Butane-butylene Fraction Research Articles

Optimization of the content of isobutane in the feed stream of the plant for sulfuric acid alkylation of isobutane with olefins

The raw materials for the industrial production of moto- and air-alkylates are isobutane and butane-butylene fractions containing in their composition a component, n-butane, which is inert for the reaction of sulfuric acid alkylation of isobutane with olefins. In accordance with the Specifications TU 0272-024-00151638-99, the content of n-butane in the isobutane fraction, depending on the grade of the fraction, is 0.7÷20% wt. Its presence reduces the useful reaction volume of the alkylation reactor, and when separating the components of the alkylation reaction mass, it is necessary to use a distillation column (debutanizer). The possibility of including an additional column in the technological scheme for removing n-butane from the composition of the fraction (respectively, isobutane concentration) before it is fed into the alkylation reactor is being considered. This is of particular importance for factions with a brand below "High Brand". The study is conducted using the Honeywell UniSim Design software system. The Peng-Robinson method was used to calculate the properties of process stream components. The theoretically optimal design of the apparatus was calculated: when using a distillation column with a pressure in the apparatus of about 400 kPa to reduce the content of n-propane in the distillate (obtained isobutane fraction) to 0.001 mol. the share will require 48 theoretical plates, the accepted reflux ratio R = 8.9, the temperatures in the condenser and reboiler are 26.88 and 47.27 °C, respectively. A computational experiment has shown that in order to achieve the practical absence of n-butane in the obtained isobutane fraction (concentration of about 0.1% wt.), it is possible to use a distillation column with the following technological modes: the number of plates is 60, the feed plate is 15, the efficiency of contact devices is 0.8; the pressure in the column is about 400 kPa, the temperature in the condenser and reboiler is Тk=28.91÷29.05 ℃ and Тр=46.72÷47.25 ℃, respectively, reflux ratio R=20.41. This fraction also does not contain pentanes.

Zeolite-Containing Catalysts in Alkylation Processes

This article provides an overview of zeolite-containing catalysts used in the alkylation of benzene and toluene with olefins, isobutane with butenes and butane-butene fractions, gasoline and oil fractions with olefins, propane-propylene, and butane-butylene fractions of catalytic cracking. Zeolites have various types of structures, including BEA, MFI, MWW, FAU, etc., which differ in pore size and the number and location of the channels. High-silica zeolites have a large pore volume, high acidity, good hydrothermal stability, and molecular sieve properties that provide high selectivity in alkylation processes.

Solution of the inverse kinetics problem for the catalytic cracking process based on a 16-component kinetic model

This article presents a 16-lump model of catalytic cracking of vacuum gasoil, which allows to take into account the quantity and quality of the main products of the process: gasoline, propane-propylene and butane-butylene fractions; and by-products of the process: light and heavy catalytic gasoil. To solve the direct problem of solving a system of differential equations, the Runge-Kutta method of order 4 is used, to solve the inverse problem of choosing the constants of the rate of chemical transformations, the method of direct search for minimizing the function of the sum of deviations of calculated values from experimental ones is applied. Thus, the reaction rate constants were chosen for the developed model.

The Influence of Stream Treatment on the Activity of Iron-Pillared Montmorillonite in Vacuum Gas Oil Cracking

This study considers the influence of stream treatment on the activity if iron-pillared montmorillonite in vacuum gas oil cracking and the change in its physical-chemical characteristics. Stream treatment was demonstrated to result in a decreased specific surface area and iron and silicon content, as well as in the strengthening of the catalysts. After stream treatment, gasoline and gas yield is reduced and raw material conversion decreases. Before stream treatment, the proportion of aromatic hydrocarbons in cracking gasoline does not exceed 24.1%, while the isoparaffin content is 24,5%. After stream treatment, the aromatization of gasoline increases and the content of paraffin-naphthenic hydrocarbons decreases. The main component of cracking gases is butane-butylene fraction with a content equal to about 40% before stream treatment, which remains unchanged after processing.

