Heavy Paraffin Research Articles

Full-period operation optimization of the semi-regenerative reactor based on dehydrogenation reaction and deactivation kinetics

Semi-regenerative reactors are adopted in many catalytic processes. Based on industrial data, a one-dimensional pseudo-homogeneous reactor model was established for the semi-regenerative reactor of the dehydrogenation of heavy paraffins. The validation results show high accuracy of the model prediction. The Sequential Quadratic Programming (SQP) algorithm was employed for the full-period operation optimization of the reactor, resulting in a 3.04% increase in the yield of mono-olefins, but the optimized operation conditions are not consistent with common combination according to the practical production experience described in the literature. Further investigations for semi-regenerative reactors with different dehydrogenation systems show that the optimized combination of operation conditions in a full period is dependent on the depth of dehydrogenation, the rate of catalyst deactivation, and the duration of the period.

HYDROCARBON CONTAMINATION IMPACT ON SANDY SOILS WITHIN THE DZUNBAYAN OIL FIELD (EASTERN MONGOLIA)

The data are presented on the particle-size distribution, content of hydrocarbons, n-alkanes in their composition and the number of microorganisms in the soils of Dzunbayan oil production area (Mongolia, the Eastern Gobi desert steppe). The soils studied are characterized by the dominance of sand and fluid fraction (99.50–99.8%) with particles of 2–20 μm. The soils show alkaline reaction (pH 8.2–8.7), they are slightly saline in the control areas and highly saline (water extract salinity 0.13–2.34‰) near the production well. The content of petroleum hydrocarbons (HC) in soils of the study area varied from 9 to 60 mg/kg, with a maximum near the well. The study of the molecular composition of n-alkanes revealed the dominance of long-chain homologues (66.3–79.2% of the total n-alkanes), occurring at various stages of physicochemical and microbiological weathering. According to a number of features, the microbial community of soils is characterized by a high degree of adaptation to the conditions of the arid zone, salinity, and high pH values; at the same time, these conditions limit the development of typical representatives of soil microbiocenoses, i.e., actinomycetes and, to a greater extent, microscopic fungi. The total number of heterotrophic bacteria (HBGs) in the studied soil samples varied within 1.22–3.49 million CFU/g of soil. The proportion of oil-oxidizing bacteria (NOB) was 12.6–18.9% OBA, which corresponded to the high adaptive capacity of the community to hydrocarbons. Specific climatic conditions, features of soil composition, as well as oil with a predominance of heavy paraffin fractions of the Dzunbayan deposit, characterize the low potential ability of soils to self-purify under the oil pollution.

Dynamic modeling, optimization and exergy analysis of novel membrane reactor for enhanced olefin and pure hydrogen production via heavy paraffin dehydrogenation

Heavy paraffin dehydrogenation (HPD) is an equilibrium limited process for olefin production; therefore, selective H2 removal enhances olefin production and simultaneously produces pure H2. A hydrogen-selective membrane reactor may be utilized for this process. Sensitivity analysis reveals that reaction side inlet temperature/pressure and feed molar flow rate greatly affect the membrane reactor performance. H2 removal lowers reacting gas temperature/pressure and total molar flow rate and increases heavy paraffin (HP) consumption as well as olefins, H2, aromatics, light paraffins, and dienes production. Equilibrium shift increases rate, H2 permeation through membrane, and pure H2 production. Results of this study reveal that the average olefin production rate and selectivity in optimized membrane reactor are 14.45 and 6.24% higher than those of radial flow traditional reactor. Membrane reactor increases olefin production by 381.0 ton and produces 602.85 ton of pure H2 in a cycle. Membrane integration into the reactor does not negatively affect its exergy efficiency.

REVIEW ON POUR POINT DEPRESSANTS FOR WAXY CRUDE OIL ISSUES

Crude oil contains heavy paraffin molecules that cause the deposition of solid wax. Wax deposition is a criticalproblem in the petroleum industry, which results in various production problems. Pour Point Depressant (PPD) is a chemical additive that prevents wax deposition. PPD is employed to lower the pour point temperature allowing crude oil to flow at a significantly lower temperature. Several types of PPD include polymer, nano-composite and a natural organic compound. This review paper provides insights regarding different types of chemical additives to solve waxy crude oil issues. The effectiveness of these chemical additives is compared based on the changes in pour point value in degrees Celsius, as it is one of the physical properties of crude oil. Ultimately, this paper provides information regarding the performance of different PPDs in reducing pour point temperature to solve wax deposition issues.Keywords: Flow assurance, paraffin wax, wax deposition, mechanism of wax deposition, chemical additives, pour point depressant

