SYNTHESIS OF SOLID ACID CATALYSTS FROM KAOLIN FOR EFFICIENT PRODUCTION OF BIODIESEL FROM SHEA BUTTER

This study reports synthesis of solidacid catalyst from cheaper raw materials for efficient biodiesel production. The dissertation consists of six main research section including: (1) Synthesis and characterization of ordered solidacid catalyst from kaolin; (2) Synthesis and characterization of hierarchical nanoporous HY zeolite from acid activated kaolin; (3) Synthesis of nanoporous HY zeolites from activated kaolin, a central composite design (CCD) optimization study; (4) Synthesis and application of hierarchical mesoporous HZSM-5 for biodiesel production; (5) Synthesis and characterization of sulfated HY zeolite (SHY) for biodiesel production; (6) Comparative pyrolysis kinetics study of biodiesel produced from Mesoporous ZSM-5 zeolites and Microporous ZSM-5. Towards synthesis of solidacid kaolinite, all the kaolinites peaks in the starting material disappeared after the thermal and acid activation. However, most of the crystalline peaks reappeared with greater intensities at the (0211) band after NaOH impregnation. Further, the crystallinity index calculated by weighted intensity ratio index (WIRI) at (0211) band showed superior crystallinity for the synthesized material than the starting kaolin. This work demonstrates that impregnation of NaOH on amorphous aluminosilicate is a novel route for synthesizing of crystalline solidacid. The results hierarchical mesoporous HYzeolites synthesis indicated that aging time and crystallization time determine the hierarchical factor of the synthesized HY zeolite. Incorporation of appropriate amount of NaCl is also towards enhancing the textural properties. Further, this process was optimized by varying the aging and crystallization time as well as amount of NaOH solvent using CCD. All the process variables were found to be statistically significant for high crystallinity and SSA while only NaOH solvent is statistically significant for optimal hierarchy factor. In the quest for facile synthesis, more active solid acid, the produced zeolite in the last section was with sulfated groups. The effect of sulfate ions was observed on the textural and acidity properties as well as its catalytic activity. SHY gave biodiesel yield of 90.76% at 200 °C for 6 h while hierarchical HY gave yield of 72.42% at the same condition. This indicates that both pore structure and acid strength decide the activity of solid acids catalysts in biodiesel production. Hierarchical mesoporous ZSM-5 (HMZeol) was also tested for biodiesel production. The catalysts synthesis was by desilication of conventional ZSM-5 with aqueous solution of NaOH (0.3 and 0.4 M). The sample treated with 0.4 M NaOH (0.4HMZeol) maximum biodiesel yield (82.12%) at 5:1 (methanol/oil) molar ratio, 1 wt % catalyst, and 3 h reaction time at 200 ᵒC. However, further increase in the parameters decreases the yield. Contrarily, 0.3HMZeol shows increase in yield with increase in operating parameters. The pyrolysis kinetics of some biodiesel produced in section 5 and that of the shea butter were carried by thermal decomposition using TGA equipment. The average activation energy was computed based on best-fitted models. The reference ZSM-5 biodiesel exhibits lower EA (63.59 KJ/mol) compared to 0.3HMZeol and 0.4HMZeol biodiesel (66.69 and 72.98 KJ/mol respectively). This is attributed to higher acidity of the microporous zeolites used for ZBio. However, the reference ZSM-5 exhibited lower conversion due to steric hindrance

Treatment of Textile Wastewater Using a Novel Electrocoagulation Reactor Design

This study explored the best operating conditions for a novel electrocoagulation (EC) reactor with the rotating anode for textile wastewater treatment. The influence of operating parameters like interelectrode distance (IED), current density (CD), temperature, pH, operating time (RT) and rotation speed on the removal efficiency of the contaminant was studied. A comparative study was done using conventional model with static electrodes in two phases under same textile wastewater. The findings revealed that the optimal conditions for textile wastewater treatment were attained at RT = 10 min, CD = 4 mA/cm2, rotation speed = 150 rpm, temperature = 25°C, IED = 1 cm and pH = 4.57. The removal efficiencies of color, biological oxygen demand (BOD), turbidity, chemical oxygen demand (COD) and total suspended solid (TSS) were 98.50, 95.55, 96, 98 and 97.10%, respectively, within the first 10 min of the reaction. The results of the experiment reveal that the newly designed reactor incorporated with cathode rings and rotated anode impellers provide a superior treatment efficiency within a short reaction time. The novel EC reactor with a rotating anode significantly enhanced textile wastewater treatment compared to the conventional model. The values of adsorption and passivation resistance validated the pollutants removal rate

