Expanding residual gas from nitric acid mfr. - to provide coolant for pressure absorption column

摘要

In the expansion of residual gas from a pressure absorption column in HNO3 mfr., in which the residual gas is heated and then expanded in a residual gas turbine for mechanical energy prodn., the novelty is that, for cold energy prodn., the residual gas is heated to only 100-150 deg.C and then expanded with concomitant cooling to below the min. temp. level in the absorption column, the cooled residual gas then being used as coolant for cooling the absorption column and.)and/or the stream introduced into the column.