Investigating the Batch and Continuous Transesterification of Linseed Oil by Using a Alkaline Heterogeneous Catalyst in a Packed Bed Reactor

Abstract

Both the continuous and batch transesterification of linseed oil were examined in order to maximize the fatty acid methyl esters (FAME) yield. The continuous process was conducted in a packed bed reactor using calcium oxide as a heterogeneous catalyst. In addition, the impact of two variables, namely the molar ratio of methanol to oil and the flow rate (ml/min), on the FAME yield were studied. Likewise, for the batch process, the reaction was carried out in a CSTR reactor using KOH as a homogeneous catalyst. Moreover, the influence of the molar ratio of methanol to oil and of catalyst concentration (wt. %) on the FAME yield was investigated. For both the batch and continuous process, FAME yield was optimized by using the Design Expert (Ver. 7.0.0) software. The optimum conditions for the continuous method were reported as follows: a molar ratio of methanol to oil of 11.75:1, a flow rate of 1.07 ml/min, and a temperature of 50oC. Under the optimum conditions, a FAME yield of 94.2423% was achieved. For the batch process, a FAME yield of 95.0672% was reached under the optimum conditions of a molar ratio of methanol to oil of 9.12:1, a catalyst concentration of 1.52 wt. %, a temperature of 40oC, an agitation rate of 650 rpm, and a reaction time of 60 minutes.

Keywords

• transesterification
• linseed oil
• continuous biodiesel production
• batch biodiesel production
• heterogeneous and homogeneous catalyst