• Energy Research

Dans ce travail, une nouvelle méthode a été proposée pour la conversion des huiles de cuisson usagées en biodiesel. Une approche en deux étapes basée sur un prétraitement avec AlCl3•6H2O pour convertir les FFA en esters méthyliques pertinents, suivie de la transestérification complète des glycérides, sous catalyse KOH dans une colonne de distillation réactive, a été envisagée. Le prétraitement avec AlCl3•6H2O a permis d'obtenir deux phases différentes : une phase huileuse, riche en FAME et en triacylglycérols et avec une teneur très limitée en eau (100 ppm), et en FFA résiduel (1 mgKOH /goil), et une phase méthanol, dans laquelle la plupart du catalyseur, de l'eau et des monoacylglycérols ont été dissous. Le flux estérifié a été caractérisé par sa composition et utilisé pour obtenir de nouveaux paramètres cinétiques à utiliser dans le réglage de la distillation réactive. La colonne de distillation réactive s'est avérée efficace pour obtenir un flux de biodiesel avec une exigence de pureté conforme aux normes EN14214. L'étape de transestérification a été caractérisée par un besoin spécifique de chauffage de 701,3 kJ par kg de biodiesel produit. En este trabajo, se propuso un método novedoso para la conversión de aceite de cocina residual en biodiesel. Se consideró un enfoque de dos pasos basado en un pretratamiento con AlCl3•6H2O para convertir FFA en los ésteres metílicos relevantes, seguido de la transesterificación completa de glicéridos, bajo catálisis de Koh en una columna de destilación reactiva. El pretratamiento con AlCl3•6H2O permitió obtener dos fases diferentes: una fase oleosa, rica en FAME y triacilgliceroles y con un contenido muy limitado de agua (100 ppm), y FFA residual (1 mgKOH /Goil), y una fase de metanol, en la que se disolvió la mayor parte del catalizador, agua y monoacilgliceroles. La corriente esterificada se caracterizó por su composición y se utilizó para obtener nuevos parámetros cinéticos que se utilizarán en el ajuste de la destilación reactiva. La columna de destilación reactiva demostró ser eficiente en la obtención de una corriente de biodiesel con un requisito de pureza conforme a las normas EN14214. La etapa de transesterificación se caracterizó por un requisito de calentamiento específico de 701,3 kJ por kg de biodiésel producido. In this work, a novel method was proposed for the conversion of waste cooking oil into biodiesel. A two-step approach based on a pretreatment with AlCl3•6H2O to convert FFA into the relevant methyl esters, followed by the complete transesterification of glycerides, under KOH catalysis in a reactive distillation column, was considered. The pretreatment with AlCl3•6H2O allowed to obtain two different phases: an oily phase, rich in FAME and triacylglycerols and with a very limited content of water (100 ppm), and residual FFA (1 mgKOH /goil), and a methanol phase, in which most of the catalyst, water and monoacylglycerols were dissolved in. The esterified stream was characterized by its composition and used to obtain new kinetic parameters to be used in the setting of the reactive distillation. The reactive distillation column was proved to be efficient in obtaining a biodiesel stream with a purity requirement conform to the EN14214 standards. The transesterification step was characterized by a specific heating requirement of 701.3 kJ per kg of biodiesel produced. في هذا العمل، تم اقتراح طريقة جديدة لتحويل نفايات زيت الطهي إلى ديزل حيوي. تم النظر في نهج من خطوتين يعتمد على المعالجة المسبقة باستخدام AlCl3 • 6H2O لتحويل FFA إلى إسترات الميثيل ذات الصلة، يليه التحويل الكامل للغليسريدات، تحت تحفيز KOH في عمود التقطير التفاعلي. سمحت المعالجة المسبقة باستخدام AlCl3 • 6H2O بالحصول على مرحلتين مختلفتين: مرحلة زيتية، غنية بالشهرة وثلاثي أسيل الجلسرين وبمحتوى محدود جدًا من الماء (100 جزء في المليون)، وبقايا FFA (1 ملغ كوه/غويل)، ومرحلة ميثانول، حيث تم إذابة معظم المحفز والماء وأحادي أسيل الجلسرين. يتميز التيار الأستري بتكوينه ويستخدم للحصول على معلمات حركية جديدة لاستخدامها في إعداد التقطير التفاعلي. ثبت أن عمود التقطير التفاعلي فعال في الحصول على تيار ديزل حيوي مع متطلبات نقاء تتوافق مع معايير EN14214. تميزت خطوة التحويل بمتطلبات تسخين محددة تبلغ 701.3 كيلو جول لكل كيلوغرام من الديزل الحيوي المنتج.

