March 16, 1917. THE COLLIERY GUARDIAN. 533 CURRENT SCIENCE Use of Peat in Gas Producing Plants. At a recent meeting of the Liverpool section of the Society of Chemical Industry, Prof. E. C. C. Baly described a gas producing plant at the works of Messrs. Hamilton Robb, Portadown, Ireland, in which peat has been successfully used as fuel for the past five years. The plant comprises two producers, each of a.' capacity of 200 horse-power, and two Crossley gas engines of 120 horse-power, and one of 150 horse-power. The gas drawn from the producer is freed from tar and dust before use by passing it through scrubbers. All the soluble products are, however, lost. There is a small gasometer installed in order to minimise the “ periodic action of the gas engines. At present nothing is done with the tar. The peat is obtained from .a bog about 12 miles away, where -it is air-dried, and is fed direct into the .top of the producers. The working cost of the plant, as compared with the cost of running per week on coal, results in a saving of .£15 5s. 6d. per week. The by-products from peat producer gas are peculiarly valuable, especially when Irish peat is used, owing to the relatively high percentage of nitrogen in the peat. In the plant at Port/adown the ordinary -air-drying such as is obtained by stacking is amply sufficient. It is possible to utilise peat containing as much as 70 per cent, of moisture in a Mond plant, so that peat which has been air-dried in the winter months can be used without any further drying. In fact, the nitrogen is recovered as ammonia more*easily with a wet peat than with a dried peat, though the process is slower. When dried peat is fed into the producer the upper layers of peat are completely dried rapidly enough. As the peat reaches the combustion zone it is decomposed in pre- sence of the steam and air with formation of ammonia, tar, etc. It then reaches the coking zone of much higher temperature, where the combustion is completed, leaving only the ash. With a wet peat, the time taken in the drying process in the upper layers in the producer is longer, and the zone of combustion is reduced in thickness; the peat passes through it too rapidly, and does not give up all its nitrogen. It enters the coking zone, and then forms a nitrogen-containing coke, in which the nitrogen is fixed. Moreover, a poor quality of gas is obtained owing to the smallness of the com- bustion zone. The difficulty is surmounted by increasing the tem- perature of "the drying zone from 100 to 120 degs. Gent, (which it shows normally) to 250 degs. Cent. This in general is sufficient to set free the whole of the nitrogen as ammonia by the action of the steam on the peat. This temperature rise is obtained by pre-heating the air- steam blast to 450degs. Cent., which gives an inten- sive combustion of the coke, an increase in the size and temperature of the combustion zone, an almost quanti- tative recovery of the nitrogen as ammonia, an increase in the thermal -efficiency of the gas, and also a good quality of tar. The amount of steam used should not exceed half the weight of the peat gasified, and its partial pressure should fall below 250 mm. A certain quantity of the gas produced is used to heat the preheaters for the steam-air blast. One ton of theoretically dried peat gives altogether from 88,000 to 92,000 cu. ft. of gas. Of this 89,000 cu. ft. are used in the pre-heaters, leaving 49,000 to 53,000 cu. ft. in excess, from which are developed 700 to 750 horse-power hours. Further, from 70 to 85 per cent, of the nitrogen is obtained as ammonia, and the yield of tar is from 8 to 6 per cent. The Composition of Power Gases. In the course of a paper, read before the Society of Chemical Industry .in London, Mr. W. A. Tookey remarked that the use of gas engines had developed inde- pendently of the nature of the gas employed; instancing the fact that in 1864 even spirits of turpentine had been used, by means of introducing plenty of air into the cylinder. Scientific research had not given much help to gas engine makers, and he proposed to deal with gas composition from the point -of view of the engineer, not of the chemist. In recent years he had carried out over 1,500 tests with -gas, kerosene, and oil fuels, about 1,000 having been undertaken for two great London gas com- panies to investigate the value of their gas as -an .engine fuel. As a basis of comparison between different engines was taken the pressure to which a charge of air was compressed by the piston, the power output being obtained in terms of mean pressure instead of horse- power. The gas was also measured by British thermal units as well as cubic feet, -and thus were calculated the number of pounds of mean pressure obtained from each British thermal unit. Comparative tests were made of kerosene vapour and -air mixtures, and liquid fuel mists in engines of the Diesel types, as well as town gas and producer gas. Compared on the basis explained above, it was found that by careful adjustment a- remarkable- similarity of results was obtained, as was illustrated by a series of curves and graphs. From this was deduced the author’s main conclusion, which was that the com- position of the fuel had very little influence on the results, but that the regulation of the mixture was of the greatest importance. It was pointed out that con- stancy of calorific value and uniformity of supply pres- sure were desirable, as simplifying the control of the mixture. It was also important to maintain the effici- ency of rubber diaphragms and anti-pulsating valves, and renew them when necessary. The p-re-ignition difficulty often attributed to an excess