Coal-fired steam turbine power plant using oxygen-rich air as oxidizer

Mitigation of harmful and greenhouse gas emissions produced by the coal combustion in thermal power plant is a topic goal. Reduction of the nitrogen oxides, sulfur and ash emissions makes remarkable progress but the carbon dioxide emission still meets considerable difficulties mostly caused by the low greenhouse gas content in the flue gas. A prospective solution to this problem may be the fuel combustion in oxygen-enriched air, which increases the flue gas carbon dioxide content. In this technology, the carbon dioxide content in flue gas is higher and this results in its easier capture. This paper presents the thermodynamic analysis results of a steam turbine power production facility that burns coal in the air with high oxygen content. The computer simulation shows that the oxygen content increase from 21 to 95.6% increases the carbon dioxide content in flue gas by a factor of 3.3 and lowers the power consumption for carbon dioxide capture by 11%. On the other side, the power consumption for pure oxygen production reduces the facility’s net efficiency from 28.54 to 21.59%.

A Sight of Zinc Corrosion in Various Alkaline Media

This review concentrates on corrosion properties that expose to zinc by various alkaline media. The assumption has been advanced that zinc corrodes electrochemically in the first stage of exposition, but the chemical corrosion prevails after a longer time. Different types of electrolyte had been tested on zinc such as sodium chloride, sodium hydroxide and potassium hydroxide. Each of alkaline media can produced corrosion product such as zinc hydroxide chloride, zinc hydroxide carbonate, zinc oxide, and zinc hydroxide. The production of corrosion products is depending on the carbon dioxide content that introduced to the air. Potassium hydroxide is the highest and active alkaline where it contains the highest ionic conductivity potassium ions, K+ after hydronium, H3O+ among the cations and hydroxide, OH ? has the highest ionic conductivity among the anions.

Microalgae Strains Monoraphidium Griffithi and Chlorella sp. for the Carbon Dioxide Capture from Biogas

One of the most important tools for mitigating climate change is biogas production. Increasing their use requires improving the energy value of biogas by reducing its carbon dioxide content while increasing the methane concentration in biogas. Biological purification of biogas using microalgae strains − merging biogas upgrading method where microalgae use carbon dioxide for their growth during the process of photosynthesis. A four-column photobioreactor was constructed with Monoraphidium Griffithi, Chlorella sp. microalgae strains, distilled water and MWH medium for purification of biogas. Experimental studies determined sizes, shapes and of microalgae cells, the pH changes of mediums used after biogas treatment and the composition of biogas before and after upgrading using photobioabsorber. Microalgae Monoraphidium Griffithi was estimated to have the greatest contribution to CO2 reduction by decreasing from 31.0% to 10.0%. The smallest reduction in CO2 was recorded when biogas was flowing through MWH medium. Experiments have shown that the absorption of biogas components results in the release of oxygen. As the biogas was flowing through all suspensions, the oxygen concentration increased from 3.6 to 5.2%.