@misc{MuellerFleigeRachowetal., author = {M{\"u}ller, Klaus and Fleige, Michael and Rachow, Fabian and Schmeißer, Dieter}, title = {Sabatier based CO2-methanation of flue gas emitted by conventional power plants}, series = {Energy Procedia}, volume = {40}, journal = {Energy Procedia}, issn = {1876-6102}, doi = {10.1016/j.egypro.2013.08.028}, pages = {240 -- 248}, abstract = {The hydrogenation CO2+ 4H2 ->CH4 + 2H2O discovered by Paul Sabatier nowadays is discussed as "Power-to-approach" to utilize excess energy from renewable electricity generation. In a laboratory scale, we investigate the Sabatier process in a simulated flue gas atmosphere of conventional base load power plants. The reaction is investigated with regard to conversion rates, yield, selectivity and long-term stability. Using a catalyst based on nickel,we extract selectivities near 100\% with a conversion around 85\%. Beside the influence of oxygen, we investigate further typical contaminations like NO2 and SO2.}, language = {en} } @misc{MuellerStaedterRachowetal., author = {M{\"u}ller, Klaus and St{\"a}dter, Matthias and Rachow, Fabian and Hoffmannbeck, David and Schmeißer, Dieter}, title = {Sabatier-based CO2-methanation by catalytic conversion}, series = {Environmental Earth Sciences}, volume = {70}, journal = {Environmental Earth Sciences}, number = {8}, issn = {1866-6280}, doi = {10.1007/s12665-013-2609-3}, pages = {3771 -- 3778}, abstract = {The catalytic conversion of CO2is an important component for the reintegration of secondary products like CO2 or H2 into the energy supply. An example is the "power to gas'" concept with a conversion of CO2 into CH4. The CO2 is transferred into a carrier of chemical energy, with the possibility to feed the produced CH4 into the existing network of natural gas. At temperatures of around 350 °C, hydrogenation of CO2 to CH4 is possible by the Sabatier reaction CO2+4H2->CH4+H2O. One prerequisite for efficient kinetics of the Sabatier reaction is the application and optimization of catalysts. The focus of catalyst development is given to their performance under the conditions to be expected in the special application. As a part of the project Geoenergy-Research (GeoEn), we address questions related to the catalytic utilization of CO2 produced in the course of the oxyfuel combustion of lignite. In this contribution, we report on the experimental setup in laboratory scale, which enables an advanced characterization of the catalytic performance, including thermodesorption measurements at atmospheric pressure in order to determine the amount of adsorbed CO2 under real conditions. We also show data for activation energies, the catalytic performance as function of temperature and the long time stability of a commercial Ru-based catalyst.}, language = {en} } @misc{StaedterMuellerRachowetal., author = {St{\"a}dter, Matthias and M{\"u}ller, Klaus and Rachow, Fabian and Richter, Matthias and Schmeißer, Dieter}, title = {Ambient pressure thermal desorption spectroscopy (AP-TDS) of NiO/SiO2 catalysts}, series = {Environmental Earth Sciences}, volume = {70}, journal = {Environmental Earth Sciences}, number = {8}, issn = {1866-6280}, doi = {10.1007/s12665-013-2835-8}, pages = {3779 -- 3784}, abstract = {The Sabatier reaction is a key process in the "power-to-gas" application which is considered to con-tribute to future chemical energy storage systems. In this contribution we focus on the catalytic active sites of a NiO catalyst supported on SiO2(NiO/SiO2) which is commonly used in the Sabatier reaction. A novel technique for the characterization of the active sites is presented and dis-cussed using thermal desorption spectroscopy at ambient pressure. This analytical tool is operated under reaction conditions and allows element specific measurements during the catalytic process of CO2 reforming towards methane. Beside the desorption experiments, XPS and XAS measurements of pristine and catalytically used samples are performed to determine the influence of the Sabatier reaction conditions on the surface structure of the catalyst.