Catalyst Ratio Research Articles

Biodiesel Production from Animal Fats Using Blast Furnace Geopolymer Heterogeneous Catalyst: Optimisation and Kinetic Study

Abstract Biodiesel is a sustainable fuel alternative that is typically produced through a transesterification process that primarily employs homogeneous catalysts. However, they generate significant amounts of wastewater and are often non-\recyclable. This study aims to investigate the application of heterogeneous blast furnace slag geopolymer catalyst for biodiesel production from animal fat. Central composite design was employed to optimise the transesterification process, considering four key variables: the methanol-to-oil ratio (20–50 wt.%), reaction time (3–7 h), reaction temperature (30–70 °C) and catalyst-to-oil ratio (3–15 wt.%). The heterogeneous geopolymer catalyst was characterised using Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. These analyses confirmed the geopolymerisation of the blast furnace slag and revealed no modifications to the geopolymer structure following the transesterification reaction. RSM optimisation resulted in 97.436% biodiesel yield, which was achieved at a constant stirring rate of 450 RPM, a reaction time of 6.254 h, a catalyst ratio of 9.996 wt.%, a methanol-to-animal fat ratio of 33.435 wt.%, and a reaction temperature of 50.509 °C, which was experimentally validated. The transesterification process followed pseudo-first-order reaction kinetics, with an activation energy of 43.76 kJ/mol. These findings demonstrate the potential of animal fat as a low-cost feedstock for biodiesel production catalysed by blast furnace slag geopolymer, offering a more sustainable and environmentally friendly alternative to traditional homogeneous catalysts.

Optimization and Analysis of Pyrolysis-Supercritical Fluid Extraction for Tobacco Waste Biomass

ABSTRACT A large amount of tobacco product waste is discarded directly, resulting in a waste of resources and environmental issues. Nicotine is a natural organic compound found in tobacco waste. As an important substance in treating neurological disorders, it is of high market value. Pyrolytic and supercritical fluid extraction is a method to extract nicotine from tobacco waste. We used the orthogonal experimental method to optimize the pyrolysis process of tobacco waste and found the optimal pyrolysis conditions to be the temperature of 450°C, time of 3 h, and catalyst ratio of 1:1.5. The mathematical model of extraction conditions and extraction rate of supercritical fluid extraction was established with R2 = 0.9884. This model showed that the extraction rate of nicotine could reach as high as 70.53%. The optimal conditions for nicotine extraction included the entraining agent concentration of 70%, temperature of 45°C, pressure of 30 MPa, and time of 2 hours. We also carried out response surface analysis to explore the relationship between extraction conditions and the extraction rate. According to our findings, entrainer concentration has a strong relationship with pressure. Ethanol can alter the microstructure of the substrate, increasing its porosity and thus reducing the embedding or adsorption depth of the nicotine molecules. As a result, the nicotine extraction efficiency is improved. Compared with traditional nicotine extraction process, the pyrolysis and supercritical fluid extraction has a higher extraction efficiency and less pollution.

Access to Polyhydroxyalkanoates with Diverse Syndiotacticity via Polymerization by Spiro-Salen Complexes and Insights into the Stereocontrol Mechanism.

Polyhydroxyalkanoates (PHAs) have attracted broad interest as promising sustainable materials to address plastic pollution and resource scarcity. However, the chemical synthesis of stereoregular PHAs via ring-opening polymerization (ROP) has long been an elusive endeavor. In this contribution, we exploited a robust spiro-salen yttrium complex (Y3) as the catalyst to successfully prepare syndiotactic PHAs with diverse pendent groups. Simply altering the ratio of enantiomeric catalysts allowed to access of PHAs with diverse syndiotacticity (Pr = 0.5-0.99, from sticky oil to tough materials), delivering tunable thermal properties (glass transition temperature, Tg from -52 to 70 °C and melting transition temperature, Tm from 38 to 223 °C). A combined experimental and computational study suggested a polymeric exchange mechanism could boost the polymerization activity and control the syndioselectivity.

