Biodiesel production using CaO impregnated with silica as catalyst

Currently, biodiesel is produced by performing a transesterification reaction with homogeneous base catalysts such as KOH or NaOH dissolved in methanol. This production process can provide high FAME yields under mild conditions. However, the homogeneous catalytic process suffers some drawbacks of an inevitable production of wastewater from washing process of catalyst residues and unreusability of the catalysts. Thus, in this study, it is proposed to synthesize and characterize a renewable low cost heterogeneous hybrid catalyst through utilization of waste material; rice husk ash (RHA) and egg shell (ES) for transesterification reaction. The hybrid RHA-ES was synthesized via a wet impregnation method. Then, the synthesized hybrid catalyst was characterized using BET and SEM analysis. The effectiveness of the hybrid catalyst will be tested on biodiesel yield. From BET results, surface area of hybrid catalyst was found to have higher surface area than CaO catalyst. It could be due to the strong interaction of the CaO with silica support, which reduced the surface diffusion of Ca, inhibited sintering and stabilized the surface of CaO [Omar and Amin, 2011]. Furthermore, this result was supported by SEM image, whereby the significant agglomeration of the silica particles with a heterogeneous distribution was observed on the surface of CaO catalysts. In the transesterification study, it was found that the CaO supported with silica had a higher yield of methyl ester than CaO individually. This might be due to the solid state reaction between silica compound and the surface of CaO in the activation process, whereby the silica could have inserted in the vacant sites of CaO. Therefore, it can be concluded that the hybrid RHA-ES catalyst derived from waste materials can be an excellent catalyst in biodiesel production

α-chymotrypsin immobilized enzyme: physical, activity and stability properties

In this study, α-chymotrypsin enzyme was used as a substrate while micropore Y-zeolite, which is HY, USY and NaY as a support. The purpose of this study was to compare the physical properties of zeolite and immobilization of enzyme with zeolite. The characteristics such as BET surface area, isotherm adsorption, BJH adsorption, pore size, t-plot and pore volume have been studied. Furthermore, a comparison has been conducted between immobilized and mobile enzyme for their ability to adsorb hydrolysate at ?=410 nm. The stability of the immobilized enzyme was also determined by varying the parameters of phosphate and tris-chloride buffer and loading of sample solution. Based on the result obtained, HY zeolite has the best physical properties compared to USY and NaY zeolite. Besides that, immobilized enzyme gave higher hydrolysate adsorption activity than the free enzyme. Stability results showed that pH of phosphate and tris-chloride buffer and amount of sample solution play an important role in obtaining the stable immobilized enzyme

Isobutanol and 3-methyl-1-butanol production by saccharomyces cerevisiae in aerobic condition

Alternative fuels from renewable sources are receiving public and scientific attention due to continuous depletion of petroleum fuel-reserves and environmental problem such as global warming and climate change. Higher alcohols (C3-C5) possess many advantages thus become suitable candidate in replacing gasoline as transprtation fuel. This paper investigates the production of isobutanol and 3-methyl-1-butanol as well as the toxicity of these alcohols towards Saccharomyces cerevisiae. This yeast was able to produce both alcohols with the highest concentration of 92 mg/ L (isobutanol) and 245 mg/L (3-methyl-1-butanol). Saccharomyces cerevisiae was capable to grow in more than 2% isobutanol but unable in concentration of 3-methyl-1-butanol higher than 1%

Synthesis of magnetic cellulose as flocculant for PreTreatment of anaerobically treated palm oil mill effluent

Recently, more attentions have been paid to natural polymer-based flocculants in wastewater treatment, since they are believed to be low-cost, nontoxic, and environmentally friendly materials. In present work, a hybrid flocculant namely magnetic cellulose (Magcell) was successfully synthesised through simple crosslinking method. As preliminary study, effect of ratio between magnetite powder and cellulose and also volume of glutaraldehyde as crosslinking agent were selected in this research. Meanwhile, the effectiveness of flocculant was determined by performing a jar test to treat an anaerobically treated palm oil mill effluent (AnPOME). The best ratio cellulose to magnetite powder and volume of closslinker was chose based on optimum removal of turbidity, total suspended solid (TSS), colour and chemical oxygen demand (COD) from sample wastewater. Result shows that the best combination cellulose to magnetite powder are 1: 1 (g/g) with glutaraldehyde volume of 1.5 mL. This optimum parameters show about 74.60 %, 63.90 %, 77.20 %, and 55.80 % reduction in turbidity, colour, TSS, and COD. Overall, approach to produce magnetic cellulose as newly hybrid flocculant has potential to substitute existence flocculants due to the better performance

