The issue of mercury emission and the need to take action in this direction was noticed in 2013 via the Minamata Convention. Therefore, more and more often, work and new law regulations are commencing to reduce this chemical compound from the environment. The paper presents the problem of removing mercury from waste gases due to new BREF/BAT restrictions, in which the problem of the need to look for new, more efficient solutions to remove this pollution was also indicated. Attention is paid to the problem of the occurrence of mercury in the exhaust gases in the elemental form and the need to carry out laboratory tests. A prototype installation for the sorption of elemental mercury in a pure gas stream on solid sorbents is presented. The installation was built as part of the LIDER project, financed by the National Center for Research and Development in a project entitled: “The Application of Waste Materials From the Energy Sector to Capture Mercury Gaseous Forms from Flue Gas”. The installation is used for tests in laboratory conditions in which the carrier gas of elemental mercury is argon. The first tests on the zeolite sorbent were made on the described apparatus. The tested material was synthetic zeolite X obtained as a result of a two-stage reaction of synthesis of fly ash type C with sodium hydroxide. Due to an increase, the chemical affinity of the tested material in relation to mercury, the obtained zeolite material was activated with silver ions (Ag+) by an ion exchange using silver nitrate (AgNO3). The first test was specified for a period of time of about 240 minutes. During this time, the breakthrough of the tested zeolite material was not recorded, and therefore it can be concluded that the tested material may be promising in the development of new solutions for capturing mercury in the energy sector. The results presented in this paper may be of interest to the energy sector due to the solution of several environmental aspects. The first of them is mercury sorption tests for the development of new exhaust gases treatment technologies. On the other hand, the second aspect raises the possibility of presenting a new direction for the management and utilization of combustion by-products such as fly ash.
In the 21st century the way to increase the efficiency of new sources of energy is directly related with extended exploration of renewable energy. This modern tendency ensures the fuel economy needs to be realized with nature protection. The increasing of new power sources efficiency (cogeneration, trigeneration systems, fuel cells, photovoltaic systems) can be performed by application of solid sorption heat pumps, regrigerators, heat and cold accumulators, heat transformers, natural gas and hydrogen storage systems and efficient heat exchangers.
The article comprises synthesis of magnetically susceptible carbon sorbents based on bio raw materials – beet pulp. The synthesis was performed by one- and two-step methodology using FeCl3 as an activating agent. X-ray diffraction methods showed an increase in the distance between graphene layers to 3.7 Å in biocarbon synthesized by a two-step tech-nique and a slight decrease in inter-graphene distance to 3.55 Å for biocarbon synthesized by an one-step technique. In both magnetically susceptible samples, the Fe3O4 magnetite phase was identified. Biocarbon synthesized by a two-step technique is characterized by a microporous structure in which a significant volume fraction (about 35%) is made by pores of 2.2 and 5 nm radius. In the sample after a one-step synthesis, a significant increase in the fraction of pores with radii from 5 to 30 nm and a decrease in the proportion of pores with radii greater than 30 nm can be detected. Based on the analysis of low-angle X-ray scattering data, it is established that carbon without magnetic activation has the smallest specific area of 212 m2∙сm–3, carbon after one-stage synthesis has a slightly larger area of 280 m2∙сm–3, and after two-stage synthesis has the largest specific surface area in 480 m2∙сm–3. The adsorption isotherms of blue methylene have been studied. Biocarbon ob-tained by two-step synthesis has been shown to have significantly better adsorption properties than other synthesized bio-carbons. Isotherms have been analysed based on the Langmuir model.
CaO sorbent dissolved in chloride molten salts was investigated to identify its CO2 capture property. Various molten salt systems with different melting points (CaCl2, LiCl, LiCl-CaCl2, and LiCl-KCl) were used to control the operation temperature from 450 to 850ºC in order to determine the effect of the operation temperature on the chemical reaction between CaO and CO2. The CaO sorbent showed the best performance at 550ºC in the LiCl-CaCl2 molten salt (conversion ratio of 85.25%). This temperature is lower than typical operation temperature of the solid-state CaO sorbent (~700ºC).
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