Catalytic dehydrogenation of formic acidtriethanolamine mixture using copper nanoparticles

In a bid to compliment the lost reversed fron fossils recent advances in research are tailored towards producing hydrogen as an alternative source of fuel which is aimed at fostering a globally sustainable and reliable energy-economy. In this work, hydrogen was produced from formic acid (FA) using a new technology that involves the use of copper nanoparticles (CuNPs) supported on triethanolamine. The CuNP-catalysts of variant concentrations (i.e. 0.6e1.2 M) were synthesized using the conventional chemical deposition method. Also, a novel approach that bothers on the application of the Differential Method of Analysis (DMA) was used in determining the kinetic parameters for the FAdehydrogenation. Based on the results, the volume of H2 produced varied with time, pH, concentration and catalyst-size. At 6 h, the 1 M CuNPs gave the highest volume (815 mL) of hydrogen with corresponding pH, particle size and approximate conversion of 3.19, 1.5 nm and 100% respectively, whereas, over extended periods i.e. over 6 h, the approximate volume-conversions of FA increased insignificantly for all catalysts. According to the investigation, the optimum CuNP-catalyst concentration required to produce 815 mL H2 in 6 h is 1 M. The decomposition was a first-order-type with a rate constant (k-value) of 1.0041 s�1

Comparative study of catalytic performance and degradation kinetics of biodiesels produced using heterogeneous catalysts from kaolinite

This study comparatively investigates the catalytic activities and degradation kinetics of the produced biodiesels using kaolinite-based heterogeneous catalysts to examine the stability. The performance of the catalysts was tested under the same operating parameter (methanol/oil ratio, 5:1, at 200 °C for 6 h). The obtained biodiesel was analyzed using TGA equipment to obtain the yield, as well as the degradation kinetic parameters. It was observed that the solid superacid SHY zeolite gave the highest biodiesel yield (90.76%) because of higher acid strength. The catalysts performance is in the order of HY<ALK<HLK<NaLK<SHY zeolite. The lower performance of HY (72.42% yield) is attributed to the presence of high basic sites, being that shea butter has high FFA. The degradation kinetics of each biodiesel sample was performed using the TGA data to examine the thermal and oxidative stability. The frequency factor (A), activation energy, and reaction order were determined by employing the Coats-Redfern model. It was observed that first-order reaction mechanism can satisfactorily describe all the biodiesel kinetics. Further, the biodiesel from SHY zeolite gives the highest EA (98.65 kJ/mol). This result indicates that SHY zeolite is the best catalyst in terms of biodiesel yield and stability

Equilibrium, kinetic, and thermodynamic studies of lead ion and zinc ion adsorption from aqueous solution onto activated carbon prepared from palm oil mill effluent

An efficient activated carbon was prepared using palm oil mill effluent as a precursor. The adsorption capacity of activated carbon for lead ion and zinc ion from aqueous media was investigated under equilibrium conditions between 303.15 and 353.15 K. The activated carbon was analyzed using fourier transform infrared spectroscopy, field emission scanning electron microscope, energy dispersive X-Ray, and Nitrogen adsorption-desorption analysis. The adsorption capacity of activated carbon was studied by varying adsorbent dosage, contact time, and temperature. The equilibrium time was attained after 50 min for both ions. The data analysis was performed with different isotherm and kinetic models. Pseudo-second-order kinetic rather than pseudo first-order model is best fitted for both lead ion and zinc ion removal from wastewater. Further, the rate-determining step for both metal ions is chemisorption based on the suitability of the Elovich equation. Langmuir model provides the best fit for both removal of lead ion and zinc ion. The thermodynamic parameters shows the feasibility of adsorption of both ions is endothermi

Insight into catalytic reduction of CO2: Catalysis and reactor design

Catalytic reduction of CO2 to produce specialty chemicals or renewable energy sources has attracted immense attention because of the possibility of renewable, sustainable alternative energy, and safer environment. Utilization of CO2 as an alternative feedstock for synthesis of biorenewable fuel is one of the numerous strategies essential for mitigation of the greenhouse gases emission into the atmosphere. CO2 reduction occurs at temperature above 413 K and pressure above 1 MPa by using a suitable hydrogenation catalyst. This study investigates the recent advances in catalytic reduction of CO2 via hydrogenation, focusing on catalysis, reactor, and process intensification. Several factors for the effective catalytic reduction of CO2 and recent progress in the reactor design for the system are also highlighted

