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Storage of hydrogenous gas in geological formations: self-organisation methane gas

Toleukhanov A., Kaltayev A., Panfilov M.

AGH Drilling, Oil, Gas

2013

Vol. 30, no. 1

241--245

In the case of producing large amounts of hydrogenous gas, currently there are no problems related to basic techniques of hydrogen production and distribution, but the main technological problem will consists of storing it in order to regulate the difference between permanent or increasing gas production and seasonally modulated gas consumption. The most efficient and most inexpensive method of storing large amounts of hydrogen is to inject them in geological formations like aquifers, depleted gas reservoirs, or salt caverns (Zittel and Wurster 1996). The cost is of order $ 3.5 per 1 GJ (Taylor et al. 1986). Several underground storages of hydrogen (USH) or town gas exist in the word, as for instance, Teeside in the UK, in Texas, in Russia, Kiel in Germany, Lobodice in Czechoslovakia, Beynes - an ex-storage in France. During several tens of years the storage of hydrogen was considered as something deja-vu, to be similar to that of natural gas, which is amplified by the chemical inactivity of hydrogen and its very low solvability in groundwater [Bulatov 1979; Carden and Paterson 1979; Lindblom 1985; Paterson 1983]. Nevertheless, quite unusual behaviour of UHS was discovered by in situ monitoring of the gas composition extracted during the cycle "production" which followed the cycle "injection". These observations (Smigai et al. 1990; Buzek et al. 1994) revealed high variations of gas composition in time and space. In particular, a significant reduction in the H2 and CO2 contents and a simultaneous increase in CH4 contents were observed in the Lobodice town gas storage facility (Smigai et al. 1990). Similar phenomena were recorded in Beynes. After several months of injection and storage, at the beginning of the cycle "production" the twofold increase of the methane contents in the reservoir gas and the twofold reduction of the CO2 CO contents was observed. The contents of hydrogen decreased by 1.4. The explanation to these observations has been done in (Buzek et al. 1994) in terms of the in situ methane generators by methanogenic bacteria which catalyse the reaction between hydrogen and CO2/CO, by producing methane and water. Further observations have revealed even more unusual effects within the storage facility, such as creating a spatial alternation of the areas saturated preferably by hydrogen or methane. This proved an in situ natural separation of chemical components in space. Thus, we are dealing with a natural reactor which partially destroys CO2 and H2 and doubles the mass of methane. It is clear that the problem is important for industry as it concerns both the energy sector and ecology. The resulting economical efficiency of such a process can be estimated only after the physical and mathematical modeling of all possible scenarios of the reservoir behaviour. The development of such a model represents the main objective of this paper.

Modelowanie transportu substancji podlegających procesom fizykochemicznym i reakcjom chemicznym w strumieniu wód podziemnych

Nawalany M.

Biuletyn Państwowego Instytutu Geologicznego

2008

nr 431, Hydrogeologia

169--177

Artykuł zawiera przegląd aktualnych problemów badawczych towarzyszących modelowaniu matematycznemu transportu substancji, które w strumieniu wód podziemnych podlegają procesom fizykochemicznym lub reakcjom chemicznym. Na wstępie omówiono motywy uzasadniające pilną konieczność poszukiwania rozwiązań o charakterze praktycznym oraz odpowiedzi na szereg związanych z nimi fundamentalnych pytań teoretycznych. Następnie przedyskutowano zagadnienia podstawowe dotyczące formułowania modeli matematycznych tych procesów w odpowiedniej skali.W szczególności przedstawiono problemy związane z metodyką przejścia ze skal niższych do wyższych, która z punktu widzenia zastosowań jest najbardziej interesująca. Zaczerpnięty z literatury przykład transportu substancji podlegających sorpcji zilustrował problemy, jakie występują w przypadku zmiany skali. Podobne kwestie dotyczą także sytuacji, w których w strumieniu wody podziemnej zachodzą reakcje chemiczne. Na koniec krótko omówiono wyzwania o charakterze naukowym, jakie stawia modelowanie procesów fizykochemicznych i reakcji chemicznych w strumieniu wód podziemnych.

The article presents an overview of the research problems accompanying the mathematical modelling of reactive transport of substances which undergo physical-chemical processes or chemical reactions in groundwater flow. In the introductory part motives that justify an urgent need for finding practical and theoretical solutions are discussed. There are discussed basic issues concerning formulation of mathematical physics models of these processes in the appropriate scales. In particular, problems arising in up-scaling is illustrated by an example involving process of sorption in groundwater flow, cited from the literature. Similar problems arise also in the presence of chemical reactions in groundwater. The article is concluded with a short overview of scientific challenges set by mathematical modelling of reactive transport in subsoil.