The effect of the process temperature on the composition and characteristics of the products, obtained by the refining of straight-run diesel fraction using the zeolite catalyst

Активное освоение арктических территорий и климат Российской Федерации в целом, обуславливают ежегодно растущую потребность рынка страны в низкозастывающих марках дизельного топлива. Существующие технологии производства зимних и арктических дизельных топлив, как правило, основываются на использовании зарубежных катализаторов, содержащих благородные металлы и требуют подачи водородосодержащего газа. Таким образом, актуальной задачей является создание новых технологий производства низкозастывающих дизельных топлив, не требующих вовлечения водородосодержащего газа и использующих более доступные катализаторы. Целью данной работы является исследование влияния температуры процесса переработки прямогонной дизельной фракции на цеолитном катализаторе без вовлечения водоросодержащего газа на состав и характеристики получаемых продуктов. В данной работе на лабораторной каталитической установке реализован процесс переработки прямогонной дизельной фракции на цеолитном катализаторе структурного типа ZSM-5 без вовлечения водородосодержащего газа в интервале изменения температур 375-475°С. Для исходной прямогонной дизельной фракции и полученных продуктов переработки исследован групповой углеводородный состав, физико-химические свойства и эксплуатационные характеристики. Проведена оценка соответствия характеристик полученных продуктов требованиям действующих стандартов. Рассмотрены возможные направления превращений углеводородов, входящих в состав дизельных фракций, в процессе переработки на цеолитном катализаторе. Установлено, что в интервале 375-475 °С оптимальной температурой процесса переработки на цеолитном катализаторе, позволяющей получить арктическое дизельное топливо, не требующее дополнительного компаундирования и удовлетворяющее требованиям действующих стандартов, в части основных эксплуатационных характеристик является температура 375 °С (при давлении процесса 0,35 МПа и объемной скорости подачи сырья 3 ч-1). The Russian Federation climate and active development of the Arctic territories determine the annually growing demand of the country's market for low-freezing brands of diesel fuel. The existing technologies for the production of winter and arctic diesel fuels, as a rule, are based on the use of foreign catalysts containing noble metals and require the use of hydrogen-containing gas. Thus, an urgent task is to create new technologies for the production of low-freezing diesel fuels that do not require the involvement of hydrogen-containing gas and use more affordable catalysts. This work aim is to study the effect of the process temperature on the composition and characteristics of the products, obtained by the refining of straight-run diesel fraction using the zeolite catalyst and without the involvement of hydrogen-containing gas. In this work, on a laboratory catalytic unit, the process of refining a straight-run diesel fraction on a zeolite catalyst of the ZSM-5 structural type without involving a hydrogen-containing gas in the temperature range of 375-475 °C is implemented. The group hydrocarbon composition, physicochemical properties, and operational characteristics are investigated for the initial straight-run diesel fraction and the obtained products. An assessment of the compliance of the characteristics of the obtained products with the requirements of the current standards is made. Possible directions of included in the composition of diesel fractions hydrocarbons transformations, during its processing on a zeolite catalyst, are considered. It is established that in the range of 375-475 °C, the most optimal temperature for the implementation of the refining process on a zeolite catalyst is 375 °C (at a process pressure of 0.35 MPa, and feedstock space velocity of 3 h-1). Refining at this temperature makes it possible to obtain arctic diesel fuel that does not require additional compounding, and meets the requirements of current standards in terms of the main operational characteristics.

Study dearomatization of diesel fuel under the infulence of magnetic field by IR spectroscopy

The purification process of polycyclic aromatic hydrocarbons was carried out by extraction of diesel fraction from the primary oil refining using the effect of magnetic field. A mixture of N-methylpyrrolidone with sulfuric acid was used as an extractant. The content of aromatic hydrocarbons in the diesel fraction decreased by 39.8% under normal conditions and by 50.8% under the influence of magnetic field after extraction. The samples were investigated by infrared (IR) spectroscopy method before and after extraction. Vibartional modes corresponding to different atomic bonds have been observed. Deodorization of diesel was determined by interpreting obtained modes.

