Synthesis and characterization of fat-liquor from waste tallow

The fat-liquoring is an important step in leather making before dying to improve the glossiness, appearance, physical and chemical qualities of the leather. Synthetic sulphonated or sulphited oils are generally used to fill fibrous leather & to give it soft, elastic and loose characteristics. Natural fat-liquors (vegetable and animal-based) and synthetic fat-liquors are the two types of emulsions. The emulsion’s charge can be anionic, cationic, or nonionic. In this study, fat-liquor has been made from a bio-waste, namely tallow, which is obtained from a slaughterhouse as a byproduct of the animal hides and skin processing for leather. Triglycerides, a combination of oleic, stearic, and palmitic fatty acids, and glycerol make up the majority of this animal fat. Fat-liquor is made through a series of three reactions, namely, amidation, esterification, and sulphitation. Amidation helps to increase the hydroxyl groups. To react with fat, alkanol amine with a wide emulsifying characteristic isutilised. Anhydrides derived from di-carboxylic acids were then esterified with amidated fat in the next phase. By altering the process recipe, the stability of the emulsion product has been examined, and required raw materials are optimized. Finally, aqueous hydrolyzed sodium metabisulphite is used to sulphite the product, yielding bisulphite and hydroxide ions. The saponification and acid values are computed. The end product has a distinct advantage (anti-foaming & fire-retardant) over traditional fat-liquoring techniques. Material balance is performed once the process flow sheet was created. The process has been scaled up with the help of a preliminary reactor design. The degree of fat-liquoring and the process’ performance are revealed by FTIR spectrum. NMR was used to determine the final product’s structure.

Electrocatalytic performance of sonochemically synthesized Pt–Ni/C nanoparticles in fuel cell application

Developing high-performance electrocatalysts using simple and controllable methods is of interest to reduce the cost of polymer electrolyte membrane fuel cells. In this study, platinum is alloyed with nickel and supported on carbon (Pt–Ni/C) via an ultrasound-assisted route. The crystallite and particle sizes of the obtained nanoparticles were smaller than the commercial carbon-supported Pt nanoparticles. The sonochemically synthesized Pt–Ni/C nanoparticles exhibited superior electrocatalytic properties than the commercial Pt/C nanoparticles in the fuel cell operation. Electrochemical measurements performed with Pt–Ni/C electrocatalyst displayed excellent oxygen reduction and higher electrochemical active surface area (EASA). Optimum fuel cell performance based on peak power density using Pt–Ni/C electrocatalyst was observed as 0.28 W/cm2 at 0.39 V.

Modelling and performance analysis for cumene production process in a four-layer packed bed reactor

A mathematical model is developed and designed for the cumene reactor in cumene production process in Hindustan Organic Chemicals Limited (HOCL), Kochi with improved operating conditions. High purity cumene is produced by the alkylation of benzene with propylene in this catalytic condensation process where solid phosphoric acid (SPA) is used as the catalyst. The mathematical model has been derived from mass and energy balance equations considering the reactor as fixed packed bed reactor and two different numerical methods are presented here to solve the modelling equations. The explicit finite difference method (FDM) involves the approximation of derivatives into finite differences, and in the other one, orthogonal collocation (OC), Ordinary Diffeential Equations (ODEs) are formed at the collocation points and are solved using Runge–Kutta fourth order numerical scheme. Here the analysis shows that the predictions from the model are in good alignment with the plant data. The combined feed has the optimum value of 1:2:8 for propylene, propane and benzene and the profiles of temperature and concentration can be obtained along the reactor. The model has been implemented in COMSOL Multiphysics as a packed bed reactor using the same parameters collected from the plant of study. It has been found that the reaction occurs at a satisfactory level even with a low temperature than the reactor temperature at the plant by changing the catalytic particle size. The reaction performance is also analysed for the physical properties like porosity and catalyst size.