of hydrogen or methane, could be overcome by weakening the mixture; other- wise natural gas, with its 90 per cent, methane content, could not be used at all. With coke oven gas, too, it was necessary to weaken the mixture by the addition of exhaust to prevent pre-ignition. It was important to- AND TECHNOLOGY. bear in mind that the working mixture contained resi- duals from previous charges besides gas and air. Replying to points raised in the subsequent discussion, the author -said he would investigate the minor consti- tuents, but doubted whether they were the cause of pre- ignition, as, if so, this trouble would be of much more frequent occurrence. Here, again, the question of mix- ture strength arose, as CS2, for instance, might be so greatly diluted that its ignition temperature would not matter. As to the lowest calorific value of gas it was in the public interest to supply, that was purely a question of £ s. d. He did not regard density as of great impor- tance, as it was possible to start with town gas and switch over to producer gas—a difference of from 0'4 to 0-8. It was only necessary to set the pressure valve so as to lower the induction line. The ignition point could be regulated by means of the- gas valve, the air valve, or the water jacket. In the cas-e of stripped gas, the ignition was late and irregular, and, again, the mix- ture needed adjustment. Suction gas plants were doing good service with cotton seed, waste wood, charcoal, etc., and his remarks had been intended to indicate that they needed careful management. The Norwegian Diesel engine was actually the most efficient, but it was a special type, built for use with tar oil. COAL MINES REGULATION (AMENDMENT) BILL. The shortage of imported mineral oil having made it urgently necess-ary to increase as far as possible the output from shale oil mines in this country, and com- mittees of the- owners and workpeople in the shale mining- industry having passed resolutions agreeing to the sus- pension -of the Eight Hours Act as respects this class of mine, the Government have introduced the following Bill (which was read a second time in the House of Commons on Wednesday) to extend section 4 of the Eight Hours Act, which authorises the suspension of the Act in the event of war and other emergencies, so as to render this section applicable to all mines within the Coal Mines Act, 1911, i.e., mines of coal, mines of stratified ironstone, mines of shale, and mines of fire- clay :— 1. Section 4 of the Coal Mines Regulation Act, 1908, which authorises the suspension of that Act as respects coal mines in the event of war and other emergencies, shall extend to all mines to which the other provisions of that Act apply in like manner as it extends to coal mines, -and accordingly in that section after the words “ demand for coal ” there shall be inserted the words ‘ ‘ or for the product of any other mines to which this Act applies ” and for the words “ coal mines ” where- ever they occur there shall be substituted the word “ mines.” 2. This Act may be cited as the Coal Mines Regula- tion (Amendment) Act, 1917, and the Coal Mines Acts, 1887 to 1914, and this Act may be cited together as the Coal Mines Acts, 1887 to 1917. IMDIAM AMD COLOMIAL MOTES. Africa. State Collieries.—The question of State mining is assum- ing prominence :in South Africa, and a Government Com- mission has been appointed to investigate and report upon the subject. As the railways in South Africa are all the property of the Government, the question of State collieries has cropped up several times during the Government enquiry. Sir William Hoy, the general manager of the Government Railways, states that it may be found necessary in the near future for the State to open collieries to supply the railways with coal, but so long as coal -is available at a reasonable price for the railways, he does not see the need for the inauguration of State collieries. The Administration of the South African Railways some time ago acquired some valu- able coal-bearing properties in the neighbourhood of Twee- fontein, in the Middelburg district of the Transvaal, and it is these properties to which the general manager draws atten- tion as likely to be opened up. A large coal field near K-omati Poort has also been reserved on behalf of the State Railways, but the coal here has proved so inferior in quality, that it is doubtful whether this coal field will ever be of any value to the railways. The coal is semi-anthracite, carries too high a percentage of ash, and is too liable to clinker, to be of any service on the railway, whereas the coal area acquired In the Middelburg district contains the class of coal best suited to the locomotives. The consumption of coal on the Government Railways is one-fifth of the whole coal output of South Africa, and the adoption of State mining to -supply the railways with coal will prove a severe blow to the South African coal trade. Last June, when the railway locomotive contracts expired, the Transvaal Coal Owners’ Association asked for higher prices, and the Railway Administration at that time seriously considered the advis- ability of opening up the Middelburg coal property. Fortu- nately, however, concessions were made on both sides, and thus the necessity of establishing State collieries in the Transvaal was avoided. When the Transvaal railways were worked as a Netherlands concession, the concessionaires worked a colliery at Springs to supply the railway with coal, but it cannot be said that the movement was a success. The railways soon required more coal than -a single colliery could supply, and to avoid going to privately-worked