TY - JOUR A1 - Schröder, Volkmar A1 - Schalau, Bernd A1 - Molnarne, M. T1 - Explosion protection in biogas and hybrid power plants N2 - Renewable energies became more and more important in the last years. The production of biogas using agricultural waste and the use of wind and solar energy in combination with water electrolysis is one way to substitute natural gas. Therefore the number of biogas plants is growing very fast in Germany. In the meantime, the operation of such plants is responsible for a significant number of accidents. New safety regulations on biogas plants and a short statistical summary of accidents in Germany are presented in the first part of this presentation. The main focus of the paper is the principle hazards arising from the substances and materials in biogas and hybrid power plants. Primarily, these are the hazards of fire and explosion induced by flammable methane gas. However, further hazards are the dangers of asphyxiation and poisoning by gases such as carbon dioxide, hydrogen sulphide and ammonia. Furthermore, hydrogen is produced by water electrolysis in hybrid power plants and mixed with bio methane in some cases. In order to prevent explosions when handling biogas and hydrogen it is necessary to know the explosion limits of gas and gas mixtures in mixture with air. However, biogas from agricultural plants can vary significantly in its composition. Therefore, for each gas composition the explosion limits would have to be determined. This would require a considerable amount of time and effort. Due to this fact, the explosion limits of biogas are frequently referred to only by the methane fraction of the gas mixture in the safety-relevant literature. In reality as biogas can consist of methane, carbon dioxide and further residual gases the explosion limits are generally over or underestimated. A calculation method for explosion limits was developed by means of explosion diagrams to avoid such errors. In a last topic methods are shown for the calculation of gas spreading in case of leakages in gas buffers for risk evaluation and land use planning. For this purpose the German directive VDI 3783 was evaluated. KW - Biogas KW - Explosion protection KW - Hybrid power plants KW - Safety characteristics KW - Technical regulations PY - 2014 DO - https://doi.org/10.1016/j.proeng.2014.10.433 SN - 1877-7058 VL - 84 SP - 259 EP - 272 PB - Elsevier CY - Amsterdam [u.a.] AN - OPUS4-32085 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Molnarne, M. A1 - Seifert, Alexander A1 - Schröder, Volkmar T1 - Explosion protection according to the EU directives using the data from CHEMSAFE database N2 - For international trade and production of machinery used in potentially explosive atmospheres it is important to know about the regulations within the European Union. This paper presents an application of CHEMSAFE flammability data for fulfilling the requirements of the EU explosion protection directives. Most of the published data for flammability of substances are measured under atmospheric conditions although chemical processes operate often under non-atmospheric conditions. A couple of R&D projects were initiated in Germany to get more knowledge on explosion characteristics for non-atmospheric conditions. The explosion protection for machinery operated under non-atmospheric conditions is defined in the 2006/42/EU Directive. CHEMSAFE fulfills this requirement while it contains data of flammable compounds measured under non-atmospheric conditions and with other oxidizers than air. Furthermore it includes flammability data for gas mixtures consisting of flammable, inert, and different oxidizing components and most of the data are measured according to international standards. Safety data on flammable dusts - such as minimum ignition energy, maximum explosion pressure, ignition temperatures - represents also an important part of the database. The potentially explosive atmospheres are defined in revised Directive 2014/34/EU. For preparing risk assessment documents the following data for flammable gases and vapors, relating to the use of equipment, among others are necessary: Flammability limit, flash point, temperature class - auto-ignition temperature, maximum experimental safe gap. CHEMSAFE'2013 includes not only these data but also more than 200 triangular explosion diagrams, e.g. the newly measured methane/nitrogen/oxygen system under pressures up to 50 bars. The international standard Draft of IEC 80079-1-1 publishes data tables for flammable substances originated from CHEMSAFE which represents the international acceptance of these data. KW - Flammability limits KW - Gas and dust explosion KW - Explosion protection KW - Safety characteristics KW - Technical regulations KW - Safety data KW - CHEMSAFE database PY - 2014 DO - https://doi.org/10.1016/j.proeng.2014.10.432 SN - 1877-7058 VL - 84 SP - 247 EP - 258 PB - Elsevier CY - Amsterdam [u.a.] AN - OPUS4-32086 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Láng-lázi, M. A1 - Heszberger, J. A1 - Molnarne, Maria A1 - Viczián, G. T1 - Spline functions in chemistry: approximation of surfaces over triangle domains KW - Approximation of triangle surfaces KW - Spline functions in chemistry KW - CHEMSAFE KW - TRIANGLE Program KW - Spline interpolation PY - 2008 DO - https://doi.org/10.1080/00207160801965206 SN - 0020-7160 SN - 1029-0265 