The disclosure provides use of an efficient, recyclable, green and friendly catalyst to realize a method of hydrogenation of an unsaturated alkene, and a method for preparing biodiesel through the transesterification of soybean oil with ethanol. The method of hydrogenation of the unsaturated alkene comprises performing a hydrogenation reaction of an unsaturated alkene at ambient temperature and atmospheric pressure by using a CO.sub.2 and magnetic dual-responsive mesoporous poly(ionic liquid) as a catalyst I, and using n-hexane and water as a solvent, to obtain a corresponding saturated alkane. The method for preparing biodiesel through transesterification of soybean oil with ethanol comprises performing a transesterification reaction of soybean oil with ethanol at a temperature of 25-90° C. and atmospheric pressure by using a CO.sub.2 and magnetic dual-responsive mesoporous poly(ionic liquid) as a catalyst II, to obtain the biodiesel.

Processes for separating conjunct polymer from an organic phase are described. A mixture comprising an ionic liquid phase and the organic phase into the ionic phase and an organic phase comprising the conjunct polymer and at least one silyl or boryl compound. The organic phase is separated in a fractionation column into an overhead fraction comprising unreacted silane or borane compound and a bottoms fraction comprising the conjunct polymer and the silyl or boryl compound. The bottoms fraction is passed through an adsorption zone, and the silyl or boryl compound is recovered. Alternatively, the organic phase is passed through an adsorption zone first to remove the conjunct polymer and then a fractionation zone to separate the unreacted silane or borane compound from the silyl or boryl compound.

One or more processes for recovering entrained ionic liquid from a hydrocarbon phase containing droplets of ionic liquid are described. The processes includes contacting the hydrocarbon phase containing the droplets of ionic liquid with a retaining material in a separation zone. The droplets of ionic liquid are retained by the retaining material. The ionic liquid may be recovered from the retaining material with a solvent or desorbent. The retaining material may be regenerated and the ionic liquid may be reactivated. The retaining material may be used in a wash vessel to retain or remove contaminant solids within the reactor or other vessels.

A method for regenerating deactivated acidic ionic liquid is described. The method involves reducing a level of free hydrochloric acid in the deactivated acidic ionic liquid in a removal zone using at least one of heat, a stripping fluid, reduced pressure, and liquid-liquid extraction to form a deactivated acidic ionic liquid having a reduced level of free hydrochloric acid; and regenerating the deactivated acidic ionic liquid having the reduced level of free hydrochloric acid.