Lubricant performance against white etching areas (WEAs) formation in AISI 52100 bearing steel under cyclic compressive loading

Premature bearing failures commonly occur in applications that operate under extreme boundary conditions. The lubrication engineers and tribologists are confronting a key challenge in these bearing failures associated with microstructure decay, such as White Etching Cracks (WECs) and White Etching Areas (WEAs). Lubricant degradation is one of the critical factors for the subsurface decay in the bearing steel. This work evaluates the performance of mineral oil (heavy paraffin oil) and synthetic poly alkyl glycol (PAG) against WEAs formation under pure sliding with cyclic compressive loading. The performance of lubricants was evaluated using Infrared Fourier Transform (FTIR) and Electron Spin Resonance (ESR) spectroscopy. The outcomes reveal that the free radical formation rate is higher for paraffin than PAG. This study found that WEAs formation in the bearing steel is delayed in the PAG tested samples compared to paraffin.

Computational Design of Pore Structure in Heavy Paraffin Dehydrogenation Catalyst Pellets

Computational Design of Pore Structure in Heavy Paraffin Dehydrogenation Catalyst Pellets

Hydrodynamic and axial mixing studies in asymmetric rotating impeller column at high dispersed to continuous phase ratios

In the present work, hydrodynamics characteristics such as dispersed phase holdup (εD), Sauter mean diameter (d32), drop size distribution (DSD), and continuous phase axial mixing was investigated in an asymmetric rotating impeller column (ARIC). Water – heavy normal paraffin (HNP) liquid system was used in ARIC to carry out the experiments. The effect of operating parameters such as impeller speed (N), superficial velocity of the continuous phase (Vc) was investigated. Experiments were performed at several dispersed to continuous phase (O/A) ratios. Volume displacement method and an image analysis technique were utilized to investigate the εD and d32, respectively. The pulse tracer technique was used to study the axial mixing in the continuous phase. The εD and d32 were strongly influenced by the impeller speed. More than 50% increase in εD was noticed when impeller speed increases from 100 to 350 rpm. The increase in dispersion coefficients (Dc) is observed with impeller speed. Whereas, it was noticed that O/A has a significant impact on Dc. About 80% decrease in Dc was observed when O/A increases from 5 to 25. The generalize equations have been developed for the prediction εD, d32, and Pec.

Simulation and Optimization of Industrial Reactors for Dehydrogenation of Heavy Paraffins with Different Carbon Numbers

Simulation and Optimization of Industrial Reactors for Dehydrogenation of Heavy Paraffins with Different Carbon Numbers

Solid–Liquid Equilibria for Five Binary Mixtures of Tetradecanoic Acid or Dodecanoic Acid with Three Heavy Paraffins Using DSC Measurements

Solid–liquid equilibrium (SLE) results for binary mixtures of either tetradecanoic acid (C14H28O2) or dodecanoic acid (C12H24O2) with three heavy paraffins of octadecane (C18H38), eicosane (C20H42), and docosane (C22H46) are presented in this study. The experimental measurements were conducted using differential scanning calorimetry (DSC). The experimental SLE data for five binary systems are reported and all systems show simple eutectic behavior. The fractional transformation values were determined using the heat generated during various time intervals from DSC analyses. Eutectic compositions were evaluated by plotting the eutectic fraction against composition. These experimental SLE data were correlated using the Wilson activity coefficient model, and the best-fitted binary parameters for all systems are illustrated. These novel SLE data supply useful information for the separation process or the design of phase-change materials (PCMs).

Fluid-fluid and fluid-solid phase equilibria in carbon dioxide + waxy systems 1. CO2 + n-C17

The objective of the present work is to investigate the full phase diagram of a binary system composed of carbon dioxide and a heavy paraffin. An alkane with an odd carbon number was chosen since mixtures of paraffins crystallize in the orthorhombic structure like pure odd paraffins do. The normal-heptadecane was taken into consideration for this study as it has a melting temperature close to the ambient condition (295 K). The work consists in measuring both fluid phase equilibria and fluid-solid phase transition conditions. The measurement of liquid-vapor and liquid-liquid phase transition in the temperature range 273 - 363 K has been made as well as the measurements of solid crystallization up to 70 MPa. The influence of carbon dioxide content has been studied from 0 to 99%.

Cobalt-Containing Dispersion Catalysts for Three-Phase Fischer-Tropsch Synthesis.

