THE CUBA REVIEW 31 



I 



another in suspension — the latter as per Dalton's law of partial pressures — both operate 

 to prevent the recovery of a pure product; 96 per cent, alcohol, which is commercially 

 pure, contains nearly 4 per cent, water and a few traces of other impurities. 



The apparatus which is standard for this purpose is what is known as the three- 

 column still, in which the first column, known as the analyser, picks up all the volatiles 

 from the mash, that is, alcohol, aldehydes, ethers and oils. The second column, or 

 purifier, gets these volatiles and separates the oils, etc., passing the alcohol along to 

 the third column, or rectifier, where the final purification of the alcohol takes place. 



The process of conversion of alcohol to ether involves: 



(a) Treatment of alcohol with sulphuric acid. This is a catalytic action in 

 which, theoretically, there should be realized 80.5 per cent, ether and 19.5 per cent, 

 water from 100 per cent, alcohol. The acid is returned intact, except that it is diluted 

 by the water. Actually, the reaction does not convert all the alcohol, nor does the acid 

 completely separate, so that further treatment is required as follows: 



(b) Neutralization with caustic, and 



(c) Rectification to purity desired. In this case the principal impurity is alcohol, 

 and as the ether is to be mixed with more alcohol finally, a comparatively simple 

 distilling apparatus is all that is required. 



Denaturing and Mixing 

 Denaturing and mixing is performed under government supervision, and the 

 particular method will depend on the regulations prescribed. The apparatus consists 

 of gauging or measuring tanks for each component of the motor fuel, so proportioned 

 as to give the correct quantities. Mechanical mixing in a suitable apparatus completes 

 the process, and it only remains to place the mixture in suitable containers for shipment. 

 The whole process requires considerable steam for operating the stills and a small 

 amount of power for pumping, lighting and mixing. The plant may be divided into 

 the following departments : 



Power house, 



Fermenting house. 



Still house. 



Bonded storage warehouse. 



Denaturing room, 



Storage house for denaturants, acid and caustic, 



Shipping and product storage. 



The buildings should be of steel frame construction, and of a t\pe similar to 

 those of a sugar plant, except as the regulations prescribe certain features in regard 

 to the still house and the bonded storage warehouse, to insure that no taxable alcohol 

 is illegally removed. 



Now we approach the final test: Will it pay? Can this fuel be produced cheaply 

 enough to allow a good profit to the manufacturer and sufficient margin for distribution 

 on top of that? To determine this, let us assume a fuel plant with capacity for utilizing 

 the daily molasses output of a 3,000-ton raw sugar plant, and assume further, that it 

 will be supplied from outside sources with additional molasses sufiicient to keep it in 

 operation the year around. Such a plant will turn out, in round figures, 7,200 gallons of 

 motor fuel per 24-hour day. 



Cost of Production 



The cost of production will be made up as follows: 

 Materials: 



Fuel oil, 22,000 lbs. per day @0.7c. per lb S154.00 



Molasses, 18,000 gallons per day @ Ic. (present value) 180.00 



Acid, caustic and denaturant, per day 90.00 



Miscellaneous supplies, per day 5 .00 



$429.00 



