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ABSTRACT This study deals with the operating behavior, the liquid disintegration, and the aerosol collection efficiency of a venturi scrubber working in self-priming mode. In the case of a forced feed venturi scrubber, the scrubbing liquid is injected into the throat by means of a pump. The liquid load is adjustable independently from the gas flow rate. In contrast, the venturi scrubber analyzed in the present investigation works in a self-priming mode. The washing liquid is introduced due to a pressure difference between the inside and the outside of the venturi throat. This pressure difference is composed of the hydrostatic pressure of the liquid and the static pressure of the flowing gas. The atomization process of the injected liquid is equivalent to the observations made with forced feed venturi scrubbers. However, the jet penetration is most sensitive to the operating conditions of the scrubber. The cleaning efficiency of a venturi scrubber as well as the overall pressure loss grow with an increasin...

This paper presents a real and application-based scenario for a dynamically driven catalytic methanation unit, using off-gases from an integrated steel mill as input. Several parameters are subject to dynamic changes during the standard production of steel, such as the available amount and composition of the accumulating process gases, the temperature and operating pressure as well as their periodicity. In addition, the available amount of hydrogen can vary depending on the available fluctuating renewable energy for the installed electrolyzer. Analysis of operating parameters and process routes in steelmaking revealed that among many theoretically possible modes of driving a dynamic methanation unit, which are defined in the literature, there is only one realistic application-based scenario. The definition of this case is supported by experiments performed with a three-stage methanation setup in lab-scale. This experimental campaign covered real cases with dynamic flow rates, adjusting the amount of blast furnace and converter gases based on high variations in the availability of hydrogen. It was possible to achieve very stable product gas compositions, even though load changes in gas input power up to 64% in the range of one to 120 min were executed. The dynamic variations did not result in any additional catalyst deactivation through the whole experimental campaign.

AbstractThe present work describes the results achieved during a study aiming at the full replacement of the natural gas demand of an integrated hot metal production. This work implements a novel approach using a biomass gasification plant combined with an electrolysis unit to substitute the present natural gas demand of an integrated hot metal production. Therefore, a simulation platform, including mathematical models for all relevant process units, enabling the calculation of all relevant mass and energy balances was created. As a result, the calculations show that a natural gas demand of about 385 MW can be replaced and an additional 100 MW hydrogen-rich reducing gas can be produced by the use of 132 MW of biomass together with 571 MW electricity produced from renewable energy. The results achieved indicate that a full replacement of the natural gas demand would be possible from a technological point of view. At the same time, the technological readiness level of available electrolysis units shows that a production at such a large scale has not been demonstrated yet.

Die Umstellung der Energieversorgung auf erneuerbare Quellen (Wind, Photovoltaik) wird in Zukunft verstarkt die Volatilitat in der Stromerzeugung erhohen. Um eine ausgeglichene Leistungsbilanz im Stromnetz sicherzustellen, werden Speicher benotigt – nicht nur kurzzeitig, sondern auch saisonal. Die bidirektionale Kopplung bestehender Energieinfrastruktur mit dem Stromnetz kann hier Abhilfe schaffen, indem der Strom in Elektrolyseanlagen zur Wasserstofferzeugung genutzt wird. Der Wasserstoff kann Erdgas in der vorhandenen Infrastruktur (Gasspeicher, Pipelines) in begrenztem Umfang beigemischt werden oder in einer gaskatalytischen Reaktion, der Methanisierung, mit Kohlendioxid und/oder Kohlenmonoxid direkt zu Methan umgesetzt werden. Durch den Ruckgriff auf die Erdgasinfrastruktur wird eine Entlastung der Stromnetze erreicht und eine Speicherung der erneuerbaren Energien auch uber lange Zeitraume ermoglicht. Ein weiterer Vorteil dieser als „Power-to-Gas“ bezeichneten Technologie ist, dass das so erzeugte Methan eine Senke fur CO2-Emissionen darstellt, da damit fossile Quellen substituiert werden und so CO2 in einem geschlossenen Kreislauf gefuhrt wird.

Fluctuating energy sources require enhanced energy storage demand, in order to ensure safe energy supply. Power to gas offers a promising pathway for energy storage in existing natural gas infrastructure, if valid regulations are met. To improve interaction between energy supply and storage, a flexible power to gas process is necessary. An innovative multibed methanation concept, based on ceramic honeycomb catalysts combined with polyimide membrane gas upgrading, is presented in this study. Cordierite monoliths are coated with γ-Al2O3 and catalytically active nickel, and used in a two-stage methanation process at different operation conditions (p = 6–14 bar, GHSV = 3000–6000 h−1). To fulfill the requirements of the Austrian natural gas network, the product gas must achieve a CH4 content of ≥96 vol %. Hence, CH4 rich gas from methanation is fed to the subsequent gas upgrading unit, to separate remaining H2 and CO2. In the present study, two different membrane modules were investigated. The results of methanation and gas separation clearly indicate the high potential of the presented process. At preferred operation conditions, target concentration of 96 vol % CH4 can be achieved.

The current work investigates the feasibility of a novel Carbon Capture and Utilization (CCU) approach—also known as Underground Sun Conversion (USC) or geo-methanation. The overall objective of the current work is a comprehensive assessment on the technical, economic and legal aspects as well as greenhouse gas impacts to be concerned for establishing USC technology concept. This is achieved by applying multidisciplinary research approach combining process simulation, techno-economic and greenhouse gas assessment as well as legal analysis allows answering questions about technical, economic feasibility and greenhouse gas performance as well as on legal constraints related to large scale CCU using geo-methanation in depleted hydrocarbon reservoirs. CO2 from the industry and renewable H2 from the electrolyser are converted to geomethane in an underground gas storage and used in industry again to close the carbon cycle. Process simulation results showed the conversion rates vary due to operation mode and gas cleaning is necessary in any case to achieve natural gas grid compliant feed in quality. The geomethane production costs are found to be similar or even lower than the costs for synthetic methane from Above Ground Methanation (AGM). The GHG-assessment shows a significant saving compared to fossil natural gas and conventional power-to-gas applications. From a legal perspective the major challenge arises from a regulative gap of CCU in the ETS regime. Accordingly, a far-reaching exemption from the obligation to surrender certificates would be fraught with many legal and technical problems and uncertainties.

Abstract The permanent storage of carbon dioxide in form of stable carbonates is one of many options to utilize CO 2 . The Research Studio Austria “Carbo Resources” evaluates three different carbonation routes and also different input materials from primary and secondary origin, to find the optimal process parameters for the development of a multistage process with the aim to gain commercially valuable mineral carbonates and also marketable by-products. Laboratory experiments have made it possible to balance all process steps in order to generate a mass balance study for the overall process. The results of this ongoing project are presented in this paper.