Liquid hydrocarbon fuels from catalytic cracking of waste cooking oils using ultrastable zeolite USY as catalyst

The effective utilization of waste cooking oil (WCO) has been a focus of concern in recent years, and is an important environmental issue. In this work, catalytic cracking of WCO to produce liquid hydrocarbon fuels without any pre-processing has been studied using ultrastable zeolite USY as a catalyst. The USY exhibited higher catalytic activity for the cracking of WCO than traditional base catalysts such as Na2CO3 and K2CO3. Moreover, the cracking of WCO generated fuels (containing C8C9 alkanes or olefins) that have a similar chemical composition to gasoil-based fuels. The influences of temperature, time, and USY dosage on the cracking have been examined. Under conditions of temperature 430 °C, reaction time 100 min, and m(USY):m(WCO) = 1:30, the yield of liquid products was over 64%. The USY could be reused up to six times without an apparent decrease in catalytic activity. XRD, FTIR, and N2 adsorption/desorption have been used to characterize the structures of the fresh and used USY. The results showed that USY having an integrated structure after use is an excellent catalyst for the cracking reaction.