Access to Polyhydroxyalkanoates with Diverse Syndiotacticity via Polymerization by Spiro‐Salen Complexes and Insights into the Stereocontrol Mechanism

Polyhydroxyalkanoates (PHAs) have attracted broad interest as promising sustainable materials to address plastic pollution and resource scarcity. However, the chemical synthesis of stereoregular PHAs via ring‐opening polymerization (ROP) has long been an elusive endeavor. In this contribution, we exploited a robust spiro‐salen yttrium complex (Y3) as the catalyst to successfully prepare syndiotactic PHAs with diverse pendent groups. Simply altering the ratio of enantiomeric catalysts allowed to access of PHAs with diverse syndiotacticity (Pr = 0.5−0.99, from sticky oil to tough materials), delivering tunable thermal properties (glass transition temperature, Tg from –52 to 70 °C and melting transition temperature, Tm from 38 to 223 °C). A combined experimental and computational study suggested a polymeric exchange mechanism could boost the polymerization activity and control the syndioselectivity.

Going from Pt to PGM-free Catalysts: Effects of Ink Compositions on PEM Water Electrolysis.

The commercialisation of PEM water electrolysis is still hindered by the necessity of using noble metals that are rare, expensive and therefore unsustainable. To replace the benchmark HER catalyst Pt with more abundant materials, promising non-noble catalysts need to be identified and optimal electrode preparation and electrolysis conditions need to be transferred between catalyst materials to reveal their full potential under industrially relevant conditions. This study investigates the optimal ink composition for spray-coating the cathode regarding the effects on electrode structure, performance and catalyst layer composition. The ratio of catalyst to binder and carbon support was varied as well as the specific carbon material and the resulting electrodes were analysed via polarisation curves, electrochemical impedance spectroscopy, X-ray photo-electron spectroscopy and scanning electron microscopy for three different catalysts. These results show that ink compositions with a catalyst : carbon : binder ratio of 3:1:1 using Carbon Vulcan give the highest performance. Interestingly, resulting trends concerning electrochemical behaviour and electrode structure observed with different characterisation techniques can be transferred between Pt catalysts and non-noble transition metal chalcogenide materials. Boosting the performance via ink optimisation is much more pronounced for the non-noble catalysts, narrowing the gap to competing with noble standard Pt materials.

Electro-activated peroxymonosulfate based on hollow cubic skeleton nanoflower cathode catalyst MoSe2/cubic nanocage (CNC) for enhanced degradation of norfloxacin: Performance, mechanism, degradation pathways and toxicity

Recently, antibiotic wastewater pollution has become increasingly serious. In this study, a novel hollow cubic framework self-supported nanoflower-like cathode catalyst (MoSe2/CNC) based on Co Fe prussian blue analogues (CoFePBA)-derived cubic nanocage (CNC) loaded with MoSe2 was successfully prepared and utilized in an electro-activated peroxymonosulfate (PMS) system for norfloxacin (NOR) degradation. Benefit from the combined structures of MoSe2, MoC, and Co/FeNC, the electrocatalytic activity and specific surface area were greatly improved. The effects of catalyst dosage and ratio, current, PMS concentration, electrolyte type, pH, as well as initial concentration were comprehensively investigated. Under the optimal conditions, NOR and TOC removal reached 92.70% and 82.17%, respectively, which was superior to the previous studies. Additionally, ·O2− was proved to be the primary reactive species for NOR degradation.·Based on density functional theory (DFT) and intermediates analysis, NOR underwent substitution and ring-opening reactions in the piperazine ring, substitution of fluoride ions, and cleavage of the carboxyl group and tetrahydropyridine ring, ultimately converting into water, carbon dioxide, and inorganic ions. Moreover, toxicity assessment and seed germination experiments demonstrated that the toxicity of NOR and intermediates were strongly decreased by electro-activated PMS system based on MoSe2/CNC cathode. Overall, this study not only contributes to the evolution of efficient and sustainable wastewater purification technology, but also provides valuable insights into the degradation of antibiotic wastewater.

Polyhydroxykanoate-Assisted Photocatalytic TiO2 Films for Hydrogen Production.

