Molybdenum carbide co-catalyst and carbon nanofiber matrix are suggested to improve the nickel activity toward methanol electrooxidation process. The proposed electrocatalyst has been synthesized by calcination electrospun nanofiber mats composed of molybdenum chloride, nickel acetate, and poly (vinyl alcohol) under vacuum at elevated temperatures. The fabricated catalyst has been characterized using XRD, SEM, and TEM analysis. The electrochemical measurements demonstrated that the fabricated composite acquired specific activity for methanol electrooxidation when molybdenum content and calcination temperature were tuned. In terms of the current density, the highest performance is attributed to the nanofibers obtained from electrospun solution having 5% molybdenum precursor compared to nickel acetate as a current density of 107 mA/cm2 was generated. The process operating parameters have been optimized and expressed mathematically using the Taguchi robust design method. Experimental design has been employed in investigating the key operating parameters of methanol electrooxidation reaction to obtain the highest oxidation current density peak. The main effective operating parameters of the methanol oxidation reaction are Mo content in the electrocatalyst, methanol concentration, and reaction temperature. Employing Taguchi’s robust design helped to capture the optimum conditions yielding the maximum current density. The calculations revealed that the optimum parameters are as follows: Mo content, 5 wt.%; methanol concentration, 2.65 M; and reaction temperature, 50 °C. A mathematical model has been statistically derived to describe the experimental data adequately with an R2 value of 0. 979. The optimization process indicated that the maximum current density can be identified statistically at 5% Mo, 2.0 M methanol concentration, and 45 °C operating temperature.

Green fuel is growing in popularity in recent years. Bio-reactive waste converted to green fuel through anaerobic digestion technology. The performance of biogas unit has been optimized and formulated as interval programming problems as function of inlet feed rate, retention time fermentation temperature and pH. A new treatment for solving the interval nonlinear programming problem (INPP) is discussed. All the intervals in the INPP are replaced by new variables. This the modified nonlinear programming problem (MIPP). We presented three hybrid evolutionary algorithms (EAs) which are chaotic genetic algorithm (CGA), chaotic particle swarm optimization (CPSO) and chaotic firefly algorithm (CFA) to solve MIPP. The Karush–Kuhn–Tucker (KKT) conditions for MIPP are gotten. These equations are solved as algebraic equations. Its solutions may be represented as a function of new variables to get the stability set of first kind. The staring points in EAs is gotten by the Newton method. Finally, the comparison between the stability set of first kind, CGA, CPSO and CFA are presented with discussion. An empirical optimization model of biogas production has been constructed with accuracy of 90%.

To enhance the treatment of real industrial wastewater effluents, a new design of an electromagnetic field-enhanced electrochemical cell consisting of a tubular screen roll anode and two cathodes (an inner and outer cathode) has been used. The treatment of real beet sugar mill effluent by the electrocoagulation process has been studied. The cell has a uniform current distribution, a low IR drop, and good mixing. Different parameters have been investigated, like: current density (CD), effluent concentration, NaCl concentration, rpm, number of screen layers per anode, and the effect of the addition of an electromagnetic field. The results showed that, under the optimum conditions of CD at 3.13 Am− 2, two screens per anode, NaCl concentration of 12 g/L, and rotation speed at 120 rpm, the percentage of color removal was 85. 5% and the electrical energy consumption was 3.595 kWhm− 3. In addition, the presence of electromagnetic field enhanced the energy consumption for the wastewater treatment by accelerating the coagulation step as indicated by simulation results. Numerically, applying the magnetic field resulted in performing a color removal efficiency of 97.7% using a power consumption of 2.569 KWh/m3 which is considered a distinct achievement in industrial wastewater treatment process. This design has proven to be a promising one for continuous treatment of industrial effluents and to be a possible competent to the currently available techniques due to the high removal efficiency and low energy consumption.

The treatment of real beet sugar mill effluent by a modified electrocoagulation process is proposed. An innovative design of an electromagnetic field-enhanced electrochemical cell consisting of a tubular screen roll anode and two cathodes (an inner and outer cathode) has been used. Different parameters have been investigated including current density, effluent concentration, NaCl concentration, rpm, number of screen layers per anode, and the effect of addition and direction of an electromagnetic field. The results showed that, under the optimum conditions, current density of 3.13 A/m2, two screens per anode, NaCl concentration of 12 g/l, and rotation speed of 120 rpm, the percentage of color removal was 85.5% and the electrical energy consumption was 3.595 kWh/m3. However, the presence of an electromagnetic field distinctly enhanced the energy consumption and the color removal percentage. Numerically, applying the magnetic field resulted in performing a color removal efficiency of 97.7% using a power consumption of 2.569 KWh/m3 which is considered a distinct achievement in industrial wastewater treatment process. The strong enhancement in color removal using a low power consumption significantly reduced the required treatment cost; the estimated treatment cost was 0.00017 $/h.m2. This design has proven to be a promising one for the continuous treatment of beet sugar industrial effluents and to be a competitor to the currently available techniques.