Heterogeneous Catalyst For Biodiesel Production Research Articles

Fabrication of hollow cage-like CaO catalyst for the enhanced biodiesel production via transesterification of soybean oil and methanol

Designing a cost-effective and environmentally-friendly heterogeneous catalyst for biodiesel production is an essential yet a challenging aspect for renewable energy applications. To achieve this, a newly fabricated hollow cage-like CaO catalyst (CaO-700N) was prepared by the pyrolysis of hollow CaCO3 under precisely controlled calcination temperature (700 °C) and N2 atmosphere. The prepared catalyst was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, temperature programmed desorption of CO2 and N2-adsorption/desorption. The newly fabricated CaO catalyst exhibited porous hollow cage-like structure, high basic strength and density, leading to high catalytic activity for the production of biodiesel via the transesterification of soybean oil with methanol. A biodiesel yield of 97.80 % was attained under the optimal reaction conditions of 3 wt% catalyst concentration, 15:1 methanol/oil molar ratio, 65 °C reaction temperature and reaction time of 2 h. The catalyst remained highly stable and maintained biodiesel yield of above 90.30 % after the fifth reuse. Based on the characterization and activity results, a suitable reaction mechanism for the catalytic conversion of soybean oil to biodiesel using hollow cage-like CaO catalyst was proposed. Moreover, the scaling up of transesterification with the synthetic biodiesel production of over 95.69 % for 4 h was reported. The physiochemical properties of synthetic biodiesel were in accord with the biodiesel standards. Attributed to the intriguing properties like cost-effectiveness, ease of synthesis and environmental greenness, the hollow cage-like CaO catalyst could be considered as a potential candidate for the production of biodiesel on industrial level application.

Production of biodiesel from waste cooking oil using ZnCuO/N-doped graphene nanocomposite as an efficient heterogeneous catalyst

The use of heterogeneous catalyst for biodiesel production can reduce the price of separation process and therefore minimize the biodiesel cost. ZnCuO/N-doped graphene (NDG) catalyst synthesized by facile mechanochemical procedure was tested in the transesterification of waste cooking oil (WCO) with methanol to produce biodiesel. The effects of catalyst loading (0–15 wt%), weight percentage of NDG (10–100%), methanol to oil molar ratio (6:1–18:1), reaction time (2–10 h) and reaction temperature (120–200 °C) were systematically studied at the optimal conditions. Additionally, the properties of the fabricated catalysts were assessed via XRD, FTIR, N2 sorption studies, HRTEM, TGA and Raman spectroscopy. It was found that the ZnCuO/(X%)NDG nanocomposites exhibit enhanced catalytic performance when compared with the ZnCuO catalyst (without NDG) under the identical conditions. The efficacy of the ZnCuO/(X%)NDG nanocomposites has improved owing to the inclusion of NDG in the catalytic system, which in-turn enhanced the properties of the mixed metal oxides (MMO’s) such as surface area, defective sites to a great extent. The ZnCuO/(30%)NDG catalyst displayed a highest catalytic activity towards transesterification of WCO (97.1%) at the optimized conditions of 10 wt% catalyst loading, 15:1 methanol:oil molar ratio, 8 h reaction time and 180 °C reaction temperature. Moreover, the recovered catalyst was successfully reused six cycles with no discernible loss in its activity.

Utilization of Naturally Available Moringa Oleifera Leaves as a Heterogeneous Catalyst for Biodiesel Production: Catalyst Characterization, Process Optimization and ANN Modeling

In this work, naturally available moringa oleifera leaves are chosen as a heterogeneous catalyst for biodiesel production from palm oil. The dry moringa oleifera leaves are calcinated up to 7000C for 3 hours to improve their adsorbing property. The calcinated catalyst characterization analysis from XRD and EDX highlights the presence of calcium, potassium, and other elements. Response surface method (RSM) optimization and artificial neural network (ANN) modeling were carried out to elucidate the interaction effect of significant process variables on biodiesel yield. The results show that a maximum biodiesel yield of 92.82% was achieved at optimum conditions of catalyst usage (9 wt.%), molar ratio (7:1), temperature (500C) and reaction time (180 min). The catalyst usage (wt.%) was identified as a significant process variable followed by molar ratio. Furthermore, the significant fuel properties of the biodiesel related to thermal, physical, chemical and elemental match with the established standards of ASTM. The reutilization analysis of the catalyst reveals that more than 50% of the biodiesel yield was achieved after five cycles of reuse.

