Process optimization of super phosphoric acid-catalyzed esterification of palm fatty acid distillate using response surface methodology

Abstract

The present study reports the findings of experiments carried out to optimize super phosphoric acidcatalyzed esterification of palm fatty acid distillate-a low-cost by-product of the palm oil refining process for biodiesel production. The main objectives were to develop an approach that would enable us to better understand the relationships between the governing variables, i.e., oil to methanol ratio, temperature and catalyst concentration, and the response (conversion of the biodiesel), and to obtain the optimum conditions for biodiesel production using central composite design (CCD) and response surface methodology (RSM). All the three variables significantly affected the acid value of the product, oil to methanol ratio being the most effective followed by temperature and catalyst concentration. Using response surface methodology, a quadratic polynomial equation was obtained for acid value by multiple regression analysis. Verification experiments confirmed the validity of the predicted model. Various properties of the biodiesel were evaluated and compared in relation to that of conventional petro-diesel. The prepared biodiesel blended with different proportion of petro-diesel was then subjected to performance and emission tests at varying loads in order to evaluate its actual performance, when used as a diesel engine fuel.

Microwave‐assisted biodiesel conversion of palm fatty acid distillate with performance tests in a single‐cylinder diesel engine

“…Normally, PFAD is a white‐yellow soft wax at room temperature and takes the form of a clear liquid with light brown color at around 50 °C, 10 so before using PFAD, it was heated to 50 °C and mixed in the desired molar ratio with methanol (MeOH), and commercial sulfuric acid (H 2 SO 4 at 98% concentration) was added to 2 wt% of the liquid mixture as an acid catalyst, so that the total volume of the liquid mixture was 1800 mL in every experimental run. The liquid mixture was then loaded into the Duran batch reactor, which was placed inside the microwave cavity to produce MWBD by esterification.…”

“…The liquid mixture properties, which depend on the molar fraction (x c c i i tot = / ; concentration of species i, and total concentration) of each component, were calculated using the molar fractions as weights. The relative complex permittivity, the dynamic viscosity, thermal conductivity, specific heat capacity, and density of liquid mixture for a species i (PFAD and methanol) were therefore calculated as molar-weighted averages, as expressed in Eqns ( 5)- (10). The initial parameters and properties needed in this model are listed in Table 2.…”

“…Natthapon and Krit 9 have reported a single‐step process to produce biodiesel from PFAD and MeOH with the following esterification conditions: MeOH‐to‐oil molar ratio 8:3; H 2 SO 4 catalyst 9.4 wt%; reaction time 92 min; reaction temperature 60 °C. Metre and Nath 10 report 12:1; 9 wt% super phosphoric acid, 300 min and 70 °C. Kanjaikaew et al 11 .…”

Biorefinery solid cake waste to biocrude via hydrothermal treatment: optimization of process parameters using statistical approach

“…where κ 0 ,κ i ,κ ii andκ ij are regression coefficients for linear, interaction and quadratic terms for the statistical analysis [17].…”