The Usage of Saccharomyces cerevisiae in Microbial Fuel Cell System for Electricity Energy Production

A laboratory-scale MFC （microbial fuel cell） was studied in order to determine the capacity and the efficiency of electricity production in microbial fuel cell system by using microorganisms. The medium used is an isolated culture ofSaccharomces cereviciae. A number of media has been evaluated to provide the best growth phase for Saccharomces cereviciae using optical density method with spectrophotometer at a wavelength of 550 nm. Nation 117, Lyntech, USA is used as proton exchange membrane and graphites with surface area 1.46 x 10.3 m2 are used as cathodes. Cathode chamber is fulfilled with a mixture of electrolyte compounds K3Fe（CN）6 and a buffer solution. Microbes that have been cultured are applied into anode chamber. A number of factors need to be controlled so that microbes can generate electrical energy efficiently, such as by measuring the degree of acidity and DO value in the anode compartment. In this research, the usage of riboflavin as a mediator is also investigated, while the usage of riboflavin increase production efficiency 53.90% compare to MFC without riboflavin as a mediator.

Performance of Sewage Sludge Treatment and Electricity Generation by Different Configuration Microbial Fuel Cells

This paper compared the degradation efficiency of sludge organic matters and electric-production by two typical microbial fuel cells——dual-chamber microbial fuel cell(DMFC)and single chamber air cathode microbial fuel cell(SAMFC),and the variations of sludge protein,polysaccharide and ammonia nitrogen within the systems were also investigated.The results showed that the concentration of sludge soluble chemical oxygen demand,protein and carbohydrate of DMFC are higher than these of SAMFC during the systems operation,while DMFC can achieve a better ammonia nitrogen removal than SAMFC.Under the same operation condition,the stable voltage output of DMFC and SAMFC is 0.61 V and 0.37 V;the maximum power density of DMFC and SAMFC is 2.79 W/m3and 1.25 W/m3;TCOD removal efficiency of DMFC and SAMFC is 34.14%and 28.63%for 12 d,respectively.Meanwhile,DMFC has a higher coulomb efficiency than SAMFC,but both are less than5%.The results showed that DMFC present a better performance on sludge degradation and electric-production.

Assessment of Electricity Productivity in China:Regional Differences and Convergence

Electricity productivity is regarded as a major assessment indicator in the design of energy saving policies,given that China has entered a“New Normal”of economic development.In fact,enhancing electricity productivity in an all-round way,as is one of the binding indicators for energy and environmental issues,means that non-growth target of total electric energy consumption in the economic development is feasible.The Gini coefficient,Theil index,and Mean log deviation are utilized to measure regional differences in China’s electricity productivity from 1997 to 2016 in five regions,and conditionalβconvergence is empirically analyzed with the spatial Durbin model.The results show that:(1)China’s electricity productivity is improving,while the overall feature is that the eastern area has a higher efficiency than the western area.(2)The difference in electricity productivity is the smallest in the northeast and the largest in the northwest.Interregional difference plays an important role and is the main cause for the differences.(3)The electricity productivity in China exhibitsβconvergence,except for the northwest.The positive driving factor is urbanization level(0.0485%),and the negative driving factor is FDI(–0.0104%).Moreover,the urbanization rate(0.0669%),foreign direct investment(0.0960%),and the industrial structure(–0.0769%)have a spatial spillover effect on improving regional electricity productivity.Based on this conclusion,the study provides some recommendations for saving energy policy design in China’s power industry.

Electricity Generation in Turkey by Geothermal Energy Resources

Electricity generation generally is made in thermal, hydro, geothermal power plants and windfarms/windparks. Because of some advantages such as renewability, low-cost, clean, safe and naturality geothermal and wind energy will have been electricity generation source in the near future. Turkey has hot water springs suitable for electricity generation between 130-242 ~C with natural vapor and hydrothermal alterations in connection with grabens limited to active faults and diffuse young volcanism in Western Anatolia Region. Other renewable energy and electricity generation resource is wind energy. In Turkey electricity generation is made by windfarms/windparks. These parks/farms are generated 1,414.55 MW electricity. The year 2010 electricity general total installed capacity in Turkey is about 49,524.1 MW. According to the total installed capacity, thermal power plants have 65.18%, hydro power plants have 31.97%, geothermal power plants and wind farms have 2.85%. Electricity generation generally was obtained from 15 thermal power plants. In this study high temperature geothermal fields and windparks/windfarms in Turkey which are suitable for electricity generation potential were investigated.

On Some Issues of Assessing the Efficiency of Renewable Energy Power Plants and the Share of Renewables in the World＇s Electricity Generation

The paper considers some issues related to the evaluation of power plants using renewable energy sources： energy efficiency, economic efficiency, the share of renewable energy in the world＇s electricity generation. At one time in the world there was a myth that more energy is expended on the construction of wind and photoelectric power stations, than they produce for the service life. Adherents of this myth are still found in Russia. In response to this myth, numerous studies have been carried out for the manufacturers of wind turbines and photovoltaic modules. It was proved that these power plants spent energy on them are produced within a period of less than a year and the energy consumed by them cannot be taken into account, since it is renewable. The author showed that power plants on organic fuel and existing nuclear plants using depleted fuel with a coefficient less than unity fundamentally cannot compensate for the energy used during their construction. In the world, the concept of the LEC （Levelized Energy Cost） produced by any power plant is widely used to estimate economic efficiency. However, the formula for determining it, in the author＇s opinion, contains an inaccuracy, which is proposed to be eliminated. At present, there are different opinions on the role of RES （Renewable Energy Sources） in the production of electricity. A summary indicator is the share of renewable energy in the world＇s electricity generation. The determination of the actual share of RES and the forecast of its growth is of significant importance for the development of the world economy. The author shows the differences in the estimates and suggests an approach for establishing agreed estimates.

Generation of Electricity by Electrogenic Bacteria in a Microbial Fuel Cell Powered by Waste Water

The present study aimed at isolation characterization and evaluation of electrogenic bacteria for electricity generation using waste water. In this context, waste water samples were collected from University of Nizwa waste water treatment plant. A total of eight distinct bacterial isolates were isolated from these samples by serial dilution and plating on LB Agar medium. The bacterial isolates were than grown at different temperatures and pH. DNA from bacterial samples was isolated and 16S rRNA gene amplification was carried out. The 16S rRNA gene PCR products were directly sequenced and the resulting sequence was blasted using BLASTn. Based on BLAST results, the bacterial strains were identified. The bacteria were used in different combinations to generate electricity from waste water in microbial fuel cells constructed using plastic bottles. The microbial isolates were found to produce varying levels of currents and their electrogenic potential in waste water was observed to increase with the passage of time.