}, language = {en} } @incollection{PohleGaedekeKochetal., author = {Pohle, Ina and G{\"a}deke, Anne and Koch, Hagen and Gr{\"u}newald, Uwe and Schramm, Martina and Redetzky, Michael and M{\"u}ller, Fabian and Kaltofen, Michael}, title = {Auswirkungen potenzieller {\"A}nderungen des Klimas und der Braunkohlef{\"o}rderung und -verstromung auf nat{\"u}rliche und bewirtschaftete Abfl{\"u}sse in den Lausitzer Flusseinzugsgebieten}, series = {Wassermanagement im Klimawandel : M{\"o}glichkeiten und Grenzen von Anpassungsmaßnahmen}, booktitle = {Wassermanagement im Klimawandel : M{\"o}glichkeiten und Grenzen von Anpassungsmaßnahmen}, editor = {Kaden, Stephan and Dietrich, O. and Theobald, S.}, publisher = {oekom verlag}, address = {M{\"u}nchen}, isbn = {978-3-86581-480-7}, pages = {121 -- 140}, abstract = {In den Flusseinzugsgebieten von Schwarzer Elster, Dahme, Spree und Lausitzer Neiße wurden die Auswirkungen von klimatischen {\"A}nderungen auf nat{\"u}rliche und bewirtschaftete Abfl{\"u}sse mittels eines Modellensembles aus regionalen Klimamodellen, hydrologischen Modellen und einem Langfristbewirtschaftungsmodell untersucht. F{\"u}r Teileinzugsgebiete wurden unter Nutzung von Klimavariablen der Regionalen Klimamodelle STAR und WettReg mit den hydrologischen Modellen SWIM, EGMO, WaSiM-ETH und HBV-light abnehmende nat{\"u}rliche Abfl{\"u}sse simuliert. Die mit dem Klimaszenario verbundenen Unsicherheiten sind dabei gr{\"o}ßer als jene aufgrund der Wahl des hydrologischen Modells. Die Auswirkungen m{\"o}glicher Entwicklungen der Braunkohlef{\"o}rderung und -verstromung wurden im Sinne eines Szenarios der Entwicklung der Grundwasserabsenkungstrichter mit SWIM simuliert. Diese Auswirkungen sind denen der klimatischen {\"A}nderungen untergeordnet. Die hydrologischen Modelle SWIM und EGMO wurden f{\"u}r die Gesamteinzugsgebiete aufgebaut und parametrisiert. Die mit diesen Modellen unter STAR-Szenarien simulierten nat{\"u}rlichen Abfl{\"u}sse dienten als Eingangsdaten f{\"u}r die Wasserbewirtschaftungsmodellierung mit WBalMo. Aufgrund von abnehmenden nat{\"u}rlichen Abfl{\"u}ssen und unter der Annahme eines Szenarios zur Entwicklung der Braunkohlef{\"o}rderung und -verstromung, bei dem die Fl{\"a}che der Grundwasserabsenkungstrichter, aber auch die S{\"u}mpfungswassermengen zur{\"u}ckgehen, wurden abnehmende bewirtschaftete Abfl{\"u}sse simuliert. Auch bei diesen {\"u}berwiegen im Gesamtjahr die mit den Klimaszenarien verbundenen Unsicherheiten, wobei insbesondere im Jahresverlauf die Ergebnisse mit den hydrologischen Modellen deutlich unterschiedlich sind. Die Studie liefert im Ergebnis eine Bandbreite denkbarer Entwicklungsszenarien, welche als Grundlage f{\"u}r Klimawandelanpassungsmaßnahmen der regionalen Wasserbewirtschaftung dienen k{\"o}nnen.