Potato Peels as a Sustainable Source for Biochar, Bio-Oil and a Green Heterogeneous Catalyst for Biodiesel Production

Potato Peels as a Sustainable Source for Biochar, Bio-Oil and a Green Heterogeneous Catalyst for Biodiesel Production

Biodiesel: An Overview II

The crescent number of scientific articles published per year shows that research on biodiesel continues to play an important role to support the growing demand for this biofuel. The second edition of Biodiesel: An Overview presents the worldwide research in the last 15 years. Microalgae biomass is the most studied raw material alternative in this period and several studies have been carried out to develop basic heterogeneous catalysts for biodiesel production. Concerning to production technologies, supercritical conditions and intensification process have been extensively investigated. The development of new antioxidants additives has focused mainly on biomass-derived formulations and there are few studies on biocide candidates. In terms of pollutant emissions, in general, the studies showed that the addition of biodiesel generates lower concentrations of polycyclic aromatic hydrocarbons (PAH), CO and n-alkanes pollutants, but carbonyl compounds, major ions and NOx are emitted in a higher concentration compared to pure diesel.

Indonesia Natural Zeolite as Heterogeneous Catalyst for Biodiesel Production

The problem associated with biodiesel production is economic feasibility. The biodiesel cost will reduce when the low cost feedstock was used. Kapok seed oil (KSO) is a promising candidate as raw material for biodiesel synthesis. In this research, the investigation of biodiesel synthesis from KSO was studied using Indonesia Natural Zeolite as heterogeneous catalysts. The catalyst was tested to synthesize biodiesel from KSO. The reaction temperatures, KSO to methanol mole ratio, and catalyst amount were varied to examine their effects on biodiesel synthesis. The highest biodiesel yield of 84% were obtained at 65°C of reaction temperature, 1:16 of KSO to methanol mole ratio, and 10% of catalyst amount.

Synthesis of the SrO–CaO–Al2O3 trimetallic oxide catalyst for transesterification to produce biodiesel

Calcium oxide is one of the most promising heterogeneous catalysts for biodiesel production. However, an inherent drawback of CaO is the leaching of active species into the reaction solution with the degraded reusability. To strengthen the stability, different supports are composited with the SrO–CaO oxide through the hydrothermal method and mass ratio of SrO to CaO are optimized to get the best outcome of the catalyst. Meanwhile, various characterization methods, including TG, XRD, SEM-EDX, CO2-TPD, XPS, ATR-FTIR and ICP-AES, are used to explore the physicochemical properties of catalysts. The 0.4-SrO-CaO-Al2O3 catalyst shows the best catalytic capability in transesterification of palm oil with methanol to produce biodiesel, where the FAME yield of 98.16% is achieved with the molar ratio of methanol to oil of 18:1 and catalyst concentration of 7.5 wt% at 65 °C for 3 h. Besides, ascribed to the greatly reduced leaching out of the active species, this catalyst presents the satisfying reusability and the FAME yield is slightly decreased to 92.61% for the fifth reused cycle. Therefore, this modification method for SrO–CaO–Al2O3 is feasible for enhancing the catalytic stability in transesterification.

Modified ZnO to Indonesia Limestone as heterogeneous catalysts for biodiesel production from Reutealis trisperma Oil

The Bukit Jaddih Madura limestone has been modified as a heterogeneous catalyst in the transesterification reaction for biodiesel production. Limestone has been calcined at 900 ° C for 3 hours (CL) and it has been modified with ZnO using a wet impregnation method (ZnO/CL) to improve its catalytic activity. Catalysts were characterized by infrared spectroscopy (FTIR), X-ray diffraction (XRD), SEM-EDX and basicity test. FTIR analysis showed that BKK and ZnO/CL were easily hydrated and carbonated. XRD analysis showed that CL and ZnO/CL catalysts contained CaO, MgO and a little Ca(OH)2. SEM analysis showed that CL and ZnO/CL had different morphologies and sizes. Basicity test showed base strength of CL was 15,0 <H_ <18,4 and ZnO/CL was 8,2 <H_ <15,0. The catalyst activity on the transesterification reaction of Reutealis trisperma oil with methanol showed that biodiesel yield increased with increasing ZnO concentration.