HYDROPROCESSING OF PETROLEUM FRACTIONS OVER MODIFIED ALUMINIUM OXIDE CATALYSTS

The hydro processing of gasoline and diesel oil fractions over aluminum-nickel-molybdenum catalysts modified by additives HY, ZSM-5, phosphorus and rare earth elements were studied. At the hydro processing of straight-run gasoline over NiO-MoO3- Ce2О3-Р2О5–ZSM(30%)-Al2O3 the content of isoalkanes increases in comparison with the initial from 26.3 to 35.7- 38.3% at 320-400оС. The octane number of refined gasoline at 400оС is 83.7 (RON) and 69.7 (MON). The sulfur content decreases from 0.037% (initial gasoline) to 0.0022%. At hydro processing of straight-run gasoline over NiO-MoO3-La2О3-Р2О5-ZSM-Al2O3 in the range of 320–400 oC the content of isoalkanes is 30.7- 44.3%. The octane number of refined gasoline at 400oC is maximum and is equal to 91.8 (RON) and 72.4 (MON). Under these conditions the sulfur content decreases from 0.0092% to 0.0028%. The optimal conditions for the hydro processing of straight-run gasoline were revealed: T=400˚С, V=2 h-1, Р = 4.0MPa. The catalyst NiO-MoO3-La2О3-Р2О5-ZSM-HY-Al2O3 has the highest hydro desulfurizing activity, the residual sulfur content at 400oС is 0.0012%. The catalyst NiO-MoO3-La2О3-Р2О5-ZSM-Al2O3 has the highest hydro desulfurizing activity. At hydro processing of straight-run diesel fraction on this catalyst under optimal conditions the sulfur content decreases from 0.6400 % to 0.0740 % and during hydro processing of a straight-run diesel fraction with a higher sulfur content 0.8042% - up to 0.053%, which, apparently, is associated with the presence in the feedstock of various types of organosulfur compounds. The lowest pour point and cloud point under optimal conditions reaches minus 39.6oС and minus 30.5oС respectively. Thus, developed modified zeolite-containing catalysts for the hydro processing of gasoline and diesel fractions carry out hydro processing, hydro isomerization and hydrogenation in one stage. The developed catalysts make possible to obtain high-octane low-sulfur gasoline and low-solidification low-sulfur diesel fuel.

HYDROTREATMENT OF DIESEL FRACTIONS ON A MODIFIED ALUMINUM-NICKEL-MOLYBDENUM CATALYST KGO-12

The paper presents the results of the study of hydrotreatment of hexane, decane and diesel oil fractions on a new aluminum oxide zeolite-containing catalyst KGO – 12, modified with metals with variable valence, phosphorus and lanthanum additives. The hydrotreatment process was studied in a high-pressure flow unit with a stationary catalyst bed at temperatures of 320 – 400° C, a pressure of 4.0 MPa, and a volumetric feed rate of 2 h-1. After hydrotreating the diesel fraction of oil on the KGO – 12 catalyst at 400° C, the sulfur content in the catalysate decreases from 0.141 to 0.0092%, and the solidification temperature decreases from minus 27 to minus 57° C. The study of the process of hydrotreatment of the n-alcanes diesel fraction on the KGO – 12 catalyst showed that hydrotreatment, hydroisomerization and hydrocracking reactions occur simultaneously. It is established that the developed KGO – 12 catalyst has a high activity in the process of hydrotreating the diesel fraction of oil and makes it possible to obtain low-setting low-sulfur diesel fuel.

Adsorption as alternative process in the preliminary production of automotive additive

Nitrogenous contaminants in the diesel fraction are converted to NOx compounds in an automotive combustion chamber. Afterwards, they are reduced to nitrogen by catalytic reduction/oxidation reactions in presence of ammonia derived from a 32.5 wt.% urea solution. This process is named selective catalytic reduction (SCR). In Brazil, the urea solution for SCR is ARLA 32 and must comply with the limit content of 0.3 wt.% of biuret. However, the commercial Brazilian urea solution has an average biuret content of 0.5 wt.%. Thus, it is necessary to adjust the biuret content in urea solution to be used as ARLA 32, and adsorption is a low energy option. The objective of this study was to evaluate commercial adsorbents for removing biuret from solution of commercial urea to adjust it to the specification of ARLA 32. Two activated coals and one ion exchange resin were tested in adsorption assays, with best performances of both coals.

Expansion of the feedstock base for the production of diesel fuel by involving the heavy fractions and cold flow improvers

In this paper, the viability of expanding the feedstock base of diesel fuel production by the involvement of the heavy diesel fraction and the use of cold flow improvers was shown. The influence of the heavy diesel fraction content in the diesel fuel composition on its low-temperature properties and the effectiveness of the cold flow improver were studied. It was established that the involvement of a small amount of the heavy diesel fraction (up to 3 vol%) increases the effectiveness of the cold flow improver in relation to the cold filter plugging point. The following recipes of diesel fuel production were recommended: the involvement of up to 5 vol% heavy diesel fraction allows producing fuel of the summer grade; the involvement of up to 5 vol% heavy diesel fraction and the cold flow improver allows producing fuel of the inter-season grade; and the involvement of up to 3 vol% heavy diesel fraction and the cold flow improver to produce fuel of the winter grade.