehyde resins. About 20% is used for the production of methyl -butyl ether, which is used as an additive alone, and in blends with methanol as a fuel component. Further uses are for the esterification of terephthalic, and acrylic acids, and for acetic acid preparation, about 10% each. 

The only deviation from this pattern is the DMFC (direct methanol fuel cell) which uses methanol as a fuel without intermediate reforming and microbial fuel cells that use sugar as a fuel and derive current from the metabolic activity of yeast. Both types use a solid ion exchange membrane type electrolyte (proton exchange membrane). 

DME is superior to methanol as a fuel in terms of environmental friendliness and chemical toxicity (7d). It is considered to be an additive to diesel or LPG and not a replacement. Firing DME-diesel blends creates challenges for the engine manufacturer. The fuel must be injected at a high enough pressure to keep the dimethyl ether in liquid form. The specific wear characteristics of engines operating with this fuel remains to be studied (77). 

One of the arguments regarding the adoption of methanol as a fuel is that it emits higher amounts of formaldehyde, a contributor to ozone formation and a suspected carcinogen, compared to gasoline. Proponents of... 

H. Menrad, Possibilities to Introduce Methanol as a Fuel, An Example from Germany," 6th Int. Symp. on Alcohol Fuels Technology, (Ottawa, Canada,... 

NEDO (New Energy Development Organization) (1987) Toxicological Research of Methanol as a fuel for Power Station. NEDO, Tokyo, p 296... 

The use of methanol as a fuel in comparison with hydrogen has several advantages. Methanol is a liquid fuel available at low cost, which can be easily handled, stored, and transported without an intermediate reformer. However, there are a few problems limiting the wide spread commercial application of the DMFC [xiii,14,15] and among them ... 

Because of the great potential of methanol as a fuel for low-temperature fuel cells, the electro-oxidation of methanol on Pt or Pt-based alloy electrodes has been studied extensively in the past decades [112-115]. It is generally accepted that methanol is oxidized to CO2 by the so-called dual-path mechanism [112] via adsorbed CO (poison) and non-CO reactive intermediates. The formation of CO by dehydrogenation of methanol has been well confirmed, but no consensus has been reached so far on the nature of the reactive intermediates in the non-CO pathway. Various adsorbates such as CHxOH [116], -COH [116], formyl (-HCO), [117] carboxy (-COOH) [117], a dimer of formic acid [35], and COO [38] have been claimed to be the reactive intermediates from IRAS and other physicochemical measurements. However, the spectra of the reaction intermediates are not well reproduced by other groups. 

The environment in chemical tanks is amongst the severest to which marine coatings are subjected. Each tank may have to transport some 1500 bulk, liquid cargoes that include crude oil, refined gasoline, aviation spirit, diesel oil, solvents, vegetable oils, or wine. Inorganic cargoes are also carried in solution (e.g., alkalis and acids). New demands also appear such as methanol as a fuel and feedstock, and methyl rert-butyl ether as an additive for lead-free petrol. 

Methanol is a much more realistic fuel for fuel cells. The specific energy content of methanol when electrochemically completely oxidized to CO2 is 0.84 Ah/g. For fuel cells with methanol as a fuel, acidic electrolyte solutions must be used. Alkaline solutions are inappropriate, as the alkali combines with CO2 produced in the fuel cell to insoluble carbonates. In the early 1960s, first laboratory models of methanol-air fuel cells were built. As large amounts of expensive platinum catalysts were used in these fuel cells, work in this direction soon ended and was not taken up again for many years. 

Two possibilities exist for the use of methanol as a fuel (i) its prior catalytic or oxidizing conversion to technical hydrogen, (ii) its direct anodic oxidation at the electrodes in the fuel cell. The former possibility implies that additional unwieldy equipment for the conversion of methanol to technical hydrogen and for subsequent purification of this hydrogen is needed. The second possibility is more attractive but involves certain difficulties related to the relatively slow anodic oxidation of methanol even at highly active platinum electrodes. In the view of these difficulties, much attention is given at present to the development of such direct methanol fuel cells. 

Formaldehyde (HGHO), the simplest aldehyde, is obtained by oxidation of methanol. It is a gas at room temperature but is often used as a 40% aqueous solution called formalin. Although formaldehyde is an important starting material for polymers, it presents a number of health hazards because of its toxicity and carcinogenicity. Formaldehyde is also an air pollutant, being produced in trace amounts in the incomplete combustion of fossil fuels. One of the concerns about methanol as a fuel (Section 12.5) is the potential for increased levels of formaldehyde in urban areas because of the production of formaldehyde from incomplete combustion of methanol. 

With this in mind a methanol economy has been proposed by Olah and coworkers [6] as an alternative, or a previous step, to a future hydrogen ecmiomy . Methanol (CH3OH), is the simplest, safest, and easiest way to store and transport hydrogen as a liquid hydrocarbon. It is prepared almost exclusively from a mixture of CO and H2 (syn-gas) resulting from the incomplete combustion of natural gas or coal. Methanol economy involves not only the use of methanol as a fuel and gasoline additive, but also its conversion to synthetic hydrocarbons and their products and materials, which are essential part of our life [6]. 

Regarding the use of methanol as a fuel for transportation in DMFC, it could have the same driving distance as gasoline in an ICE because the fuel cell works with an efficiency that is twice that of the ICE or diesel engine [8]. 

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