Lucyna WIĘCŁAW-SOLNY, Marek ŚCIĄŻKO
Removal of CO2 from power boiler flue gases by absorption process
Presented is an overview of international experience and results obtained by various firms and technologies in the field of CO2 removal from flue gases in the way of absorption process. Described are also the works carried on in the Instytut Chemicznej Przeróbki Węgla in Zabrze. As the first stage, a laboratory station for CO2 removal with the input gas flow intensity of 5 mn3/h and another station for amine absorption CO2 removal with the flow intensity of 100 m3n/h were opened being one of the key installations for Centrum Czystych Technologii Węglowych, technology section in Zabrze. The obtained knowledge and experience allowed the ICHPW and its Industrial Partners from the Tauron Group to build a pilot installation and carry on tests on a real power industry object. As to the installation scale, the intake of flue gases from a typical coal-fired boiler in the amount of 200 m3n/h (containing about 13% CO2 in volume) allows to remove about 50 kg/h of CO2 that gives about 1,2 ton of carbon dioxide per day. The preliminary obtained results of the first tests carried out on the pilot installation confirm the possibility to achieve in future a high efficiency in CO2 capture.
Keywords: CO2 removal from power boiler flue gases, absorption method, pilot installations
Wojciech NOWAK, Izabela MAJCHRZAK-KUCĘBA, Dariusz WAWRZYŃCZAK, Jakub BIENIEK, Kamil SROKOSZ, Ludomir BŁESZYŃSKI, Joanna ZAJĄCZKOWSKA
Adsorption method of CO2 removal from power boiler flue gases
Discussed is an experience gained during pilot research of an average CO2 concentration in a CO2 enriched product as well as the efficiency of separation process of carbon dioxide coming from conventional coal-fired boilers in TAURON Wytwarzanie S.A. – Oddział Elektrownia Łagisza (separation of CO2 from feed gas) in which the so-called DR-VPSA (Dual-Reflux Vacuum-Pressure Swing Adsorption) technology was used. This technology has not been used in pilot studies anywhere in the world so far. The carried out research allowed to achieve 60% CO2 concentration in the enriched gas with the high efficiency of the process. Ascertained was also a big influence of carbon dioxide concentration in the feed gas on CO2 concentration in the enriched gas. That is why in further examinations, apart from testing various pressure values in successive process stages with different time and flow values, some other process formulas will be analysed. It seems that, on the basis of the obtained results, particularly essential is the application of two adsorber sections from which the first one enables the gas enrichment while the second its further cleaning and achieving a high CO2 concentration.
Keywords: adsorption method of CO2 removal from power boiler flue gases, vacuum-pressure swing adsorption, dual reflux cycle
Józef DUBIŃSKI, Aleksandra KOTERAS
Possibilities of CO2 storage in geological formations
Described is the characteristics of underground CO2 storage in appropriately selected deep geological structures as an essential and final element of the CCS technology. It was pointed out that potential geological structures for underground CO2 storage must meet a series of specific requirements to prove that the CO2 will be safely and permanently stored. Both Polish and global research studies demonstrated that the sandstone saline aquifers have the largest potential storage capacity of CO2. Significantly lower storage capacity have depleted oil and gas reservoirs and the smallest one the deep and unmineable coal seams. CO2 storage potential in Polish deep geological structures was estimated on the basis of the results of the project carried out by research institutions under the supervision of the Polish Geological Institute and amounts to 10-15 billion tonnes of CO2. The significance of research and demonstration projects of underground CO2 storage, both for understanding the technology and recognizing its real potential, has been indicated.
Keywords: CCS technology, possibilities of CO2 storage, Poland’s geological structures
Agata CZARDYBON, Lucyna WIĘCŁAW-SOLNY, Marek ŚCIĄŻKO
Technological perspectives of carbon dioxide utilization
An overview is made of technologies utilizing carbon dioxide on a commercial scale either directly, i.e. without convertion into some other chemical form, or in a processed form – both in the fields of enhanced oil recovery, methane extraction from coal beds, advanced geothermal systems, algae cultivation, CO2 mineralization and concrete curing as well as production of fuels, polymers and valuable chemical raw materials. The development of the market for chemical raw materials based on carbon dioxide is caused mainly by commercialization of ecological and non-phosgene synthesis methods as well as by the possiblity to obtain high quality products indispensable for potential applications. The disadvantages of processes based on phosgene and running very quickly because of the high reactivity of this compound are constraints connected with work safety and production of a big amount of harmful byproducts. Many of the developed chemical processes are realized on a laboratory scale only and there is the need of further investigation and improvement of its economics based mainly on elaboration of efficient, selective, stable catalytic systems enabling application of more benign process conditions. In many cases the utilization of a supercritical state carbon dioxide increases the reaction control when compared to the processes based on conventional solvents. Problems connected with elaboration of efficient and economically justified systems converting CO2 into useful materials, though they are a big challenge, seem to have promising future in the days of continuous rise in fuel prices and the need of CO2 emission reduction. The estimated amount of carbon dioxide utilized nowadays for chemical syntheses equals about 10% of total CO2 emitted to the atmosphere. The amount of emitted CO2 that can be processed is in the range of 5-7%. It is caused by the need of bearing certain costs like those of chemical conversion of carbon dioxide and other reactants and also of separation, cleaning, storage and CO2 transportation.