Development of Microwave-Assisted Sulfonated Glucose Catalyst for Biodiesel Production from Palm Fatty Acid Distillate (PFAD)

Microwave-heating method for catalyst preparation has been utilized recently due to its shorter operation time compared to the conventional method. Glucose, a renewable carbon source can be partially carbonized and sulfonated via microwave heating which could result in highly potential heterogeneous carbon-based acid catalyst. In this study, the impacts of the carbonization and sulfonation parameters during the catalyst preparation were investigated. Catalysts prepared were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), X-Ray Diffraction (XRD), Brunauer-Emmet-Teller (BET), and Temperature Programmed Desorption–Ammonia (TPD-NH3). Analysis of the carbonization screening process discovered that the best incomplete carbonized glucose (ICG) prepared was at 20 minutes, 20 g of D(+)-glucose with medium microwave power level (400W) which exhibited the highest percentage yield (91.41%) of fatty acid methyl ester (FAME). The total surface area and acid site density obtained were 16.94 m2/g and 25.65 mmol/g, respectively. Regeneration test was further carried out and succeeded to achieve 6 cycles. The highest turnover frequency (TOF) of the sulfonated catalyst was methyl palmitate, 25.214´10−3 s−1 compared to other component of the methyl ester. Kinetic study was developed throughout the esterification process and activation energy from the forward and reverse reaction was 3.36 kJ/mol and 11.96 kJ/mol, respectively. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

A Two-Step SO3H/ICG Catalyst Synthesis for Biodiesel Production: Optimization of Sulfonation Step via Microwave Irradiation

Conventional heating, a common method used for heterogeneous solid acid catalyst synthesis unknowingly consumes massive time and energy. In this study, acid catalyst was prepared through sulfonation process of incomplete carbonized glucose (ICG) via microwave-assisted technique to shorten the heating time and energy consumption. Optimization of the sulfonation process of ICG via microwave-assisted was carried out. Four-factor-three-level central composite design (CCD) was used to develop the design of experiments (DOE). Interaction between two factors was evaluated to determine the optimum process conditions. A quadratic model was proposed for prediction of biodiesel yield (Y) from palm fatty acid distillate (PFAD) and its conversion (C). The application of DOE successfully optimized the operating conditions for the two-step SO3H/ICG catalyst synthesis to be used for the esterification process. The optimized conditions of the best performing SO3H/ICG with maximum Y and C were at 7.5 minutes of reaction time, 159.5 mL of H2SO4 used, 671 rpm of stirring rate as well as 413.64 watt of power level. At these optimum conditions the predicted yield percentage and conversion percentage were 94.01% and 91.89%, respectively, which experimentally verified the accuracy of the model. The utilization of sulfonated glucose solid acid catalyst via microwave-assisted in biodiesel production has great potential towards sustainable and green method of synthesizing catalyst for biodiesel. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Production of biodiesel from palm oil using egg shell waste as heterogeneous catalyst

Egg shell waste was investigated in a triglyceride transesterification with a view to determine its viability as a solid catalyst for the biodiesel production. The utilization of egg shell as a catalyst not only reduces its environmental effects, but also reduces the price of biodiesel to make it competitive with petroleum diesel. In this study, egg shell waste was ground and the powder produced was calcined at 900˚C for 4 hours in a furnace. The physical properties of the catalyst were characterized by using the Fourier Transform-infrared (FTIR) spectroscopy and the biodiesel conversion was determined by the Gas Chromatography-Mass Spectrometry (GC-MS). 4wt% of catalyst dosage was fixed throughout the experiment. The results obtained indicated that CaO derived from egg shell waste was comparable with the commercial CaO. The maximum percentage yield of biodiesel by using derived CaO is 75.85% under optimum conditions of 6:1 methanol to oil ratio after 3 hours at 65˚C, while for commercial CaO, 74.97% yield of biodiesel with 3:1 methanol to oil ratio after 3 hours at 60˚C