The photocatalytic production of hydrogen using biopolymer-immobilized titanium dioxide (TiO2) is an innovative and sustainable approach to renewable energy generation. TiO2, a well-known photocatalyst, benefits from immobilization on biopolymers due to its environmental friendliness, abundance, and biodegradability. In another way, to boost the efficiency of TiO2, its surface properties can be modified by incorporating co-catalysts like platinum (Pt) to improve charge separation. In this work, the surface of commercial TiO2 PC500 was modified with Pt nanoparticles (Pt1%@PC500) and then immobilized on glass surfaces using polyhydroxyalkanoate biopolymer poly(hydroxybutyrate-co-hydroxyhexanoate) (PHBH). The as-prepared immobilized Pt-modified TiO2 photocatalysts were fully characterized using various physicochemical techniques. The photocatalytic activity of the photocatalyst film was investigated for photocatalytic hydrogen production through water reduction using ethanol as a sacrificial donor. The impact of the film preparation conditions, e.g., PHBH concentration, PHBH:catalyst ratio, and temperature, on activity and stability was studied in detail. The application of biopolymer PHBH as a binder provides a green alternative to conventional immobilization methods, and with the application of PHBH, a stable and active photocatalyst film that showed lower activity compared to that of the suspended photocatalyst but good recyclability in six runs was prepared. A long-term photocatalytic hydrogen production experiment was carried out. In 98 h of operation, 12 mmol of hydrogen was produced in three consecutive runs with a PHBH/Pt1%@PC500 film having an area of ∼5.3 cm2. A significantly lower hydrogen productivity was observed after the first run, possibly due to a change in film structure, but thereafter, the productivity remained almost constant for the second and third runs. Hydrogen was the main product in the gas phase (90%), but carbon dioxide (4-5%) and methane (4-5%) were obtained as important byproducts. The byproducts are a consequence of the use of the sacrificial reagent ethanol. The results of the film performance are very promising, with regard to large-scale continuous hydrogen production.

Bifunctional Oxygen Electrodes for PEM-Unitized Regenerative Fuel Cell Fabricated By Inkjet Printing

Hydrogen energy storage has proven to be a promising technology to balance the intermittency of renewable energy sources. The high theoretical specific energy density achieved by fuel cell-based systems makes them attractive for energy production, especially for weight and space-sensitive applications.A unitized regenerative fuel cell (URFC) is a single device that works as both an electrolyzer and a fuel cell. The cost of a URFC could be significantly reduced compared to a separate electrolyzer and a fuel cell, since material costs are nearly halved. However, working with a single unit means that the system needs to be designed for both processes, which requires compromises to optimize the overall performance. The performance of URFC systems is significantly affected by the electrode’s fabrication method, so to further develop new and more efficient, durable, and cost-effective bifunctional catalyst layers (CL) for these systems, a more fundamental understanding of the relationship between the CL structure, and performance is required.The most common approach in the literature for fabricating bifunctional CLs for the oxygen electrode in a URFC is to mix both ORR and OER catalysts in a single ink. An alternative method, however, is to deposit layers containing different catalysts next to each other. Even though the latter approach has shown promising results, with the potential for optimization, limited work has been published to date [1-5]; moreover, no study has been done using the inkjet printing technique for the fabrication of either mixed or multilayer arrangement electrodes.In this work, inkjet printing is evaluated as a feasible technique for unitized regenerative fuel cells (URFCs) electrode fabrication and to study the optimal ionomer and catalyst loading of mixed and multi-layer URFC electrodes. A physical mixture of Pt, IrOx, and Nafion ionomer was inkjet printed directly on a Nafion membrane to fabricate varying loading bifunctional oxygen electrodes for a URFC and characterized via scanning electrode microscopy and cyclic voltammetry. The results show coverage of the Pt active sites by IrOx when the catalysts are mixed, which means that reducing the IrOx catalyst compared to platinum, i.e., 3:1 Pt-IrOx ratio is necessary for optimum performance [6]. A catalyst loading study shows that a round-trip efficiency of 51% at 500 mA/cm2 can be obtained using 0.67 mgPtIrOx/cm2 PMG catalyst loading in the oxygen electrode, resulting in one of the highest efficiencies by the amount of catalyst reported. The results are compared with a multilayer arrangement electrode, showing that the partial coverage of Pt sites by the IrOx can be avoided by printing the catalysts in separate layers. The Pt to Ir ratio was critical to the successful operation of the multilayer arrangement when the IrOx layer was in contact with the GDL, due to the poor conductivity of the CL, which at the highest loadings provided a barrier for the electrons to reach the Pt layer near the membrane. A catalyst ratio study showed optimum performance with a 9:1 Pt to Ir ratio, obtained with the electrode with the IrOx layer on top of the Pt CL and these on top of the PEM. In this case, the total catalyst loading was 0.56 mgPtIrOx/cm2, reaching a round-trip efficiency of 51% at 500 mA/cm2 and 44% at 1000 mA/cm2, one of the highest RT efficiency for a multi-layer arrangement and by the amount of catalyst of any constant gas bifunctional electrode reported in the literature.[1] Guobao Chen, Huamin Zhang, Haipeng Ma, and Hexiang Zhong. Electrochimica Acta, 54(23):5454–5462, 2009.[2] Sebastian Altmann, Till Kaz, and Kaspar Andreas Friedrich. Electrochimica Acta, 56(11):4287–4293, 2011.[3] Woong Hee Lee and Hansung Kim. Journal of The Electrochemical Society, 161(6):F729, 2014.[4] Byung-Seok Lee, Hee-Young Park, Min Kyung Cho, Jea Woo Jung, Hyoung-Juhn Kim, Dirk Henkensmeier, Sung Jong Yoo, Jin Young Kim, Sehkyu Park, Kwan-Young Lee, Electrochemistry Communications, 64:14–17, 2016.[5] Seunghoe Choe, Byung-Seok Lee, and Jong Hyun Jang. Journal of Electrochemical Science and Technology, 8(1):7–14, 2017.[6] L Padilla Urbina, J Liu, N Semagina, and M Secanell. Journal of Power Sources, 580:233448, 2023.