}, language = {de} } @misc{PohleKochGaedekeetal., author = {Pohle, Ina and Koch, Hagen and G{\"a}deke, Anne and Gr{\"u}newald, Uwe and Kaltofen, Michael and Schramm, Martina and Redetzky, Michael and M{\"u}ller, Fabian}, title = {Auswirkungen von Unsicherheiten in Klimaszenarien auf die regionale Wassermengenbewirtschaftung}, series = {KW Korrespondenz Wasserwirtschaft}, volume = {7}, journal = {KW Korrespondenz Wasserwirtschaft}, number = {6}, issn = {1865-9926}, pages = {350 -- 354}, abstract = {In den Lausitzer Flusseinzugsgebieten von Schwarzer Elster, Dahme, Spree und Lausitzer Neiße zeigen sich durch Braunkohlebergbau und vielf{\"a}ltige Bewirtschaftungseinfl{\"u}sse deutliche Unterschiede zwischen nat{\"u}rlichem Abflussgeschehen und bewirtschafteten Abfl{\"u}ssen. Die m{\"o}glichen Auswirkungen klimatischer {\"A}nderungen werden durch eine Klimawandelimpaktstudie mit dem statistischen Regionalen Klimamodell STAR (3 Klimaszenarien), den hydrologischen Modellen SWIM und EGMO sowie dem Lang-fristbewirtschaftungsmodell WBalMo untersucht. Durch niedrigere nat{\"u}rliche Abfl{\"u}sse und den angenommenen R{\"u}ckgang der S{\"u}mpfungswassermengen aus dem Braunkohlebergbau werden mit WBalMo abnehmende bewirtschaftete Abfl{\"u}sse simuliert. Unsicherheiten bestehen dabei aufgrund der genutzten Klimaszenarien und hydrologischen Modelle, sowie hinsichtlich der Annahmen zur zuk{\"u}nftigen wirtschaftlichen Entwicklung (u. a. Braunkohlef{\"o}rderung und -verstromung).}, language = {de} } @inproceedings{PohleZimmermannClausetal., author = {Pohle, Ina and Zimmermann, Kai and Claus, Thomas and Koch, Hagen and G{\"a}deke, Anne and Uhlmann, Wilfried and Kaltofen, Michael and M{\"u}ller, Fabian and Redetzky, Michael and Schramm, Martina and Schoenheinz, Dagmar and Gr{\"u}newald, Uwe}, title = {Long-term integrated river basin planning and management of water quantity and water quality in mining impacted catchments}, series = {European Geosciences Union, General Assembly 2015, Vienna, Austria, 13 April - 17 May 2015}, booktitle = {European Geosciences Union, General Assembly 2015, Vienna, Austria, 13 April - 17 May 2015}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, language = {en} } @inproceedings{IsraelRachowSchwiertzetal., author = {Israel, Johannes and Rachow, Fabian and Schwiertz, Carola and Charlafti, Evgenia and M{\"u}ller, Klaus and Schmeißer, Dieter}, title = {Self restriction oft the Sabatier reaction in large scale}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, abstract = {A main goal for a sustainable energy supply is a long term energy storage system. One opportunity in this research field is the power to gas concept, where the produced gas can be fed in the existing network of natural gas. Here we show in a technical scale how the direct CO2 conversion to methane according the Sabatier reaction, CO2 + 4 H2 → CH4 + 2H2O , is self organized. At a certain limit of gas flow, a steady state equilibrium of exothermic heat production and thermal flow is reached and the reaction needs no further external annealing. We find for the maximum volume rate at the steady state equilibirum a shift of around 250 ∘C above the optimized temperature of the catalytic supported chemical equilibrium. It is shown that also with this setup the used catalyst works with a stable conversion higher than 80 \% under the reached temperature and given pressure conditions.}, language = {en} } @inproceedings{RachowIsraelSchwiertzetal., author = {Rachow, Fabian and Israel, Johannes and Schwiertz, Carola and Charlafti, Evgenia and M{\"u}ller, Klaus and Schmeißer, Dieter}, title = {CO2 Methanation with different gas mixtures}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, pages = {S. 539}, abstract = {A key issue in the Energiewende in Germany is the storage of excess energy, as it enables energy management systems to react to fluctuating sources and enhances the flexibility of an energy mix. Power to Gas may be the most reasonable approach to store the energy in the form of hydrogen or synthetic natural gas. We study the direct conversion of CO2 by the Sabatier reaction to gain a methane based mixture which can replace natural gas in CHP plants and gas motors and can help to partially reduce the CO2 emission. In laboratory scale we investigated the performance (with IR and QMS) of Ni-based catalyst for different sources of CO2 like clean CO2, CO2 emitted as flue gas from an Oxyfuel power plant or a synthetic mixture with O2, N2 and SO2 in concentration typical for conventional power plants. Measurements from an up-scaled system are also presented, showing data important for a technical application. Here, we are able to convert more than 200kg CO2/day with conversion rates up to 90\%.