Modeling of a supercritical power plant with an oxy type pulverized fuel boiler, a carbon dioxide capture unit and a ‘four-end’ type membrane air separator

The analysis of a 600 MW supercritical power plant with parameters of life steam at 30 MPa/ /650o C and of reheated steam 6 MPa/670o C was made. Power plant is equipped with the following units: oxy type pulverized fuel boiler, ‘four-end’ high temperature membrane air separator and carbon dioxide capture system which were modeled. With the assumption of a constant gross power of the analyzed power plant, the thermal efficiency of the boiler and the steam cycle efficiency were calculated. These parameters were designated as a function of the recovery rate of oxygen in the air separation unit. This allowed to determine gross and net efficiency of electricity generation

The characteristics of a modern oxy-fuel power plant

This paper presents the thermodynamic and economic analyses of four variants of a supercritical oxy-type plant. These variants differed in terms of air separation units (ASU, variants: V1—cryogenic; V2—hybrid; equipped with a three-end (V3a) or four-end (V3b) high-temperature membrane) and boilers (V1 and V3a—lignite-fired fluidized-bed; V2 and V3b—hard-coal-fired pulverized-fuel). The gross power of steam turbine unit (STU) was 600 MW. The live and reheated steam parameters were 650 °C/30 MPa and 670 °C/6.5 MPa, respectively. The influence of the ASUs’ operating parameters on the ASUs’ auxiliary power rate and boiler efficiency (V3a and V3b only) was studied. The ASUs’ operating parameters for maximum net efficiency were then determined. The decrease in the net efficiency compared to a reference plant (with a classic fluidized-bed or pulverized-fuel boiler) fluctuated in the range 7.2 (V3b)–11.2 (V1) p.p. An analysis of the waste heat utilization was performed (fuel drying—V1 and V3a; STU steam-water heat exchangers replacing). Thus, the efficiency decreases fluctuated in the range 4.3 (V3b)–10.2 (V1) p.p. The economic analysis showed that in order for the variants to be economically viable, the unit CO2 emission cost should be greater than 42.2 (V1) or 22.0 (V3b) EUR/MgCO2

The Characteristics of a Modern Oxy-Fuel Power Plant

This paper presents the thermodynamic and economic analyses of four variants of a supercritical oxy-type plant. These variants differed in terms of air separation units (ASU, variants: V1—cryogenic; V2—hybrid; equipped with a three-end (V3a) or four-end (V3b) high-temperature membrane) and boilers (V1 and V3a—lignite-fired fluidized-bed; V2 and V3b—hard-coal-fired pulverized-fuel). The gross power of steam turbine unit (STU) was 600 MW. The live and reheated steam parameters were 650 °C/30 MPa and 670 °C/6.5 MPa, respectively. The influence of the ASUs’ operating parameters on the ASUs’ auxiliary power rate and boiler efficiency (V3a and V3b only) was studied. The ASUs’ operating parameters for maximum net efficiency were then determined. The decrease in the net efficiency compared to a reference plant (with a classic fluidized-bed or pulverized-fuel boiler) fluctuated in the range 7.2 (V3b)–11.2 (V1) p.p. An analysis of the waste heat utilization was performed (fuel drying—V1 and V3a; STU steam-water heat exchangers replacing). Thus, the efficiency decreases fluctuated in the range 4.3 (V3b)–10.2 (V1) p.p. The economic analysis showed that in order for the variants to be economically viable, the unit CO2 emission cost should be greater than 42.2 (V1) or 22.0 (V3b) EUR/MgCO2

Methanol Production in the Brayton Cycle

This article presents the concept of renewable methanol production in the gas turbine cycle. As part of the work, an analysis was performed, including the impact of changing the parameters in the methanol reactor on the obtained values of power, yield and efficiency of the reactor, and chemical conversion. The aim of this research was to investigate the possibility of integrating the system for the production of renewable methanol and additional production of electricity in the system. The efficiency of the chemical conversion process and the efficiency of the methanol reactor increases with increasing pressure and decreasing temperature. The highest efficiency values, respectively η = 0.4388 and ηR = 0.3649, are obtained for parameters in the reactor equal to 160 °C and 14 MPa. The amount of heat exchanged in all exchangers reached the highest value for 14 MPa and 160 °C and amounted to Q˙ = 2.28 kW. Additionally, it has been calculated that if an additional exchanger is used before the expander (heating the medium to 560 °C), the expander’s power will cover the compressor’s electricity demand

Liquid methanol energy storage technology

The paper presents technologies currently being developed for methanol production and its applications. Particular attention was paid to energy storage technology in the form of “renewable” methanol, which is produced from hydrogen generated from surplus energy from renewable energy sources and from captured CO2. The global methanol market was characterized, i.e. global demand, major producers and global demand for products made from methanol. The installation of methanol production and purification with stoichiometry as well as the methodology for assessing the efficiency of such an installation are also presented. The results of the analysis of such an installation were discussed in accordance with the methodology given

