Increasing the efficiency of the pyrolysis process

Increasing the production volume of organic synthesis products demands improvements to the technology of the pyrolysis process to reduce costs and increase the yield of desired products, particularly ethylene, which is the dominant raw material in the petrochemical industry. The aim of the present work is the substantiation of the methods that increase the pyrolysis selectivity for ethylene by influencing the stages of the radical chain process. Based on the study of the relative reactivity of the various C-H bonds in their interaction with the methyl radicals and with hydrogen atoms, which are the basic particles that determine the chain propagation in the pyrolysis, the possibility of increasing the process selectivity for ethylene was established, while simultaneously reducing the yield of the condensation products and suppressing the formation of pyrolytic carbon by replacing the methyl radical with hydrogen atoms, which was made possible by adding hydrogen to the feedstock in the amount of approximately 2% by weight. It was found that allene lowers the activation energy of the thermal decomposition of hydrocarbons, thus increasing the depth of the reaction. Accelerating the rate of initiation of the radical chain process was observed at the temperatures below 1,000 K. This opens up the possibility of increasing the efficiency of the pyrolysis process by recycling the propane fraction containing allene into the pyrolysis feedstock. This speeds up the process at low temperatures and suppresses the yield of the condensation products. Experimental data demonstrating the results of application of the proposed method are presented. © 2017 WIT Press

Increasing efficiency of the pyrolysis process by influencing the initiation of thermal decomposition of hydrocarbons

Mono-olefins produced in the process of pyrolysis of the hydrocarbon feedstock are one of the main sources for petrochemical synthesis, that accounts for the importance of searching for methods to improve the process. The aim of the work is to develop a method for increasing efficiency of the pyrolysis process on the basis of the allene effect on thermal decomposition of hydrocarbons, which are the pyrolysis feedstock constituents and also form in the process. Effect of the allene addition on thermal decomposition of hexene-1, hexane and gasoline fraction of oil was studied. It was shown that in the presence of allene the rate of thermal decomposition of hydrocarbons significantly increases. Carrying out the pyrolysis process in the presence of allene additionves allows one to lower the temperature of the process at a given time or the reaction time at a given temperature.ACKNOWLEDGEMENT This research was supported by Act 211 Government of the Russian Federation, contract № 02. A03.21.0006

Increasing the selectivity of the hydrocarbon feedstock pyrolysis

The process of hydrocarbon feedstock pyrolysis is the principal method used to produce ethylene which is a primary product utilized in the fabrication of plastic materials, synthetic resins, fibers and other similar products. The current level of process capacity and the necessity to steadily increase the petrochemical industry’s potential make the problem of improving the efficiency of the process an urgent one. The aim of the present work in terms of the pyrolysis mechanism analysis is to develop a method of increasing the pyrolysis selectivity for ethylene with minimal hydrogen consumption. It was shown on the base of established relative reactivity of different type C–H bonds in the reactions of interaction with H atoms and CH3 radicals, that the selectivity of the hydrogen atoms and methyl radicals in the substitution reactions at high temperatures are notably different. This makes possible a new method of controlling the selectivity of ethylene formation based solely on the influence of the concentration ratio of the chain carrier radicals [H]:[CH3] in the reaction mixture on the reaction output irrespective of changes in temperature, pressure and contact time. The minimum amount of hydrogen required to produce the desired effect was estimated. © 2014 WIT Press.International Journal of Sustainable Development and Planning;WIT Transactions on Ecology and the Environmen

Improvement of the pyrolysis process

In modern chemistry pyrolysis is the principal process and large-tonnage provider, primarily, of lower olefins - ethylene, propylene - as well as butadiene, benzene and other products. The level of efficiency of the pyrolysis process largely determines the development of the petrochemical industry in whole, therefore rationalization of the process is an ongoing task of high relevance. The aim of this work is to develop a method for increasing the efficiency of the pyrolysis for lower olefins on the base of the analysis of the mechanism of the process with the possibility of controlling it. The kinetics of the interaction of the hydrocarbons with hydrogen atoms, methyl radicals and their mixtures were determined. The data on the relative reactivity of bonds of different types in reactions with hydrogen atoms and methyl radicals and the data on the effective relative reactivity when using an inert diluent increase our knowledge of the pyrolysis of feedstock of any given composition. A method based on the influence of hydrogen on the thermal reactions of alkanes and alkenes was developed to increase the selectivity of the process for the target product (lower olefins) and to reduce the yield of the liquid products of condensation and specific energy consumption. © 2018 WIT Press.ACKNOWLEDGEMENTS This research was supported by Act 211 Government of the Russian Federation, contract № 02.A03.21.0006

