592 



The Weekly Florists' Review, 



September 3. 1903. 



Coal gas contains only about 20 per cent 

 beating value of coal, and could not 

 profitably be used except in an extreme 

 emergency. Its production, like coke, is 

 di pendent upon tbe output and d- 

 coal, so cannot be regarded as a reliable 

 substitute for coal. 



Blast furnace gas Is tbat which is given 

 oft" by the partial burning of coal in a 

 blast furnace. This gas usually represents 

 about 00 per cent of the heating value of the 

 coal: its composition, however, is irregular 

 and its use practically limited to the fir- 

 ing of boilers connected with the blast fur- 

 nace establishment. 



Water gas is produced by passing water 

 vapor or steam over hot coal : this process 

 produces a gas containing about 58 per 

 cent of the heating value of the coal. 



Coal Gas. 



There is a system of gas production from 

 coal, now in use in England and two or 

 three places in this country, known as the 

 Hand system, by which it is claimed a 

 great saving of coal is secured. As the 

 difficulties of securing a sufficient supply of 

 coal increase, the consumer will learn to 

 adopt methods whereby greater economy 

 may be effected. In the production of Mond 

 gas a very costly plant is necessary and 

 its use would only be possible in large 

 communities where the interests were large- 

 ly In common. It is claimed by this com- 

 pany that in the production of power .hey 

 have attained the ideal of "one horse-power, 

 one hour, one pound of coal." This, how- 

 ever cannot be realized by burning the gas 

 under boilers, and may be possible only by 

 converting the gas directly into power by 

 means of gas engines. 



iiond gas is a highly efficient form of 

 water gas, containing upwards of SO per 

 cent of the heating value of the coal. The 

 gas contains about 140 heat units per cubic 

 foot, and a gross ton of rough slack coal 

 produces 1 40.000 cubic feet of gas. or 19,- 

 600.0(10 heat units to the ton as compared 

 with ::.. '■>■■'''. 2"0 heat units in a ton of the 

 best semi-bituminous coal, or 29,120.000 

 heat units in ordinary bituminous coal. 

 Although a greater number of heat units 

 are contained in a ton of coal than in the 

 gas produced from a ton of coal, the heat 

 contained in the gas is much more available 

 than that in the coal, as shown by the 

 results obtained in the recent tests made 

 by the Naval Fuel Board, in which only 

 about half the heating value of coal was 

 realized. It is intended, however, that this 

 gas shall be produced from the coal screen- 

 ings and the waste products, which are 

 usually sold very cheaply, and it is claimed 

 that a ton of the poorest slack will pro- 

 duce as much gas as a ton of lump coal of 

 the same grade. 



By comparing the data already given it 

 will readily be seen that aside from wood 

 and natural gas. where it can be obtained, 

 there is very little among the solid and 

 gaseous fuels that can be depended upon 

 as substitutes for coal. We now T turn our 

 attention to the liquid fuels, of which there 

 are but two that are worthy of consid- 

 eration : these are petroleum, either as it 

 comes from the well, or some of its prod- 

 ucts, and alcohol. The present supply and 

 the methods of the manufacture of alcohol 

 would not warrant its extensive use as a 

 fuel, but the time may not be far distant 

 when it may be produced in great quanti- 

 ties from plants, perhaps ten to fifteen tons 

 from an acre of ground. The thermal effi- 

 ciency of alcohol is not exceptionally high, 



being about 12.600 units per pound, or 

 2,000 units less than the best semi-bitumin- 

 ous coal. Alcohol is exceptionally efficient 

 as a fuel owing to the fact that most of 

 the heat is available and very little is lost 

 in the process of combustion. 



Petroleu 



Fuel. 