The effect of operating parameters of hydrodynamic cavitation – assisted alkaline catalyzed transesterification of sunflower oil with methanol on the degree of triglyceride conversion

The effect of operating parameters such as reaction mixture inlet pressure p 1 (101.3–1013.2 kPa), methanol to oil molar ratio M 1 (3–12), the concentration of catalyst C c (0.0–1.0 wt%), temperature T (25–50 °C) and the number of passes of the reaction mixture through the venturi type hydrodynamic cavitation reactor n (1–12) on alkali-catalyzed transesterification of sunflower oil with methanol assisted by hydrodynamic cavitation (ACTC) on the value of the degree of triglyceride conversion (DTC) was investigated. ACTC was performed by the venturi-type hydrodynamic cavitation reactor (VCR) of our construction. It was found that the values of DTC increase with the increase in p 1, M 1, C c, and n, and decrease with the increase in T. Cavitation yield (CY) values were calculated. The ACTC was proved to be the simplest, fastest, and most highly energy-efficient current technology for the production of biodiesel.

Investigating the properties and performance of 3A molecular sieves as an adsorbent to prevent coke formation in olefin dehydration process

To study the affinity of 3A aluminosilicate adsorbents to prevent oligomerization of olefin molecules and forming green oil, physical and chemical properties of 3A molecular sieves are measured by using characterization techniques such as temperature-programmed desorption (TPD), nitrogen (N2) and water adsorptions, X-ray diffraction (XRD), X-ray fluorescence (XRF), crushing strength, and carbon dioxide (CO2) adsorption. Moreover, coke formation affinities of the understudy adsorbents are evaluated in a bench-scale system using 1-butene and 1,3-butadiene at temperatures of 220 and 260 °C, and outcomes are validated against the actual data gathered from an industrial scale olefin dehydration plant. Results confirm that the type of binder and the amount of ion exchange affect the performance of a 3A molecular sieve nominated for dehydrating olefinic streams. The binder with the least amount of acidity is preferred, and at least 35% of Na ions of the 4A zeolite should be exchanged with K ions to make it applicable for synthesizing an appropriate 3A molecular sieve. Furthermore, to control the oligomerization and inhibit green oil formation, the CO2 adsorption and acidity of Trisiv shape molecular sieves with the sizes of 1/4 inch should be less than 0.5 wt % and 1.7 mmol NH3/g, respectively. For extrudate shape with the sizes of 1/16 inch CO2 adsorption and acidity should be less than 0.2 wt % and 2.2 mmol NH3/g, respectively.

Photocatalytic degradation of acetaminophen in water via ultraviolet light and titanium dioxide thin films part II: chemical and kinetic aspects

Among the large family of emergent pharmaceutical contaminants, we find acetaminophen (ACE) that critically needs to be removed from wastewater. Advanced Oxidation Process (AOP) have proven effective in the degradation of large molecular contaminants from water. To the best of our knowledge this is the first study reported on the degradation of ACE based on immobilized TiO2 thin films. In an effort to increase the understanding of the efficiency of the degradation process, an in-depth investigation of the effects of the structure, i.e., coating layers and the amount of surface, i.e., number of coated slides used, is needed. Transparent, anatase-form TiO2 thin films were prepared via the sol-gel method (Rawal, S., S. Buer, J. R. Sanders, and P. E. Arce. 2021. “Photocatalytic Degradation of Acetaminophen from Water Solutions Via Thin Films. Part I: Synthesis and Characterization of TiO2 Thin Films.” International Journal of Reactor Engineering [Accepted]) and deposited onto glass microscope slides using a novel spraying technique, with coatings ranging from one to 10 layers. This contribution summarizes the effect of several key factors including initial concentration of the ACE, the number of coating layers (6, 8, and 10) on the glass slides and the number (4 and 6) of slides on the degradation levels for three selected media, e.g., acid, neutral and base. Comparisons studies, supported by statistical analysis between two different sets (4 and 6) of slides with discussion of potential physical-chemical reasons behind the behaviors are reported. Finally, global, first order kinetic rate constants are also reported for the different conditions used in the investigation. Although further research would be needed, in general the results are promising for the potential degradation of ACE in continuous flow systems by using immobilized TiO2 on surfaces as thin films.

