Handbook of Solvents - George Wypych - ChemTech - Ventech!

22.2 Solvent recovery 1549
Figure 22.2.8. Flow diagram of solvent recovery process.
Table 22.2.6. Brief specification of the
cycloparaffins recovery unit
Item Specification
Solvent cycloparaffins
Capacity 70 l/min
Dimensions 1,050 x 533 x 1,355 mm
Weight 250 kg (approx.)
Steam pressure 6.0 MPa
Steam consumption 25 kg/h
Cooling water 2MPa, >20 l/min
fied as a good cleaning solvent (see Table
22.2.4).
Table 22.2.5 shows the cleaning performance
of the solvent. Figure 22.2.6
shows the vapor pressure and combustion
range of the solvent. Figure 22.2.7 shows a
process diagram of cycloparaffins solvent
use in cleaning stamped metal parts. The
solvent is recycled after recovery by distillation.
Combining the cleaning and the distillation
process gives a continuous process.
Figure 22.2.8 shows a schematic diagram
of distillation process. Table 22.2.6
shows specification of the recovery unit.
22.2.5 HALOGENATED SOLVENT RECOVERY
22.2.5.1 Coating process
A process to recover ethylene dichloride, EDC, and methylene dichloride, MDC, using activated
carbon fibers, ACF, is discussed in this section. The gas at approximately 50°C, containing
EDC and MDC is received from a painting process. It is pretreated by a filter to
remove dusts and passed through a heat exchanger to cool it down to approximately
30-40°C. The pre-treated gas is fed to adsorption columns filled with ACF where the gas is
cleaned sufficiently for it to be safely released to atmosphere.