We now come to the consideration of 

 the most important of all the substitutes 

 for coal, in fact the only substitute aside 

 from wood, that reaches any degree of 

 comparison. During the scarcity of coal 

 last year there were many attempts made 

 to replace coal with oil. some few of 

 which wore rather satisfactory. There is 

 no longer any doubt regarding the mechan- 

 ical part of oil burning, but the expense 

 connected therewith is so much greater than 

 with the use of coal as to make it imprac- 

 tical under most circumstances. 



Last year an oil burning test was made 

 at the Bureau of Printing ami F.nsraUng 

 at Washington, under the direction of the 

 officials of the Treasury Department. This 

 test was made under a 250 horse-power 

 boiler, and the oil was burned by means of 

 two "Branch" burners. The report upon 

 this test reads as follows: "The result of 

 the test shows that 13.8 pounds of water 

 were evaporated from and at 212° F. per 

 pound of oil. That the total amount of 

 oil consumed was 3,323 pounds, which at 

 320 pounds per barrel, makes the cost, at 

 SI per barrel. $10.40, and that the amount 

 of coal necessary to evaporate the same 

 quantity of water as was evaporated by 

 the oil, assuming eleven pounds of water 

 to the pound of coal would be 4.351.3 

 pounds, which at $4 per ton would make 

 the corresponding cost of coal $7.76." 



In the catalogue issued by the Babcock ,*< 

 Wilcox Company, we find the following 

 statement regarding the relative value of 

 petroleum and coal : "Petroleum has a 

 heating capacity, when fullv burned, equal 

 to from 21.000 to 22,000 per pound, or say 

 50 per cent more than coal. But, owing 

 to the ability to burn it with less losses, 

 it has been found, through extended ex- 

 periments, that under the same boilers and 

 doing the same work a pound of petroleum 

 is equal to 1.8 pounds of coal. The experi- 

 ments on locomotives in Russia have shown 

 practically the same value, or 1.77. Now, a 

 gallon of petroleum weighs 6.7 pounds 

 (though the standard buying and selling 

 weight is 6.5 pounds), and therefore an 

 actual gallon of petroleum is equivalent 

 uuder a boiler to twelve pounds of coal, 

 and 190 standard gallons are equal to a 

 gross ton of coal. It is very easy with 

 these data to determine the relative cost. 



"At the wells, if the oil is worth say 2 

 cents per gallon, the cost is equivalent to 

 $3.80 per ton for coal at the same place, 

 while say at 3 cents per gallon, the lowest 

 price at which it can be delivered in the 

 vicinity of New York, it costs the same as 

 coal at $5.70 per ton. The Standard Oil 

 Company estimates that 173 gallons are 

 equal to a gross ton of coal, allowing for 

 incidental savings, as in grate bars, cart- 

 ing ashes, attendance, etc." 



The experiments just completed by the 

 Naval Fuel Board are the most comprehen- 

 sive and thorough of any that have ever 

 been conducted. As an average for four- 

 teen tests with crude oil as fuel. 11.60 

 pounds of water were evaporated from 

 about 120° F.. under a pressure of 279 

 pounds, to each pound of oil burned. This 

 is compared with the results of seventeen 

 coal tests in which the average evaporation 



Ground Plan for Horticultural Building at St. Louis. 



was S.12 pounds of water to each pound 

 of coal burned. This evaporation, in both 

 cases, as will be observed, took place at a 

 very high pressure, and included the heat- 

 ing of the feed water to the point where It 

 was evaporated. The equivalent evapora- 

 tion from and at 212° F. for the oil would 

 be 13.30 pounds of water per pound of oil, 

 and for the entire seventeen tests with coal 

 the equivalent evaporation would be 9.21 

 pounds of water per pound of coal. In 

 these coal tests, three grades of coal were 

 used, Pocahontas run of mine. New River 

 run of mine, and Pocahontas hand picked 

 and screened. During the first three tests 

 with Pocahontas run of mine, having a cal- 

 orific value of 14.067 heat units per pound 

 of coal, and 15,391 units per pound of 

 combustible, there resulted an equivalent 

 evaporation of 8.65 pounds of water per 

 pound of coal fed into the furnace. The 

 second three tests made with the same kind 

 of coal, but with a slightly higher heating 

 efficiency, produced an equivalent evapora- 

 tion of 9.40 pounds of water per pound of 

 coal fed into the furnace. The following 

 three tests made with New River run of 

 mine, having a calorific value of 14.S41 

 units per pound of coal, and 15.6S4 units 

 per pound of combustible, yielded an equiv- 

 alent evaporation of 9.36 pounds of water 

 per pound of coal fed into the furnace. 

