|GWF Gas Erdgas 12/2010|
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|GWF gas solutions International|
|GWF Gas Erdgas 07-08/2010|
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- Oxygen Content in Natural Gas Infrastructure
- Results of a DVGW Biogas Monitoring Program
|Collaborative Natural Gas R&D in Europe â The GERG Approach|
Dr. Klaus Altfeld, Dave Pinchbeck
Natural gas is and will continue to be a major contributor to the energy requirements and the well-being of Europe for many decades to come. R&D is essential to this and will ensure the continued availability and efficient use of this precious resource and, although the gas industry is mature, it is imperative that it develops the latest technology to be in a position to adapt to new and changing requirements.
|Oxygen Content in Natural Gas Infrastructure|
Dipl.-Ing. Uwe Gronemann, Dr. RĂŒdiger Forster, Dipl.-Ing Joachim Wallbrecht, Dr.rer.nat. Hubertus Schlerkmann
Traces of oxygen may cause signifi cant damage to the natural gas infrastructure due to corrosion or the formation of (elemental) sulphur if oxygen-bearing gas reaches wet areas, e.g. as in natural gas storage facilities. The amendment of the Gasnetzzugangsverordnung (GasNZV), which became effective in April 2008, foresees the fraction of biogas in the natural gas grid increasing to 10 billion cubic metres per annum until 2030. By the injection of processed biogas, oxygen will be introduced into the natural gas infrastructure. Therefore it is necessary to limit the oxygen content to a very small amount at those injection points which may be within reach of such wet areas.
|Alternative Method to Determine the CO2 Emission Factors and Inferior Calorific Values of Natural Gases|
Dr. Peter Schley
CO2 emissions trading requires certain properties of a fuel (e. g. natural gas), such as specific CO2 emission factor and inferior calorifi c value, to be determined very accurately so that the quantity of CO2 emitted may also be determined in a reliable manner. The paper presents a new calculation method as an alternative to the standard method. The alternative method uses the properties superior calorifi c value, normal density and CO2 mole fraction usually required in gas billing to calculate the relevant data. The method is particularly useful where no full gas analysis is available, for example, where gas quality tracking systems are used.
|Results of a DVGW Biogas Monitoring Program|
Dipl.-Ing. Wolfgang KĂ¶ppel, Dr.-Ing Dipl.-Wirt.-Ing. Frank Graf
Biomass and especially biogas is deemed to be part of the desired substitution of fossil energy. The majority of biogas systems in Germany have an electric power output below 500 kW (Figure 1). They are generally installed in rural areas where the efficient use of the coproduced heat is hardly possible and approximately 50 % of the energy content of the biogas is dissipated. Figure 1 shows explicitly the push effect of the German act on granting priority to renewable energy sources (EEG) in 2004 . The purpose described in article 1 of this act is to protect the climate by facilitating the use of renewable energies. This is achieved by paying a guaranteed price for the produced electric energy which includes a bonus compared to conventionally produced electrical energy. From the beginning of 2009 new payment provisions have been applied .
|Results of the DVGW Monitoring Program âCNG Quality at Filling Stationsâ|
Dipl.-Ing Kerstin KrĂ¶ger, Dr.-Ing Dipl.-Wirt.-Ing. Frank Graf, JĂ¶rg Riedl
Currently about 870 CNG filling stations exist and approx. 80,000 natural gas vehicles are registered in Germany . Since coming into force in February 2008 the gas quality requirements for CNG are specified in DIN 51624 âAutomotive fuels â natural gas â Requirements and test methodsâ. In two research projects a sampling system for the analysis of particle concentrations in CNG was developed and CNG quality was controlled within a Germany wide monitoring program with the help of 40 control samples. The results show that the distributed CNG fulfils mostly the requirements of DIN 51624. Only in six cases the limit of 10 mg/kg for the total sulphur content was exceeded. For 62 % of the analysis the particle concentration was lower than 5 mg/kg.
|Experience with the Use of Remote-Controllable CCP Protection Installations|
Dipl.-Phys Rainer Deiss, Hans Gaugler
Remote-controllable CCP protection installations have been installed in 280 places throughout Germany so far. Therefore it is time to have a look at the experience with this technology.
|Olfactory Evaluation of the Smell of a Gas: A Round Robin Test Based on the AFG Specification|
FranĂ§ois Cagnon, AmĂ©lie Louvat, Delphine Coffinet-Laguerre, BjĂ¶rn Maxeiner
The French regulation demands that all gases distributed in network be odorised. The French technical association (AFG standing for Association FranĂ§aise du Gaz) has published a guideline defining how gases have to be odorised. This document indicates that the smell shall be perceptible before the gas concentration in air reaches 20 % LEL. For natural gases and some liquefied petroleum gases (LPG) compliance is obtained by adding an odorant in the gas. In that case, with prior knowledge of the relationship between odorant concentration and smell, one can established the minimum odorant concentration necessary to comply with the regulation. Measurement of the odorant concentration in the gas can then be used to check for compliance.
|A New Apparatus for the Accurate Measurement of LNG Densities|
Dr.-Ing. Markus Richter, Prof. Dr.-Ing. Roland Span, Dr.-Ing Reiner Kleinrahm, Dr. Peter Schley, Dr.-Ing. Markus Richter
Natural gas is an important energy source of the future. To ensure a secure energy supply in Europe the trade with liquefied natural gas (LNG) is expected to increase significantly. The accurate determination of LNG densities is gaining importance not only for custody transfer calculations with regard to loading and unloading of LNG carriers and tanks but also for process simulations, e. g., for modelling of economically and ecologically optimised liquefaction and evaporation processes. Today the calculation models used for the determination of LNG densities show uncertainties of 0.3 to 0.5 %. To reduce these relatively large uncertainties new accurate sets of experimental p-Ï-T-x-data are essential.
|Influence of Thermodynamic Property Models on LNG Process Simulation|
Dr.-Ing. Florian Dauber, Prof. Dr.-Ing. Roland Span, Dr. Peter Schley
Evaporation, transport and liquefaction are essential processes in the LNG process chain. High expectations concerning the economic efficiency, the product quality and environmental safety result in increasing demands on these processes. This applies both to the design and the operation of a specific system, e.g. to the optimal use of resources while vaporising LNG. Fundamental contributions to optimisation and operation of a system are expected from a detailed simulation of the processes. Therefore an accurate representation of thermophysical properties and energy balances of the simulated process is essential.