Response surface methodology for optimization of bio‐lubricant basestock synthesis from high free fatty acids castor oil

Abstract

In this paper, an eco-friendly single-step process for the synthesis of biolubricant basestock from high free fatty acid (FFA) castor oil (CO) via epoxidation reaction was investigated. Influence of various process parameters on the structural modification of CO and their interaction with the maximum oxirane oxygen content (OOC) was optimized. Central composite design (CCD) as one of the tools in response surface methodology (RSM) was used to evaluate the effects of process variables on maximum OOC. Iodine value (IV) and OOC was used to monitor the progress of epoxidation. From the RSM study, the optimal condition inferred was H 2 O 2 , 1.65 mol; catalyst loading, 15.14 wt%; temperature, 52.81°C; and reaction time, 2.81 h. At this optimum condition, OOC was found to be 3.85 mass%. Further, the epoxide product was confirmed by 1 H, 13 C NMR spectral technique and OOC was determined by the standard HBr method. Finally, the significant physico-chemical properties for the prepared epoxide were determined and compared with the castor oil. 372

The Optimization of RBD Palm Oil Epoxidation Process using D-Optimal Design

“…Currently, plant oils based lubricant are increasingly used in lubricant industry to replace petrochemicals based lubricants due to their depletion at a faster rate, increasing cost of petrochemicals and rising concern for the environmental pollution (Borugadda & Goud 2015Kotwal et al 2013). It is due to plant oils are renewable resources, cheaper, biodegradable and non-toxic, compared to conventional source of petrochemicals.…”

“…However, plant oils have some drawbacks which will restrict their direct application as lubricant. One of the drawbacks is its low oxidative stabilty (Salimon et al 2011;Wu et al 2000) due to the presence of bis-allylic protons in plant oils structure which are highly susceptible to free radical attack and therefore undergoes oxidative degradation to form polar oxy compounds (Adhvaryu et al 2005;Borugadda & Goud 2015;Erhan et al 2006;Sharma et al 2007;Singh & Chhibber 2013). The rate of the oxidation process can be attributed to the numbers of unsaturated fatty acids presence in its composition (Borugadda & Goud 2015.…”

“…Percentage of epoxide product, EPO (yield), oxirane oxygen content value (OOC) and iodin value (IV) were chosen as responses in this optimization. The mathematical relationship between the process variables and responses were calculated by quadratic polynomial equation (Borugadda & Goud 2015;Salimon et al 2016):…”

“…where β 0 ; β i ; β ii and β ij are constant, linear, square and interaction regression coefficient terms, respectively and x i and x j are independent variables (Razali et al 2010;Salimon et al 2016). Analysis of variance (ANOVA) was carried out to estimate the effects of process variables and their possible interaction effects on the higher yield and OOC and lower IV in the response surface regression procedure (Borugadda & Goud 2015;Salimon et al 2016). The goodness and best fit of the model were evaluated by a regression coefficient R 2 (Borugadda & Goud 2015).…”

“…Analysis of variance (ANOVA) was carried out to estimate the effects of process variables and their possible interaction effects on the higher yield and OOC and lower IV in the response surface regression procedure (Borugadda & Goud 2015;Salimon et al 2016). The goodness and best fit of the model were evaluated by a regression coefficient R 2 (Borugadda & Goud 2015).…”