One of the first questions asked by the practical gas maker will be: "What guarantee can you give that as soon as we have erected plant, and got used to the new process of manufacture, a sudden rise in the price of oil will not take place, and leave us in worse plight than we were before?" and the only answer to this is that, as far as it is possible to judge anything, this event is not likely to take place in our time. A year ago the prospects of the oil trade looked black, as the output of American oil was in the hands of a powerful ring, who seemed likely also to obtain control of the Russian supplies; but, fortunately, this was averted, and, at the present moment, the Russian pipe lines are flooding the market with an abundant supply, which those best able to judge tell us is practically inexhaustible, so that prices may be expected to have a downward rather than an upward tendency. But even should a huge monopoly be created, I think I have found a source of light at home which will hold its own against any foreign illuminant in the market.
For a long time I have felt that in this country we had sources of light and power which only needed development, and the discovery of the right way to use them, in order to give an entirely new complexion to the question of carbureting; and now by the aid of the engineering skill and technical knowledge of Mr. Staveley, of Baghill, near Pontefract, I think it is found.
At three or four of the Scotch iron works the Furnace Gases Co. are paying a yearly rental for the right of collecting the smoke and gases from the blast furnaces. These are passed through several miles of wrought iron tubing, diminishing in size from 6 feet down to about 18 inches; and as the gases cool, so there is deposited a considerable yield of oil.
At Messrs. Dixon's, at Glasgow, which is the smallest of these installations, they pump and collect about 60,000,000 cubic feet of furnace gas per day; and recover, on an average, 25,000 gallons of furnace oils per week, using the residual gases, consisting chiefly of carbon monoxide, as fuel for distilling and other purposes, while a considerable yield of sulphate of ammonia is also obtained. In the same way a small percentage of the coke ovens are fitted with condensing gear, and produce a considerable yield of oil, for which, however, there is a very limited market, the chief use being for lucigen and other lamps of the same description, and for pickling timber for railway sleepers, etc.; the result being that, four years ago, it could be obtained in any quantity at 1/2d. per gallon, while since that it has been as high as 21/2d. a gallon, but is now about 2d., and shows a falling tendency. Make a market for this product, and the supply will be practically unlimited, as every blast furnace and coke oven in the kingdom will put up plant for the recovery of the oil, and as with the limited plant now at work it would be perfectly easy to obtain 4,000,000 or 5,000,000 gallons per annum, an extension of the recovery process would mean a supply sufficiently large to meet all demands.
Many gas managers have, from time to time, tried if they could not use some of their creosote for gas producing, but on heating it in retorts, etc., they have found the result has generally been a copious deposit of carbon, and a gas which has possessed little or no illuminating value. Now, the furnace and coke oven oils are in composition somewhat akin to the creosote oil, so that at first sight it does not seem a hopeful field for search after a good carbureter, but the furnace oils have several points in which they differ from the coal tar products. In the first place, they contain a certain percentage of paraffin oil, and in the next, do not contain much naphthalene, in which the coal tar oil is especially rich, and which would be a distinct drawback to their use.
The furnace oil as condensed contains about 30 to 50 per cent. of water, and in any case this has to be removed by distilling; and Mr. Staveley has patented a process by which the distillation is continued after the water has gone off, and by condensing in a fractionating column of special construction, he is able to remove all the paraffin oil, a considerable quantity of cresol, a small quantity of phenol, and about 10 per cent. of pyridine bases, leaving the remainder of the oil in a better condition, and more valuable for pickling timber, which is its chief use.
If the mixed oil so obtained, which we may call "phenoloid oil," is cracked by itself, no very striking result is obtained, the 40 percent. of paraffin present cracking in the usual way, and yielding a certain amount of illuminants, but if this oil be cracked in the presence of carbon, and be made to pass over and through a body of carbon heated to a dull red heat, then it is converted largely into benzene, the most valuable of the illuminants, and also being the one to which coal gas owes the largest proportion of its illuminating power, it is manifestly the right one to use in order to enrich it.
On cracking the phenoloid oil, the paraffins yield ethane, propane, and marsh gas, etc., in the usual way, while the phenol interacts with the carbon to form benzene—
| Phenol. | Benzene. | |
|---|---|---|
| C6H5HO + C | = | C6H6 + CO. |
And in the same way the cresol first breaks down to toluene in the presence of the carbon, and this in turn is broken down by the heat to benzene.