The deposition of asphaltenes in the petroleum industry has been found to be a significant factor affecting the profitability of petroleum production and refining. For this reason, many efforts have been made to clarify the mechanism of deposition formation and to find measures to reduce its harmful impact on the efficiency of oil production and refining. Recent reports on the mechanism of deposit formation by asphaltenes suggest that it is a phase transition phenomenon. Many studies have shown that this process can be slowed by using chemical inhibitors. Different classes of chemical substances (non-polymeric, organic compounds, polymers, ionic liquids and nanomaterials) have been found to be capable of inhibiting asphaltene precipitation. This paper presents a comprehensive review of asphaltene deposition research and makes an attempt to decipher the convoluted asphaltene deposition phenomena and relate the chemistry of asphaltene inhibitors to the nature of treated petroleum oils. The choice of appropriate additives to mitigate asphaltene deposition in commercial oil and gas facilities requires comprehensive knowledge of chemistry of oils, asphaltenes, and the chemical substances, along with the appropriate laboratory techniques that best mimic the commercial operation conditions.

A huge amount of waste tires is generated every day in the world. This determines the search for ways to use them. The extended process of production and application of scrap tires leads to their significant mass accumulation, thus representing environmental risk. Tires are inert materials, extremely difficult to treat, and nonbiodegradable. In recent years, many plants have been built for processing, treatment, and utilization of this kind of waste. A problem has emerged to find a suitable, environmentally friendly application of the products (gaseous, liquid, and solid) from pyrolysis of the tires. Pyrolysis oil, which is a liquid product, is not suitable for direct use as fuel because of its high sulfur content. Therefore, the desulfurization of pyrolytic tire oil is an important part of the oil production process prior to its use. The objective of this article is to review the methods used for desulfurization of waste tire pyrolysis oils and the possibility of using scrap tires as a source of energy.

An expected increase in the demand for aviation transport service will result in the deterioration of the environment and human health, respectively, due to extra greenhouse gas (GHG) emissions. Concerns from EU institutions about the issue have led to legislation initiatives and, later, to development of Regulation (EU) 2023/2405 for the reduction of GHG emissions via the substitution of fossil kerosene with an increasing share of sustainable components. Hydroprocessed esters and fatty acids (HEFAs) are the most commercially acceptable sustainable alternative but their influence on aviation fuel properties needs to be further evaluated in terms of all required and extended properties, as per ASTM D1655. The main properties, together with the rarely reported upon existent gum, water separation, corrosion, and the electrical conductivity of HEFAs and their blends with fossil kerosene were quantitatively evaluated in this study. For every increase of 10% (v/v) of HEFAs, the following fuel properties improve: the freezing point decreases by 1.3 °C, the smoke point increases by an average of 3 mm, and the specific net energy increases by 0.08 MJ/kg. The acidity of HEFAs are an order of magnitude higher than that of conventional aviation fuel and, thus, close to the limit. The existent gum of the studied SAF is higher than that of fossil kerosene due to, most probably, the presence of non-evaporated residual material.

Ebullated bed vacuum residue hydrocracking and fluid catalytic cracking (FCC) are among the most profitable processes in modern refining. Their optimal performance is vital for petroleum refining profitability. That is why a better understanding of their combined action and the interrelations between these two heavy oil conversion processes in a real-world refinery could provide valuable information for further performance optimization. Nine distinct petroleum crudes belonging to the extra light, light, and medium petroleum crude types were processed in the LUKOIL Neftohim Burgas refinery to study the combined performance of two processes: FCC of vacuum gas oil and ebullated bed vacuum residue H-Oil hydrocracking. The operating conditions along with the characterization data of the feeds and products of both processes were evaluated through the employment of intercriteria analysis to define the variables with statistically significant relationships. Maple 2023 Academic Edition mathematics software was used to develop models to predict the vacuum residue conversion level under different operating conditions. The plug flow reactor model with an activation energy of 215 kJ/mol and a reaction order of 1.59 was found to provide the highest accuracy of vacuum residue conversion, with an average absolute deviation of 2.2%. H-Oil yields were found to correlate with the vacuum residue conversion level and the content of FCC slurry oil (SLO), the recycling of partially blended fuel oil, a material boiling point below 360 °C, and the vacuum gas oil (VGO) in the H-Oil feed. FCC conversion was found to depend on the H-Oil VGO content in the FCC feed and the content of FCC SLO in the H-Oil feed.

A comprehensive investigation of a highly complex petroleum refinery (Nelson complexity index of 10.7) during the processing of 11 crude oils and an imported atmospheric residue replacing the design Urals crude oil was performed. Various laboratory oil tests were carried out to characterize both crude oils, and their fractions. The results of oil laboratory assays along with intercriteria and regression analyses were employed to find quantitative relations between crude oil mixture quality and refining unit performance. It was found that the acidity of petroleum cannot be judged by its total acid number, and acid crudes with lower than 0.5 mg KOH/g and low sulphur content required repeated caustic treatment enhancement and provoked increased corrosion rate and sodium contamination of the hydrocracking catalyst. Increased fouling in the H-Oil hydrocracker was observed during the transfer of design Urals crude oil to other petroleum crudes. The vacuum residues with higher sulphur, lower nitrogen contents, and a lower colloidal instability index provide a higher conversion rate and lower fouling rate in the H-Oil unit. The regression equations developed in this work allow quantitative assessment of the performance of crucial refining units like the H-Oil, fluid catalytic cracker, naphtha reformer, and gas oil hydrotreatment based on laboratory oil test results.