Exploring the Impact of Cathode Ionomer Content on Alkaline Exchange Membrane Fuel Cells (AEMFCs) Using Inkjet Printing Technique

Hydrogen proton exchange membrane fuel cells (PEMFCs) typically rely on expensive platinum group metals (PGMs) as catalysts. A promising strategy to eliminate the need for PGM catalysts is to operate the cell under alkaline conditions. Non-PGM based AEMFCs have achieved power densities exceeding 1 W/cm2, and various commercial electrolytes, such as Tokuyama A201/A901/AS-4, FumaTech Fumasep, Ionomr Aemion, and Versogen PiperION, have been developed and are available for researchers to explore and enhance AEMFC performance. Unfortunately, AEMFCs using commercial materials have not yet demonstrated performance and stability comparable to PEMFCs even though their ion transport properties are similar. Therefore, there is a need to study the physical processes that are limiting the performance of these materials in AEMFC membrane electrode assemblies (MEAs).AEMFCs electrode performance is very sensitive to a myriad of factors with two key factors being: a) the fabrication method; and b) ionomer to catalyst ratio. Regarding the former, unlike in PEMFCs, the number of fabrication techniques studied to fabricate AEMFC electrodes in the literature has been limited with only a handful of studies utilizing techniques such as ultrasonic spray-coating and doctor blade to control the catalyst layer structure. The development of novel fabrication techniques would therefore help the development of these technologies and allow more systematic studies to be performed, such as a detailed analysis of the ionomer to catalyst ratio. Even though previous research already showed the sensitivity of AEMFC performance to variations in ionomer content [2,4-6,11,17], its influence at varying temperatures and with newly developed commercial materials has not been thoroughly investigated. Furthermore, its effect on cell stability has not received sufficient attention.In this work, inkjet printing is introduced as a novel fabrication method for AEMFC electrode fabrication and applied to fabricate low-loading PGM-based CCMs with varying and graded cathode ionomer loading for AEMFCs. The inkjet-printed CCMs were tested in operating AEMFCs with H2/O2 at 60 °C, demonstrating a cell power density of 0.53 W/cm2 with a total loading of 0.3 mgPt/cm2, one of the highest reported in the literature using commercial materials (see figure), along with high repeatability and stability. The effect of cathode ionomer content and grading was studied at 60 °C and 80 °C with 90% RH inlet gases. The optimal cathode ionomer content at the beginning of life was identified as 20 wt% under both conditions, but the cell experienced unstable performance over time at 80 °C, with a decrease in cell voltage during constant current holds. Adding more ionomer to the cathode decreased the rate of cell degradation, which we hypothesize is due to increased water retention. The graded cathode, with more ionomer close to the AEM, appears to be the best strategy to minimize the observed instability.[1] T. Reshetenko et al., Journal of Power Sources 375 (2018) 185–190.[2] R. B. Kaspar et al., Journal of the Electrochemical Society 162 (6) (2015) F483.[3] D. Yang et al., Chinese Journal of Catalysis 35 (7) (2014) 1091–1097.[4] D. Yang et al., Journal of Power Sources 267 (2014) 39–47.[5] A. Carlson et al., Electrochimica Acta 277 (2018) 151–160.[6] X. Xie et al., International Journal of Energy Research 43 (14) (2019) 8522–8535.[7] P. S. Khadke and U. Krewer, Electrochemistry Communications 51 (2015) 117–120.[8] B. Britton and S. Holdcroft, Journal of The Electrochemical Society 163 (5) (2016) F353.[9] J. Zhang et al., Cell Reports Physical Science 2 (3).[10] D. Sebastian et al., Catalysts 10 (11) (2020) 1353.[11] S. Kim et al., Electrochimica Acta 400 (2021) 139439.[12] I. Gatto et al., ChemElectroChem 10 (3) (2023) e202201052.[13] N. U. Saidin et al., Asia-Pacific Journal of Chemical Engineering e3024.21[14] V. M. Truong et al., Materials 12 (13) (2019) 2048.[15] T. Novalin et al., Journal of Power Sources 507 (2021) 230287.[16] Q. Wei, et al., Sustainable Energy & Fuels 6 (15) (2022) 3551–3564.[17] J. Hyun et al., Journal of Power Sources 573 (2023) 233161.[18] E. Sediva et al., Journal of Power Sources 558 (2023)232608. Figure 1

