Oil removal from spent bleaching clay by solvent extraction
Titel:
Oil removal from spent bleaching clay by solvent extraction
Auteur:
Al-Zahrani, A. A. Alhamed, Y. A.
Verschenen in:
Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering
Paginering:
Jaargang 35 (2000) nr. 9 pagina's 1577-1590
Jaar:
2000-10
Inhoud:
Solvents screening experiments using a Soxhelt extractor were conducted to determine the best solvents for oil removal from spent bleaching clay. The solvents extracted oil in the following decreasing amount: methylethylketone > benzene-ethanol mixture (1:1 by volume) > acetone > trichloroethylene = dichloromethane > chloroform > petroleum ether > benzene > n-hexane > methanol. Four of the safest solvents, methylethylketone, acetone, petroleum ether and n-Hexane were selected for further studies. Large scale treatment of spent clay with the selected solvents were conducted in a batch stirred reactor. The effect of solvent type, solvent to clay ratio (SCR), time of extraction and extent of mixing on the percentage of oil extracted (POE) were investigated. The corresponding optimum conditions for the four solvents were: extraction time time = 5 minutes, solvent to clay ratio = 4 to 5, extraction temperature = 25 °C (room temperature) and mixing rate = 150 to 200 RPM. The bleaching efficiency (compaerd to to fresh clay) of the clay deoiled by methylethylketone, acetone, petroleum ether and n-hexane were 77%, 65%, 51% and 27%, respectively.
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