Broxburn oil works 1879

Broxburn Oil Works

Each retort is capable of containing 17½ cwt. of shale. By way of showing the saving of coal effected by using the spent shale, it may be said that, while the Henderson patent retort takes 2¼ cwt. of coal to every ton of shale distilled – that amount of coal being added to the spent shale to keep combustion lively, and to raise steam – the old retorts, which are heated mainly by coal, require 6 cwts. per ton of shale. As about 320 tons of shale are daily treated at the Broxburn Works, the saving which will ultimately be effected in the one article of coal alone will be seen at a glance to be very considerable. The estimated saving is, we believe, about 1s. 0d. per ton of shale; but in addition to that, the quality of the oil produced is worth fully ½d. per gallon more from its superior quality. The difference in colour of the crude oil as it leaves the condensers is very perceptible – the new retort sending out a product of an olive green colour, while the oil from the old retort is of a much blacker hue. It has also been found that a larger yield of the sulphate of ammonia is obtained by the new retort, which was all the more surprising considering the low heats used. It may be put briefly that, while under the old system 61 per cent. of products are obtained, under the new there is a yield of 68 per cent. of better quality and at a much less cost.

A notable feature at the Broxburn Works is the way in which the natural situation of the ground on which they stand has been taken advantage of to do away as much as possible with manual labour. Built on the rising ground to the north of the village, the various departments of the extensive works are so arranged that both minerals and oil are made to travel from one to the other to a great extent by gravitation. A railway with numerous sidings also encircles the works, and goods can thus be put upon the waggons at any point. At the refinery, which has been designed to put through 4,000,000 gallons of crude oil per annum, simplicity in the arrangements has been secured by the introduction of agitators in the shape of horizontal cylinders of a very large size. Five hundred gallons was about the quantity that used to be treated at one time, first with vitriol and then with caustic soda; the agitators, however, in use at Broxburn are capable of dealing with 9000 gallons at once; and as the oil, after being treated with vitriol, passes by gravitation to the caustic soda agitators, the multiplicity of stirrers and pumps not unfrequently seen in such refineries have been abolished, and less labour in consequence required to look after the machinery. At the beginning of the distillation the burning oil comes over, and at the end the heavy oils saturated with paraffin. These last are sent off by themselves to the paraffin house, where they are cooled down by a large ether freezing machine, and the paraffin scale extracted by pressure. In this department are introduced a number of improved machines, including some powerful filter presses for separating the paraffin from the oil, which is afterwards refined for lubricating purposes.

The arrangements connected with the Broxburn Works for the utilisation of all by-products are of a complete description, and are deserving of a word of notice. Oil-makers found out some time ago that the ammoniacal liquid which comes off with the crude oil from the condensers was too valuable to be allowed to run to waste. The free gas which the water gives off after it is pumped into the steam boilers and boiled, combines with sulphuric acid, and forms sulphate of ammonia – a valuable product to the agriculturalist. At Broxburn, however, the sulphuric acid is now recovered from the vitriol tar which is given of by the green oil at the refinery, when treated in the agitators with oil of vitriol. Then again, by neutralising the two tars given of by the vitriol and caustic soda agitators, sulphate of soda is obtained, which though a much less valuable is still a useful product. The residue of the tar is pumped to a tank, where it is run by gravitation into the furnaces connected with the refining stills, and makes an excellent liquid fuel. Or this tar can be distilled and gas oil extracted from it, which also realises a considerable price in the market. Then, again, from some of the stills which are distilled to dryness, a coke is obtained which is of great value to iron smelters.

Not an ounce of water is allowed to escape from the works to pollute any stream; and that no pollution is caused in that way is shown by the fact that very good trout are caught in the Broxburn, which flows past the works. In order to ensure that no water should escape, it was found necessary to prevent the drainage from the lands above entering the works; and for this purpose an open cutting was made which carries the water gathered there past them altogether. This left only the water which fell upon the area of 40 acres on which the works stand to be dealt with, and that was found to be a comparatively simple matter. This, along with all water from the boilers and otherwise, is made to pass, as it flows to the low grounds, through a series of catch-pits, the water in which is regularly skimmed so as to remove any oil which may be floating on the top. Ultimately the water travels on into two large storage ponds, where it is cooled and pumped up again to the boilers. It should have been mentioned before that in connection with the oilworks is a brickwork, at which the shale, after it had been burned in the furnace and practically reduced to clay, was mixed with a seam of clay found in the field, so as to make bricks. The quality of the article turned out by this combination was not very high, and with low prices prevailing for a first-rate brick, this branch of the company's operations for the present has been abandoned.

Employed at the Broxburn works and pits are 700 men; and to accommodate these and their families about 100 new double houses – 2 storeys in height – have been built, which, as may be supposed, form an important addition to the size of the village. The managing director of the Broxburn works is Mr William Kennedy, and the manager Mr Norman M. F. Henderson, the patentee of the retort which bears his name.