AIChE Journal, Vol.48, No.7, 1572-1580, 2002
Supercritical fluid extraction of surfactant from Si-MCM-41
Supercritical fluid extraction has been carried out on as-synthesized Si-MCM-41 in a study to evaluate the efficiency of SFE in the recovery of the organic template cetyltrimethylammonium hydroxide (CTMAOH) from the pores of Si-MCM-41. Effects of different extraction parameters on the extraction efficiencies were investigated. The results show that modified CO, is required to extract CTMAOH. High extraction efficiencies are obtained at 85degreesC and at both 100 and 350 bar, while the lowest efficiency is obtained at 150 bar. The extraction efficiency also increases initially on increasing the modifier concentration and reaches a limiting value when the concentration is increased further. Among a series of modifiers studied, methanol and acidic methanol (modified with acetic acid) are effective. The modifiers used in the extraction have a significant impact on the properties of the final material. The compound extracted was characterized and identified as CTMAOH.