Synthesis of activated carbon from spent tea leaves for aspirin removal

Adsorption capacity of activated carbon prepared from spent tea leaves (STL-AC) for the removal of aspirin from aqueous solution was investigated in this study. Preliminary studies have shown that treatment with phosphoric acid (H3PO4) increased removal efficiency of STL-AC. Characterizations on STL-AC revealed excellent textural properties (1200 m2·g− 1, 51% mesoporosity), as well as distinctive surface chemistry (1.08 mmol·g− 1 and 0.54 mmol·g− 1 for acidic and basic oxygenated groups, pHpzc = 2.02). Maximum removal efficiency of aspirin observed was 94.28% after 60 min when the initial concentration was 100 mg·L− 1, 0.5 g of adsorbent used, pH 3 and at a temperature of 30 °C. The adsorption data were well fitted to the Freundlich isotherm model and obeyed the pseudo-second order kinetics model. The adsorption of aspirin onto STL-AC was exothermic in nature (ΔHϴ = − 13.808 kJ·mol− 1) and had a negative entropy change, ΔSϴ (− 41.444 J·mol− 1). A negative Gibbs free energy, ΔGϴ was obtained indicating feasibility and spontaneity of the adsorption process. The adsorption capacity of AC-STL (178.57 mg·g− 1) is considerably high compared to most adsorbents synthesized from various sources, due to the well-defined textural properties coupled with surface chemistry of STL-AC which favors aspirin adsorption. The results demonstrate the potential of STL-AC as aspirin adsorbent

Preparation of Ti-SO3H/ICG using microwave-assisted for esterification of palm fatty acid distillate to methyl ester

The utilisation of low-cost yet valuable feedstock such as palm fatty acid distillate (PFAD) in the replacement of edible oils have a great potential in solving high-cost problem in biodiesel industries. Heterogeneous solid acid catalyst is the most proficient to esterify the feedstock containing high free fatty acid (FFA). Most of the prepared catalysts from the previous studies were produced using a conventional heating method which is basically time and energy consuming. The development of heterogeneous solid acid catalyst from sulfonated glucose and impregnation with titanium (Ti-SO3H/ICG) was prepared by using a microwave-assisted heating method with various heating time during the sulfonation process. The heating times taken were 3, 5, 7 and 9 min for acid treatment using H2SO4. The catalysts showed an outstanding result in reducing the catalyst separation problem and efficiently producing high percentage yield of biodiesel. The physical and chemical properties of the modified catalyst were analysed by using Temperature Programmed Desorption-Ammonia (TPD-NH3) and Brunauer-Emmett-Teller (BET). 7 min Ti-SO3/ICG showed the best performance catalyst due to its high surface area and acid site density, which were 78.37 m2/g and 15.16 mmol/g. The catalyst showed highest percentage yield and conversion of 98.92 % and 80.24 % at 70 °C, with a molar ratio of methanol to PFAD of 10: 1, 2.5 wt% of catalyst loading and 90 min of reaction time. A kinetic model was studied and the activation energy (Ea) obtained was 13.43 kJ/mol.K, the lowest value recorded as compared with the activation energy from previous studies in related field

Guidelines for Process Safety Hazard Assessment Based on Process Information

In any new chemical process development and design, process safety is a critical aspect to be considered besides economic and technical feasibility of the manufacture of the product. A lack of proper hazard assessment during the design phase may later result in accidents with disastrous consequences to workers, the public as well as the environment. Many methods have been introduced to qualitatively and quantitatively assess the safety level of processes. Despite the availability of a large amount of methods, a systematic framework that details guidelines for hazard identification, risk assessment, safety measure design, and safe critical decision-making is still missing. To address this issue, the main objective of this study was to propose a systematic framework that outlines comprehensive guidelines for assessing the safety performance of processes based on information from the piping and instrumentation diagram (P&ID). Apart from proposing the framework, appropriate strategies for minimizing safety hazards and risks are also recommended. In addition, the user is assisted in selecting the most appropriate assessment method according to his or her needs and the scope and constraints of the assessment. A case study is presented to illustrate the application of the proposed framework