Leveraging Machine Learning and Data Mining for Enhanced PEM-Electrolysis Using Standardized Data Management

Green Hydrogen production by water electrolysis is paramount in the transition from fossil fuels towards a carbon neutral industry. Hydrogen is expected to function as energy carrier in mobility, energy storage medium in electricity grids and as regenerative fuel in industrial processes such as steel production. Proton exchange membrane water electrolysis (PEMWE) stands out as a promising technology for hydrogen production due to high current densities with high efficiencies and highly dynamic operation. While the number of publications on the production of PEM electrolysers grows steadily, a lack of standardized methodologies and experimental guidelines persists. Many studies focus on specific components and their manufacturing steps, hindering direct comparison and complicating data interpretation. Consequently, standardization of research data and specification of parameters is the objective of the current research landscape.In this work, we systematically analyzed literature and gathered meta data regarding experimental procedures for lab-scale production of PEM electrolysers. Thereby, special attention is on the identification of potential improvement in data management. The production of electrolysers can be divided into the various tasks as the fabrication of membrane electrode assemblies (MEAs), which includes catalyst ink production, coating and assembly, electrolyser design and characterization. All areas are in turn subdivided into metadata, for example the ionomer to catalyst ratio and catalyst content for the catalyst ink, the coating technology such as spray or slot coating for the coating. In total, over 60 different parameters were considered and a database with over 600 different samples from publications around the world was created. Incomplete datasets were determined by classification using various methods, such as k-nearest-neighbors.The extensive database was implemented in various machine learning algorithms with the goal of identifying parameters with a significant influence on the target variable based on the polarization curve. We then identify correlations between different parameters and formulate guidelines for individual fabrication steps and materials for electrolyzers. An optimization is then applied to determine the most favorable procedure for MEA fabrication and assembling electrolysers, incorporating all the parameters from the database.This work lays the foundation for future publications regarding the standardization of research data and shows how correlations between different parameters can be identified and optimized with the help of data management.

Research on Catalytic Pyrolysis Process of Coconut Coat of Tropical Agricultural and Forestry Wastes

The effects of reaction temperature, reaction time, heating rate, nitrogen flow rate, and catalyst quality on the oil yield and oxygen content in oil were investigated by using the single-factor principle. Too high and too low reaction temperature, nitrogen flow rate, heating rate, and reaction time improved the yield of bio-oil, but the oxygen content in bio-oil was higher. The reduction in catalytic dose is beneficial to the increase in oil yield but not conducive to the increase in aromatic compound content. The optimal reaction conditions were observed as a reaction temperature of 500 °C, a nitrogen flow rate of 110 mL/min, a heating rate of 20 °C/min, a reaction time of 15 min, a mass ratio of catalyst to coconut coat powder of 1, an oil yield of 4.97%, a water yield of 35.80%, and a solid yield of 30.78%. The gas yield was 28.45%, the oxygen content was 10.3%, and the aromatic compound content was 89.7%. The analysis of the catalytic cracking mechanism shows that most of the oxygen-containing compounds in bio-oil are generated into water and aromatic compounds by a catalytic cracking reaction at high temperature, thus removing oxygen.

