Pollutec Recycling

Solvent Recovery From Hazardous Wastes

Table 22.2.5. Cleaning performance of solvents

Table 22.2.4. Properties of cycloparaffins as a cleaning solvent

Property	Value
Appearance	transparent
Color (Seibolt)	+30
Specific gravity	0.839
Viscosity, 40°C Cst	1.6
Flash point, °C	76
Aniline point	58
Cycloparaffins content, %	80
Alkylbenzene content, %	10
Aromatics content, %	1

Table 22.2.5. Cleaning performance of solvents

Cleaning solvent	Oils	Residual oil, mg/cm2
	press oil	0.0017
cycloparaffins	fan press oil	0.0015
	bender oil	0.0017
	press oil	0.0021
trichloroethane	fan press oil	0.0013
	bender oil	0.0013

The process was previously used for chlorine compounds represented by perchloroethylene and trichloroethyl-ene and for fluorine compounds used for cleaning of press stamped metal parts. However, these compounds are now prohibited for use and production by environmental regulations. The current replacements include emulsions, organic and inorganic solutions, etc. Cycloparaffins originating from petroleum products were quali-

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20 40 60 80 100 120 140 160 Temperature {"O

20 40 60 80 100 120 140 160 Temperature {"O

Figure 22.2.6. Vapor pressure and combustion range of cycloparaffins.

Figure 22.2.7. Metal parts cleaning employing cycloparaffins.

(ultrasonic) spray

Figure 22.2.7. Metal parts cleaning employing cycloparaffins.

Feed

Used solvent

solvent)

Figure 22.2.8. Flow diagram of solvent recovery process.

solvent)

PumP Settling tank

Figure 22.2.8. Flow diagram of solvent recovery process.

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.

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