concerns for coal, the railway-owned colliery could not afford to screen the coal properly, whilst the cost of working the coal was always greater than the railway could purchase a better article ’from privately-owned concerns. It was therefore no real loss to the railway in 1899 when the colliery workings were closed owing to the spread of underground fires. Since that date, the Government Railways have depended on privately-owned collieries for their locomotive coal, and' up to the present no disposition has been shown by the Railway Administration to recommend the opening of a State coal mine. Some uneasiness was felt in railway circles when the Transvaal Coal Owners’ Association was first formed, as it was feared that coal prices would be unduly forced up against the railway. The same feeling was displayed when the Natal Coal Owners’ Association was formed. To pre- vent the whole of the collieries joining the association, the railways have consistently adopted a benevolent attitude to several collieries agreeing to remain outside the association, both in Natal and the Transvaal, favouring them with large locomotive contracts and construction of needed railway con- nection on easy terms. The result is that quite an impor- tant minority of Transvaal and Natal collieries remain out- side the association, and whilst that state of affairs exists there does not seem much prospect of State-owned collieries being opened in the Transvaal. Canada. Mining in Alaska.—About 8,000 tons of coal was mined in Alaska during 1916 from half-a-dozen small mines. The largest producer was the Bluff Point mine, on Cook Inlet, where a lignite bed was exploited for the local market. The mining of coal in the lower end of the Matanuska field, for the use of the Alaska Engineering Commission, was also a significant event. This part of the field is already made accessible by the Government railroad, now under construc- tion. The construction of a private railroad from Bering River into the Bering River coal field was also begun, -and a little coal was mined at the south-west end of the Bering River field. Tenders for leases of coal lands in both the Bering River and Matanuska coal fields under the new law have been received by the Interior Department. Another important event was the completion by the Geological Survey of a detailed examination of the more accessible part of the Nenana coal field, lying about 60 miles south of Fair- banks. All these facts indicate that systematic exploitation of the Alaska coal fields will soon be undertaken. MAXIMUM PRICES IM FRAMCE. • The Mure anthracite mines have petitioned the Central Committee on Coal Prices for an advance on the maximum rates,* which are admittedly lower than those for coals of the same class in other districts; and the Committee have amended the list -as follows :— Egg coals, 35/55 mm., 49 fr.; nuts, 28/55 mm., 49 fr.; “ gresil ” No. 1, 16/25 mm., 40 fr.; broken screened, 25/35 mm., 44 fr.; ibid., 40/80 mm., 48 fr.; screened, above 16 mm., 37 fr.; small, 21 fr.; “ bar rd casse,” 26 fr.; ovoids, 40 fr. per ton. The Peronniere and .Haute-Cappe, of the Rive-de-Gier basin, having granted an increase in wages to their workmen, have requested the Committee to raise, the maximum prices by 1*75 fr. per ton, but the latter con- sider that an increase of 1 fr. per ton will be sufficient to meet the situation. * Colliery Guardian, August 8, 1916, p. 306. MIMIMG TIMBER TRADE OF SOUTH WALES. At the annual meetings of the Powell Duffryn Coal Com- pany Limited and the Celtic Colliery Company Limited references were made to the serious problem which has con- fronted South Wales colliery proprietors respecting the supply of pitwood. The high cost of mining timber is bear- ing' unduly hard upon South Wales collieries, inasmuch as very few are in the position to transfer the increased cost to the consumer. The bulk of the coal produced is under contract, while the prices for inland consumption and for the supply of coal to our Allies are fixed. This week, quota- tions for French fir were quoted 75s. to 80s. ex ship Cardiff, but these prices were purely nominal, owing to the scarcity of wood. The authorities have now allowed cargoes to be imported as before, no licences to import wood being required. For the week ending March 9, the imports of foreign mining timber were heavier, but supplies quickly went into consumption. The following were the actual imports :— Cardiff, Barry and Penarth : To From Loads. Evans and Reid Oporto ... 1,200 T. Beynon Morlaix ... 216 T. P. Thomas Bl.ane, Wright and Lisbon .... 2,040 Martinez Lisbon ... 2,400 Lysberg Limited L’Orient ... 780 Grant Hayward Granville ... 230 T. G. Duncan Bordeaux 96 Vyvyan Kelly Bayonne ... 1,542 Newport:—. Total ... 8,504 Powell Duffryn Company Bordeaux ... 1,480 Evans and Reid L’Orient ... 300 E. Marcesche L’Orient ... 960 Swansea: — Total ... 2,740 Evans and Rogers Pauillac ... 110 Morgan and Cadogan ... La Rochelle ... 230 Do L’Orient ... 296 Lysberg Limited L’Orient ... 125 Port Talbot:— Total ... 761 Lysberg Limited La Rochelle ... 350 E. Marcesche Sables d’Olonne ... ... 180 Lysberg Limited Sables d’Olonne... 720 Total....... 1,250 Goal Owners’ Pitwood Association. The question is being discussed whether the South Wales Coal Owners’ Pitwood Association will prove a success. The great difficulty will be experienced in endeavouring to give regular supplies, as most of the forests in the district have been purchased, and to go further afield naturally increases the cost of transport. A number of colliery owners antici- pate that no tangible relief will be afforded by the associa- tion for some time,