Oil Coke Research Articles

Vacuum residue coking process simulation using molecular-level kinetic model coupled with vapor-liquid phase separation

In this work, a molecular-level kinetic model was built to simulate the vacuum residue (VR) coking process in a semi-batch laboratory-scale reaction kettle. A series of reaction rules for heavy oil coking were summarized and formulated based on the free radical reaction mechanism. Then, a large-scale molecular-level reaction network was automatically generated by applying the reaction rules on the vacuum residue molecules. In order to accurately describe the physical change of each molecule in the reactor, we coupled the molecular-level kinetic model with a vapor–liquid phase separation model. The vapor–liquid phase separation model adopted the Peng-Robinson equation of state to calculate vapor–liquid equilibrium. A separation efficiency coefficient was introduced to represent the mass transfer during the phase separation. We used six sets of experimental data under various reaction conditions to regress the model parameters. The tuned model showed that there was an excellent agreement between the calculated values and experimental data. Moreover, we investigated the effect of reaction temperature and reaction time on the product yields. After a comprehensive evaluation of the reaction temperature and reaction time, the optimal reaction condition for the vacuum residue coking was also obtained.

Inhibiting Coking of Lubricating Oil and Thermal Insulation of Bearing Chamber Wall by TCA-2 Nitride Ceramic Coating.

High temperature around the rear bearing chamber of supersonic aero-engines often causes the coking of the lubricating oil on the shaft end cover. To figure out the problem, a method using the TCA-2 nitride ceramic coating with the thickness of several micrometers is proposed. A simulation experiment method of lubricating oil coking for high-temperature parts is developed, and the anticoking performance of the samples with the coating is studied. The results showed that the TCA-2 coating inhibits the coke of lubricating oil on the metal surface within a certain temperature range by about 40.7% under the 500 °C attributed to the decrease in the surface activity of high-temperature metal and increase in the heat resistance. The TCA-2 coating also shows good compatibility with the lubricating oil since the acid value change of lubricating oil decreases after the thermal oxidation experiment. The TCA-2 coating can effectively reduce the surface temperature of the oil side.

The mechanism of ultrasonic irradiation effect on viscosity variations of heavy crude oil

Viscosity reduction of heavy oil has economic benefits and applicational value in the field. Applying viscosity reduction technology of heavy oil with ultrasound, this paper examines the influence of ultrasonic irradiation time and the addition of tetralin and ethylene glycol on viscosity reduction of heavy oil. Fourier Transform Infrared Spectrometer (FTIR) and Gas Chromatograph (GC) were used to analyze the chemical compositions and structural changes of oil samples before and after ultrasonic irradiation, and the effects of ultrasound on viscosity changes are presented. The viscosity reduction rate (VRR) was best at an irradiation time of 6 mins under the current experimental conditions, with VRR reaching more than 80%. When the irradiation time reached 12 mins, the viscosity of oil samples increased conversely. Chemical analysis reveals that the light components in the oil samples increased after the ultrasonic irradiation, indicating that the cavitation, thermal, and mechanical effects of ultrasound could play a role in breaking long chains of carbon, thus reducing the viscosity. The increase in viscosity may have been caused by a reassociation between molecules and/or the coking of heavy oil.

Sustainable production of graphene from petroleum coke using electrochemical exfoliation

Petroleum coke is a solid, carbonaceous by-product of oil refining and is normally used for heating or as an anode in aluminum and steel production. These applications contribute to carbon emissions, but here we show that petroleum coke has another potential avenue: as a precursor for graphene production. This path presents an environmentally and economically sustainable use for a low-value industrial stream. Electrochemical exfoliation is used to produce graphene nanosheets from petroleum coke, rather than graphite. The final product is separated from the unreacted material by a two-step centrifuging process. SEM and TEM images confirm that the final product contains few-layered nanosheets, and the Raman spectra confirm that the exfoliated coke product is indeed graphene. Post-annealing of this product substantially increases the electrical conductivity. This new finding holds potential for the petroleum industry to produce a value-added nanomaterial and enhance the economic impact of slurry oil and slurry oil-derived coke streams by orders of magnitude; this route also allows these streams to be directed away from high-emissions uses.