VL - 83 IS - 1 SP - 1 EP - 15 PB - Gordon and Breach CY - London [u.a.] AN - OPUS4-19037 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Molnarne, M. A1 - Schröder, Volkmar T1 - Flammability of Gases in Focus of European and US Standards N2 - The presentation will discuss the difference between EU and US standards for the determination of explosion (flammability) limits and limiting oxygen concentration. Small differences observed in measured values can be traced back to the different test apparatuses and criteria. The discrepancies can be much greater in the case of limiting oxygen concentration because of the high amount of inert gases and the corresponding low laminar burning velocities. The paper describes some examples and the influence of the chosen criteria on the results. The European and US standards use the criteria of flame propagation in open test vessels and of pressure rise in closed ones. The examples discussed show that flame propagation is still possible at very small pressure rise values, as observed much below the pressure rise criterion of usual standards. However, flame propagation in a process plant can cause an accident or explosion and must be avoided. Therefore, the flame propagation criterion is recommended to be used in chemical safety engineering. The European safety database CHEMSAFE contains expert-evaluated safety data for cases where the determination method and criteria are known. Flammability characteristics based on the pressure rise criterion may suffice in certain cases, e.g. for explosion protection in closed vessels without any connecting pipes. T2 - 2016 International Symposium on Safety Science and Technology (ISSST) CY - Kunming, China DA - 17.10.2016 KW - Flammability KW - Limiting oxygen concentration KW - Test methods KW - Standardization PY - 2016 AN - OPUS4-37897 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Molnarne, M. A1 - Schröder, Volkmar T1 - Flammability of Gases in Focus of European and US Standards N2 - The presentation will discuss the difference between EU and US standards for the determination of explosion (flammability) limits and limiting oxygen concentration. Small differences observed in measured values can be traced back to the different test apparatuses and criteria. The discrepancies can be much greater in the case of limiting oxygen concentration because of the high amount of inert gases and the corresponding low laminar burning velocities. The paper describes some examples and the influence of the chosen criteria on the results. The European and US standards use the criteria of flame propagation in open test vessels and of pressure rise in closed ones. The examples discussed show that flame propagation is still possible at very small pressure rise values, as observed much below the pressure rise criterion of usual standards. However, flame propagation in a process plant can cause an accident or explosion and must be avoided. Therefore, the flame propagation criterion is recommended to be used in chemical safety engineering. The European safety database CHEMSAFE contains expert-evaluated safety data for cases where the determination method and criteria are known. Flammability characteristics based on the pressure rise criterion may suffice in certain cases, e.g. for explosion protection in closed vessels without any connecting pipes. T2 - 2016 International Symposium on Safety Science and Technology CY - Kunming, China DA - 17.10.2016 KW - Flammability KW - Limiting oxygen concentration KW - Standardization KW - Explosion protection KW - Test methods PY - 2016 VL - Vol. XI SP - 400 EP - 409 AN - OPUS4-37951 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schröder, Volkmar A1 - Molnarne, M. T1 - Hazardous properties of hydrogen and hydrogen containing fuel gases N2 - The paper provides a summary of safety characteristics of hydrogen and hydrogen fuel gases. The inves-tigations focus on water electrolysis, the feeding of hydrogen into the natural gas grid and the use ofhydrogen for the fermentation process in biogas plants. The safety characteristics of hydrogen such as avery low minimum ignition energy, very large explosion range and high flame velocity with the resultingrapid pressure increase of hydrogen explosions are of particular importance for explosion protection andthey differ strongly from those of natural gas. Explosion ranges of hydrogen-methane-carbon dioxidemixtures have been measured for the use of hydrogen in biomethane production. The paper also showsand discusses explosion ranges of hydrogen and hydrogen-natural gas mixtures. Pressure and tempera-ture dependencies of the explosion limits of mixtures were investigated. Furthermore, pressure rise rates(KGvalues) were measured with regard to constructive explosion protection. The maximum experimen-tal safe gaps were determined for the classification of the mixtures and assignment to explosion groupsaccording to the European ATEX directives. It was found that admixture of 10% hydrogen to natural gashas only a minor influence on the safety characteristics of gas explosions. KW - Hydrogen safety KW - Biogas KW - Renewable energy KW - Natural gas mixtures KW - Flammability PY - 2019 DO - https://doi.org/10.1016/j.psep.2019.07.012 SN - 0957-5820 VL - 130 SP - 1 EP - 5 PB - Elsevier AN - OPUS4-49032 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -