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DOI - 10.32743/UniTech.2024.129.12.18881 EXTRACTION BENZENE FROM PYROLYSIS DISTILLATE
Laylo Jurayeva
Docent of the department of Chemical engineering Bukhara engineering technological institute, Uzbekistan, Bukhara E-mail: [email protected]
ПОЛУЧЕНИЕ БЕНЗОЛА ИЗ ПИРОЛИЗНОГО ДИСТИЛЛЯТА
Джураева Лайло Рахматиллаевна
доц. кафедры химической технологии, Бухарский инженерно-технологический институт, Республика Узбекистан, г. Бухара
ABSTRACT
This article explores the process of extracting benzene and its homologs from the composition of pyrolysis distillate using various extractants. The study focuses on the application of advanced extraction techniques to effectively separate aromatic hydrocarbons, such as benzene, toluene, and xylene, which are valuable raw materials for numerous industrial applications. A series of experiments were carried out using a model mixture composed of 35% n-hexane and 65% benzene as the feedstock to investigate how the extraction properties of both individual and mixed solvents vary under different extraction conditions. hen using a mixture of DEG (diethylene glycol) and DMSO (dimethyl sulfoxide) as extractants, the separation of benzene and its homologs from pyrolysis distillate demonstrated highly effective results. At a temperature of 40°C, the benzene content in the extract reached 87.8%, indicating the efficiency of this extraction method under the specified conditions.
АННОТАЦИЯ
В данной статье рассматривается процесс извлечения бензола и его гомологов из состава пиролизного дистиллята с использованием различных экстрагентов. Исследование сосредоточено на применении современных методов экстракции для эффективного разделения ароматических углеводородов, таких как бензол, толуол и ксилол, которые являются ценным сырьем для множества промышленных применений. Серия экспериментов была проведена с использованием модельной смеси, состоящей из 35% н-гексана и 65% бензола в качестве сырья, для изучения изменений свойств экстракции как отдельных, так и смешанных растворителей в зависимости от условий экстракции. При использовании смеси ДЭГ (диэтиленгликоля) и ДМСО (диметилсульфоксида) в качестве экстрагентов разделение бензола и его гомологов из пиролизного дистиллята показало высокую эффективность. При температуре 40°C содержание бензола в экстракте достигло 87.8%, что подтверждает эффективность данного метода экстракции при заданных условиях.
Keywords: extraction of aromatic hydrocarbons, diethylene glycol, benzene, xylene, toluene, extract, reformate, sulfolane, dimethyl sulfoxide.
Ключевые слова: экстракция ароматических углеводородов, диэтиленгликоль, бензол, ксилол, толуол, экстракт, риформат, сульфолан, диметилсульфоксид.
Intoduction. In the Republic of Uzbekistan, the presence and expansion of pyrolysis facilities makes it possible to produce pyrolysis benzene by pyrolysis of gas condensate and catalytic reforming of oil products, followed by extraction separation of catalyzates and pyrocondensates with selective solvents. Benzene is the most important raw material of the petrochemical industry,
on the basis of which large-tonnage products of organic synthesis are produced[1-3]. Currently, the advancement of the chemical and oil-and-gas industries, the efficient processing of diverse organic wastes, and the localization of industrial production remain critical and pressing issues globally. The extraction and utilization of various organic compounds, particularly aromatic hydrocarbons such
Библиографическое описание: Jurayeva L.R. EXTRACTION BENZENE FROM PYROLYSIS DISTILLATE // Universum: технические науки : электрон. научн. журн. 2024. 12(129). URL: https://7universum.com/ru/tech/ar-chive/item/18881
as benzene, xylene, and toluene from petroleum derivatives, hold significant potential across a wide spectrum of industrial applications[4-6]. Aromatic hydrocarbons, owing to their unique chemical properties, serve as essential precursors in the synthesis of a broad array of chemical products, including polymers, resins, and pharmaceuticals. Furthermore, their role in the production of solvents, dyes, and agrochemicals underscores their versatility and economic importance. The integration of advanced technologies for their recovery and purification not only enhances the efficiency of oil refining processes but also contributes to minimizing environmental impact by reducing waste. In this context, the development of innovative methods for the valorization of organic by-products and the optimization of extraction techniques for aromatic compounds are key to addressing global challenges related to resource sustainability and industrial competitiveness. Such advancements can significantly support the transition toward a circular economy, fostering economic growth while ensuring environmental stewardship[7-10].
Materials and methods. The process of single-step extraction of aromatic hydrocarbons from the composition of pyrolysis products was carried out as follows: the tubular column was rinsed with a small amount of solvent,
9
Results and discussion. Several experiments were conducted in a model mixture system consisting of 35% n-hexane and 65% benzene as raw materials in order to determine the change patterns of extraction properties of individual and mixed solvents depending on the extraction conditions. The effect of temperature on the degree of separation of benzene from the model mixture, its content in the extract and raffinate, the yield of the extract and raffinate was studied under the conditions of the duration of the extraction process of 45 minutes, the raw material: solvent mass ratio 1:1 and the amount of water in the solvent 5%.
декабрь, 2024 г.
the heater was connected, the temperature was brought to the required level and stabilized, and the operation of heating in one system was ensured by an external mixer. The measuring devices were weighed and rinsed with a small amount of model compound system. The raw material and the solvent in the tube column were mixed for 15-20 minutes until a homogeneous mixture was formed, then the mixing was stopped and allowed to stand at the specified temperature for 40-45 minutes. Upon cooling, the mixture separated into extract and raffinate phases. The resulting products were separated into measuring devices and weighed.
