Energy, fuels, and chemicals 321 1 



Addition of methanol and ethanol increases the octane rating of gasoline, 

 much in the way that tetraethyl lead and other additives do. Potential problems 

 include loss of performance (especially in blends higher than 1 5 percent alco- 

 hol), possible phase separation of the alcohol from the gasoline caused by 

 excessive moisture, and corrosion of fuel system parts. Although these problems 

 will not be difficult to overcome, correction will cost the consumer. 



Methanol can be used as a straight automotive fuel, not blended with gasoline. 

 Although there is no mechanical problem in using straight methanol in the 

 engines currently used in passenger cars, the engines and cars would require 

 minor modifications. Because of the solvent properties of methanol, different 

 gaskets would be required, and since the energy in a gallon of methanol is less 

 than in a gallon of gasoline, larger fuel tanks would be required to obtain the 

 same distance range (Flaim and Hill 1981). Walters (1980, 1981) concluded that 

 automobiles fueled with methanol would have lower fuel cost per mile than if 

 they burned gasoline and engine life would be significantly lengthened. Flaim 

 and Hill (1981) concluded that biomass-derived methanol can be competitive 

 with natural-gas-based methanol. 



For economic analyses of ethanol production from southern hardwoods see 

 section 28-5 (small scale) and 28-33 (large-scale). Readers needing additional 

 information on alcohol fuels will find useful the bibliography produced by the 

 Solar Energy Research Institute (1981). 



A national gasahol plan for the United States has become a major controversy 

 (Anderson 1978). Proponents contend that by blending 5 to 10 percent ethanol or 

 methanol with gasoline, oil imports could be reduced as much as 20 percent. 

 Opponents consider this uneconomic as long as gasoline reamins cheaper than 

 the alcohols. In late 1981 the prices of fuel-grade methanol, ethanol, and gaso- 

 line at the refinery gate were about $0.60, $0.61, and $1.00 per gallon, 

 respectively. 



In Brazil, a $400 million program is now underway to produce ethanol from 

 sugar cane and cassava to replace 20 percent of the country's gasoline require- 

 ments by the early 1980's (Hall 1978; Hammond 1977). But in Brazil, which 

 imports over 80 percent of its oil, ethanol costs the consumer $1 per gallon 

 compared with $1.50 per gallon for gasoline. 



Park et al. (1978ab) indicate in a preliminary report to the Department of 

 Energy that a national gasahol program appears premature. After 1990, the 

 potential for such a program should be more promising. By then, however, 

 methanol and ethanol might be economically converted to gasoline. 



A new process to convert methanol into gasoline (fig. 26-29) has been 



developed by Mobil Research and Development Corporation (Meisel et al. 



1976; Chang and Silvestri 1977). The Mobil process uses a newly discovered 



zeolite catalyst to quantitatively convert methanol to hydrocarbons and water. 



XCHjOH^!!!!!!!^ (CH,), +XH2O (26-17) 



99 + % 



Most of the hydrocarbon molecules produced are in the gasoline boiling range 

 (C4 to C,o); total gasoline yield is about 80 percent of the hydrocarbon product. 

 This synthetic gasoline has unleaded Research Octane Numbers (RON) of from 