Synthesis and Characterization of Sodium Silicate Produced from Corncobs as a Heterogeneous Catalyst in Biodiesel Production

In this study, silica derived from corncobs impregnated with sodium hydroxide to obtain sodium silicate was calcined, prepared, and employed as a solid base catalyst for the conversion of oils to biodiesel. The catalyst was characterized by X-Ray Diffraction (XRD), Fourier-Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope Energy Dispersive X-Ray Spectroscopy (SEM-EDS), and Brunauer-Emmet-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods. Gas Chromatography-Mass Spectrometry (GC-MS) was used to characterize the biodiesel products. The optimum catalyst conditions were calcination temperature of 400 °C for 2 h, catalyst loading of 2%, and methanol: oil molar ratio of 12:1 at 60 °C for 60 min, that resulted in a yield of 79.49%. The final product conforms to the selected biodiesel fuel properties of European standard (EN14214) specifications. Calcined corncob-derived sodium silicate showed high potential for use as a low-cost, high-performance, simple-to-prepare solid catalyst for biodiesel synthesis.

Synthesis of hierarchical flower-shaped hollow MgO microspheres via ethylene-glycol-mediated process as a base heterogeneous catalyst for transesterification for biodiesel production

Hierarchical flower-shaped hollow MgO (f-MgO) spheres were synthesized through an ethylene-glycol-mediated polyol process via hydrothermal reactions. The structure of f-MgO originates from intermediate flower-shaped Mg glycolate through the Ostwald ripening process. The surface of f-MgO consists of uniform petal-like nanosheets that provide high surface area and excellent accessibility to catalytic sites. Also, the f-MgO microsphere can prevent aggregation and stacking problems of nanosheets and control a surface area for catalytic activity. The morphology and structure of f-MgO were investigated using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The density of basic catalytic sites was derived from CO2-temperature-programmed desorption measurements. The f-MgO exhibits a basic site density of 0.5134 mmol/g, which is much higher than that of commercial MgO (c-MgO, 0.0288 mmol/g). Experimental results for the fatty acid methyl ester revealed that the catalytic strength of f-MgO as a heterogeneous catalyst for biodiesel production is greater than that of c-MgO. The maximum biodiesel conversion efficiency of f-MgO from canola oil is 93.4%, which is greater than the value of 91.4% for c-MgO.

Application of Heterogeneous Catalysts for Biodiesel Production from Microalgal Oil—A Review

The depletion of fossil fuel reserves and increased environmental concerns related to fossil fuel production and combustion has forced the global communities to search for renewable fuels. In this regard, microalgae-based biodiesel has been considered as one of the interesting alternatives. Biodiesel production from the cultivation of microalgae is eco-friendly and sustainable. Moreover, microalgae have several advantages over other bioenergy sources, including their good photosynthetic capacity and faster growth rates. The productivity of microalgae per unit land area is also significantly higher than that of terrestrial plants. The produced microalgae biomass is rich with high quality lipids, which can be converted into biodiesel by transesterification reactions. Generally, the transesterification reactions are carried out in the presence of a homogeneous or heterogeneous catalyst. The homogeneous catalysts have many disadvantages, including their single use, slow reaction rate and saponification issues due to the presence of fatty acids in the feedstock. The acidic nature of the homogeneous catalysts also causes equipment corrosion. On the other hand, the heterogeneous catalysts offer several advantages, including their reusability, higher reaction rate and selectivity, easy product/catalyst separation and low cost. Due to these facts, the development of solid phase transesterification catalysts have been receiving growing interest. The present review is focused on the use of heterogeneous catalysts for biodiesel production from microalgal oil as a reliable feedstock with a comparison to other available feedstocks. It also highlights optimal reaction conditions for maximum biodiesel yields, reusability of the solid catalysts, cost, and environmental impact. The superior lipid content of microalgae and the efficient concurrent esterification and transesterification of the solid acid−base catalysts can offer new advancements in biodiesel production.

