ACHIEVEMENTS OF CHEMICAL INDUSTRY DUISBERG. 233 



The moorland, after removal of the peat, is rendered serviceable for 

 agricultural purposes. 



At that place nearly 2,500 to 2,600 cubic meters of gas, ^dth 1,000 

 to 1,300 calories of heat, were obtamed from 1 ,000 -Ivilograms of abso- 

 lutely water-free peat in the form of air-dried peat, with 45 to 60 or 70 

 per cent of moisture. This gas represents energy equal to 1 ,000 horse- 

 power hours, equal to 700 kilowatt hours, after deducting the heat 

 and power used for the operation of the gas works. In addition 35 

 kilograms of ammonium sulphate were produced from the above 

 quantity of peat, wliich contains 1 per cent of nitrogen. 



The greatest problem of power production, the direct conversion of 

 coal into electric energy by means of gas batteries, a problem which 

 we had hoped to solve 25 years ago, is still to-day nothing more than 

 a dream. 



PRODUCTION OF COLD. 



Besides the problem of power and heat, the question of refrigera- 

 tion is one of glowing importance to the chemical industry. Instead 

 of the ammonia machines with which a temperature of minus 20° C. 

 can be attained, we emplo}' to-day sulphurous-acid machines, or, 

 better still, resort to the carbonic-acid gasifier, which yields a tempera- 

 ture of 40° C. below zero. It is hoped in the near future to produce 

 refrigerating machines which, by the use of suitable hydrocarbons, 

 will give temperatures of minus 80° C. Plants for the liquefaction of 

 air, producing as low a temperature as minus 190° C, are becom- 

 ing more and more common, and are especially profitable where 

 gas mixtures rich in oxygen, or where pure nitrogen, which are 

 simultaneously produced, can be utilized. Diagrams showing the 

 process invented by Linde for the rectification of liquid air with 

 the object of isolating nitrogen and oxj^gen are exhibited here. The 

 Badische Anilin and Soda Fabrik in Ludwigshafen on the Rhine in- 

 tends to manufacture hydrogen from water gas in a similar way and 

 to utilize the carbon monoxide, which is simultaneously obtained, 

 as a source of power. In a large plant which is being erected the 

 firm is going to produce ammonia synthetically by combining, accord- 

 ing to Ilaber's invention, pure nitrogen, obtained by the liquefaction 

 and rectification of air, with hydrogen manufactured as above. 

 Particulars about tliis process will bo given during the congress by 

 Prof. Bernthsen in his lecture on '^ Synthetic ammonia. " 



SIZE OF APPARATUS. 



Influenced bj the Solvay process for the manufacture of soda and 

 its pecuniary advantages, the apparatus used in the chemical indus- 

 try have enormously increased in size. In this respect the United 

 States, no doubt on account of the example sot by the u'on industry, 



