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The liquid–solid mass transfer behavior of 8 cylindrical blade impeller it can act as electrode or catalyst support in a new stirred tank reactor was studied in relation to catalytic and electrochemical reactor design by the electrochemical technique which involved measuring the limiting current of the cathodic reduction of K 3 Fe(CN) 6 . Variables studied were blade length, impeller rotation speed, physical properties of the solution, effect of baffles, effect of immiscible liquids, effect of superimposed solution flow (continuous operation), effect of the distance between successive impellers in case of multi-impeller reactor and the effect of drag reducing polymers. The mass transfer data for single rotating impeller were found to fit the following equation: S h = 0.429     S c 0.33     R e 0.42 Superimposed solution flow and impeller separation were found to have little effect on the rate of mass transfer, baffles were found to increase the rate of mass transfer while the presence of immiscible liquid decreases the rate of mass transfer. Addition of drag reducing polymers (Polyox WSR-301) was found to reduce the rate of mass transfer at single impeller by a maximum of 15.8%. Examination of heavy metal removal from dilute solutions revealed that the rate of metal deposition agrees fairly with the prediction of the equation despite the presence of surface roughness and H 2 evolution. The advantages of this reactor in conducting diffusion controlled catalytic and electrochemical liquid–solid reactions and liquid–solid reactions involving sparingly soluble reactants that to be dispersed such as gases, solid particles and immiscible liquids were highlighted. [ABSTRACT FROM AUTHOR]

Abstract: The effect of vertical plate electrode pulsation on the rate of cathodic copper deposition and anodic oxidation of ferrous sulphate was studied in a divided cell. Electrode oscillation was found to enhance the rate of diffusion controlled copper deposition and ferrous sulphate anodic oxidation by a factor ranging from 1.9 to 7.8 compared to the natural convection value depending on the vibration velocity. Electrode pulsation was found to increase the current efficiency of copper deposition from 52% to 98%, while the current efficiency of anodic oxidation of FeSO4 increased from 35% to 92% depending on the vibration velocity. Also, electrode vibration was found to decrease electrical energy consumption of copper deposition from 4 to 1.56kWh/kg; for anodic oxidation of FeSO4 electrode vibration reduces energy consumption from 3.35 to 1.25kWh/kg depending on vibration velocity. The importance of the present results for treating dilute solutions containing copper and ferrous ions such as printed circuit etching solution, pickling waste solutions, chemical machining waste solution, mine drainage water, leaching liquor obtained by leaching low grade copper sulphide ore by ferric salts was highlighted. The present technique has the advantage of recovering a precious metal and recycling a valuable chemical in one step, this satisfies the policy of zero discharge industry. [ABSTRACT FROM AUTHOR]

This paper discusses the technical and economic feasibility of a renewable energy-based system, aimed to replace the traditional diesel engines implemented on a pushed and pusher bulk carrier barge. This barge has a challenging navigational route in the Nile River from Alexandria to Aswan and vice versa. It is scheduled to complete 30 trips annually while carrying 850 tons/trip. The system is based on photovoltaic panels, and was selected with its excess energy to be stored primarily in the form of H 2 gas through electrolysis, and batteries (i.e. Power to Gas technology) to be later converted back to electrical energy through fuel cells. Hence, an operation algorithm was formulated to optimize the performance of the system by defining operating modes that use solar energy, hydrogen energy, batteries, or hybrid energy coming from multiple sources that result in an internal rate of return (IRR) of 15.1% and overall efficiency of 57.9%. This high efficiency is due to the nature of water current that flows from south to north of Egypt, therefore, causing a significant reduction in power demand in the trip from Aswan to Alexandria that requires 11,980 kW h, compared to the trip from Alexandria to Aswan that requires 21,064 kW h. • Zero emission solution combining solar energy, hydrogen generation and fuel cell propulsion for a barge in Nile River. • Preparation to achieve the 7th goal of sustainable development ensuring green propulsion in Nile River cargo transport. • Efficient use of natural resources, solar energy and water current from south to north of Egypt. • Integrating electrolizer, fuel cell, solar energy pv, batteries, and hydrogen storage to form an autonomous barge. [ABSTRACT FROM AUTHOR]