Keywords: CO2 utilization, commercial technologies, CO2 conversion into useful materials
Adam WÓJCICKI, Stanisław NAGY
Legal and substantive aspects connected with the safety of CO2 storage in geological formations
Presented are legal and substantive problems connected with the safety of CO2 storage in geological formations. Defined is the notion and the range of geological storage. Presented are the possibilities of CO2 storage in the light of the existing law and to what extent it will be possible according to the latest amendment. Given are legal and substantive conditions of the projects that have been so far realized on a little scale in Poland and concerning high pressure pumping of CO2 (Kaniów) and of acid gas (Borzęcin). Presented are the main issues of the EU Flagship Project (European Technology Platform for Zero Emission Fossil Fuel Power Plants) concerning construction of CCS demo installations, its realization and connections with the implementation of the Climate and Energy Package and the Union Directive referring to CO2 geological storage in Poland, also known as the CCS Directive. Characterized is transposition of the CCS Directive into the national law and the most essential provisions concerning the changes in the Polish Geological and Mining Act and some other Acts transposing this Directive in the Polish law. Discussed is the condition and character of the CCS legislation in Europe and in the world. Characterized are, on the basis of B&R Union projects results, the requirements connected with the safety of CO2 storage. These requirements concern the geological and geophysical characteristics of potential storage locations, prognosing the behaviour of the CO2 pumped into geological formations (including gas and oil deposits), identification and elimination of the CO2 possible escape risk and also the monitoring plans before the pumping starts, during the storage facility operation and after its closure.
Keywords: geological CO2 storage safety, CCS Directive
Janusz KOTOWICZ
System conditions of CCS installation integration with a coal-fired power unit
Analysed are two different types of power plants with CCS installations. Both plants are the coal-fired ones and are equipped with ultra-supercritical steam power units. The first one is working using the oxy-combustion technology while the other is using the technology of post-combustion with CO2 capture from flue gas by the chemical absorption method. Determined is the investigated plants efficiency and elaborated is a general methodology to increase it. Shown is the influence of CCS installation and steam power unit thermal integration on efficiency and output capacity of a power plant. Presented is an impact of a sorbent energy consumption and methods of CCS installation waste heat utilization on a power plant performance. Analysed is an integration of ASU installation with a coal dryer, organization of flue gas recirculation and integration of ASU installation and a CCS installation with a steam turbine to increase its performance.
Keywords: steam power units, CCS installation, integration of CCS installation with a coal-fired power unit
Tomasz GOLEC, Bartosz ŚWIĄTKOWSKI, Ewa LUŚNIA
Pilot research of a coal oxy-combustion and its development perspectives
Numerical analyses show that it is not necessary to build new power units to utilize the combustion process in the oxygen enriched atmosphere. The retrofit of the so far existing objects can be based on installation of additional elements. Coal dust oxy-combustion in the existing combustion chambers designed for atmospheric combustion is possible without even redevelopment of a boiler heating surface but under the condition of rarefying the oxygen with recirculation flue gases in the amount of 73-75% dependending on a unit load. In such conditions one can get a comparable flame temperature profile and conditions of the heat exchange like for the air. When combusting the coal dust in the O2 /CO2 atmosphere it is necessary to use some specially designed burners. This necessity is caused by the change in oxidizer properties, endothermic reactions occurrence and the change in the amount of the oxidizer flowing through a burner that remarkably reduces flame stability after a burner. The burner developed in Instytut Energetyki enables even a fivefold increase of the stable work range. Except lower emission of NOx (lack of thermal oxides) from the combustion chamber during the O2/CO2 atmosphere combustion, the gradation of an oxidizer application is needed. The technology based on O2/CO2 atmosphere combustion is still in the research phase. There must still be solved some problems like high costs of oxidizing O2/CO2 atmosphere preparation, CO2 storage or reduction of a power boiler efficiency but despite all this the oxy-combustion brings many benefits.
Keywords: coal oxy-combustion, oxy-combustion technologies, octagonal combustion chamber boiler