A GREAT NATIONAL ECONOMY.

[TO THE EDITOR OF THE SPECTITOLI SIR,—I have read with much interest the excellent and pertinent letter under the above heading written to you by Colonel Robert Standen and appearing in your issue of June 17th. Colonel Standen and the authorities whom he quotes seem to fear lest by the low-temperature distillation of coal a coke will be left as residue which might be difficult to sell. I can reassure them on that point. A smokeless fuel has been, and can be, produced on a sound commercial and scientific basis, which will ignite as easily as bituminous coal in the domestic hearth, will burn with a cheery flame to satisfy the Englishman's love for a bright fireside, will give off no objectionable fumes, will give a stronger radiant heat than coal, and will leave practically no ash. I write from ex- perience, as some of my friends and I have been burning this fuel during the last winter. Unfortunately, the supplies available have been very limited up to the present; but we and our households are longing for the time when all our heating will be done with this " super- coke," which has none of the disadvantages of gasworks coke—the latter being a dull and emaciated form of destroyed coal, owing to the high-temperature process employed to extract the last fraction of gas per ton of coal. In my opinion, this particular process of which I am writing is the only one of all the suggested low-temperature processes which offers every advantage to the householder, and has received the official seal of the Coal-Smoke Abatement Society ; whilst it also produces the largest percentage of valuable by-products in elastic proportions, so that the varying needs of the various chemical users may bo met proportionately to the requirements of the day, so as to avoid excessive production or shortage of any constituent. Had St not been for the war, this process would have been in the hands of one of the largest German coke-oven builders, who had been testing the system with all sorts and conditions of coals for over a year. A contract had been concluded just before the war broke out, under which the German company (supported of course by German banks !) guaranteed the inventor and pioneers of this scheme a royalty over a long period, and their idea was to start with London and gradually apply the system to all the large cities, towns, and centres in Britain. When the war broke out this arrangement was cancelled, so now the system is ones more in the hands of a British company ; otherwise, the Germans would have had our trade in the hollow of their hands for benzol, tolnol (for high explosives), pitch, sulphate of ammonia, petrol, aniline dyes, &c. A plant is now in course of erection, somewhere in England, having for its objective the production of a high-grade smokeless fuel, which will, it is believed, displace to a great extent the use of house coal in ordinary grates, and, as a natural consequence, avoid the production of large volumes of black smoke which pollute the atmosphere of our large cities and cause considerable damage to property of all kinds. In the manufacture of this fuel there are produced large quantities of rich tar, a very rich gas having great heating capacity, a considerable quantity of ammonia, and about fifty per cent. surplus gas, which is available for the production of power either by direct combustion in gas engines or combustion under water-tube or other boilers for steam raising and use of steam in turbo-generators. Dealing with the rich gases, it is found that by a process of washing with a special oil, the benzols, toluols, and higher derivatives of the benzol series can be easily and economically eliminated, and without a loss of more than from seven to ten per cent. in heating value of the gas so treated. The recovery of these light spirits is an essential part of the process, since as much as three gallons of ninety per cent. benzol can be recovered per ton of coal ; and, further, about half-a-gallon of toluol, the important basis now used for the production of T.N.T. (tri-nitro-tolueno), the high explosive. A further yield of these light spirits (benzol and toluol) is recovered from the low-temperature tars, and from reoont trials in a six-ton day plant these light spirits gave a yield of 0.62 gallons benzol and 0.41 gallons toluol per ton of ooal respectively. Tabulating the yields of useful products after refining to oommereial (90 per cent. pure), we have as follows :-

Total yield of tar per ton of coal treated .. „

Yield of refined products per ton of coal treated from both tar and rich gas :

1. Benzol 2. Toluol 3. Xylol 4. Solvent naphtha 5. Heavy naphtha 6. Carbolic acid 7. Cresylic acid 8. Creosote oil

9. Lubricating oil

10. Diesel oil .. 12.495 Loss by refining and pitch 7.510 20.000

From the foregoing, one can readily see the great importance of low- temperature tars, since the yields are quite double those obtained by any high-temperature process. The total yield per day from the plant now in course of erection will be about 10,000,000 cubic fast of gas, of which part is used for treating batteries.

