Identification of Microbiological Activities in Wet Flue Gas Desulfurization Systems

Thermoelectric power generation from coal requires large amounts of water, much of which is used for wet flue gas desulfurization (wFGD) systems that minimize sulfur emissions, and consequently, acid rain. The microbial communities in wFGDs and throughout thermoelectric power plants can influence system performance, waste processing, and the long term stewardship of residual wastes. Any microorganisms that survive in wFGD slurries must tolerate high total dissolved solids concentrations (TDS) and temperatures (50–60°C), but the inocula for wFGDs are typically from fresh surface waters (e.g., lakes or rivers) of low TDS and temperatures, and whose activity might be limited under the physicochemically extreme conditions of the wFGD. To determine the extents of microbiological activities in wFGDs, we examined the microbial activities and communities associated with three wFGDs. O2 consumption rates of three wFGD slurries were optimal at 55°C, and living cells could be detected microscopically, indicating that living and active communities of organisms were present in the wFGD and could metabolize at the high temperature of the wFGD. A 16S rRNA gene-based survey revealed that the wFGD-associated microbial communities included taxa attributable to both thermophilic and mesophilic lineages. Metatranscriptomic analysis of one of the wFGDs indicated an abundance of active Burholderiaceae and several Gammaproteobacteria, and production of transcripts associated with carbohydrate metabolism, osmotic stress response, as well as phage, prophages, and transposable elements. These results illustrate that microbial activities can be sustained in physicochemically extreme wFGDs, and these activities may influence the performance and environmental impacts of thermoelectric power plants.

Study on the Integral Compensator Using Supercapacitor for Energy Harvesting in Low-Power Sections of Solar Energy

The risk of environmental pollution is a consequence of every kind of energy, including fossil fuels, nuclear power plants, and thermoelectric power plants. For the purpose of reducing the use ratio of such energy, research on eco-friendly energy is being actively carried out, and has shown that among all kinds of energy, solar energy has an advantage: it can supply us with inexhaustible clean energy. However, since solar energy depends on sunlight, the output may be unstable as it is influenced by weather or surrounding structures. In this paper, there is presented a control system which transmits power to a storage device, in a specific state, after the energy of the low-illumination section is charged in a supercapacitor using the accumulation-type controller by use of a supercapacitor. Feedback from the power output of photovoltaic panels (PVs) demonstrates that the power of the low-illumination section can be charged without being discarded. The charging rate was compared with other solar controllers being sold on the market, and the comparison was made through state of charge (SOC) measurements after the battery had been charged by photovoltaic panels for a whole day. It was confirmed that the solar controller, by use of supercapacitor integrator proposed in this paper, stored higher levels of energy than the existing solar controllers over the same hours and under the same conditions.

Management of affected areas by the pollution of the slag and ash deposits of CET Mintia

The technological processes from the combustion of certain materials in boilers results in significant amounts of slag and ash waste. Such industries that produce waste as slag and ash as a result of the process obtain electricity in the thermoelectric power plants. The biggest environmental problems caused by the thermoelectric power plants are air pollution and landscaping. In order to reduce the pollution caused by the slag and ash deposits, they should be ecologized upon completion of the slag and ash deposition process. An environmental management system aims at finding the most effective solutions for complying with environmental protection requirements. In this case, more economic solutions are needed to comply with the legislation. In this paper we will present a method of greening the slag and ash deposits of the thermoelectric power plants Mintia and the related costs.

Optimizing Current and Future Hydroelectric Energy Production and Water Uses of the Complex Multi-Reservoir System in the Aliakmon River, Greece

In this work we study long-term maximization of hydroelectric energy generation from complex multi-purpose reservoir systems, using the reservoir system of the Aliakmon River, Greece, as an application example. This system serves various purposes, like urban water supply, irrigation, hydroelectric energy production, cooling thermoelectric power plants and flood control, while preserving environmental flow. The system operator uses institutional rules for the annual scheduling of the outflows of the 2 largest reservoirs (Ilarion and Polyfyto) for additional safety and smooth distribution of energy production through the year. In this work, we focus on maximization of energy production. We have considered three different hydrological scenarios (dry, average and wet), both for the current and for anticipated future water demand. The multi-reservoir system’s operation was simulated and then optimized using a rather simple form of genetic algorithms, in order to maximize hydro energy production. All other water uses were taken into account as constraints. Our conceptual and computational approach succeeded to identify and quantify hydro energy production increase and to indicate necessary changes to the operating rule curves of the reservoirs. The methodology can be easily adapted to other large-scale multi reservoir systems.

Extraction of Silica from the residue of Thermoelectric Power Plants

Brazil presents the second largest coal reserves in Latin America, whose exploration is mainly focused on electricity generation. The present study was carried out to systematically evaluate the influence of various physical and chemical factors on the extraction of pure amorphous silica precipitated from coal-fired bottom ash. The coal bottom ashes (CBA) is a disposable waste from thermoelectric plants, which basically consists of oxides of silicon (80-60%), aluminium (25-20%) and iron (10-2%), being considered as raw material for silica production, by the sol-gel process. The CBA characterization was carried out by determining moisture, elemental composition (XRF), amorphism (XRD) and granulometry.The process evaluation tookplace in two stages: the quantitative evaluation that wasrelated to the quantification of the amount of silica obtained and the process variables (NaOH concentration and temperature); and the qualitative evaluationof the silica extracted. The extracted silica particles were characterized by TG, BET, XRD.Silica and aluminium contents were obtained by gravimetric analysis. Among the factors analysed, the concentration of sodium hydroxide and temperature interference were the most important. Likewise, the repeat process for the same ash sample (sequential extraction) proved to be more effective than increasing the NaOH concentration. The obtained yield was 51.34%. The silica is 89.4% pure, when 5,63% of impurities are related to aluminium oxide .