Kinetic modelling of hydrogen transfer deoxygenation of a prototypical fatty acid over a bimetallic Pd60Cu40 catalyst: an investigation of the surface reaction mechanism and rate limiting step

Herein, for the first time, we demonstrate a novel continuous flow process involving the application of tetralin as a hydrogendonor solvent for the catalytic conversion of oleic acid to diesel-like hydrocarbons, using an efficient and stable carbonsupported bimetallic PdCu catalyst. Using Pd60Cu40/C, where 60:40 is the molar ratio of each metal, at optimum reactionconditions (360 °C and WHSV = 1 h-1), 90.5% oleic acid conversion and 80.5% selectivity to C17 and C18 paraffinic hydrocarbonswere achieved. Furthermore, a comprehensive mechanistic based kinetic modelling - considering power rate law, L-H andE-R models was conducted. Kinetic expressions derived from the three kinetic models were investigated in rate data fittingthrough nonlinear regression using a Levenberg-Marquardt algorithm. Based on the statistical discrimination criteria, theexperimental data of the dehydrogenation reaction of tetralin was best fitted by an L-H rate equation assuming the surfacereaction as the rate controlling step. On the contrary, the kinetic data of the oleic acid deoxygenation reaction was wellcorrelated with an L-H rate equation assuming single site adsorption of oleic acid with dissociative H2 adsorption. It wasfound that the rate limiting step of the overall reaction was the hydrogenation of oleic acid with an activation energy of 75.0± 5.1 kJ mol-1 whereas the dehydrogenation of tetralin had a lower activation energy of 66.4 ± 2.7 kJ mol-1

Advanced oxidation technologies for the treatment and detoxification of olive mill wastewater: a general review

Abstract Olive oil production has an economic importance for Mediterranean countries, ensuring employment opportunities and export earnings. The crushing units produce two types of residues, one solid (pomace) and the other liquid, called olive mill wastewater (OMW). This by-product has adverse effects on the olive oil sector and particularly on the quality of waters into which they are discharged. Hence, there is a critical need to orient the scientific research toward the treatment of this hazardous waste. Several techniques have been proposed and developed for OMW management. However, the advanced oxidation processes (AOP) remain the most advantageous with high treatment efficiencies. This trend allowed achieving a significant detoxification of OMW. A considerable amount of effort has been expanded to provide detailed and critical reviews on the use of this alternative technology in the treatment of water and wastewaters. Regrettably most, if not all, of these review papers were not focused mainly on OMW application. This paper aims to highlight the ancient and recent progress of various types of oxidation techniques for OMW treatment. Moreover, principles, advantages, limitations, and efficiencies of each method are presented, to gain a more scientific understanding of the most feasible approach regarding the treatment of this harmful residue.</jats:p

UPGRADING OF MOROCCAN OLIVE MILL WASTEWATER USING ELECTROCOAGULATION: KINETIC STUDY AND PROCESS PERFORMANCE EVALUATION

Treatment of olive mill wastewater (OMW) by electrocoagulation (EC) was investigated in a stirred tank reactor (STR), the effect of dif ferent influential parameters , namely, contact time, current density and pH was determined. O ver 72 % of COD, 93 % of polyphenols and 95 % of color intensity were re moved efficiently at pH of 5.2, current density of 58.33 mA/cm 2 and a residence time of 45 min. A kinetic study of these three parameters was carried out and both COD an d dark color removal obey the first-order law model. On the other hand, the polyphen ols reduction, fits the pseudo second-order model with cu rrent- dependent parameters. A variable order kinetic (VOK) model derived fro m the Langmuir-Freundlish equati on was proposed to determine the kinetics of pollutant removal reactions with EC. Results showed that the model equations strongly fit the experimental concentrations of the three pollutants

UPGRADING OF MOROCCAN OLIVE MILL WASTEWATER USING ELECTROCOAGULATION: KINETIC STUDY AND PROCESS PERFORMANCE EVALUATION

Treatment of olive mill wastewater (OMW) by electrocoagulation (EC) was investigated in a stirred tank reactor (STR), the effect of different influential parameters, namely, contact time, current density and pH was determined. Over 72 % of COD, 93 % of polyphenols and 95 % of color intensity were removed efficiently at pH of 5.2, current density of 58.33 mA/cm2 and a residence time of 45 min. A kinetic study of these three parameters was carried out and both COD and dark color removal obey the first-order law model. On the other hand, the polyphenols reduction, fits the pseudo second-order model with current- dependent parameters. A variable order kinetic (VOK) model derived from the Langmuir-Freundlish equation was proposed to determine the kinetics of pollutant removal reactions with EC. Results showed that the model equations strongly fit the experimental concentrations of the three pollutants.</jats:p

UPGRADING OF MOROCCAN OLIVE MILL WASTEWATER USING ELECTROCOAGULATION: KINETIC STUDY AND PROCESS PERFORMANCE EVALUATION

Treatment of olive mill wastewater (OMW) by electrocoagulation (EC) was investigated in a stirred tank reactor (STR), the effect of different influential parameters, namely, contact time, current density and pH was determined. Over 72 % of COD, 93 % of polyphenols and 95 % of color intensity were removed efficiently at pH of 5.2, current density of 58.33 mA/cm2 and a residence time of 45 min. A kinetic study of these three parameters was carried out and both COD and dark color removal obey the first-order law model. On the other hand, the polyphenols reduction, fits the pseudo second-order model with current- dependent parameters. A variable order kinetic (VOK) model derived from the Langmuir-Freundlish equation was proposed to determine the kinetics of pollutant removal reactions with EC. Results showed that the model equations strongly fit the experimental concentrations of the three pollutants.</jats:p