34 research outputs found
Monitoring and Quality Control of Diesel Fraction Production Process
In this work the mathematical model of diesel fraction and atmospheric gasoil catalytic dewaxing process has been developed. Also the pattern of applying the created model to solving such problems as monitoring and quality control of diesel fraction production in the catalytic dewaxing process. It has been represented that to meet such challenges, the model should take into consideration thermodynamic and kinetic laws of hydrocarbon conversion on the catalyst surface, and instability factors that are specified by catalyst deactivation. The developed model allows controlling the quality of obtained diesel fraction depending on feed and temperature regime in the reactor. The value of model calculation absolute error does not exceed 2%, which corroborates the adequacy of the model to actual process. The computations using the model have shown that to provide the desired product yield (not less than 40% wt. of overall yield of the unit products) of programmed quality (cold filtering plugging point not higher than minus 34Β°C for winter diesel fuels and not lower than minus 40Β°C for arctic ones) at long-time catalyst operation (during 4 years), it is necessary to sustain the reactor temperature at the average level of 19Β°C higher than when working with fresh catalyst. This must be done to compensate catalyst activity loss due to its deactivation
Influence of technological parameters of stabilization column operation (a part of diesel fuel production unit) on the content of hydrogen sulphide in stable gasoline
Monitoring and Quality Control of Diesel Fraction Production Process
In this work the mathematical model of diesel fraction and atmospheric gasoil catalytic dewaxing process has been developed. Also the pattern of applying the created model to solving such problems as monitoring and quality control of diesel fraction production in the catalytic dewaxing process. It has been represented that to meet such challenges, the model should take into consideration thermodynamic and kinetic laws of hydrocarbon conversion on the catalyst surface, and instability factors that are specified by catalyst deactivation. The developed model allows controlling the quality of obtained diesel fraction depending on feed and temperature regime in the reactor. The value of model calculation absolute error does not exceed 2%, which corroborates the adequacy of the model to actual process. The computations using the model have shown that to provide the desired product yield (not less than 40% wt. of overall yield of the unit products) of programmed quality (cold filtering plugging point not higher than minus 34Β°C for winter diesel fuels and not lower than minus 40Β°C for arctic ones) at long-time catalyst operation (during 4 years), it is necessary to sustain the reactor temperature at the average level of 19Β°C higher than when working with fresh catalyst. This must be done to compensate catalyst activity loss due to its deactivation
Intensification and forecasting of low-pour-point diesel fuel production via modelling reactor and stabilizer column at industrial unit
In this work forecast calculation of stabilizer column in the technology of low-pour- point diesel fuel production was modelled. The results of forecast calculation were proved by full-scale experiment at diesel fuel catalytic dewaxing unit. The forecast calculation and full- scale experiment made it possible to determine the ways of mass transfer intensification, as well as to increase the degree of hydrogen sulphide removal in the column, and thereby to decrease corrosiveness of the product stream. It was found out that maintenance of the reflux rate in the range of 80-90 m3/h and injection of additional vapourizing streams, such as stable naphtha from distillation unit (in the volume of 10-22 m{3}/h) and hydrogen-containing gas (in the volume of 100-300 m{3}/h), ensure complete elimination of corrosive hydrogen sulphide from the product stream. Reduction of stream corrosive activity due to suggested solutions extends service life of equipment and pipelines at industrial catalytic dewaxing unit
Monitoring of industrial hydrodewaxing plant in the context of cetane number and low temperature characteristics of diesel fuel
Intensification and forecasting of low-pour-point diesel fuel production via modelling reactor and stabilizer column at industrial unit
In this work forecast calculation of stabilizer column in the technology of low-pour- point diesel fuel production was modelled. The results of forecast calculation were proved by full-scale experiment at diesel fuel catalytic dewaxing unit. The forecast calculation and full- scale experiment made it possible to determine the ways of mass transfer intensification, as well as to increase the degree of hydrogen sulphide removal in the column, and thereby to decrease corrosiveness of the product stream. It was found out that maintenance of the reflux rate in the range of 80-90 m3/h and injection of additional vapourizing streams, such as stable naphtha from distillation unit (in the volume of 10-22 m{3}/h) and hydrogen-containing gas (in the volume of 100-300 m{3}/h), ensure complete elimination of corrosive hydrogen sulphide from the product stream. Reduction of stream corrosive activity due to suggested solutions extends service life of equipment and pipelines at industrial catalytic dewaxing unit
Formalization of hydrocarbon conversion scheme of catalytic cracking for mathematical model development
The issue of improving the energy and resource efficiency of advanced petroleum processing can be solved by the development of adequate mathematical model based on physical and chemical regularities of process reactions with a high predictive potential in the advanced petroleum refining. In this work, the development of formalized hydrocarbon conversion scheme of catalytic cracking was performed using thermodynamic parameters of reaction defined by the Density Functional Theory. The list of reaction was compiled according to the results of feedstock structural-group composition definition, which was done by the n-d-m-method, the Hazelvuda method, qualitative composition of feedstock defined by gas chromatography-mass spectrometry and individual composition of catalytic cracking gasoline fraction. Formalized hydrocarbon conversion scheme of catalytic cracking will become the basis for the development of the catalytic cracking kinetic model
Listeria monocytogenes meningoencephalitis against the background of the new coronavirus infection: a clinical case
Background: Among the bacteria that affect the central nervous system, Listeria monocytogenes (facultative intracellular bacterium) is one of the most lethal to humans and animals. Listeriosis affects domestic and farm animals (pigs, small and large cattle, horses, rabbits, less often cats and dogs), as well as domestic and ornamental birds (geese, chickens, ducks, turkeys, pigeons, parrots and canaries). L. monocytogenes can be detected in fish and seafood (shrimp). The source of L. monocytogenes infection are animals in which the disease may manifest itself or occur in erased and asymptomatic forms followed by the transition to a long-term carriage. This pathogen is found throughout the world in foodstuffs, and most cases of infection occur through the ingestion of contaminated food. Particularly susceptible to the disease are embryos, newborns, the elderly and individuals with immunodeficiencies and chronic diseases. L. monocytogenes can cause intracranial hemorrhage, meningitis, meningoencephalitis, and rhombencephalitis. Clinical case description: This paper presents our own clinical observation of the development of severe listeriosis meningoencephalitis in a 47 year-old patient against the background of the new coronavirus infection (COVID-19). We describe the details of the clinical presentation, the treatment and the favorable outcome in our patient. Conclusion: Invasive listeriosis is a rare disease. The knowledge about the clinical manifestations of this disease is needed not only for epidemiologists and infectious disease specialists, but also for physicians of other specialties. Untimely diagnosis and inadequate antibacterial therapy are dangerous leading to severe somatic and neurological complications with a lethal outcome or disability both in children and adult persons