Nanosized catalyst dispersions have significant potential for improving hydrocarbon production from carbon monoxide and hydrogen via Fischer–Tropsch synthesis, an essential alternative to the use of petroleum as a raw material. New dispersed cobalt catalysts and dispersed-phase cobalt-based catalysts with Pd, Al2O3, or ZrO2 additives for the Fischer–Tropsch synthesis were synthesized in the present work. A dispersed cobalt phase was prepared in a heavy paraffin medium using ex situ and in situ approaches through thermal decomposition of a nitrate precursor at various temperatures. Analyses showed that an increase in the temperature for catalytic suspension formation from 215 to 260°C enlarged the particles in the dispersed phase from 190 to 264 nm, which was probably due to increased agglomeration at elevated temperatures. The rheological properties of the obtained catalytic suspensions can be described by the Bingham equation. Furthermore, the concentration of the dispersed phase had a direct impact on the structure of the entire catalytic system. Ultrafine suspensions of palladium-promoted catalytic systems were tested for the Fischer–Tropsch synthesis. The overall yield of C5+ hydrocarbons was as high as 50 g/m3, and the productivity of the Pd-promoted catalytic systems reached 270–290 g/(kgCo · h).

Enhancement of antroquinonol and antrodin C productions via in situ extractive fermentation of Antrodia camphorata S-29.

This study describes the application of in situ extractive fermentation (ISEF) to increase the yields of antroquinonol (AQ) and antrodin C (AC) from Antrodia camphorata S-29. In initial screening experiments, nine solvents were tested to identify the most suitable extractant for the in situ extraction of AQ and AC. These solvents included n-tetradecane, n-dodecane, n-decane, heavy paraffin, light paraffin, oleyl alcohol, oleic acid, butyl oleate, and isopropyl myristate. Of these, oleic acid was the most suitable solvent for the in situ extraction of AQ and AC. The use of oleic acid as an in situ extractant significantly improved AQ and AC productions, which were approximately 5-fold and 8-fold that of the control, respectively. The recovered oleic acid was treated with a silica gel solid-phase extraction column, which was able to rapidly adsorb the bioactive metabolites. The separated solvent hardly contained fermentation products and could be directly reused in ISEF. AQ and AC were obtained with purities of over 75% by silica gel column chromatography. The recoveries of AQ and AC reached 70.7 ± 0.8% and 81.5 ± 1.2%, respectively.

Evaluation of Heavy Paraffin Solvent Injection in Langgak Oil Field

LGK 14 and LGK 25 wells are oil production wells with high paraffin levels. The presence of paraffin around well perforation causes many problems. One of which is a decrease in the rate of production. It solved with rig less workover / well service (WO/WS) is an injection of heavy paraffin solvent. LGK 14 well uses sucker rod pump and LGK 25 uses an electrical submersible pump. Main steps in LGK 14 are injecting heavy parasol, soaking, displacing and producing. The other wells have differences where before the heavy parasol injecting, pump washed first. The challenges are high static bottom hole pressure (SBHP) and fluid reactions. The results show for LGK 14 well decreased oil rate from 25 BOPD to 21.77 BOPD after the heavy parasol injection. LGK 25 well increased the production rate from 21 BOPD to 29.99 BOPD.

Bulk features of catalytic co-pyrolysis of sugarcane bagasse and a hydrogen-rich waste: The case of waste heavy paraffin

In this study, catalytic and non-catalytic pyrolysis and co-pyrolysis of pretreated and intact sugarcane bagasse was investigated using waste heavy paraffin (as an in-situ supply of hydrogen). A Y-type commercial zeolite catalyst (HGY-A) which is a gasoline boosting catalyst suitable for hydrocracking reactions in oil refining was used for catalytic pyrolysis. Co-feeding of bagasse with paraffin produced higher liquid product yields and lower solid yields. The improved effective hydrogen to carbon ratio (H/Ceff) of the feedstock, and primary cracking and fragmentation reactions of heavy paraffin at temperatures around 600 °C are responsible for considerable improvement of bio-oil yield. Use of HGY-A catalyst did change the composition of the produced bio-oil; however, it did not have any appreciable impact on the bio-oil yield under various operational conditions. Results showed that acidic pretreatment of bagasse (with a 30% w/w HCl) reduced the bio-oil yield and increased the char yield.

Prediction of Wax Disappearance Temperature by Intelligent Models

It is well-known that reservoir hydrocarbon fluids contain heavy paraffins that may form solid phases of wax at low temperatures. Problems associated with wax formation and deposition are a major c...

