Heavy Vacuum Gas Oil Upregulates the Rhamnosyltransferases and Quorum Sensing Cascades of Rhamnolipids Biosynthesis in Pseudomonas sp. AK6U

We followed a comparative approach to investigate how heavy vacuum gas oil (HVGO) affects the expression of genes involved in biosurfactants biosynthesis and the composition of the rhamnolipid congeners in Pseudomonas sp. AK6U. HVGO stimulated biosurfactants production as indicated by the lower surface tension (26 mN/m) and higher yield (7.8 g/L) compared to a glucose culture (49.7 mN/m, 0.305 g/L). Quantitative real-time PCR showed that the biosurfactants production genes rhlA and rhlB were strongly upregulated in the HVGO culture during the early and late exponential growth phases. To the contrary, the rhamnose biosynthesis genes algC, rmlA and rmlC were downregulated in the HVGO culture. Genes of the quorum sensing systems which regulate biosurfactants biosynthesis exhibited a hierarchical expression profile. The lasI gene was strongly upregulated (20-fold) in the HVGO culture during the early log phase, whereas both rhlI and pqsE were upregulated during the late log phase. Rhamnolipid congener analysis using high-performance liquid chromatography-mass spectrometry revealed a much higher proportion (up to 69%) of the high-molecularweight homologue Rha–Rha–C10–C10 in the HVGO culture. The results shed light on the temporal and carbon source-mediated shifts in rhamonlipids’ composition and regulation of biosynthesis which can be potentially exploited to produce different rhamnolipid formulations tailored for specific applications.

Development of Technological Schemes for Increasing the Selection of Vacuum Gas Oil

The analysis of the operation of the vacuum columns of the ELOU AVT units showed that in a number of cases the half-gas contains up to 30% of vacuum gas oil with a boiling point of up to 560 ° C. A comparative analysis of three options for deepening the selection of heavy vacuum gas oil during the distillation of fuel oil has been carried out. A traditional scheme with a pressure reduction at the top of the vacuum column, the rectification of a half-sludge without heating it after the main vacuum column in an additional its subsequent rectification in the second column, with the selection of heavy vacuum gas oil. The analysis of the operation of the vacuum column of the vacuum rectification unit ELOU AVT-6 was carried out. The process was simulated in the environment of the software product Aspen HYSYS, the possibility of increasing the selection of heavy vacuum gas oil in the process of deep vacuum rectification of tar was theoretically proved. The advantages and disadvantages of two-column vacuum distillation of fuel oil are considered. Structural design of the rectification column and raw material input device is proposed.

Hydrocracking of a Heavy Vacuum Gas Oil with Fischer–Tropsch Wax

Catalytic hydrocracking represents an optimal process for both heavy petroleum fractions and Fischer–Tropsch (FT) wax upgrading because it offers high flexibility regarding the feedstock, reaction conditions and products’ quality. The hydrocracking of a heavy vacuum gas oil with FT wax was carried out in a continuous-flow catalytic unit with a fixed-bed reactor and a co-current flow of the feedstock and hydrogen at the reaction temperatures of 390, 400 and 410 °C and a pressure of 8 MPa. The increasing reaction temperature and content of the FT wax in the feedstock caused an increasing yield in the gaseous products and a decreasing yield in the liquid products. The utilisation of the higher reaction temperatures and feedstocks containing the FT wax showed a positive influence on the conversion of the fraction boiling above 400 °C to lighter fractions. Although the naphtha and middle distillate fractions obtained via atmospheric and vacuum distillations of the liquid products of hydrocracking did not comply with the particular quality standards of automotive gasolines and diesel fuels, the obtained products still present valuable materials which could be utilised within an oil refinery and in the petrochemical industry.

Investigation and Resolution of the Fluid Structure Interaction of High Rate HVGO Pumps

A suite of High Rate Heavy Vacuum Gas Oil (HVGO) pumps in an operating Upgrader Plant experienced repeated failures; typically, less than 7 weeks. The need for online measuring tools arose that could measure pump and piping system strain changes with dynamic thermal gradients. The challenge was to record the effect on the entirety of pump component alignment and vibration. In current industrial practices no such tools and techniques are directly and comprehensively available for rotary equipment. Strain gauges are not accurate, and cannot provide broader real time strain mapping. Optical metrology can analyze the mechanical properties and behavior of all kinds of materials in various test scenarios. To date such methods are experimental and principally found in advanced application environments. At the time the method was unknown and especially in such a difficult industrial plant. In such a complex and extreme hot and cold operating service warm-up, cooling, with variations in flow and temperature, can directly and dynamically affect strain measurements. It was not certain whether optical meorology measurement techniques would be able to identify and correlate dynamic operating scenarios with the source of the pump and pipe hardware issues experienced in these Heavy Vacuum Gas Oil (HVGO) pump systems. The influence of the casing thickness and stiffness on the resulting vibration characteristics was investigated by using FEA and operational testing and dynamic analysis. Increasing the interface web thickness results in notable reduction in deformation. Comparison of the results of the live testing against the initial design was performed and studied for remedial action. Materials and heat treatment options were also evaluated and reported. The three-dimensional turbulent flow was modelled and analyzed. The application of those tools for this type of problem are described along with the other rigorous techniques employed. The range of tools included modal and vibration analysis, thermography, rotor and shaft dynamics, baseplate, frame, metallurgical analysis and ultimately compared with FEA, pipe stress modelling and strain analysis. This paper should be read in conjunction with PVP 2020-21204; Piping & Equipment Dynamics of High Rate HVGO Pumps.

Study the Effect of Catalyst -to- Oil Ratio Parameter (COR) on Catalytic Cracking of Heavy Vacuum Gas Oil

This work deals with the production of light fuel cuts of (gasoline, kerosene and gas oil) by catalytic cracking treatment of secondary product mater (heavy vacuum gas oil) which was produced from the vacuum distillation unit in any petroleum refinery. The objective of this research was to study the effect of the catalyst -to- oil ratio parameter on catalytic cracking process of heavy vacuum gas oil feed at constant temperature (450 °C). The first step of this treatment was, catalytic cracking of this material by constructed batch reactor occupied with auxiliary control devices, at selective range of the catalyst –to- oil ratio parameter ( 2, 2.5, 3 and 3.5) respectively. The conversion of heavy vacuum gas oil which was obtained, reaches to (50, 70, 75 and 80) % for (2, 2.5, 3 and 3.5 catalysts -to- oil ratio parameter respectively. The second step for this study was distillation of this cracking heavy vacuum gas oil liquid by atmospheric distillation device for these several catalyst -to- oil ratio parameter, according to obtained light fuel cuts (gasoline, kerosene and gas oil). The percentage volume of light fractions at various COR are (7, 25 and 18) for COR 2, (10, 20 and 40) for COR 2.5, (10, 30 and 35) for COR 3 and (15, 30 and 35) for COR 3.5 which separates according to its boiling point. The light cuts were distilled by atmospheric distillation device in order to obtained distillation curve. The third step was study the major physical and chemical properties for feed (heavy vacuum gas oil) and catalytic cracking liquid of HVGO at various COR with its light fuel fractions, the results refers to acceptable properties compared with other commercial properties.