Synthesis and study of unsymmetrical ethylene glycol diesters

The article is devoted to the synthesis and study of unsymmetrical (mixed) ethylene glycol diesters in the presence of a ZnO catalyst based on fatty acids of the C5-C7 series and synthetic petroleum acids obtained by oxidation of naphthene-paraffin concentrate isolated from the mineral oil distillate T-1500 of a mixture of Azerbaijani oils. In order to select optimal conditions under which a high yield of target products, was studied the influence of temperature, amount of catalyst and molar ratio of reaction components on the yield and were determined optimal conditions (T, oC = 110–120, acid:alcohol – 2:1.5 mol, ZnO – 2 % mass) where a yield of mixed diesters of 89.5–91.4 %.. The properties of the diesters were studied, their indicators were determined by analytical and spectral methods, and the material balance of their production process was compiled. The mixing of the synthesized mixed diesters into polyvinyl chloride resin was studied by preparing compositions by adding 30–70 parts by weight of mixed diesters and 1 part by weight of stabilizer (calcium stearate) to 100 parts of polyvinyl chloride. It was determined that the optimal mixing limit is 30 parts by weight at 75 oC. Additionally, by adding ethylene glycol diesters to diesel fuel, the amount of sediment and the cloud point significantly decreased. Thus, the synthesized diesters can be recommended as an efficient plasticizer for polymer materials and as a new antioxidant-antidepressant improving the quality characteristics of diesel fuel.

Study of the process of catalytic oxidation of a mixture of naphthene-paraffin hydrocarbons isolated from oil distillate of T-46

The article presents deromatization of oil distillate T-46 of Azerbaijan oil mixture by sulfonation method, preparation of naphthene-paraffin hydrocarbon mixture, oxidation of naphthene-paraffin hydrocarbons isolated from oil distillate T-46 in liquid phase with atmospheric oxygen in presence of salts of Mn- and Cr- natural petroleum acids as catalyst, taken in different concentrations, and their mixtures in different proportions. It has been established that the best results in the liquid-phase oxidation of naphthene-paraffin hydrocarbons isolated from a mixture of Azerbaijan oils of oil distillate T-46 are obtained in presence of Mn-salt of natural petroleum acids (NPA Mn) with concentration of 0.3 wt. %, with reaction duration of 5 hours, where yield of acids is 33–34 %. When using catalysts together, the best results are observed with a catalyst ratio of NPA Cr:NPA Mn - 3:1, with a reaction duration of 5 hours, where the yield of the acid mixture is 36.7 %. The composition of the synthesized synthetic petroleum acids obtained by liquid-phase oxidation of a mixture of naphthene-paraffin hydrocarbons isolated from the oil distillate of T-46, with atmospheric oxygen with the catalytic presence of NPA Mn, was confirmed by IR spectroscopy on an Alpha Fourier spectrometer manufactured by Bruker, Germany.

COMPARISON OF BIODIESEL PRODUCTION FROM OLEIC ACID IN BATCH REACTOR AND MEMBRANE REACTOR

This study examines the production of biodiesel by the esterification reaction between oleic acid and ethanol. Conversions between reactions carried out with batch reactors and membrane reactors are compared and the advantages of membrane reactors are stated. The parameters examined in the study are catalyst concentration (2%, 4%, 6%), ethanol/oleic acid molar ratio (3,6,9) and temperature (between 45-65°C). The effect of these parameters on oleic acid conversion was evaluated and the reactions were carried out under the conditions determined because of the optimization. The highest conversion value in the batch reactor was obtained as 85.5% at 65°C, with an alcohol: acid molar feed ratio of 6:1 and a catalyst concentration of 4%. In addition, 50% conversion was achieved in the batch reactor with an ethanol/oleic acid molar ratio of 3, temperature 55°C and 4% catalyst ratio, while 75% conversion was achieved in the membrane reactor. These results show that the acid conversion achieved in the membrane reactor is 26% higher compared to batch reactors under the same operating conditions.