}, language = {en} } @misc{PohleKochZimmermannetal., author = {Pohle, Ina and Koch, Hagen and Zimmermann, Kai and G{\"a}deke, Anne and Claus, Thomas and Uhlmann, Wilfried and Kaltofen, Michael and Redetzky, Michael and Schramm, Martina and M{\"u}ller, Fabian and Schoenheinz, Dagmar and Gr{\"u}newald, Uwe}, title = {Analyse von Wassermenge und Wasserbeschaffenheit f{\"u}r Klima- und Bewirtschaftungsszenarien: Aufbau und Nutzung einer Modellkaskade f{\"u}r das Spreeeinzugsgebiet}, series = {Hydrologie und Wasserbewirtschaftung}, volume = {60}, journal = {Hydrologie und Wasserbewirtschaftung}, number = {3}, doi = {10.5675/HyWa_2016,3_2}, pages = {176 -- 195}, abstract = {Klima{\"a}nderungen und sozio{\"o}konomische Entwicklungen k{\"o}nnen Konsequenzen f{\"u}r die Wassermengenbewirtschaftung und die Wasserbeschaffenheit nach sich ziehen. Zur Absch{\"a}tzung der Auswirkungen regionaler Entwicklungen wurde in dieser Studie eine Modellkaskade aus (i) den hydrologischen Modellen SWIM und EGMO, (ii) dem Langfristbewirtschaftungsmodell WBalMo und (iii) dem Wasserg{\"u}temodell GGM entwickelt, implementiert und angewandt. Die Modellkaskade bietet zudem die M{\"o}glichkeit,Anpassungsoptionen der Wassermengen- und -g{\"u}tebewirtschaftung einzubeziehen. Als Untersuchungsgebiet dient das Einzugsgebiet der Spree, in dem in Folge des jahrzehntelangen Braunkohlebergbaus und dessen R{\"u}ckgangs seit den 1990er Jahren vielf{\"a}ltige Herausforderungen hinsichtlich Wassermenge und -beschaffenheit bestehen (z. B. niedrige pH-Werte in den Tagebauseen, hohe Sulfatkonzentrationen in den Tagebauseen und Vorflutern). Die grundlegende Fragestellung ist, ob sich die bestehenden Wassermengen- und beschaffenheitsprobleme unter zuk{\"u}nftig potenziell trockeneren Bedingungen versch{\"a}rfen bzw. wie sie durch Anpassungsmaßnahmen gelindert werden k{\"o}nnen. Als klimatischer Antrieb der Modellkaskade werden stochastisch generierte Zeitreihen (Realisierungen) des Regionalen Klimamodells STAR genutzt. Die Realisierungen des Szenarios STAR 0K werden im Sinne einer Referenzvariante der rezenten klimatischen Bedingungen verwendet, um die Konsequenzen des R{\"u}ckgangs von Bergbauaktivit{\"a}ten separat zu betrachten. Zur Ermittlung der Sensitivit{\"a}t der Wasserressourcen gegen{\"u}ber einer potenziell trockeneren Zukunft dient das Szenario STAR 2K, bei dem eine weitere Erh{\"o}hung der Jahresmitteltemperatur um 2 K sowie im Mittel eine Abnahme des Jahresniederschlages projiziert wird. Die Betrachtung der sozio{\"o}konomischen Entwicklung der Region wird anhand eines Bewirtschaftungsszenarios betrachtet, welches von einem weiteren R{\"u}ckgang der Bergbauaktivit{\"a}ten in der Region ausgeht. Im Verlauf des Zeitraums 2018 2052 zeigen sich im Szenario STAR 0K nur geringe Auswirkungen auf das nat{\"u}rliche Wasserdargebot, die bewirtschafteten Abfl{\"u}sse gehen durch sinkende S{\"u}mpfungswassereinleitungen leicht zur{\"u}ck. Im Szenario STAR 2K geht das nat{\"u}rliche Wasserdargebot zur{\"u}ck und die wasserwirtschaftlichen Speicher werden st{\"a}rker in Anspruch genommen. Die bewirtschafteten Abfl{\"u}sse in der Region sinken, was