Graphitic carbon nitrides: Efficient heterogeneous catalysts for biodiesel production

Abstract Biodiesel remains one of the most promising sustainable alternatives to fossil fuel-derived energy; however, current process limitations and steep production costs associated with the use of homogeneous catalysts have limited global-wide acceptance and adoption. While heterogeneous catalysts have been put forth as suitable alternatives, they suffer from numerous drawbacks including high metal content and cost. As such, the search for novel and inexpensive alternatives is currently underway. Graphitic carbon nitride macrostructures have been widely investigated for photocatalytic applications yet their role in driving chemically-catalyzed reactions remains relatively unexplored. Herein, we synthesized and investigated the use of bulk, fiber, acid- and thermal-treated carbon nitrides as heterogeneous catalysts for the transesterification of canola oil to biodiesel. A conversion of 96% was achieved using 1 wt% catalyst loading, a low oil to methanol ratio of 1:24 and a reaction temperature and time of 150 °C and 3 h, respectively. Carbon nitrides offer a high thermal stability, cost effective and metal-free alternative to the many proposed metal-containing heterogeneous catalysts for biodiesel production, while maintaining high biodiesel conversions of >90%.

Preparation of calcium modified Zn-Ce/Al2O3 heterogeneous catalyst for biodiesel production through transesterification of palm oil with methanol optimized by response surface methodology

The calcium modified Zn-Ce/Al2O3 heterogeneous base catalysts are synthesized by the hydrothermal method, impregnation method and co-precipitation method, respectively. Further, they are applied to catalyze transesterification of palm oil with methanol for the biodiesel production. The hydrothermal method with the Ca: Zn: Ce: Al molar ratio of 5: 4: 1: 1 is preferred to synthesize the catalyst due to the best catalytic performance. The catalyst shows strong reusability, where the biodiesel yield of 87.37% is obtained for the fifth reused cycle and the weakened catalytic capability is mainly ascribed to the leaching out of the active sites. The response surface methodology with the central composite design (RSM-CCD) is employed to optimize thetransesterification parameters and predict the biodiesel yield. The predicted maximum biodiesel yield of 99.44% is achieved at the reaction temperature of 66.12 °C, methanol to oil molar ratio of 18.53 and catalyst amount of 8.19 wt.% with 3 h, which is consistent with the experimental result of 99.41%. Also, the physical properties of the produced biodiesel meet the ASTM D 6751 standard. This study reveals the Ca-Ce-Zn/Al2O3 catalyst gains a good application prospect in the biodiesel production and the response surface methodology is effective in optimizing the transesterification parameters and predicting the optimal values.

Reusable and efficient heterogeneous catalysts for biodiesel production from free fatty acids and oils: Self-solidifying hybrid ionic liquids

A series of self-solidifying hybrid ionic liquids (SHILs) were synthesised via a mild nucleophilic substitution reaction between (3-aminopropyl)trimethoxysilane and 1,3-propanesultone followed by a facile sol-gel reaction, during which not any acid, catalyst or support was introduced. Part of the grafted –SO3H groups would make SHILs become solid nature by forming the zwitterion, while the rest of –SO3H groups could endue SHILs with acidic catalytic sites. Besides, –Si–O–Si– networks formed by the sol-gel reaction would further impart the water-tolerance and heterogeneity to SHILs, conducive to the easy separation and good reusability. For the oleic acid esterification catalysed by P-APTMS-PS-5 SHIL, 96.55% conversion was achieved under appropriate conditions (optimised by response surface methodology), and the catalytic activity well remained after 7 cycles. More importantly, SHILs exhibited excellent catalytic activity and satisfactory generality in the esterification of various free fatty acids, as well as in the transesterification of different oils, signifying the great potential for biodiesel production.