Interplay of the adsorption of light and heavy paraffins in hydroisomerization over H-beta zeolite

Hydroisomerization: controlling selectivity by tuning the Pt/zeolite properties.

Alkane Cross-Metathesis Reaction between Light and Heavy Linear Alkanes, on a Silica Supported Well-Defined Single-Site Catalyst

Alkane cross-metathesis of light and heavy paraffins is a compelling way to upgrade two low cost streams into more valuable products, in only one step and using a single catalyst. Herein, we report the cross-metathesis reaction between light and heavy paraffins that occurs under mild conditions on a well-defined catalyst precursor [(≡SiO)W(Me)5] treated under hydrogen at 150 °C. Experiments with isotopic labeled alkanes (13C 1-propane + n decane or n-propane + C10D22) allow us to unambiguously prove the occurrence of the cross-metathesis reaction and to elucidate the plausible reaction mechanism. In order to optimize the percent cross-metathesis between propane and n-decane, we varied several parameters; in particular, the influence of the C3/C10 ratio was found to be the most important one due to the difference in the reactivity of the two components in the alkane mixtures.

“Dehydrogenation Kinetic Model of Heavy Paraffins”: Comments on the article by H. Jiang et al.

“Dehydrogenation Kinetic Model of Heavy Paraffins”: Comments on the article by H. Jiang et al.

Исследование процесса струйного размыва донных отложений в нефтяных резервуарах

Актуальность. При эксплуатации нефтяных резервуаров часто возникает проблема отложения твердых частиц и тяжелых парафинистых осадков на днище резервуара. Выпадение данных осадков влечет за собой уменьшение полезного объема резервуара, препятствует свободному перемешиванию слоев нефти, что в свою очередь способствует концентрации агрессивных растворов солей в районе днища и развитию коррозионных разрушений нефтяных резервуаров. Для предотвращения подобных ситуаций предусмотрен комплекс мер (например, ручная и механизированная очистка резервуаров с использованием горячей воды и химических реагентов), однако существенный интерес представляют устройства, препятствующие выпадению донных осадков без остановки эксплуатации резервуара, например, винтовые устройства, размывающие донные отложения с помощью турбулентной струи. Цель исследования: расчет гидродинамических характеристик турбулентной затопленной струи в резервуаре при различных температурах нефти; определение реологических параметров нефти, при которых возможно размытие донных отложений в резервуаре. Объекты исследования: конструкция винтового устройства размыва донных отложений в резервуарах с нефтью, влияние основных режимных и конструктивных характеристик винта устройства на параметры турбулентной струи, моделирование процесса гидродинамического течения нефти в замкнутом объеме резервуара. Методы: метод конечных объемов с использованием ANSYS CFX. В результате расчетов конструкций показаны зависимость скорости размыва от расстояния до винта для разных значений температур и соответствующей им вязкости нефти, показаны условия, при которых возможен размыв донных отложений в резервуаре для данной геометрии гребного винта.

Paraffin effects on the stability and precipitation of crude oil asphaltenes: Experimental onset determination and phase behavior approach

Asphaltene precipitation has been related with flow assurance problems in all the stages of crude oil production and processing. The destabilization of asphaltenes in crudes depends on temperature, pressure and composition variations. The latter variable was specifically studied in this work throughout compositional modifications of Brazilian dead oils, by adding three different paraffins on the crudes (n-hexadecane, docosane and a commercial paraffinic pool). These paraffins were firstly added in a crude oil, here named P1 (16.5 °API, 6.34 wt % asphaltenes), and the resulting modified crudes were analyzed in terms of asphaltene yield and stability using n-heptane as precipitant. Asphaltenes precipitation onset was affected by the inclusion of all the paraffins tested in the same extension; at the maximum paraffin addition of 10 wt%, onset decreases by 5 ± 1 n-heptane wt %. Similar results were verified for other two different oils P2 (17.7 °API, 6.29 wt% asphaltenes) and P3 (16.7 °API, 1.55 wt% asphaltenes). The solids obtained from the different systems were analyzed by FT-IR spectroscopy, observing that the alkyl content of the asphaltenes was not affected by the inclusion of heavy paraffins. Precipitation behavior was evaluated by using literature reported thermodynamic models based on modifications of the Regular Solution Theory. This model reproduced qualitatively the experimental precipitation behavior and the asphaltene solvency affectation by paraffin addition in the crudes.