The Haber-Bosch process is developed for manufacturing ammonia in large scale from coke oven gas which is produced by coking of coal, coke which is rich in carbon and hydrogen and free from other volatile matter is used by gasification to produce carbon dioxide, carbon monoxide and hydrogen-rich gas. Water gas rich in Hydrogen is formed by scrubbing out carbon dioxide gas and a trace of carbon monoxide is removed by ammonical cuprous solution in the scrubber. The reaction mixture containing nitrogen and hydrogen is fed to the synthesis loop. This process is 1913 based design plant description which is not much economical in recent days because the shift conversion CO and CO2 require larger facilities and operating equipment for water gas.
Haber Bosch Ammonia production Flowsheet
|
A water gas generator is used for producing water gas from coke using air and steam (high pressure), the products formed by partial combustion contain CO, CO2, N2, and H2, is passed to the scrubber cooler where dust particles are removed. Gas holders are provided for the continuous supply of the gas and collection of settled residual liquids and condensed particles to the bottom for drain out. Carbon monoxide is converted to carbon dioxide and hydrogen by reacting with steam on the catalyst in a shift reactor.
The gas mixture is compressed in a compressor and sent to carbon dioxide purifier for removal of carbon dioxide fraction. Ammonia converter having packed bed of catalyst converts the synthesis gas to the ammonia gas, and is sucked by a circulating compressor which feds the product mixture to the ammonia absorber where is water is fed from the top of the column. Ammonia water is cooled to by the water cooler and stored. circulation of unreacted gas is done by the recirculation system for acquiring high conversion rates.
Haber Bosch Process Condition in the converter
Pressure = 330 atm
Temperature = 500-550 deg centigrade
conversion = 10-30%