The following extract from the report of a committee, made to the American Society of Mechanical Engineers at a recent meeting, gives an idea of the value of the new fuel: "Natural gas, next to hydrogen, is the most powerful of the gaseous fuels, and, if properly applied, one of the most economical, as very nearly its theoretical heating power can be utilized in evaporating water. Being so free from all deleterious elements, notably sulphur, it makes better iron, steel, and glass than coal fuel. It makes steam more regularly, as there is no opening of doors, and no blank spaces are left on the grate bars to let cold air in, and, when properly arranged, regulates the steam pressure, leaving the man in charge nothing to do but to look after the water, and even that could be accomplished if one cared to trust to such a volatile water-tender. Boilers will last longer, and there will be fewer explosions from unequal expansion and contraction, due from cold draughts of air being let in on hot plates.
"An experiment was made to ascertain the value of gas as a fuel in comparison with coal in generating steam, using a retort or boiler of 42 inches diameter, 10 feet long, with 4 inch tubes. It was first fired with selected Youghiogheny coal, broken to about 4 inch cubes, and the furnace was charged in a manner to obtain the best results possible with the stack that was attached to the boiler. Nine pounds of water evaporated to the pound of coal consumed was the best result obtained. The water was measured by two meters, one in the suction and the other in the discharge. The water was fed into a heater at a temperature of from 60° to 62°; the heater was placed in the flue leading from the boiler to the stack in both gas and coal experiments. In making the calculations, the standard 76 lb. bushel of the Pittsburg district was used. Six hundred and eighty-four pounds of water were evaporated per bushel, which was 60.9 per cent. of the theoretical value of the coal. Where gas was burned under the same boiler, but with a different furnace, and taking 1 lb. of gas to be 2.35 cubic feet, the water evaporated was found to be 20.31 lb., or 83.4 per cent. of the theoretical heat units were utilized.
The steam was under the atmospheric pressure, there being a large enough opening to prevent any back pressure, the combustion of both gas and coal was not hurried. It was found that the lower row of tubes could be plugged and the same amount of water could be evaporated with the coal; but with gas, by closing all the tubes - on the end next the stack - except enough to get rid of the products of combustion, when the pressure on the walls of the furnace was three ounces, and the fire forced to its best, it was found that very nearly the same results could be obtained. Hence it was concluded that the most of the work was done on the shell of the boiler."
In no other way can I give the members of the Iron and Steel Institute so much information in regard to this new fuel as by including in this paper a very able communication from the chief chemist at our Edgar Thomson Steel Works, Mr. S.A. Ford, who is to-day the highest authority upon the subject:
"So much has been claimed for natural gas as regards the superiority of its heating properties as compared with coal, that some analyses of this gas, together with calculations showing the comparison between its heating power and that of coal, may be of interest. These calculations are, of course, theoretical in both cases, and it must not be imagined that the total amount of heat, either in a ton of coal or 1,000 cubic feet of natural gas, can ever be fully utilized. In making these calculations I employed as a basis what in my estimation was a gas of an average chemical composition, as I have found that gas from the same well varies continually in its composition. Thus, samples of gas from the same well, but taken on different days, vary in nitrogen from 23 per cent. to nil, carbonic acid from 2 per cent. to nil, oxygen from 4 per cent, to 0.4 per cent., and so with all the component gases. Before giving the theoretical heating power of 1,000 cubic feet of this gas I will note a few analyses. The first four are of gas from the same well; samples taken on the same day that they were analyzed.
The two last are from two different wells in the East Liberty district:
ANALYSES OF NATURAL GAS. --------------------+--------+--------+--------+--------+--------+--------+ | 1 | 2 | 3 | 4 | 5 | 6 | --------------------+--------+--------+--------+--------+--------+--------+ When tested.........|10-28-84|10-29-84|11-24-84|12-4-84 |10-18-84|10-25-84| | per ct.| per ct.| per ct.| per ct.| per ct.| per ct.| Carbonic acid ......| 0.8 | 0.6 | Nil. | 0.4 | Nil. | 0.30| Carbonic oxide......| 1.0 | 0.8 | .58 | 0.4 | 1.0 | 0.30| Oxygen... ... ......| 1.1 | 0.8 | .78 | 0.8 | 2.10| 1.20| Olefiant gas .......| 0.7 | 0.8 | 0.98| 0.6 | 0.80| 0.6 | Ethylic hydride ....| 3.6 | 5.5 | 7.92| 12.30 | 5.20| 4.8 | Marsh gas ..........| 72.18| 65.25| 60.70| 49.58 | 57.85| 75.16| Hydrogen ...........| 20.02| 26.16| 29.03| 35.92 | 9.64| 14.45| Nitrogen ...........| Nil. | Nil. | Nil. | Nil. | 23.41| 2.89| Heat units .........|728,746 |698,852 |627,170 |745,813 |592,380 |745,591 | --------------------+--------+--------+--------+--------+--------+--------+
"We will now show how the natural gas compares with coal, weight for weight, or, in other words, how many cubic feet of natural gas contain as many heat units as a given weight of coal, say a ton. In order to accomplish this end we will be obliged, as I have said before, to assume as a basis for our calculations what I consider a gas of an average chemical composition, viz.:
Per cent. Carbonic acid............................ 0.60 Carbonic oxide........................... 0.60 Oxygen................................... 0.80 Olefiant gas............................. 1.00 Ethylic hydride.......................... 5.00 Marsh gas............................... 67.00