Improving the efficiency of the stabilization columns in oil and gas processing

Rectification process is widely used in oil and gas processing and petrochemistry. The composition of the bottom product of the rectification column usually differs from the equilibrium composition due to significantly higher content of light components or fractions. This stipulates a necessity to include into the technological schemes of several oil refining processes a stabilization unit that are meant to ensure separation of gases and liquid products. A highly relevant task is to explore new possibilities for improving the stabilization process. The aim of the present work was to improve the stabilization process by changing the operating pressure. It was found that increasing the pressure in the stabilization column enhanced the sharpness of separation of butanes from pentanes, which resulted in improving the quality of the products. The experimental-industrial runs confirmed the possibility of increasing the efficiency of stabilization columns in various processes by increasing the pressure within acceptable limits. © 2019 WIT PressACKNOWLEDGEMENT This research was supported by Act 211 Government of the Russian Federation, contract № 02.A03.21.0006

An investigation of the feasibility of the organic municipal solid waste processing by coking

In the context of transition to a circular economy, one of the strategic priorities is the development of technological innovations aimed at waste processing. In this study, the foundations have been developed for a low-temperature, environmentally safe method for efficient processing of organic municipal solid waste, which may be further applied for processing both municipal and industrial waste organics in order to obtain liquid products. The maximum yield of liquid products is ensured when conducting the coking of a mixture of organic waste with long residuum in the temperature range of 400-420 °C, with a heating rate of 5-70 °C/min, and with an optimal heating time to the coking temperature of 80 min. Recommendations on the use of the waste recycling products are given. The proposed process is consistent with the principles of circular economy and does not require external energy costs because the energy needed for the process is generated by burning the gas produced during the waste coking. The process does not produce emissions into the environment and, in combination with standard refining processes, can be used to obtain commercial petroleum products. © 2019 by the authors.Government Council on Grants, Russian FederationFunding: This research received no external funding. Funding: This research received no external funding.  Acknowledgments: The work was supported by Act 211 of the Government of the Russian Federation, contract Acknowledgments: The work was supported by Act 211 of the Government of the Russian Federation, contract

Aqueous vapour substitution for hydrogen in the process of pyrolysis

In order to decrease hydrocarbons fractional pressure in the process of ethylene pyrolysis, 0.5-1.5 kilograms of aqueous vapour is added to each kilo of feedstock. In the pyrolysis of hydrocarbon feed, a considerable part of the process' power consumption is connected with water vaporization; heating up of the diluent to 800°C and more with the subsequent condensation. The aim of this work is to reduce specific energy consumption and improve selectivity to ethylene of pyrolysis process. The same hydrocarbons fractional pressure can be created as during diluting by aqueous vapour if we use hydrogen as a diluent with its mass 9 times less. It was found that if hydrogen is purged to the furnace inlet under different feedstock temperatures prior to the pyrolitic reaction, hydrogen will become a homogeneous catalyst for the subsequent radical-chain reactions. The depth of the reaction (according to Korzun and Magaril in Thermal processes of refining 2008) will be greater, under otherwise equal conditions, than without hydrogen. Specific heat energy consumption for the production of ethylene, as well as for the amount of ethylene and propylene, with aqueous vapour substitution to hydrogen decreases. When replacing the vapour for a considerably smaller amount of hydrogen, the latter is involved in a radical chain process, providing greater selectivity for ethylene production, thereby increasing the yield of ethylene at 15% relative. As a result, ethylene production costs are significantly reduced. © 2014 WIT Press.International Journal of Safety and Security Engineering;International Journal of Sustainable Development and Planning;WIT Transactions on Ecology and the Environmen

Efficiency improvement of pyrolysis

Ethylene production by pyrolysis of hydrocarbon gases (ethane, propane, butane) and liquid fractions provides better selectivity to ethylene at higher temperatures, as has been well documented in studies. Temperature increase accelerates chainradical reactions of ethylene formation. Acceleration of chain-radical process can be achieved at a given temperature by the presence of an initiating agent of radical formation in the feedstock. Bimolecular reaction of allene (propadiene) with either alkane or alkene hydrocarbons and is an extremely rapid reaction of radicals formation because the endothermicity of this reaction is small and steric ratio is high. This paper considers the use of allene as the initiator of chainradical reactions of pyrolysis. © 2014 WIT Press.International Journal of Safety and Security Engineering;International Journal of Sustainable Development and Planning;WIT Transactions on Ecology and the Environmen

Acceleration of boiling in the desired conditions: Application of its effect in the refinery and petrochemical industries

Rectification is used in almost all the processes of refinery and petrochemical industries. In most cases light fractions or individual components in the bottom of rectification towers are significantly higher than the thermodynamic equilibrium. The reason for this is that in the specified heat supply to the distillation residue of the fractionating tower and its specific volume, the boil-up rate of the light fractions or of some hydrocarbons is lower than the required value. The authors prove that the injection of the surface active agent in a feed stream of the fractionating tower in optimal concentration aimed at the potential content of the bottom product doubles the boiling rate of the residual light fractions in the distillation residue of the fractionating tower. It reduces the residual content of the light components in the bottom of rectification towers and improves quality of the previous fraction. The described effect has an industrial approbation. The result can be used in the running of fractionating towers for various purposes. © 2014 WIT Press.International Journal of Sustainable Development and Planning;WIT Transactions on Ecology and the Environmen