Ti-Co mixed oxide as photocatalysts in the generation of hydrogen from water

The effect of Co into the titanium oxide matrix as photocatalysts in the generation of hydrogen from water is herein reported. Ti–Co mixed oxides and pure titania were synthetized by sol-gel. The Co content was 0, 1, 3, 5, and 10 wt.%. The solids were characterized by Scanning electron microscope-energy dispersive spectrometer (SEM-EDS), N2 physisorption, X-ray difrraction (XRD), ultraviolet visible spectroscopy (UV–Vis), spectroscopy Raman, X-ray photoelectron spectroscopy (XPS) spectroscopy and High resolution transmission electron microscope (HRTEM). The results showed that the mixed oxides show larger specific surface areas (73–186 m2/g) compare to that of pure TiO2 (64 m2/g). The XRD patterns of the Ti-Co samples resemble that of anatase and segregation of Co was not observed by this technique. The band gap energies of these solids vary from 3.05 to 2.85 eV which are smaller than that of pure TiO2 (3.2 eV). The Ti-Co oxides showed an enhancement in the hydrogen production (∼3056 μmol/h) compare to that of TiO2 (190 μmol/h) when using UV light. Furthermore, the photocatalytic activity of titania (110 μmol/h) for this reaction was also smaller than those observed for the Ti-Co mixed oxides (∼4056 μmol/h) under visible light.

Characteristics of carbide slag slurry flow in a bubble column carbonation reactor

The direct aqueous mineral carbonation of carbide slag was investigated. The flow characteristics of carbide slag-CO2-water reaction system in a bubble column were studied, which included the bubble Sauter mean diameter, gas holdup, bubble residence time, and the gas-liquid interfacial area. Bubble flow behaviors in the reactor were characterized by analyzing the bed pressure signals. The effects of the gas velocity (U g ) and liquid to solid ratio (L/S ratio) were discussed and analyzed. The results showed that the larger bubbles were easy to form at the larger L/S ratio, which indicated that the bubble coalescence was promoted. The gas holdup was larger when increasing U g or reducing the L/S ratio. The better gas-liquid interfacial areas were found in a wide range of L/S ratio at U g = 0.082 m/s. The optimum conditions were found at U g = 0.082 m/s and L/S ratio = 15–30 mL/g for the better gas-liquid interfacial area and the higher carbide slag conversion. The work provided the theoretical basis for the direct aqueous carbonation of the carbide slag and the operation condition optimization.

Simple microwave pyrolysis kinetics of lignocellulosic biomass (oil palm shell) with activated carbon and palm oil fuel ash catalysts

The important parameters characterizing microwave pyrolysis kinetics, namely the activation energy (E a) and the rate constant pre-exponential factor (A), were investigated for oil palm shell mixed with activated carbon and palm oil fuel ash as microwave absorbers, using simple lab-scale equipment. These parameters were estimated for the Kissinger model. The estimates for E a ranged within 31.55–58.04 kJ mol−1 and for A within 6.40E0–6.84E+1 s−1, in good agreement with prior studies that employed standard techniques: Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). The E a and A were used with the Arrhenius reaction rate equation, solved by the 4th order Runge-Kutta method. The statistical parameters coefficient of determination (R 2) and root mean square error (RMSE) were used to verify the good fit of simulation to the experimental results. The best fit had R 2 = 0.900 and RMSE = 4.438, respectively, for MW pyrolysis at power 440 W for OPS with AC as MW absorber.

Synthesis of NPK fertilizer from low-grade phosphate raw material

The article presents the results of studies of the process of obtaining NPK fertilizer from low-grade phosphate raw materials with P2O5 of about 18%. Phosphate raw materials were leached with a mixture of nitric-phosphoric acids with the addition of potassium carbonate, which serves as a source of potassium in the final product. The main parameters determined were the content of the main nutrients P2O5:N:K2O, temperature and time of the leaching process. According to the graphical method, the “apparent” activation energy of the heterogeneous process is found, which is equal to 3.8 kJ/mol indicates the intradiffusion nature of the process. Methods of chemical analysis, scanning electron microscopy and XRD analysis were used for a comprehensive study of raw materials and final products.