Preparation and evaluation of alpha‐cellulose sulfate based new heterogeneous catalyst for production of biodiesel

AbstractAlpha‐cellulose obtained from wood sawdust wastes in 29.0% yield was reacted with sulfuric acid to produce alpha‐cellulose sulfate materials. These catalyst materials were characterized by Fourier transform infrared and specular reflectance‐UV spectroscopy, scanning electron microscopy, and laser scattering particle size distribution. The concentration of sulfate groups on the cellulosic matrix was determined by turbidimetry. The obtained alpha‐cellulose sulfates can be used as efficient heterogeneous catalysts for biodiesel production from palm oil when evaluated with methylation of palmitic acid and oleic acid as the model reaction. The density of sulfate functional groups on the alpha‐cellulose sulfate materials was 2.18–16.74% wt/wt as determined by turbidimetry. Standardization of deployed alpha‐cellulose sulfate catalysts was achieved using different ratios of alpha‐cellulose and sulfate (1:0.5, 1:1, 1:2, and 1:4 m/v). Additionally, the Bronsted acid sites on the alpha‐cellulose sulfate catalyst play a pivotal role in the catalytic process.

Synthesis of sodium titanate catalysts using a factorial design for biodiesel production

AbstractIn this work, the synthesis of sodium titanate for the biodiesel production was evaluated with emphasis on the synthesis parameters of titanates in the conversion of vegetable oil to biodiesel. Sodium titanate catalysts were synthesized via sol–gel hydrothermal method and tested as heterogeneous catalysts for biodiesel production, using a factorial design 2k. Four experimental factors were considered: NaOH concentration, hydrothermal temperature, TiO2/NaOH ratio, and calcination temperature, using as response variable the catalysts activity in soybean oil conversion to biodiesel. Titanates were characterized by XRD, SEM, and N2 physisorption techniques. The presence of tri and hexatitanate were confirmed. Trititanate was the most efficient in the conversion of soybean oil to biodiesel, achieving around 80% with an alcohol:oil molar ratio of 6:1 at 55°C for 5 hr and 300 rpm. Among the trititanate catalysts, the best performing sample showed a surface area of 217 m2/g with a porous size average of 4.8 nm related to nanotube structure with inter and intra particle mesoporosity. Conditions to prepare the efficient performing catalyst were as follows: NaOH concentration, 7.5 M; hydrothermal temperature, 130°C; TiO2/NaOH ratio, 0.06 g/mL; and calcination temperature, 600°C.

Synthesis of sodium zincsilicate (Na2ZnSiO4) and heterogeneous catalysis towards biodiesel production via Box-Behnken design

This study synthesizes a Na2ZnSiO4 phase as efficient and low-cost heterogeneous catalyst for biodiesel production. X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) along with Energy Dispersive X-Ray Spectroscopy (EDS), Brunauer–Emmett–Teller (BET) surface area analysis isotherms are herein conducted to characterize the structure, texture, composition and surface area of the catalyst, respectively. A Box-Behnken design (BBD) is performed to screen out: the methanol: oil ratio (6:1 to 14:1), catalyst load (0.5 to 5.5 wt%) and stirring rate (500 to 800 RPM), affecting the transesterification reaction using commercial soybean oil as a triglyceride source while fixing the temperature reaction at 65 °C. The oil and its fatty acid methyl esters (FAME) are characterized using Fourier Transform Infrared Spectroscopy with an Attenuated Total Reflectance modulus (FT-IR-ATR). XRD and SEM confirm the successful synthesis of the monoclinic Na2ZnSiO4 phase with low traces of ZnO (<5 wt%) and undetectable for Na2SiO3; presenting a BET surface area around 1.9 m2 g−1. The material is quite active towards the biodiesel production since a conversion superior to 99% is achieved in 45 min, using the statistical optimization conditions estimated with the BBD, 500 RPM, 5.30 wt% and 14:1 MeOH: Oil ratio. According to the response surface methodology, the sensitivity of the parameters increases in the following order: catalyst load > methanol: oil ratio > stirring rate. The FAME conversions drop to 48.4 and 62.42% after 5 cycles of continuous catalyst reuse, according to FT-IR-ATR and proton nuclear magnetic resonance (1H NMR) measurements, respectively.