Dans ce travail, une nouvelle méthode a été proposée pour la conversion des huiles de cuisson usagées en biodiesel. Une approche en deux étapes basée sur un prétraitement avec AlCl3•6H2O pour convertir les FFA en esters méthyliques pertinents, suivie de la transestérification complète des glycérides, sous catalyse KOH dans une colonne de distillation réactive, a été envisagée. Le prétraitement avec AlCl3•6H2O a permis d'obtenir deux phases différentes : une phase huileuse, riche en FAME et en triacylglycérols et avec une teneur très limitée en eau (100 ppm), et en FFA résiduel (1 mgKOH /goil), et une phase méthanol, dans laquelle la plupart du catalyseur, de l'eau et des monoacylglycérols ont été dissous. Le flux estérifié a été caractérisé par sa composition et utilisé pour obtenir de nouveaux paramètres cinétiques à utiliser dans le réglage de la distillation réactive. La colonne de distillation réactive s'est avérée efficace pour obtenir un flux de biodiesel avec une exigence de pureté conforme aux normes EN14214. L'étape de transestérification a été caractérisée par un besoin spécifique de chauffage de 701,3 kJ par kg de biodiesel produit. En este trabajo, se propuso un método novedoso para la conversión de aceite de cocina residual en biodiesel. Se consideró un enfoque de dos pasos basado en un pretratamiento con AlCl3•6H2O para convertir FFA en los ésteres metílicos relevantes, seguido de la transesterificación completa de glicéridos, bajo catálisis de Koh en una columna de destilación reactiva. El pretratamiento con AlCl3•6H2O permitió obtener dos fases diferentes: una fase oleosa, rica en FAME y triacilgliceroles y con un contenido muy limitado de agua (100 ppm), y FFA residual (1 mgKOH /Goil), y una fase de metanol, en la que se disolvió la mayor parte del catalizador, agua y monoacilgliceroles. La corriente esterificada se caracterizó por su composición y se utilizó para obtener nuevos parámetros cinéticos que se utilizarán en el ajuste de la destilación reactiva. La columna de destilación reactiva demostró ser eficiente en la obtención de una corriente de biodiesel con un requisito de pureza conforme a las normas EN14214. La etapa de transesterificación se caracterizó por un requisito de calentamiento específico de 701,3 kJ por kg de biodiésel producido. In this work, a novel method was proposed for the conversion of waste cooking oil into biodiesel. A two-step approach based on a pretreatment with AlCl3•6H2O to convert FFA into the relevant methyl esters, followed by the complete transesterification of glycerides, under KOH catalysis in a reactive distillation column, was considered. The pretreatment with AlCl3•6H2O allowed to obtain two different phases: an oily phase, rich in FAME and triacylglycerols and with a very limited content of water (100 ppm), and residual FFA (1 mgKOH /goil), and a methanol phase, in which most of the catalyst, water and monoacylglycerols were dissolved in. The esterified stream was characterized by its composition and used to obtain new kinetic parameters to be used in the setting of the reactive distillation. The reactive distillation column was proved to be efficient in obtaining a biodiesel stream with a purity requirement conform to the EN14214 standards. The transesterification step was characterized by a specific heating requirement of 701.3 kJ per kg of biodiesel produced. في هذا العمل، تم اقتراح طريقة جديدة لتحويل نفايات زيت الطهي إلى ديزل حيوي. تم النظر في نهج من خطوتين يعتمد على المعالجة المسبقة باستخدام AlCl3 • 6H2O لتحويل FFA إلى إسترات الميثيل ذات الصلة، يليه التحويل الكامل للغليسريدات، تحت تحفيز KOH في عمود التقطير التفاعلي. سمحت المعالجة المسبقة باستخدام AlCl3 • 6H2O بالحصول على مرحلتين مختلفتين: مرحلة زيتية، غنية بالشهرة وثلاثي أسيل الجلسرين وبمحتوى محدود جدًا من الماء (100 جزء في المليون)، وبقايا FFA (1 ملغ كوه/غويل)، ومرحلة ميثانول، حيث تم إذابة معظم المحفز والماء وأحادي أسيل الجلسرين. يتميز التيار الأستري بتكوينه ويستخدم للحصول على معلمات حركية جديدة لاستخدامها في إعداد التقطير التفاعلي. ثبت أن عمود التقطير التفاعلي فعال في الحصول على تيار ديزل حيوي مع متطلبات نقاء تتوافق مع معايير EN14214. تميزت خطوة التحويل بمتطلبات تسخين محددة تبلغ 701.3 كيلو جول لكل كيلوغرام من الديزل الحيوي المنتج.

In this work, avocado seeds were successfully used as precursors to produce carbon-based calcium catalysts for biodiesel production. The catalysts were synthetized via precipitation method, by loading different amounts of calcium nitrate on carbonized supports obtained by pyrolysis under nitrogen flow of dried biomass. The effect of Ca loaded on the structure and the activity of the catalysts for biodiesel synthesis from sunflower oil with methanol was investigated. Results showed that supported catalyst loaded with 20%wt of Ca, efficiently promote the trans-esterification process (FAMEs content >80%) with the catalyst that was easily recovered and reused. Reaction conditions were then optimised using the desirability function applied on the response surface methodology analysis of a Box-Behnken factorial design of experiments. Finally, the optimized conditions were adopted on several non-edible oils with Free Fatty Acids content range between 1 and 15 mg KOH/g. In all cases, a FAMEs content >95% was in any case obtained.

