Refrigerating ammonia absorption plant

Although ammonia condensation was already used in Haber s lab-scale ammonia plant and in early pilot plants of Bosch, the first commercial units of BASF used ammonia absorption in water to remove the product from the cool synthesis loop gas, because various technical problems were encountered with refrigeration at that time. It was only in 1926 that ammonia condensation was introduced in the Haber-Bosch... 

The refrigeration system consists of a large aqua-ammonia absorption refrigerator instead of a compression plant, mainly because of the ease with which the refrigeration load can be varied by controlling the oil feed to the boiler that heats the absorber. 

Use of heat downstream of the low temperature shift converter for absorption refrigeration which is used in the ammonia recovery section. In conventional plants this low level heat is used for reboiling in the carbon dioxide removal process. 

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