The equation of State of Biogas

The presented work deals with a state behavior of real gas, biogas. Theoretical approach was utilized for processing of this work. Compressibility factor was calculated with help of two equation of state . Van der Waals equation and Redlich.Kwong equation. Constants a and b of both equations were calculated using geometric average of the constants of pure substances. On the basis of calculated data charts showing the dependence of compressibility factor and the pressure were created. These charts were created for temperatures 20 oC and 40 oC. Statistical analyses of data were carried out. The results showed that compressibility factor reached value from 0.997 to 0.97 (20 oC) and from 0.997 to 0.974 (40 oC) in the case Van der Waals equation and in the range of pressure from 100 kPa to 1000 kPa. In the case of Redlich-Kwong equation these values were from 0.997 to 0.967 (20 oC) and from 0.997 to 0.974 (40 oC) in the same range of pressures.O

Quantitative Risk Assessment of Biogas Plant – Determination of Assumptions and Estimation of Selected Top Event

Biogas plants are a specific facility from the QRA (Quantitative Risk Assessment) methodologies' point of view, especially in the case of the determination of the event frequency of accident scenarios for biogas leakage from a gas holder and subsequent initiation. QRA methodologies determine event frequencies for different types of accident events related to vessels made of steel. Gas holders installed at biogas plants are predominantly made of other materials and are often integrated with the fermenter. It is therefore a specific type of gas holder, differing from that which is commonly used in the chemical industry. In addition, long-term experience is not available for the operation of biogas plants, unlike in the chemical industry. The event frequencies listed in the QRA methodologies are not relevant for the risk assessment of biogas plants. This work is focused on setting the prerequisites for QRA of biogas storage, including for example: information on hazardous chemical substances occurring at biogas plants, their classification, and information on the construction of integrated gas holders. For the purpose of the work, a scenario was applied where the greatest damage (to life or property) is expected. This scenario is the leakage of the total volume of hazardous gas substance from the gas holder and subsequent initiation. Based on this information, a "tree" was processed for "Fault Tree Analysis" (FTA), and frequencies were estimated for each event. Thereafter, an "Event Tree Analysis" was carried out. This work follows up on a discussion by experts on the determination of scenario frequencies for biogas plants that was conducted in the past

Particle Number of Aerosol in Specific Conditions of Biotechnology Laboratory Cleanroom

This paper presents the results of experimental measurements of the number of aerosol particles in cleanroom air of a biotechnology laboratory for DNA analysis. The aerosol content in the air can harm the accuracy of any analysis performed. The experimental measurements demonstrate compliance with the ISO cleanroom requirements for class 7. The indoor environment of the investigated biotechnology laboratory cleanroom can be classified as ISO cleanroom class 8. The particle count values depend on the month in which the measurement is made. The location of the measurement site, on the other hand, does not have too much influence. Our results showed that the values of particle number in the laboratory ranged from 325,965 to 2,740,877 pc/m3 for particles of 0.5 μm and more. From these measurements, it can be concluded that the biotechnology laboratory premises were not very suitable locations to perform for the intended DNA tests since microbiological contamination had the capacity to distort the results of these tests. As such, the authors propose several strategies to improve the current situation. These strategies are based on changing the laboratory work organization and cleaning methodology. In addition, the monitoring of particles with a size of 5 µm or more is recommended.O

The Safety of Biogas Gasholders

Příspěvek se zaměřuje na bezpečnost zásobníků bioplynu. V první části jsou vymezeny konstrukční typy zásobníků, které se využívají na bioplynových stanicích. Další část shrnuje nejčastější příčiny havárií na zásobnících plynných a kapalných uhlovodíků a uvádí je do souvislosti s havarijními situacemi na bioplynových stanicích. Poslední část upozorňuje na základní bezpečnostní zařízení, jimiž musí být tyto zásobníky vybaveny.The work is focused on safety of biogas gasholder. In the fi rst part design types of gasholder utilizing on biogas stations are defi ned. The next part of work summarizes the most common causes of accidents on gasholders of gaseous and liquid hydrocarbons. These causes are given to relationship with emergency situations on biogas plants. The last part warns on elementary safety barriers, which must be included in gear of a gasholder

Anaerobic Fermentation of Silage from the Above-Ground Biomass of Jerusalem Artichoke (Helianthus tuberosus L.) and Maize (Zea mayse L.) as a New and Promising Input Raw Material for Biogas Production

Research of new input raw materials for biogas plants is a very actual topic. There are only a very few studies dealing with the possibility of using silage prepared from the above-ground parts of the Jerusalem artichoke (Helianthus tuberosus L.) and maize (Zea mayse L.) for methane production. This study deals with the determination of methane production and methane content in biogas during the fermentation of maize silage with dissimilar additions of the biomass of the Jerusalem artichoke (JA). Except for the effect of the JA's addition on the yield of methane, we also studied its potential influence on the inhibition of the process of anaerobic digestion and the bacterial and methanogenic archaeal composition of anaerobic digestate. There were five model silages prepared; two of them contained only maize or JAs, and the remaining three were mixtures of maize and JA silages (30%wt; 50%wt and 70%wt). The fermentation tests showed that the JA addition (from 30 to 70%wt) resulted in the production of biogas decreasing, on average, by 15%. Based on the performed metagenomic analysis, we cannot confirm an essential influence of JA biomass addition on the composition of the community of microorganisms during fermentation.O

Mechanické předčištění z pohledu stávající legislativy :

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The measurement of heat loss with use of a thermal imaging system

The aim of this work was to verify the method of determining the heat loss of boiler by using of thermal infrared camera. Waste sawdust and wood shavings from the manufacturing of wooden furniture has been used as fuel in considered boiler with an installed heat output of 130 kW. The temperature distribution on the shell of the boiler has been discovered by using of infrared thermal camera, subsequently heat loss caused by radiation and convection has been calculated. For calculating of heat loss caused by radiation Stefan-Boltzmann Law has been used, for calculating of heat loss caused by convection three approaches have been used, Mc Adams, Michijev’s and King‘s. The results of the different approaches have been compared between themselves and the mean heat loss

Microbiological characteristics of bioaerosol at the composting plant

The diversion of biodegradable waste from landfill is of key importance in developing a sustainable waste strategy for the next decade and beyond. The proliferation of waste treatment technologies such as mechanical biological treatment, anaerobic digestion and composting will be paramount in achieving this strategic goal. Composting plant is one of the end technology, which is widely used in waste processing of the biodegradable waste. These wastes originate from the maintenance of green areas in the cities and the municipalities and from the separatelly collected biodegradable waste from the citizens. There is also possible to process other biodegradable materials whose origin may be in other technologies of waste management at the composting plant. The most commonly used technology of composting is windrow system. Technological operations, which are necessary for the proper conduct of the composting process, may have negative influence on the environment in the immediate vicinity of composting plant. As pollutants we can mark particular odor and microorganisms. The largest group of microorganisms in the monitored air were psychrophilic and mesophilic bacteria and microscopic thermotolerant fungi. The amount of thermophillic actinomycetes ranged from 10 to 84.000 CFU∙m−3 (colony forming units per m3). Furthermore, it was confirmed that the maximum air contamination has been found during aeration of windrow by compost turner and during the sieving of the mature compost. For each indicator, the increase in concentrations due to the turning of compost windrow as compared to the background concentration obtained in natural environments and upwind of composting plants was determined. At a distance of 150 m from the composting plant, only low numbers of indicator organisms at a regular occurrence in the air has been found