To carry out the practical part of the scientific research work in laboratory conditions, the extraction processes were carried out in the device shown in Fig. 1, which operates periodically. To carry out the extraction process, the tubular column 1 was placed inside the thermostat 2 with distilled water to ensure temperature stability. The liquid was heated using the heater 11 installed in the thermostat, the heater was connected to the contact thermometer 6 through the thermorelay 7, and the temperature was controlled using the standard thermometer 10 installed in the thermostat. Nozzles inside the column ensured uniform mixing of the solvent and raw materials. The mixer 8 ensures uniformity of the temperature of the 2 thermostatic fluids in the thermostat.
Table 1 shows the results obtained during the one-step extraction process under conditions of temperature change in the range from 20°C to 60°C. Increasing the temperature resulted in an increase in the amount of extract in the DMSO solvent environment, and had a positive effect on increasing the extract yield between 20°C and 50°C in the DEG and mixed solvent systems. The degree of separation of benzene from the composition of the model solution increased in the temperature range of 20-40°C in all individual and mixed solvent systems. When the temperature increased to 60°C, it was observed that the release rate of benzene decreased in DEG solvent medium, and increased further in DMSO medium.
1 - column with nozzle; 2 - thermostat; 3 - valve; 4 - mixer; 5 - rheostat; 6 - contact thermometer; 7 - thermal relay; 8 - mixer; - transformer; 10 - standard thermometer; 11 - heater.
The multi-stage extraction was carried out in a well-known method, in a counter-current extraction column in a single extraction cycle.
Figure 1. Laboratory extraction device
Table 1.
Results of one-step extraction of benzene from the composition of the model solution at different temperatures
The temperature of the extraction process, °С Benzene release rate, % Benzene content, %
Extract Refining
DEG
20 45.8 58.7 26.4
30 49.7 62.4 24.2
40 52.2 68.7 21.6
50 51.1 64.5 22.5
60 50.8 60.9 23.5
DMSO
20 49.5 61.1 24.6
30 52.2 64.8 23.1
40 56.7 69.7 20.4
50 54.5 66.4 21.1
60 52.4 62.2 20.6
50% DMSO - 50% DEG mixed solvent
20 57.8 82.4 22.4
30 62.4 84.7 20.7
40 66.5 87.8 17.4
50 61.7 82.2 18.5
60 62.5 78.9 19.2
Compared to the results of the extraction processes based on individual solvents, the extract with the highest concentration was obtained in the extraction processes
carried out in a mixed solvent at a temperature of 30°С-40°С (Fig. 2).
¡temperature.
♦ DEG ■ DMSO AW. DMSO 50% DEG
Figure 2. The influence of the temperature of the extraction process on the amount of benzene in the extract
A further increase in temperature resulted in a decrease in the quality of the extracts in all solvent systems. The amount of benzene in the extract decreased when the temperature of extraction processes based on individual and mixed solvents exceeded 60°C. In order to compare the reliability of the obtained results, the extraction process was carried out in the pyrolysis distillate, the extraction conditions were kept the same as in the process carried out in the model solution.
The release rate of aromatic hydrocarbons increased in DMSO and mixed solvent as the process temperature increased from 20°C to 40°C. Further increase in temperature decreased the extraction property of DEG and mixed solvent, while the extraction property of DMSO solvent increased. The content of aromatic hydrocarbons in the raffinate obtained at a temperature of 40°C-50°C is small, and the raffinates containing the least arenes were obtained at a temperature of 40°C and this value was 18.6%.
Table 2.
Results of one-step extraction process of aromatic hydrocarbons from pyrolysis distillate at different temperatures
The temperature of the extraction process, °C The degree of separation of aromatic hydrocarbons, % Amount of aromatic hydrocarbons, %
Extract Refining
DEG
20 52.7 52.4 24.6
30 54.8 54.5 25.3
40 56.9 56.7 22.6
50 56.4 54.5 23.5
60 53.4 51.2 24.8
DMSO
20 54.5 59.4 23.5
30 56.8 61.2 22.4
40 59.4 67.5 19.2
50 57.2 62.4 20.2
60 54.7 58.8 22.4
50% DMSO - 50% DEG mixed solvent
20 63.5 82.4 20.5
30 65.4 85.4 21.4
40 72.4 87.8 18.6
50 70.2 79.9 20.4
60 65.4 78.4 21.1
The concentration of aromatic hydrocarbons in the extract did not change significantly when the extraction temperature was increased from 20°C to 40°C when the individual substances DEG and DMSO were used as solvents. A decrease in extract quality was observed when extracting with DMSO at 50°C. The extract containing the highest concentration of aromatic hydrocarbons was obtained in a mixed solvent environment at a temperature of 30-40°C.
Conclusion. Based on the experimental data and their mathematical analysis conducted under laboratory conditions, the optimal parameters for the efficient extraction of benzene from model hydrocarbon mixtures and pyrolysis distillate using a mixed solvent system of DMSO (dimethyl sulfoxide) and DEG (diethylene glycol) were successfully determined. The study demonstrated the superiority and practicality of substituting diethylene glycol with the mixed solvent DMSO + DEG,
highlighting its enhanced extraction performance under the specified conditions. The findings underline the significant potential of the DMSO + DEG system in improving the selectivity and yield of benzene during the extraction process. These results not only contribute to the optimization of solvent systems for aromatic hydrocarbon separation but also provide a foundation for the design and development of industrial-scale extraction facilities. Moreover, the insights gained from this research can be effectively applied to the reconstruction and modernization of existing benzene separation installations, thereby improving their operational efficiency and economic feasibility. In conclusion, the implementation of the optimized mixed solvent system has the potential to significantly enhance the sustainability and competitiveness of industrial processes involving aromatic hydrocarbon recovery, paving the way for broader applications in the chemical and petrochemical industries.
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