negative Konsequenzen f{\"u}r die Erf{\"u}llung von Nutzeranspr{\"u}chen nach sich zieht. Die Wahrscheinlichkeit, dass die Tagebauseen wiederversauern und die Sulfatkonzentrationen ansteigen, nimmt im Szenario STAR 2K im Vergleich zu STAR 0K zu. Wasserwirtschaftliche Anpassungsoptionen wurden hinsichtlich ihrer Konsequenzen f{\"u}r Wassermenge und beschaffenheit analysiert. Durch die {\"U}berleitung von Wasser aus der Elbe k{\"o}nnen die Wassermengen und beschaffenheitsprobleme gelindert werden. Die In Lake Neutralisation von Tagebauseen kann lokale Probleme der Wasserbeschaffenheit mindern.}, language = {de} } @inproceedings{IsraelMuellerRachowetal., author = {Israel, Johannes and M{\"u}ller, Klaus and Rachow, Fabian and Beuckert, Guido and Schmeißer, Dieter}, title = {Reaction kinetics of the Sabatier Reaction in a demonstration plant}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, abstract = {We currently build up a demonstration plant for the direct catalytic conversion of CO2 into methane according to the Sabatier reaction CO2+4H2→CH4+2H2O. We have already reached conversion rates higher than 90\% and a selectivity close to unity in our laboratory experiments with NiO based catalysts. A good long term stability was obtained with a reactant gas flow density of 0.8 l/min cm2· at 350∘C. We will study the process now on a larger scale with a factor 10000. The process is controlled via mass flow controllers with a throughput of 20m3/h H2 and 5m3/h CO2 at an inlet gas pressure of up to 15 bar, the temperature is regulated by a PID multichannel controller. As water is a by-product we use an efficient cooling trap for its separation form the obtained methane. The reaction products are analyzed by a quadrupole mass spectrometer under reaction conditions. We start our experiments in using clean CO2 and H2. Later experiments will involve industrial quality (oxy-fuel) conditions also. Goal of this project is to determine the performance of the catalytic process under conditions which enable an industrial implementation in energy storage concepts. In this contribution we report of the design of a demonstration plant and on first experiments concerning the kinetics within the system.}, language = {en} } @inproceedings{RachowMuellerSchmeisser, author = {Rachow, Fabian and M{\"u}ller, Klaus and Schmeißer, Dieter}, title = {Sabatier based Methanation of carbon dioxide and Catalyst stability against contaminations}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, abstract = {The Sabatier-Reaction [CO2+4H2→CH4+2H2O] represents a possible way for the reduction and utilization of CO2 produced in the oxy-fuel combustion process. While using different ruthenium and nickel based catalysts we studied the catalytic performance with quadrupole mass spectroscopy and IR-spectroscopy in terms of conversion of CO2,yield of CH4, selectivity and stability. Conversions of up to 90\% and a selectivity of well above 95\% could be achieved. Further studies focus on the long term stability, especially with the influence of contaminations like SOx and NOx as they may occur in oxy-fuel or flue gas and could greatly reduce the life time of a catalyst. We investigate the limits of Ni based catalysts for those additives. However, technical oxy-fuel gas seems to have no particular effect on the activity of a commonly used NiO-catalyst when compared to quasi pure CO2 , showing only a small drop of performance after five days with a constant conversion rate of over 80\% at the end.