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Operation of ammonia--pyridine units

Journal Article · · Coke Chem., USSR (Engl. Transl.); (United States)
OSTI ID:6156332

Every carbonization plant has an ammonia--pyridine unit (APU), which consists of ammonia columns and equipment for extraction of crude light pyridine bases (CLBP) from the acidic solution used to absorb bases from the coke-oven gas in the saturators or absorbers of sulfate units. Two APU designs are common in Soviet plants. In designs of type I, the vapor emerging from the column is particularly condensed in a special dephlegmator; the resultant hot reflux is used to irrigate the rectification protion of the ammonia column, while the rectified vapor, containing 15 to 18% ammonia is delivered to the neutralizer for neutralization of the solution and decomposition of the base sulfates. The vapor emerging from the neutralizer is condensed in a special condenser; the resultant condensate separates into crude LPB and an aqueous layer, which is turned to the neutralizer. Systems of type II are distinguished by absence of a dephlegmator; the rectification portion of the column is irrigated with reflux cooled to 30 to 40/sup 0/ (the aqueous layer from the separator, which is rich in volatile ammonium salts). There is considerable recycling of the ammonia and the acidic gases accompanying it in both systems. This article compares the two common designs. Calculations based on simplified material and heat balances were made. Comparison of the two systems showed that system II, the newer one, had no advantages over system I.

OSTI ID:
6156332
Journal Information:
Coke Chem., USSR (Engl. Transl.); (United States), Journal Name: Coke Chem., USSR (Engl. Transl.); (United States) Vol. 4; ISSN COKCA
Country of Publication:
United States
Language:
English