Getting of Benzine from Residues of Methyl-Tret-Butyl ether Production Using Microwave Radiation

Benzine getting from used butane-butylene fraction from unit of methyl-tret-butyl ether production through oligomerization is one of ways to increase efficiency and ecological compatibility of process. Usually, the technology of producing oligobenzine is based on the generation of thermal energy required for the oligomerization reaction when burning solid or gaseous fuels in furnaces. Safety and ecological compatibility of this process may be significantly improved with microwave radiation used during reactions. The use of microwave energy will heat only the catalyst, which will be in contact with the butane-butylene fraction., It is possible to estimate the process parameters in the static and dynamic modes by numerically solving a system of equations that mathematically describe oligomerization under the influence of microwave radiation. It is established that the oligomerization process is intensified, and the energy costs are reduced.

Improving the Technological Scheme of Isolation of Butane–Butylene Fraction by Chemisorption Using Tubular Turbulent Apparatus

Improving the Technological Scheme of Isolation of Butane–Butylene Fraction by Chemisorption Using Tubular Turbulent Apparatus

Effect of Phosphorus Modification of Zeolites Y and ZSM-5 on the Cracking of Hydrotreated Vacuum Gas Oil and a Vacuum Gas Oil–Sunflower Oil Mixture

The effect of the preliminary impregnation of zeolites HREY and HZSM-5 with ammonium phosphate before introducing them into the composition of dual-zeolite catalysts has been studied. It has been found that the modification leads to a change in the main textural characteristics of the zeolites. Both the specific surface area and the meso- and micropore volume of the zeolites decrease. The total acidity of HREY and HZSM-5 and the number of strong acid sites in them also decrease. Tests on the conversion of hydrotreated vacuum gas oil and a vacuum gas oil–sunflower oil mixture under catalytic cracking conditions have shown that the modification of the zeolites leads to an increase in the total yield of the propane–propylene and butane–butylene fractions with a high olefin content in them, even with a decrease in the feedstock conversion.

Key Features of Cotransformation of Vacuum Gas Oils and Vegetable Oils on Dual-Zeolite Cracking Catalysts

The study of cotransformation of petroleum fractions with vegetable oils on dual-zeolite cracking catalysts has revealed that vegetable oils differing in fatty acid composition admixed to vacuum gas oil, characterized by a high aromatics content, facilitate the conversion and increase the yields of the gasoline fraction and light olefins. In the case of vacuum gas oil cocracking with a vegetable oil having a high unsaturation index (sunflower oil), the oil content in the mixture should not exceed 5 wt %, since its higher content in the mixture leads to enhanced coking of the dual-zeolite catalyst and simultaneous reduction in the yield of the desired cracking products. The effect of preliminary impregnation of HREEY and HZSM-5 zeolites with ammonium hydrogen phosphate before their incorporation into the composition of dual-zeolite catalysts has been investigated as well. It has been found that the modification results in a decrease in the total acidity of zeolites. In the cracking of a mixture of vacuum gas oil and sunflower oil, it has been determined that the modification of zeolites leads to an increase in the total yield of the propane–propylene and butane–butylene fractions with high olefin content. Keywords: vacuum gas oil, vegetable oils, dual-zeolite catalyst, gasoline fraction

Modifying Zeolite ZSM-5 to Increase the Yield of Light Olefins in Cracking Feedstocks of Petroleum and Vegetable Origin

The effect modifying the HZSM-5 zeolite contained in a bizeolite catalyst has on the conversion of hydrotreated vacuum gas oil, vegetable oil, and a vacuum gas oil–vegetable oil mixture under conditions of catalytic cracking is investigated. It is found that modification lowers both the specific surface area and the volume of the meso- and micropores of HZSM-5 zeolite; the higher the phosphorus content, the greater the reduction in the main characteristics of the pore structure of the zeolite. A drop in the total acidity of P/HZSM-5 and a quantitative redistribution of weak and medium-strength acid sites are also observed. Catalytic tests of the zeolites in the cracking process show that phosphorus modification helps increase the total yield of propane–propylene and butane–butylene fractions with high olefin contents. Alkaline treatment of HZSM-5 zeolite with a high SiO2/Al2O3 ratio facilitates the extraction of silicon and increases the specific surface area of mesopores considerably. In addition, weakening of the strong acid sites of the zeolite and/or a change in the accessibility of these sites due to the partial removal of silicon is observed.