Optimization of biodiesel synthesis from microalgal (Spirulina platensis) oil by using a novel heterogeneous catalyst, β-strontium silicate (β-Sr2SiO4)

The β-Strontium silicate (β -Sr2SiO4) was synthesized by physicochemical methods and was used as a heterogeneous catalyst in biodiesel production from microalgal oil (-Spirulina platensis) by transesterification process. The physical and chemical properties of the catalyst were analysed using TGA, XRD, ATR-FTIR, SEM-EDX, and surface area analyser. XRD and FTIR analyses confirmed the formation of β-Sr2SiO4 which was able to perform transeterification reaction. Several reaction parameter such as catalyst wt %, molar ratio (methanol :oil) and time have been optimized for transesterification reaction. The optimization of reaction parameters was accomplished by response surface methodology based on Box-Behnken design. Reusability study of catalyst was accomplished up to six run with 76.34% fatty acid methyl ester (FAME) conversion. A 97.88% maximum FAME conversion was observed at 65 °C, 600 rpm, 2.5 wt% catalyst, 1:12 methanol to oil molar ratio and 104 min reaction time.The biodiesel properties conform to ASTM standards.

Rhodotorula mucilaginosa: A source of heterogeneous catalyst for biodiesel production from yeast single cell oil and waste cooking oil

Abstract Biodiesel obtained from yeast derived single cell oil (SCO) is considered as an alternative to conventional biodiesel derived from plant oils, having the potential to substitute petroleum-derived transport fuels. In this work, we have developed a heterogeneous potassium hydroxide catalyst (K-RAC) supported on Rhodotorula mucilaginosa deoiled cake activated carbon (RAC) to enhance the conversion of R. mucilaginosa isolate R2 derived SCO as well as waste cooking oil (WCO) to biodiesel. The prepared catalyst was characterized by XRD, FTIR, EDX, SEM, BET and TGA. Basicity of the catalyst was determined by CO2-TPD and the hammet indicator test. The maximum fatty acid methyl esters (FAME) conversion of 96.6% and 98.66% for SCO and WCO respectively were obtained at optimized parameters i.e. 9:1 molar ratio (methanol/oil), 3 wt % of K-RAC loading at 60 °C and reaction time of 3 h. 1H NMR and GCMS was used to confirm the formation of biodiesel. The K-RAC was recycled effectively for five consecutive cycles.

Biodiesel Production Catalyzed by Polyvinyl Guanidineacetic Membrane

Polyvinyl guanidineacetic (PVG) was synthesized by the chemical grafting using poly (vinyl alcohol) (PVA) and guanidineacetic acid. The fourier transform infrared (FTIR), thermogravimetry (TG) and 1H nuclear magnetic resonance (1H NMR) results showed that the guanidineacetic groups were successfully introduced into the PVA. The effects of the amount of catalyst and reaction time on the PVG grafting rate were investigated. The PVG/non-woven fabrics (NWF) composite membrane as a heterogeneous catalyst for biodiesel production was successfully prepared by the solvent phase inversion. The effects of mass ratio of methanol/soybean oil, the IEC values of the composite membranes and reaction temperature on the transesterification conversions using the composite membrane for biodiesel were studied. The soybean oil conversion of 98.2% was obtained by the composite membranes under the optimum reaction conditions of reaction temperature of 338 K, methanol/oil mass ratio of 3:1, reaction time of 120 min and the alkali amount of catalytic membrane 18.0 mmol. After five runs, the conversion declined only 2.1%. And the kinetics of the reaction catalyzed by the composite membrane was performed as a first order reaction with an activation energy of 40.614 kJ/mol and pre-exponential factor of 7.60 × 104. The conversions obtained from the model are in good agreement with the experimental data. The quality of the biodiesel met the biodiesel requirements of Chinese Standard (GB/T 20828) and European Standard (EN 14214).