}, language = {en} } @inproceedings{IsraelRachowSchwiertzetal., author = {Israel, Johannes and Rachow, Fabian and Schwiertz, Carola and Charlafti, Evgenia and M{\"u}ller, Klaus and Schmeißer, Dieter}, title = {Direct CO2-Methanation of flue gas emitted by conventional power plants}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, pages = {S. 255}, abstract = {The catalytic conversion of CO2 with H2 into CH4 is possible by the Sabatier reaction CO2+4H2→CH4+2H2O. Using excess energy from renewable electricity generation, this approach offers an opportunity for recycling of CO2 as synthetic natural gas. In a new concept, we investigate the performance of the Sabatier reaction as direct methanation of flue gas, emitted by conventional power plants. We investigate the Sabatier process in an upscaled system, with a maximum input flow rate of 45 Nm3/h Gas. The performance is investigated in a simulated composition of flue gas and under real conditions at a lignite power plant in Schwarze Pumpe, Brandenburg, Germany. We can achieve a CO2-conversion of up to 90\%, with approx. 100\% selectivity towards CH4. Under flue gas conditions and at a certain limit of gas flow the system is operated at an autothermal running modus, a steady state equilibrium of exothermic heat production and thermal flow that needs neither external annealing nor cooling.}, language = {en} } @inproceedings{RachowHagendorfMuelleretal., author = {Rachow, Fabian and Hagendorf, Moritz and M{\"u}ller, Klaus and Schmeißer, Dieter}, title = {Synthesis of Methanol from CO2 for Power-to-Liquid applications}, series = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, booktitle = {Verhandlungen der Deutschen Physikalischen Gesellschaft}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, pages = {S. 256}, abstract = {The direct synthesis of methanol [CO2+3H2->CH3OH+H2O] represent a possibility to reduce the global CO2-emission by recycling the CO2 and also to store excess energy from renewable energy sources into a common fuel or chemical feedstock (Power-to-Liquid). For an acceptable conversion rate of CO2 a catalyst is needed, together with high temperatures (>200°C) and high pressure (50-200bar). Methanol is normally produced form synthesis gas, a mixture of CO and H2. By directly using CO2 for the exothermic reaction, we avoid the conversion of CO2 to CO by the reversed water gas shift reaction. We also present new concepts for the conversion from CO2-rich flue gases, eliminating the need for a separation of the CO2. The concept is backed up by measurements in laboratory scale. Here we use a Cu-ZnO catalyst on a ZrO2 substrate prepared by impregnation and compare the results with commercially available catalysts. We achieved a conversion of around 7\% and a selectivity of 60\% at a temperature of 240°C and 45bar. The reaction is thermodynamically limited with a maximum conversion rate of 15\% at 250°C and 50bar. The conversion and the selectivity towards methanol is highly influenced by the catalyst used, the temperature, the pressure as well as the flow rate of the reactants.}, language = {en} } @misc{MuellerRachowIsraeletal., author = {M{\"u}ller, Klaus and Rachow, Fabian and Israel, Johannes and Charlafti, Evgenia and Schwiertz, Carola and Schmeißer, Dieter}, title = {Direct Methanation of Flue Gas at a Lignite Power Plant}, series = {International Journal of Environmental Science}, journal = {International Journal of Environmental Science}, number = {2}, issn = {2367-8941}, pages = {425 -- 437}, abstract = {The combustion of fossil fuels results in CO2 emission, which is one of the primary causes of global warming. An important approach for solving this problem is the fixation, the chemical utilization and the recycling of CO2. Therefore, we investigate the catalytic conversion of CO2 with H2 into methane (CH4) with an upscaled test station at