SELECTION AND PILOT TESTS OF THE EFFECTIVE METHOD OF REGENERATION THE CATALYST OF THE OIL REFINING GASES OLIGOMERIZATION PROCESS

Despite the prevalence and effectiveness of the method of oxidative regeneration of catalysts, it is known that the application of this method leads to irreversible deactivation and sintering processes. The study of regeneration approaches and the search for alternative effective methods for restoring the activity of catalysts are an actual task. In the present work, the results of application of various approaches of regeneration of the oligomerization catalyst based on modified montmorillonite are presented. The efficiency of extractive regeneration by supercritical carbon dioxide and benzene-toluene-xylene (BTX) fraction has been established by the differential thermal analysis method, the latter approach allows restoring the catalyst activity practically to the level of a fresh sample. In order to determine the efficiency and stability of the catalyst during the oligomerization of the butane-butylene fraction, in complex with the regeneration of the BTX fraction, pilot tests were carried out for 4000 hours, and the high efficiency of the developed technical solution for the production of С6-С9 hydrocarbons was proved.

Modification of ZSM-5 Zeolite in order to Improve the Yield of Light Olefins during Cracking of Oil and Plant Materials

The influence of modifying HZSM-5 zeolite as a component of a bizeolite catalyst in transformations of hydrotreated vacuum gasoil, plant oil, and a mixture of vacuum gasoil and plant oil was studied. The modification with phosphorus was established to decrease the specific surface area and meso- and macropore volumes in HZSM-5 zeolite; the higher phosphorus content, the lower main characteristics of the zeolite porous structure. A decrease in the total acidity of P/HZSM-5 and quantitative redistribution between weak and moderate acid sites also was observed. Testing of the zeolites in catalytic cracking revealed that the phosphorus modification favored an increase in the total yield of propane-propylene and butane-butylene fractions containing olefins in high proportions. Alkali treatment of HZSM-4 zeolite with a high silicate module resulted in a higher silicon extraction and in a considerable increase in the specific surface area of mesopores. In addition, strong acid sites of the zeolite were transformed to weaker ones and/or their exposure changed due to partial silicon removal.

Factors Determining the Stability of Alkylation Catalysts Based on Y Zeolites

Results from studies of the influence of the physicochemical properties of synthetic alkylation catalysts based on Y zeolites on their activity for alkylation of isobutane of the butane—butylene fraction are reported.

Development and introduction of a highly efficient catalyst for the butane–butylene fraction oligomerization process for the production of a high-octane automobile gasoline compound

The main stages in developing a technology for the production of high-silica ZSM-5 zeolite-based catalyst for the butane–butylene fraction (BBF) oligomerization process are described. The application of a new zeolite surface modification procedure allows the attainment of higher selectivity and target product yields (compared to familiar analogs) and the synthesis of more branched (and thus more high-octane) oligomers at lower pressures. The introduction of promoting metal Ga raises the target gasoline fraction yield by 0.9%, compared to the unpromoted catalyst. Comparative pilot tests of industrial (BAK-70U) and the developed (Ga-ZSM-5/Al2O3) BBF oligomerization catalysts are performed under the following conditions: pressure, 1.5 MPa; initial working temperature, 300°C; feedstock hourly space velocity (FHSV), 1.5 mL BBF/(mL cat h). It is shown that using modified ZSM-5 based catalyst results in a gasoline fraction yield 7% higher than with BAK-70U. The higher quality of the oligomerizate obtained on Ga-ZSM-5/Al2O3 is observed throughout the period of tests (191 h): MON is 2 points higher, and the concentration of gums is 50% lower. The results from these studies and tests are used for the development and industrial implementation of a technology for the production of the KOB-1 zeolite oligomerization catalyst: 2.5 t of industrial catalyst has been produced by September of 2016 at the industrial facilities of ZAO Redkino Catalyst Plant. The next important stage in the implementation of the Gazprom Netf innovative development strategy in oil refining is a pilot run of the new oligomerization catalyst in the combined industrial MTBE–oligomerizate production plant of Gazprom Neft Moscow Oil Refinery. The introduction of the KOB-1 catalyst at the Gazprom Neft Oil Refinery will be an important step in improving the efficiency of technologies for the production of high-margin products, especially compounds of commercial automobile gasoline.

