Standard Operating Procedure (SoPs) for utilization of Spent Solvent
The SoPs outlined in this document have been developed after conducting trial studies based on a monitoring protocol prepared in consultation with experts/ seeking comments from public. The trial studies have been conducted by CPCB in association with SPCBs by engaging EPA/NABL/ISO17025 accredited laboratories. Few random samples, as applicable, were also collected by CPCB to ascertain the results with the third party labs. SoPs and checklists have been prepared only after examining the individual case for compliance with the monitored parameters as per trial run protocol and after evaluating requisite infrastructure for utilization.
It is endeavor of CPCB to continuously improve upon the utilization process based on the technology improvements, implementation and experience gained on larger scale. Therefore, the conditions specified in SoPs or Check-list are subjected to change from time to time, which would be circulated to SPCBs/PCCs.
CPCB will be sending updated list of SoPs from time to time, by including new SoPs which may also cover modifications if any to the existing SoPs.
This SoP is applicable only for recovery of solvent from the following spent solvents:
Type |
Source |
Recovery/Product |
Spent Solvent |
Pharma Industries |
Recovered Xylene, |
Spent Solvent |
Industrial use of spent solvent |
Recovered Acetone, |
The recovery of solvent shall involve fractional distillation of spent solvent followed by single or two stages cooling in primary and secondary condenser, based on the boiling point of the spent solvent/residue.
Water shall be used as cooling medium for condenser for recovery of spent solvents having boiling point of 1000C and above whereas for solvents with low boiling point (i.e. <1000C), the unit shall provide secondary condenser with chilled water/brine as cooling medium.
Detailed SoPs are attached here with..