Mild one-pot production of glycerol carbonate from CO2 with separation from ionic liquid catalyst

Carbon capture and utilization stands as way forward in the minimization of CO2 emissions. It complements the search for clean and effective energy, as it is challenging to achieve zero to negative CO2 net emissions. The glycerol carbonate product opens a new strategy based on a double-residue approach (glycerol and CO2) to contribute, together with ionic liquids (ILs), drafting a new one-pot concept (intensified three phase reactor) at mild conditions and using homogeneous catalysts. In this work, the catalytic activity of [P666,14][Br] in the cycloaddition of CO2 to glycidol has been demonstrated to be highly effective under mild conditions of 45 °C and 5 bar. In addition, liquid–liquid extraction approach is found to be an efficient separation strategy for carbonate product and IL catalyst. 1-Decanol (DOH) is selected as efficient extracting solvent, due to its almost complete immiscibility with glycerol carbonate, as well as the high distribution ratio of the IL catalyst in DOH rich phase. It implies an easy product separation and, simultaneously, an easy catalyst recovery. A preliminary kinetic validation of the three-phase reactor performance has been properly described, enabling the intensified concept. Finally, combining COSMO/Aspen simulation and life cycle assessment (LCA) methodologies, low energy consumption (avoiding heating) and low GWP scenarios for the CO2 conversion process have been concluded. This work enables a new concept together with concluding the path to developing this CCU technology in the search of zero to negative CO2 emissions to sustainably capture and convert CO2 into value-added products.

Feasibility Study of Rubber Seeds from North Sumatra, Indonesia as Biodiesel Feedstock; Production and Characterization

Abstract There are 5.5 million tons of rubber seeds produced annually on the 3.6 million hectares of rubber plantations that are located in Indonesia. Based on current estimates, 2.4 million tons of biodiesel may be produced if the rubber seeds are utilized as the primary raw material. Rubber seeds are a product of rubber plantations that have not been exploited; to obtain them, there is no need for new land or planting new trees. Rubber seeds are also non-edible, so their use does not conflict with foodstuffs. The purpose of this study was to assess the feasibility of rubber seed as a raw material for biodiesel and to produce and characterise biodiesel from rubber seed. The rubber seeds that have been collected from smallholder plantations in the northern Sumatra region of Indonesia are peeled to separate them from the kernels. Rubber seed kernels are boiled for 4 hours to separate the sap. Kernels that have been boiled are drained and then dried in the sun for 2 days in sunny weather. Kernels that had been dried in the sun were pressed using a screw press, and crude rubber seed oil was obtained. This crude oil is produced into biodiesel through degumming, esterification, and trans-esterification stages. Biodiesel production was carried out with variations in the catalyst ratios of 0.25, 0.5, 0.75, and 1, variations in the ratio of oil/methanol (w/v) of 1:1.25, 1:1.5, 1:1.75 (g/ml), and 1:2, variations in temperature of 50 °C, 60 °C, 70 °C, and 80 °C, and reaction times of 70 minutes, 80 minutes, 90 minutes, and 100 minutes. For each of these variables, the yield of biodiesel produced was calculated. Then the resulting biodiesel is characterised by testing its psychochemical properties against ASTM standards, which include calorific value, oxidation stability, viscosity, density, acid content, cetane number, and flash point. In the experiment on the effect of the amount of catalyst, the largest yield of 85% was obtained when the catalyst ratio (%v/v) was 0.75; in the investigation of the effect of the molar ratio of oil and methanol, the largest yield of 88% was obtained at a ratio of 1.75; the maximum yield of 85% was also obtained at a reaction temperature of 60 °C and 89% at a reaction time of 100 minutes. Almost all of the properties meet ASTM standards, except for the acid value of 0.53 mg KOH/g, which is 0.03 mg KOH/g higher, whereas according to the ASTM D6751-D 664 standard, the maximum acid value is 0.5 mg KOH/g.