New methods for the preparation of high-octane components from catalytic cracking olefins

A new method has been suggested for the preparation of high-octane components from the butane–butylene fraction (BBF) in two stages. At the first stage, the BBF olefins are oxidized with N2O into carbonyl compounds with high selectivity without forming the products of deep oxidation and water. The process occurs in the gas phase in a flow reactor without using a catalyst at a temperature of 400°C and a pressure of 2 MPa with high conversion of both olefins and nitrous oxide. The blending octane number of the oxidation product is 118–133 (RON) and 99–104 (MON). At the second stage, the mixture of carbonyl compounds is hydrogenated with hydrogen in the presence of the Ni/Al2O3 catalyst. The hydrogenation occurs at 150–160°C in a flow reactor in the gas phase. The aldehydes are completely transformed into alcohols, while the ketones can remain in the product under certain conditions. The blending octane number of the hydrogenation product is 111–112 (RON) and 95–96 (MON), which is smaller than for the BBF oxidation product, but larger than for the alkylate obtained in the course of conventional butene alkylation with isobutane (RON is 95–97 and MON is 93–95). Synthesis of high-octane components by this procedure can be useful in practice, especially in productions with huge release of nitrous oxide.

Mathematical modelling of catalytic cracking riser reactor

The quality and the yield of gasoline and light olefins from the catalytic cracking unit depend on a broad range of operation indicators including the feedstock composition, the process conditions, the type and activity of the catalyst. The aim of research is to develop the mathematical model of catalytic cracking reactor on the basis of the formalized mechanism of hydrocarbon conversion taking into account the catalyst deactivation by coke. The experimental research of the feedstock and the product of catalytic cracking using a liquid-adsorption chromatography, gas chromatography–mass spectrometry, gas-liquid chromatography and the structural-group composition methods allowed determining the list of the catalytic cracking reactions. According to the discovered reactions, the thermodynamic analysis was performed using the methods of quantum chemistry. Thermo-gravimetric analysis of the coked catalyst allowed estimating the coke structure formed on the catalyst surface. The developed mathematical model allows to predict the product yields including the content of propane-propylene (PPF) and butane-butylene (BBF) fractions, the group composition and octane number of the gasoline depending on the feedstock composition, the process conditions of reactor-regenerator unit and the catalyst activity. As a result, the high theoretical yield of the gasoline (60.4 wt.%, RON 93.5) according to requirements for the content of olefins and benzene can be achieved at the process temperature of 533°C. This temperature is possible at the keeping the catalyst circulation ratio of 6.9 toncat/tonfeed at the catalyst flow temperature after regeneration (685.8°C) with the catalyst activity of 0.79 unit and the feedstock temperature (328.0°C). The yields of rich gas and coke are 24.0wt% and 4.5 wt%, the concentrations of PPF and BBF are 31.5 and 34.8 wt%.

Butane–butylene fraction cracking over modified ZSM-5 zeolite

The effect of temperature (530–590°C), weight hourly space velocity (2.5–7.0 h–1), and the Si/Al ratio of the ZSM-5 zeolite (30, 55, 80, 300) on the cracking of a butane–butylene fraction containing 85 wt % butylenes has been studied. The HZSM-5 zeolite has been modified with phosphorus. The effect of modification on the catalyst activity in cracking reactions has been studied. The ethylene and propylene yield achieves 38.4 wt % at a degree of conversion of butylenes of 81.5%. The ethylene to propylene ratio is 0.55.