In this work, avocado seeds were successfully used as precursors to produce carbon-based calcium catalysts for biodiesel production. The catalysts were synthetized via precipitation method, by loading different amounts of calcium nitrate on carbonized supports obtained by pyrolysis under nitrogen flow of dried biomass. The effect of Ca loaded on the structure and the activity of the catalysts for biodiesel synthesis from sunflower oil with methanol was investigated. Results showed that supported catalyst loaded with 20%wt of Ca, efficiently promote the trans-esterification process (FAMEs content >80%) with the catalyst that was easily recovered and reused. Reaction conditions were then optimised using the desirability function applied on the response surface methodology analysis of a Box-Behnken factorial design of experiments. Finally, the optimized conditions were adopted on several non-edible oils with Free Fatty Acids content range between 1 and 15 mg KOH/g. In all cases, a FAMEs content >95% was in any case obtained.

Abstract Currently, monoglycerides (MG) are produced using a complicated energy-intensive technology that contributes negatively toward greenhouse gas mitigation. This work suggests a cleaner and simpler one-step enzymatic production of α-monolaurin in an inert membrane reactor, where the reaction and enzyme separation are conducted simultaneously in one unit. Candida antarctica lipase (Lipozyme 435) was used to catalyze the esterification reaction between lauric acid and glycerin in a solvent-free system under mild temperatures. Response surface methodology was used to optimize the reaction conditions. The optimal conditions were a molecular sieve of 14.85% w/w, a temperature of 56.95 °C, an enzyme amount of 5.38% w/w, and a molar ratio of 4.75% w/w. The gas chromatography (GC) analysis showed that the α-monolaurin percentage was 49.5% when the enzymatic process (ENZ) was used. The conventional chemical (CHEM) and autocatalytic (AUT) esterification methods were also performed to study their proportional MG yields. The GC results showed the MG percentages of 43.9 and 41.7% for CHEM and AUT, respectively. Economic analysis was also conducted for the suggested enzymatic technique, and the findings were compared with those of the CHEM and AUT technologies. Using a plant capacity of 4950 t/year and 11% interest for the proposed ENZ process, the total capital investment of α-monolaurin production was preferably four times less than that of the CHEM process and three times less than that of the AUT method, presenting investment possibilities. However, the ENZ process showed the least profitability (net profit per day) among the three processes. Nevertheless, the return on investment and net present value for the ENZ process were preferably higher than those of CHEM and AUT because of its interestingly lower inside battery limit plant cost and less energy consumption. The AUT/CHEM processes generated a total carbon dioxide (CO2) exhaust of 678.7 t CO2 eq./year. In contrast, the ENZ process exhausted a total CO2 of only 50 t CO2 eq./year. The present integrated techno-economic and environmental study of α-monolaurin production emphasizes the green and cost benefits of the proposed ENZ technology. Graphical Abstract

Abstract Currently, monoglycerides (MG) are produced using a complicated energy-intensive technology that contributes negatively toward greenhouse gas mitigation. This work suggests a cleaner and simpler one-step enzymatic production of α-monolaurin in an inert membrane reactor, where the reaction and enzyme separation are conducted simultaneously in one unit. Candida antarctica lipase (Lipozyme 435) was used to catalyze the esterification reaction between lauric acid and glycerin in a solvent-free system under mild temperatures. Response surface methodology was used to optimize the reaction conditions. The optimal conditions were a molecular sieve of 14.85% w/w, a temperature of 56.95 °C, an enzyme amount of 5.38% w/w, and a molar ratio of 4.75% w/w. The gas chromatography (GC) analysis showed that the α-monolaurin percentage was 49.5% when the enzymatic process (ENZ) was used. The conventional chemical (CHEM) and autocatalytic (AUT) esterification methods were also performed to study their proportional MG yields. The GC results showed the MG percentages of 43.9 and 41.7% for CHEM and AUT, respectively. Economic analysis was also conducted for the suggested enzymatic technique, and the findings were compared with those of the CHEM and AUT technologies. Using a plant capacity of 4950 t/year and 11% interest for the proposed ENZ process, the total capital investment of α-monolaurin production was preferably four times less than that of the CHEM process and three times less than that of the AUT method, presenting investment possibilities. However, the ENZ process showed the least profitability (net profit per day) among the three processes. Nevertheless, the return on investment and net present value for the ENZ process were preferably higher than those of CHEM and AUT because of its interestingly lower inside battery limit plant cost and less energy consumption. The AUT/CHEM processes generated a total carbon dioxide (CO2) exhaust of 678.7 t CO2 eq./year. In contrast, the ENZ process exhausted a total CO2 of only 50 t CO2 eq./year. The present integrated techno-economic and environmental study of α-monolaurin production emphasizes the green and cost benefits of the proposed ENZ technology. Graphical Abstract