05 bo
MODERN GASWORKS PRACTICE
Little work has been done in connection with the determination of the character of the unsaturated hydrocarbons in carburetted water gas, although it is known that these are mainly olefines with a smaller proportion of benzene hydrocarbons. B.T. Brooks,1 in studying the mode of existence of the hydrocarbons in oil gas produced by the cracking of American petroleum, has given the following results
Composition of Oil Gas
Temp. of Cracking, ° C. 600 650 700 730
Ethylene, per cent. 193 19 0 17-7 17-5
Propylene, „ 28-0 28-4 23-9 20-0
Higher olefines, „ 3-2 4-2 3-5 31
Total olefines, 50-5 51-6 45-1 40-6
RECOVERY OF BENZOL FROM CARBURETTED WATER GAS
Düring the war various attempts were made to recover the benzene hydrocarbons from carburetted water gas. The effectiveness of the process entirely depends upon the quantity of oil used for carburation, while the temperature prevailing in the carburettor infhiences the result. Temperatures between 700° and 760° C. appear to produce the maximum amount of toluene. Higher temperatures tend to increase "the proportion of benzene, while lower temperatures produce paraffins and olefines. The recovery of light oils in this country during the war was not followed up, paitly owing to the paraffins present in the recovered spirit, and also on account of the attemiated nature of the water gas which resulted from the shortage and expense of gas oil.
L. J. Willian 2 has given the following figures as an illustration, of the effect of stripping carburetted water gas :—
Effect of Stripping Cabbubettbd Water Gas
Crude spirit obtained consists of—Benzol, 35 per cent.
Toluol, 25 per cent.
Solvent naphtha, 10 per cent.
Heavy naphtha and wash oil, 30 per cent.
Crude spirit recovered amounts to 10 per cent, of oil used for enrichment.
Löss of candle power due to scrubbing = 50-8 per cent.
„ „ calorific power „ „ = 4-2 „ „
THE STORAGE OF OIL
On gasworks in this country enriching oil is nearly always stored in cylindrical steel tanks. Recently, however, reinforced concrete has been employed in the con-struction of storage vessels for all types of oil, and has given every satisfaction. The main problem is that of rendering the concrete impervious to oil, and this condi-tion is met by treating the surface of the tank with a paint-like coating which eusures
1 Ghem. and MetaUurgical Eng., April 7, 1920.
2 American Gas Inst. News, Dec., 1917.