Calculation of Thermodynamic Parameters for Producing the High-Octane Component from a Butane-Butylene Fraction Based on Thermobaric Dependences and an Informative Model

The thermodynamic parameters for the oligomerization of a butane-butylene fraction are calculated using thermobaric dependences and an informative model, which can be used further for mathematical evaluation and prediction of the possible occurrence of a reaction. Equilibrium constants and Gibbs free energy are plotted as functions of the process temperature.

A ZSM-5 zeolite-based catalyst for oligomerization of the butane–butylene fraction

The effect of localization of acid sites and the nature of the modifier metal on the activity, selectivity, and operation stability of a ZSM-5 zeolite-based catalyst in the oligomerization of the butane–butylene fraction (BBF) has been examined. It has been shown that the selective poisoning of acid sites on the external surface of zeolite crystals reduces coking and increases the yield of the desired gasoline fraction. Introduction of a promoter metal insignificantly affects the catalytic properties of the zeolite. Among Zn, Ga, and La, gallium appears to be the best modifier, which provides an increase in the yield of the desired gasoline fraction by 0.9%. As a result of the study, a BBF oligomerization catalyst has been developed that ensures a threefold increase in the catalyst on-stream time and a 7% increase in the yield of the gasoline fraction as compared with its commercial counterpart.

Development and Application of Highly Efficient Catalyst for Oligomerization of Butane-Butylene Fraction for the Production of High-Octane Component of Motor Gasoline

Main steps of the development of the technology for synthesis of a catalyst based on high-silica zeolite ZSM-5 for oligomerization of butane-butylene fraction (BBF) are reported. Application of a new procedure for the zeolite surface modification makes it possible to improve the selectivity and yield of the target product (against the known analogues), to synthesize more branched (and, hence, with a higher octane numbers) oligomers at lower pressures. Introduction of a metal-promoter, Ga, provides 0,9 % higher yield of the target gasoline fraction as compared to that over the non-promoted catalyst. Comparative pilot testing of the samples of industrial (BAC-70U) and developed (Ga-ZSM-5/Al2O3) catalysts for BBF oligomerization at 300 °C, feed flow rate 1,5 mL BBF/(mL cat·h) showed that the yield of the target fraction is 7 % higher over the modified ZSM-5 than over BAC-70U. Throughout the testing (191 h), a higher quality of the oligomerizate produced over Ga-ZSM-5/Al 2 O 3 was observed: MON was 2 points higher and concentration of gums twice as little. The results obtained during studies and testing were used for the development and industrial implementation of the technology for the production of the zeolite-containing catalyst COB-1 for oligomerization. A 2,5 t batch of the industrial catalyst was produced by September 2016 at the facilities of the Redkino Catalyst Company. The next important step in the implementation of the Gazpromneft strategy for innovative development in oil refining is to achieve a test run of the new catalyst using the industrial combined setup for the production of MTBE and oligomerizate at the Gazpromneft-Moscow Refinery. The use of COB-1 at the Refinery will be an important step to improve efficiency of the process for synthesis of high-margin products – components of the commercial motor gasoline.

Optimal control of process of pyrolysis of paraffinic hydrocarbons C2-C4 and their mixtures

This paper describes the scheme that has been developed for the optimal control of the process of pyrolysis for different types of hydrocarbon feedstock in the four-flow pyrolysis furnace at the Sumgait Ethylene-Polyethylene plant; the scheme is based on the use of a complex parameter of the process, i.e., the pyrolysis intensity function. The algorithm for this control has been constructed. In the paper, the results of optimal control of the process of propane pyrolysis, ethane pyrolysis, and pyrolysis of ethane together with the butane-butylene fraction are presented in accordance with the scheme being developed using the intensity function that corresponds to each process. Optimal values of the intensity function were found from the results of calculations carried out using the mathematical model of each process. The extended expression for the intensity function has been formulated and, with its use, it is possible to control the process both in the case of the change in the flows of feedstock and steam and the change in the inlet temperature, as well as in the case of the change in the feedstock composition.