a brown coal power plant. In a completely new strategy, we realize the direct conversion of the CO2 content of the flue gas, without a cleaning process like amine scrubbing or optimized combustion like oxyfuel. Our experiments are performed in matters of catalytic performance, heat production and stability of the catalytic Sabatier process, as a function of the gas flow rate. The catalytic performance is investigated with a simulated composition of flue gas and under real conditions directly at the power plant. The CH4 production by the Sabatier process is realized with a maximum input flow rate of near 50Nm3/h, with 30Nm3/h flue gas and 20Nm3/h hydrogen. For these values, the necessary power scale for hydrogen generation by electrolysis is around 100kW. With synthetic and real flue gas, a conversion up to 99\% (for hydrogen surplus) with 100\% selectivity is stabilized. The reaction operates in thermal steady state equilibrium without any external energy supply. In consequence, the process of CO2 recycling could be integrated directly as a post combustion process of conventional power plants, without an expensive capturing step, for example.}, language = {en} } @misc{MuellerRachowGuentheretal., author = {M{\"u}ller, Klaus and Rachow, Fabian and G{\"u}nther, Vivien and Schmeißer, Dieter}, title = {Methanation of Coke Oven Gas with Nickel-based catalysts}, series = {International Journal of Environmental Science}, journal = {International Journal of Environmental Science}, number = {4}, issn = {2367-8941}, pages = {73 -- 79}, abstract = {For a complete transition from fossil to CO₂ neutral energy supply new energy storage concepts are needed that allow energy supply in times of absence of regenerative power production as during dark doldrums. A promising renewable energy storage approach is the power to gas (to power) technique based on the production of synthetic natural gas (also called e-methane) by methanation of CO₂ with H₂. The latter is usually produced by electrolysis. In any power to gas concept, electrolysis is a very critical part, due to its high costs, stability issues, or limited power of required electrolysers. As an alternative source of hydrogen, we investigate the methanation of coke oven gas (COG). COG is a byproduct of the carbon rich coke production from coal for the steel industry, with a high amount of hydrogen (~60vol\%). Coke oven gas furthermore contains CH₄(~25vol\%), CO (5-8vol\%), and CO₂(1-3vol\%), making it an attractive feedstock for the production of synthetic energy carriers like methane. In the present study, the authors investigate the direct conversion of CO and CO₂ from COG into e-methane. Compared to stoichiometric conversion, the COG hydrogen content is too high for catalytic methanation of CO₂. In order to achieve a higher methane yield, the addition of CO₂ from air, flue gas, or coal gasification can compensate the surplus of hydrogen in the coke oven gas. The process is evaluated by the conversion of CO and CO₂, the catalyst selectivity towards higher hydrocarbons for varying temperatures, and the CH₄ yield.}, language = {en} } @incollection{MuellerIsraelRachowetal., author = {M{\"u}ller, Klaus and Israel, Johannes and Rachow, Fabian and Schmeißer, Dieter}, title = {Sabatier-Based Direct Synthesis of Methane and Methanol Using CO2 from Industrial Gas Mixtures}, series = {Engineering Solutions for CO2 Conversion}, booktitle = {Engineering Solutions for CO2 Conversion}, editor = {Ramirez Reina, Tomas and Odriozola, Jos{\´e} Antonio and Arellano-Garc{\´i}a, Harvey}, edition = {1}, publisher = {Wiley-VCH}, address = {Weinheim}, isbn = {978-3-527-34639-4}, pages = {253 -- 280}, language = {en} }