30 THE CUBA REVIEW 



In outline, the process of production of motor fuel is as follows: 

 Molasses mixing and dilution. 

 Addition of yeast, 

 Fermentation, 

 Distillation of alcohol, 

 Part conversion to ether, 

 Denaturing and mixing. 



Apparatus RzQnRED 

 The apparatus consists of: 



MLxing tanks 



Fermenters. 



Yeast breeding equipment, 



Alcohol still. 



Ether still. 



Alcohol storage tanks, 



Ether storage tanks. 



Denaturing and mixing tanks, 



Pumps, piping, etc. 



The alcohol is produced by the action of the yeast on the sucrose and glucose 

 content of the molasses in the fermentation tanks. Molasses contains about 57 p>er 

 cent, invert sugar, or about 6.9 pounds per gallon. If fermentation were complete 

 and there were no distillation losses, one gallon of molasses would produce about 0.536 

 gallon of 96 per cent, alcohol. In practice, 82 per cent, of this quantity, or 0.439 

 gallon, is usually obtained. Nothing but pure yeast should be used. Ferments of 

 various kinds, known as "wild yeasts,'" are always present, ready to attack the molasses, 

 and if not kept under control, fermentation may result in something else than alcohol. 

 Too much emphasis cannot be placed upon the necessity for cleanliness, freedom from 

 contamination, and the breeding of the proper strain of yeast in such a way as to 

 insure strength and purity. These things well attended to, with due attention to the 

 maintenance of suitable temperature during fermentation, will insure the maximum 

 production of alcohol. 



The breeding of pure yeast, as is seen from the foregoing, is an important feature. 

 It is a continuous process, carried on in special apparatus whereby the best conditions 

 for the growth of a pure yeast can be maintained, and in quantity suited to the daily 

 needs. The yeast must be of a kind that will produce the maximum quantity of alcohol 

 from the sugar contained in the molasses to the exclusion of anything else. 



It must not be understood from the above that even with the best yeast, alcohol 

 will be the sole product. Besides the carbonic acid ( CO., ) which escapes to the air, 

 there are present in the fermented mash an assortment of aldehydes, ethers and oils 

 which cannot be allowed to appear in the final product. If they do appear, acetic 

 acid will be in evidence in the engine cylinder with disastrous results. It is beside the 

 mark to say that these aldehydes, ethers and oils will bum, and are therefore properly 

 included as fuel. They all bum to complete combustion under different conditions 

 of temperature, pressure, and oxv-gen supply. As the compression and carburation 

 must be adjusted to suit the principal components of the fuel, it is evident that if these 

 other things are present in appreciable quantities some of them are not going to bum 

 to complete combustion, and the trouble will ensue. 



The Distilling App.ar.\tus 

 This consideration leads to the conclusion that the still, the office of which is to 

 recover as far as possible all the alcohol in the mash, must in the course of its operation 

 remove the aldehydes, ethers and oils as far as possible. Right here, it may be as 

 well to state that in any evaporating or distilling process the tendency of one liquid 

 to absorb another liquid or vapor, and the tendency of one vapor or gas to hold 