 The remaining eight tests made with Poca- 

 hontas coal hand picked and screened, with 

 a calorific value of 14.992 units per pound 

 of coal, and 15.475 units per pound of com- 

 bustible, yielded an equivalent evaporation 

 of 9.30 pounds of water per pound of coal 

 fed into the furnace. 



Taking the general average equivalent 

 evaporation, for the seventeen coal tests, 

 of 9.21 pounds of water per pound of coal 

 fed into the furnace, we have 20,360.4 

 pounds of water evaporated from and at 

 212° F. to each ton of coal consumed. 



Calculating the cost of coal at $4.5 r 



ton. we have a rate of .0216 of a cent per 

 pound of water evaporated. To evaporate 

 the same quantity of water, using oil as 

 the fuel, as was evaporated by a ton of 

 coal, would require 1551.1 pounds of oil. 

 Calculating 320 pounds of oil to a barrel, 

 we have 4.S5 barrels of oil equaling one 

 ton of coal. Owing to the fact that oil 

 can be burned much more economically than 

 coal, we are safe in assuming that four 

 ordinary barrels of crude , I are equal to 

 one ton of the best seini-l. Luminous coal 

 for heating purposes. With these figures 

 before us and the price of both coal and 

 oil at hand, we can very readily calculate 

 the comparative cost of each. 



Crude oil is being successfully burned in 

 locomotives throughout the southwestern 

 part of the United States, also in all kinds 

 of steam generating appliances wherever 

 near enough the oil fields to warrant a 

 cheap and plentiful supply. The minimum 

 amount of attention required to do the 

 firing adds a factor in favor of petroleum 

 as fuel : in the case of the steamship Mari- 

 posa, sailing between San Francisco and 

 Tahiti, the introduction of oil has reduced 

 the firing force from twenty-two to three 



The use of crude oil is. however, attend- 

 ed with several difficulties : it kills animaR 

 'bar take it inwardly, and plants with 

 which it comes in contact. Crude oil con- 

 tains all the more volatile elements, includ- 

 ing the naphtha, and is highly explosive 

 and care must be taken in handling it" 

 When burning it in an enclosed furnace 

 explosions are liable to occur should the 

 flow of oil become temporarily Interrupted 

 upon the oils resuming its flow the furnace 

 becomes filled with gas. which, upon ignit- 

 ing, produces an explosion. Where artificial 

 gas is available it is desirable to maintain 

 a small jet within the furnace and near the 

 burner to serve as a lighter should tbe 

 oil gas become extinguished. Broken fire 

 brick, which become white hot. will serve 

 to relight the gases. 



Appliances for Burning Oil. 



There remains no question regarding the 

 mechanical application of crude oil In gen- 

 erating heat under boilers, and the only 

 drawback to its general adoption are the 

 limitations imposed by the supply and cost. 

 With a sufficient supply in view, however. 

 the limitation of cost may be disregarded 

 during a short emergency period. 



During the shortage in the coal supply 

 last year a great number of devices for 

 burning oil were placed upon the market. 

 ami main an "oiled brick" scheme was im- 

 posed upon the public. The advantages 

 claimed for many of the so-called oil burn- 

 ing outfits, by those who had them for sale, 

 were remarkable, indeed : plenty of heat 

 with half the cost of coal at ordinary 

 prices and absolute satisfaction were lib- 



