THE CUBA REVIEW 27 



The Production of Motor Fuel from Final 

 Molasses in Cuba 



By Raymond Carpenter 



{From "Facts About Sugar, ^' New York May 20, 1Q22) 



If one may judge from the views expressed rather generally in the sugar industry, 

 the raw sugar producer is destined for some time to come to work on a smaller margin 

 between his producing costs and the price of his product than was the case before the 

 readjustment to post-war conditions. The selling price of sugar is low, and while 

 labor costs are going down, it is doubtful if they get back to pre-war levels. Statisticians 

 tell us that the general trend is, in fact, upward, and that, following each peak in the 

 curve, the succeeding valley is higher than the one before. 



Finding a Use for Wastes 



Under present conditions, therefore, unusual importance attaches to the elimination 

 of waste as completely as may be possible in the various processes of the industry. 

 One of the problems that must be worked out in this connection is that of a proper 

 disposition of by-products so as to bring in the largest possible profit. Wastes must 

 be converted into commodities for which there is a potential, if not an actual, demand 

 under conditions which insure adequate financial returns. 



The principal by-product in the manufacture of raw sugar is the residue known as 

 final molasses, which is left after all the commercially available sugar has been extracted. 

 It accumulates at the rate of about six gallons per ton of cane. For the average 

 modem plant this means about 18,000 gallons, or 110 tons per day. In the aggregate 

 it is equal to about one-fourth the tonnage of raw sugar produced. The value of any 

 material depends upon the use made of it. The principal uses which can be made of 

 molasses are: 



(a) As a liquid fuel; 



(b) As a component of cattle food; 



(c) As a raw material for the production of ethyl alcohol. 



Molasses Unprofitable as Fuel 



The last mentioned is the most important and is the one which will be considered 

 at some length in this article. In order to clear up the whole subject, it will be well, 

 however, to deal briefly with the first two. 



Molasses can be used as a liquid fuel and can be burned under boilers, thereby 

 replacing oil fuel when, for any reason, the supply of bagasse runs short. It is true 

 that it is not so used to any extent, both because it has been worth more for other 

 purposes and because there are certain difficulties encountered in its use, due principally 

 to its high content of fusible ash, which in types of burners used heretofore has caused 

 troubles by clogging. But it would be unsafe to say that these troubles could not 

 be overcome if there were enough to be gained to make the effort worth while. Treated 

 as a fuel, then, its composition is as follows: 



Sucrose 38% 



Glucose 19% 



Ash 28% 



Water 15% 



lOOC 



Its combustible value, deducting the heat necessary to evaporate the moisture it 

 contains to the temperature of the flue gases, is 3.770 B.T.U. per pound. It will 