Effect of Non-ionic Surfactant on Fe-N-C Catalyst Layers under HT-PEMFC Conditions

The effect of different non-ionic surfactant contents on Fe-N-C gas diffusion electrode (GDE) coating and performance is investigated. GDEs are tested under high temperature polymer electrolyte membrane fuel cell (HT-PEMFC) conditions at 160 °C and concentrated phosphoric acid electrolyteFe-N-C-based GDEs are fabricated through ultrasonic spray coating with Tergitol contents of 0, 1, 20 and 50 wt% in the catalyst layer (CL). Thereby, the PTFE to catalyst ratio is kept constant at 1.0 in the CL. The H2O contact angle decreases with increasing Tergitol™ content in the CL, revealing an increased wettability. H3PO4 contact angles of Tergitol containing GDEs show a same wettability at room temperature as at 160 °C. GDE half-cell setup investigations show, that Tergitol leads to flooding of the electrode by the electrolyte and coverage of the active sites by the surfactant and thus a performance decay.

Effect of Non-ionic Surfactant on Fe-N-C Catalyst Layers under HT-PEMFC Conditions

The effect of different non-ionic surfactant contents on Fe-N-C gas diffusion electrode (GDE) coating and performance is investigated. GDEs are tested under high temperature polymer electrolyte membrane fuel cell (HT-PEMFC) conditions at 160 °C and concentrated phosphoric acid electrolyteFe-N-C-based GDEs are fabricated through ultrasonic spray coating with Tergitol contents of 0, 1, 20 and 50 wt% in the catalyst layer (CL). Thereby, the PTFE to catalyst ratio is kept constant at 1.0 in the CL. The H2O contact angle decreases with increasing Tergitol™ content in the CL, revealing an increased wettability. H3PO4 contact angles of Tergitol containing GDEs show a same wettability at room temperature as at 160 °C. GDE half-cell setup investigations show, that Tergitol leads to flooding of the electrode by the electrolyte and coverage of the active sites by the surfactant and thus a performance decay.

Modeling the aspect ratio of commercial catalysts

AbstractMathematical modeling plays a diverse and crucial role in the chemical industry and academia. This manuscript describes how the physical and mechanical engineering disciplines help the commercialization of catalysts from evaluation to scale‐up and manufacturing. Forming and shaping the catalyst is the first basic step in the catalyst manufacturing industry. Part A shows some of the classic process methods that are employed for this purpose. Catalyst extrudates require proper engineering and process control of their aspect ratio. Catalyst extrudates with a high aspect ratio tend to yield a low reactor fill due to a loose packing. Catalyst extrudates with a low aspect ratio tend to yield high pressure drop. Part B introduces the tensile strength of the catalyst in order to predict the aspect ratio of catalyst extrudates in commercial plants. A force‐balance between the tensile strength of the catalyst and the impact forces due to collision experienced during manufacture leads to the dimensionless group . The group allows to introduce and quantify the severity of equipment and the severity of entire commercial plants.

Preparation of metal-modified carbon-based catalyst and experimental study on catalytic pyrolysis of distillers dried grains with solubles

Distillers dried grains with solubles (DDGS) offer high calorific value, suited for catalytic rapid pyrolysis for energy and chemical applications, yet tar and coke formation during bio-oil upgrading necessitates exploration of cost-effective, durable biocarbon-based catalysts for tar removal. In this study, a carbon-based catalyst was prepared by metal modification of alkaline biochar for catalytic pyrolysis with Distillers dried grains with solubles (DDGS) biomass. Brunauer–Emmet–Teller (BET), X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) were used to characterized the morphology and microstructure of the metal-modified carbon-based catalysts. Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) was used to analysis the pyrolysis-gas of catalytic pyrolysis. Furthermore, the effects of the loading and metal mass ratio of carbon-based monometallic catalysts (Fe and Co) and carbon-based bimetallic catalysts (Fe-Co) on the distribution of the DDGS pyrolysis products were further investigated. The results showed that the 8 wt% of loading rate of bimetallic catalyst significantly reduced the oxygenated compounds but increased the aromatic hydrocarbons. Compared with pyrolysis without catalyst, when the catalyst was 2Fe6Co (mass ratio of Fe/Co 1:3), the hydrocarbons increased from 36.42 % to 44.53 %, the oxygen-containing compounds decreased from 60.36 % to 52.35 %, and the aromatics increased significantly from 0.73 % to 25.37 %. This study provides a new route of increasing the aromatic hydrocarbon content of catalytic pyrolysis to offer theoretical basis for carbon-based catalysts of biomass conversion.