Recent Innovations in Chemical Engineering - Volume 13, Issue 3, 2020

The removal of SO2 from flue gases is necessary for eliminating haze and controlling acid rain. However, developing the traditional wet and dry flue-gas desulfurization (FGD) is challenging due to the disposal issue of several byproducts. Manganese (Mn) orebased wet FGD possesses many advantages, including good desulfurization property, low cost, and high economic benefit. The environment friendliness and reusability of MnSO4 provide new ideas and methods in the future research direction of FGD. This review summarizes the background information of Mn ore slurry desulfurization, the desulfurization mechanism, the technological process, and the desulfurization devices. The role of operating parameters, such as temperature, liquid/solid ratio, pH, SO2 concentration, and particle size, in the desulfurization efficiency and manganese leaching rate are also discussed. The temperature (20°C-80°C) has exerted little effect on the desulfurization efficiency, whereas a low pH value is beneficial for SO2 removal. Moreover, a low inlet SO2 concentration and small particle size are beneficial for SO2 removal. The control and digestion techniques related to the byproduct (manganese dithionate) are also presented, along with the future development direction of Mn ore-based wet FGD in different industries.

Formaldehyde, carcinogenic for humans, is a common indoor air pollutant emitting from furniture coatings and flooring materials. Porous carbon and silica materials have applications in the removal of formaldehyde because of their large specific surface areas, obedience to surface modification for enhanced adsorption of pollutants, high chemical and mechanical stabilities, and reusability. This work briefly summarized available porous carbon and silica materials for the removal of formaldehyde from the indoor environment.

Background: The purpose of this research is to study the solutions for improving the efficiency of a micro combined heat and power (m-CHP) system based on OHVG (OverHead Valve Gas fueled) engine. Method: In this regard, the effects of valve timing and changing the camshaft on the power and fuel consumption of the engine have been numerically and experimentally investigated. The tests have been performed for engine speed range from 1000 rpm to 3500 rpm, while the engine's fuel was natural gas. The numerical results are found to be in good agreement with experimental ones. The effect of changing the valve timing and camshaft on the performance of the m-CHP has been investigated through the experiments in the test room. The engine speed was 1500 rpm; output hot water was fixed at 55oC; and output electrical power varies from 8 kW to 13 kW in the experiments. Results & Conclusion: The experimental results of the engine test indicate that, by changing the camshaft for full load operation and speed 1500 rpm, engine torque and volumetric efficiency improved by 7.2% and 6.0%, respectively, and fuel consumption decreased by 0.8%. According to the results, the best point for the performance of m-CHP is close to the full load of the electrical power because by increasing the electrical load, electrical efficiency increases from about 25.9% to 32.3%, while the thermal efficiency decreases from about 61.9% to 56.1%.

Objective: An efficient and facile preparation route has been developed to prepare activated carbon (AC)/zinc oxide (ZnO) nanocomposite electrodes for the supercapacitor electrode. Methods: The zinc oxide nanostructure was synthesized via the sol-gel method by using conventional hexamethylenetetramine (HMTA) reagent as the reducing agent. Results: The physicochemical and electrochemical properties of the nanocomposites were characterized by X-ray diffraction analysis (XRD) and cyclic voltammetry (CV) analysis, respectively. 10 wt% of ZnO loading shows an optimum specific capacitance of 398 F/g at a scan rate of 50 mV/s. The optimum sample retained 96% of its initial specific capacitance upon 100 consecutive cycles. Conclusion: The enhanced specific capacitance can be ascribed to the synergistic effect of the individual properties of AC and ZnO.

Background: Studies pertaining to the epoxidation of fatty acids, garnered much interest in recent years due to the rising demand of eco-friendly epoxides derived from vegetable oils. Methods: Epoxide is an important chemical precursor for the production of alcohols, glycols and polymers, like polyesters and epoxy resin. Epoxidation is the name given to the reaction when the double bonds are converted into epoxide. Results: Temperature at 55oC was used as a reference material in the epoxide process, as it produces a high yield epoxide being 88%. The kinetic rate of epoxidized palm kernel oil, k was obtained to be k11= 0.5125, k12= 0.05045, k21= 0.03185, k41= 0.01 and k51= 0.01243. Conclusion: Hence, by fitting the result with the experimental work and simulation, the summation of error being stimulated by I-sight simulation was 0.731116428 and the correlation between the experimental and simulation data was 0.925544.

Objective: A new poly(ionic liquid)(PIL), poly(p-vinylbenzyltriphenylphosphine hexafluorophosphate) (P[VBTPP][PF6]), was synthesized by quaternization, anion exchange reaction, and free radical polymerization. Then a series of the PIL were synthesized at different conditions. Methods: The specific heat capacity, glass-transition temperature and melting temperature of the synthesized PILs were measured by differential scanning calorimeter. The thermal conductivities of the PILs were measured by the laser flash analysis method. Results: Results showed that, under optimized synthesis conditions, P[VBTPP][PF6] as the thermal insulator had a high glass-transition temperature of 210.1°C, high melting point of 421.6°C, and a low thermal conductivity of 0.0920 W m-1 K-1 at 40.0°C (it was 0.105 W m-1 K-1 even at 180.0°C). The foamed sample exhibited much low thermal conductivity λ=0.0340 W m-1 K-1 at room temperature, which was comparable to a commercial polyurethane thermal insulating material although the latter had a much lower density. Conclusion: In addition, mixing the P[VBTPP][PF6] sample into polypropylene could obviously increase the Oxygen Index, revealing its efficient flame resistance. Therefore, P[VBTPP][PF6] is a potential thermal insulating material.

A novel biosorbent from agricultural waste with an exceptional adsorptive capacity was prepared from the seed of blackberry (scientific name: Syzium Cumini). Methods: The biochar prepared from the waste seed by pyrolysis method had been characterized after chemical activation by different characterization techniques. (SEM, BET, TGA, FTIR, Proximate and ultimate analysis) to determine its physicochemical properties The adsorption study was carried out to inculcate the behaviour of the adsorption of Safranine-O dye from wastewater using prepared biosorbent. Results and Conclusion: The removal of adsorbate was best achieved by maintaining the following operational parameters: pH 6.3, dose of lab made biosorbent 1.26 g/L, initial concentration of Safranin-O-25 ppm, optimum contact time 120 minutes. The equilibrium data of Safranine-O (adsorbate) were analyzed in terms of different adsorption isotherm study. The isotherm data were fit to the Langmuir, Freundlich and Temkin isotherm model. It was best fit to Langmuir isotherm. The adsorption kinetics was well described by the pseudosecond- order kinetic model. The results of the adsorption experiments showed that for ABCSafranine- O system (Activated Blackberry Carbon-Safranin-O), the maximum uptake capacity of the adsorbent was found in the acidic medium.