Synthesis and characterization of hierarchical nanoporous HY zeolites from acid‐activated kaolin

Hierarchical nanoporous HY zeolites were synthesized from acid‐activated kaolin. The hierarchical factor (HF) was maximized by varying the aging and crystallization time. This was achieved by maximizing the external surface area without greatly reducing the micropore volume. The resulting products were characterized using X‐ray diffraction (XRD), X‐ray fluorescence, N2 adsorption, and NH3 temperature‐programmed desorption. The nanoporous HY zeolite with the highest HF was obtained by aging for 48 h and a crystallization time of 24 h. The acidity and crystallinity varied depending on the operating parameters. Incorporation of an appropriate amount of NaCl was also vital in maximizing the HF, crystallinity, and acidity. The sample crystallinities were determined by comparing their XRD peak intensities with those of a conventional Y zeolite. The results show that optimizing this process could lead to a widely acceptable commercial route for HY zeolite productio

Kaolinite properties and advances for solid acid and basic catalyst synthesis

Historically, clay mineral catalysts have found industrial applications since the early 1930s. However, inherent limitations such as impurities, porosity, low surface area and acidity hindered their wide and sustained acceptability, this is despite their economic advantages. Interestingly, the use of kaolinite as precursor in active catalyst synthesis has been a breakthrough for several industrial processes such as\ud petrol chemistry; especially in catalytic refining and bulk chemistry. The same is also true for processes that require solid acid catalysts, catalyst support, co-catalyst or promoter application for positive environmental impact and economic viability. Therefore, this article reviews the physicochemical properties of kaolinite and their amenability to modification towards enhancing their catalytic properties. The article also discussed modification methods such as mechanochemical activation (dealumination), thermal activation, intercalation and chemical activation. With more advances in technology and longterm commitment to investments, kaolinite will become the ideal catalyst and precursor for synthesizing novel catalysts for a sustainable “greener” future

Efficient biodiesel production via solid superacid catalysis: a critical review on recent breakthrough

Biodiesel produced from triglycerides and/or free fatty acids (FFAs) by transesterification and esterification has attracted immense attention during the past decades as a biodegradable, renewable and sustainable fuel. Currently, the use of solid superacid catalysts has proved a more efficient and “green” approach due to avoidance of environmental and corrosion problems and reduced product purification procedures. However, it is less viable economically because the reusability is low due to the lack of a hydrophilic/ hydrophobic balance in the reactions that involve the use of inedible feedstock with a high water content. Therefore, this study gives a critical review on recent strategies towards efficient and “green” production of biodiesel via solid superacid catalysis. The strategies discussed include alkyl-bridged organosilica moieties functionalized hybrid catalysis to improve the hydrothermal stability of superacid catalysts, pre- and in situ water removal, and process intensification via temperature profile reduction. The strategies enabled well-defined porosity and an excellent hydrophobicity/hydrophilicity balance, which suppressed deactivation by water and glycerol

Synthesis and characterization of highly ordered solid acid catalyst from kaolin

Crystalline solidacid catalysts exhibit higher catalytic activity and hydrothermal stability in catalytic cracking compared with their amorphous counterparts. This is because of the presence of stronger Brönsted acid sites on their surfaces. Thus, we report the synthesis of crystalline solidacid material by impregnating NaOH into the pores of thermal and acid-treated amorphous aluminosilicate. NH3-TPD, XRD, TGA and DSC revealed the surface acidity, structural and textural properties of the materials. All the kaolinites peaks in the starting material disappeared after the thermal and acid activation. Interestingly, most of the crystalline peaks reappeared with greater intensities at the (0211) band after NaOH impregnation. Further, the crystallinity index calculated by weighted intensity ratio index (WIRI) at (0211) band showed superior crystallinity for the synthesized material than the starting kaolin. This is in consonant with reemerging crystalline peaks. The acidity … This work demonstrates that impregnation of NaOH on amorphous aluminosilicate is a novel route for synthesizing of crystalline superacid catalysts