INDUSTRIAL PROCESS
OF EXTRACTION
OF THE CASHEW NUT SHEL LIQUID - CNSL.
From the operation of separation of the nut it is obtained kernel and
the shel which it is the raw material for extraction of the cashew nut
shell liquid. This caustic liquid represents about 25% of the weight
of the nut. In the process of extraction it is obtained, 18% of CNSL
and 55% of residual pie are obtained that is used as fuel in the kettles.
EXPELLER PRESS
After the heating process, the shells are pressed obtaining CNSL
and a pie with a residual level of CNSL, that is extracted
by solvents.
PURIFICATION OF CNSL
CNSL., obtained by mechanical or solvent extraction
is submitted to the purification process that has the purpose of removing
CO2 and moisture. Cylindrical tanks of sheet iron, having
a serpentine that produces steam and agitation called purifiers are
used in the operation. Inside them the CNSL is heated
until the temperature of 140ºC, with agitation of 15 rpm for variable
time.
FILTRATION
The CNSL purified is filtered, to remove impurities
through press filters.
STORAGE
After filtration, the CNSL is stored in drums of 200
liters or in metallic tanks with varied capacity.
SPECIFICATIONS FOR CNSL.
For its quality control, the CNSL is evaluated according
to the following specifications:
| 1)
Specific gravity |
0,943
a 0,968 |
| 2)
Volatile matters |
2,0%
maximum |
| 3)
Strange matters (sludges) |
1,0%
maximum |
| 4)
pH |
6
- 8 |
| 5)
Moisture content |
1,0%
maximum |
| 6)
Ashes |
1,0%
maximum |
| 7)
Polimerization |
7
½ - 16 minutes |
| 8)
Iodine Value |
280
- 360 (wijs) |
| 9)
Refraction index |
1,5212
- 1,5218 |
| 10)
Saponification value |
29,7
- 30,2 |
|