SUMMARY OF RESULTS FROM 200 TONS PLANT.

1. Smokeless fuel .. 124 tons per day. 2. Breeze .. .. .. 16 „ ,, 3. Sulphate of ammonia 31 " 4. Benzol (for motors, aeroplanes) 662 gallons 5. Toluol (for high explosives) .. .. 182 „ 6. Xylol (for high explosives) .. 41 „

7. Solvent naphtha (for rubber solvent, varnishes, &o.) 63 „

8. Heavy naphtha (for lamps, varnishes) .. .. 165 a 9. Carbolic acid (for high explosives) .. 48 „ 10. Cresylic acid (for high explosives) 507 ,, 11. Creosote oil (for timber pickling, &e.) .. 460 12. Lubricating oil (for engines) .. 180 „ 13. Diesel oil (for oil engines) a .. 190 „ 14. Pitch, carbon free (for insulation and briqueting) 9 tons 15. Mixed power gas .. about 10,000,000 cubic feet. Reviewing the motor-fuel side of the process and the demand foe petrol substitutes as lately emphasized by Lord Montagu of Beaulieu in an article in the Car (April 5th, 1916), the estimated annual consumption of petrol is 100,000,000 gallons, which is entirely an imported product. The maximum production of benzol in Great Britain in by-product plants to day, carbonizing 111 million tons of coal, will be about 23,000,000 gallons. There are still some 10,000 Beehive ovens existing, and equal to an annual consumption of 11,000,000 tons of coal, and if this were recovered it would yield as benzol about 22,000,000 gallons. From the whole of the coke- ovens in the United Kingdom we could recover after convereion of the Beehives, say, 45,000,000 gallons of benzol from 22} million tons of coaL This would equal about forty-five per cent. of require- ments to-day. It will require eight years to convert the Beehives to by-product recovery ovens, based on past progress. Gasworks carbonize about 171 million tons of coal annually, and if these all extracted bonzol from their gases they would only produce another 19,000,000 gallons, making a total of 64,000,000 gallons. Tho total coal used in Great Britain for all purposes annually is about 193,000,000 tons, and includes coal used in factories, mines, railways, brick and chemical works, iron and steel works, gasworks, and for domestis purposes. The following table gives particulars :— Factories .. • „ 85,000,000 tons. Mines.. ,. 22,000,000 ,,

Railways .. 16,500,000 Brick and chemical works .. 6,700,000 Iron and steel works .. 33,090,000 „ Gasworks .. .. 17,500,000 „ Domestic consumption .. .. 37,300,000 „ 198,000,030 toes.

If, by any chance, the bulk of this fuel could be gasified on the Ion. temperature process, and the benzol recovered and other useful oils. the yield would be on 175,000,000 tons—viz., 198,000,000 tons, less coal required for furnace coke (221 million tons)—at three gallons benzol per ton, 525,000,000 gallons, which would probably be the consumptives

Galin 20

Tar and gas Light - pp oils only only

tt

Pt Heavy OP oils

VP

Galls. Galls.

/3 31 0. 91 0.205 - 4 • to 0.315 0.825 0.900 0.240 2.535 2.300 0.050 ----- 8.065 of motor-spirit by the time this vast change could become effective. The entire proposition is one which affects the whole community. and by its adoption smoke would be abolished from our cities and towns, electricity could be generated at much leas cost at large central power stations near the coalfields, sulphate of ammonia, cyanamide and other nitrogenous fertilizers could be produced by cheap processes and electricity. All the colours required in the arts and manufactures could be made in this country, and a great number of skilled operatives and trained chemists find support by reason of a huge industry which ha possible, and, I would like to add, probable.

I regret this letter is so long, but you will see that it is impossible to explain the matter in a few lines, and the question is of paramount

n ational importance.—I am, Sir, &c., J. R. F

[We do not profess to be able to judge whether the statements con- tained in the above letter are or are not of practical value. All we can say is that, if a process can be established for converting our coal smoke Into motor-spirit and other valuable substances, and at the same time for endowing us with a smokeless coal, we shall have secured an tacomparable bl essing.—ED. Spectator.]