Wybrane sposoby zmniejszenia energochłonności instalacji w supernadkrytycznym bloku węglowym

In the paper, the influence of CO2 separation system on the efficiency of electricity production in ultra-supercritical power plant was analyzed. The installation of CO2 separation consisting of a two-stage membrane system and four-stage CO2 compressor with intercooling, which provides increasing CO2 pressure to 20 MPa, was proposed. The proposed carbon capture and storage (CCS) installation allows for the separation of 90% of emitted CO2 from the energy unit with the purity equal to 0.90 and the liquefaction of this stream. This installation requires power supply in the amount of 141.3 MW, which corresponds to the energy equal to 0.903 MJ/kgco2 removed. Several ways to reduce energy consumption of CO2 capture were presented. The paper presents the results of calculation aiming at decreasing the energy consumption of CCS installation through the use of devices with multi-stage intercooled, lowering the temperature of the gas prior to the next level of compression and partial recovery of the energy needed to compression of the separated gas stream before the second stage of the membrane (using a gas turbine). The effect of using heat from the cooling of flue gases, separated and compressed CO2 in the steam turbine regeneration system on the effectiveness of the whole system was also shown. The effect on power requirement for the CCS installation of CO2 liquefaction under pressure near to the critical pressure and then using the liquid CO2 pump in order to increase pressure to the value required for transport was presented.W artykule przedstawiono wpływ systemu separacji CO2 na sprawność wytwarzania energii elektrycznej w supernadkrytycznym bloku węglowym. Zaproponowano instalację separacji CO2 z zastosowaniem dwustopniowego układu membranowego oraz czterostopniowy kompresor dwutlenku węgla z chłodzeniem międzystopniowym, który zapewnia podniesienie ciśnienia CO2 do 20 MPa. Instalacja CCS ma na celu odseparowanie 90% strumienia emisji CO2 z bloku energetycznego przy jego czystości równej 0,9 oraz upłynnienie tego strumienia. Instalacja ta wymaga doprowadzenia mocy elektrycznej w ilości 141,3 MW, co odpowiada zapotrzebowaniu na energię w ilości 0,903 MJ/kgco2 usuniętego. Przedstawiono kilka sposobów zmniejszenia energochłonności procesu wychwytu CO2. W pracy przedstawiono wyniki obniżenia energochłonności instalacji CCS poprzez zastosowanie urządzeń wielostopniowych z chłodzeniem międzystopniowym, obniżenie temperatury gazu przed kolejnym stopniem sprężania oraz poprzez częściowy odzysk energii potrzebnej do sprężenia strumienia separowanych gazów przed drugim stopniem membranowym (zastosowanie turbiny gazowej). Badano również wpływ wykorzystania ciepła z chłodzenia spalin, separowanego i sprężanego CO2 w układzie regeneracji turbiny parowej na efektywność całego układu. Określono także, jak wpływa na zapotrzebowanie mocy instalacji CCS upłynnienie CO2 pod ciśnieniem zbliżonym do ciśnienia krytycznego, a następnie zastosowanie pompy ciekłego CO2 celem podniesienia ciśnienia do wartości wymaganej dla transportu

Wpływ wybranych parametrów na charakterystykę ekonomiczną węglowych siłowni z instalacją CCS

In this paper the influence of carbon dioxide capture installation (CCS installation) on the efficiency of a coal power plant is presented. The power demand for the membrane separation and the efficiency losses of the power plant (14.04 percentage points) after implementation of the CCS installation is shown. A method for reducing these losses through integration of the CCS installation with the power plant is proposed. The main aims of the integration are heat exchange between media and decrease of the CO2 temperature before compression. Implementing of this process can result in a significant reduction of the efficiency loss by around 7 percentage points. The influence of the integration on the unit sale price of electricity as well as on the cost of CO2 avoided emission was also determined. The influence of the fuel cost , investment cost of the CCS installation on the limit sale price of electricity and CO2 avoided emission cost was analyzed in details.W artykule przedstawiono wpływ możliwości wychwytywania dwutlenku węgla poprzez instalację CCS na efektywność elektrowni węglowych. Pokazano zapotrzebowania mocy dla separacji membranowej i straty wydajności elektrowni (14.04 punktów procentowych) po wykonaniu instalacji CCS. Zaproponowano zintegrowanie instalacji CSS jako sposobu zminimalizowania strat elektrowni. Głównym celem integracji jest wymiana ciepła pomiędzy mediami oraz spadek temperatury CO2 przed kompresją. Realizacja tego procesu może doprowadzić do znacznego zredukowania wydajności o około 7 punktów procentowych. Został również określony wpływ integracji na cenę sprzedaży jednostki energii elektrycznej, jak również na koszty poniesione na uniknięcie emisji CO2. Zanalizowano także wpływ kosztów paliwa oraz wprowadzenia instalacji CCS na limit ceny sprzedaży energii elektrycznej i uniknięcia emisji CO2