The effect of a nickel-containing catalyst on the tar carbonization process

Tar carbonization was studied in the absence or presence of the 7% Ni/CNT catalyst. It was shown that tar carbonization at a temperature of 350 °С without the catalyst leads to the formation of gaseous and liquid products and oil coke. Thermolysis products are formed via the separation of lateral hydrocarbon chains from the initial polyaromatic hydrocarbons. Gaseous products consist of С1-С6 hydrocarbons and sulfur-containing gases H2S and COS. Fractional composition of the liquid thermolysis products was studied. It was found that 50 % of the liquid products are represented by gasoline and diesel fractions. The 7% Ni/CNT catalyst was prepared by impregnation. The effect of this catalyst on the tar carbonization in the temperature range of 300–550 °С was studied. The addition of the 7% Ni/CNT catalyst to tar increased its yield and decreased the sulfur content due to partial conversion of sulfur to hydrogen sulfide and COS, which are removed with the gas phase. The electron microscopy study showed that the oil coke obtained upon catalytic tar carbonization is reinforced with carbon nanotubes.

Influential Factors and Spatiotemporal Characteristics of Carbon Intensity on Industrial Sectors in China.

Based on the extended STIRPAT model and panel data from 2005 to 2015 in 20 industrial sectors, this study investigates the influential factors of carbon intensity, including employee, industry added value, fixed-assets investment, coal consumption, and resource tax. Meanwhile, by expanding the spatial weight matrix and using the Spatial Durbin Model, we reveal the spatiotemporal characteristics of carbon intensity. The results indicate that Manufacturing of Oil Processing and Coking Processing (S7), Manufacturing of Non-metal Products (S10), Smelting and Rolling Process of Metal (S11), and Electricity, Gas, Water, Sewage Treatment, Waste and Remediation (S17) contribute most to carbon intensity in China. The carbon intensity of 20 industrial sectors presents a spatial agglomeration characteristic. Meanwhile, industry added value inhibits the carbon intensity; however, employee, coal consumption, and resource tax promote carbon intensity. Finally, coal consumption appears to have spillover effects, and the employee has an insignificant impact on the carbon intensity of industrial sectors.

Green Synthesis and Application of ZSM-5 Zeolite

A ZSM-5 molecular sieve composite with a wide pore prepared by the solid phase in-situ synthesis method and fluid catalytic cracking, and an FCC catalyst additive prepared by the same ZSM-5 molecular sieve for increasing the amount of light olefin yield were investigated. The samples were characterized by XRD, N2 adsorption/desorption, SEM, and NH3-TPD, respectively. The results showed that the structure of the ZSM-5 molecular sieve composite prepared by solid phase in-situ synthesis method was pure MFI-type zeolite material. The crystallinity of ZSM-5 molecular sieve was 59.8 wt%. The synthesized ZSM-5 molecular sieve had more acid content and a wide-pore structure. The average pore size was 5.9 nm, and BET specific surface area and micropore specific surface area of sample were 213 m2 g–1 and 124 m2 g–1, respectively. The evaluated results indicated that the FCC catalyst additive had good selectivity for LPG, propylene, and butene, increasing propylene and butene yields by 2.28 wt% and 2.15 wt%, respectively, as well as had better heavy oil cracking capability and coke selectivity.

Catalytic co-pyrolysis of polycarbonate and polyethylene/polypropylene mixtures: Promotion of oil deoxygenation and aromatic hydrocarbon formation

The co-pyrolysis of polycarbonate (PC) and polyethylene (PE)/polypropylene (PP) in the presence of HZSM-5 catalyst was studied in a two-stage tube reactor with the objective of promoting simultaneous deoxygenation and aromatic hydrocarbon formation, at atmospheric pressure and without external hydrogen addition. As the blending ratio of PE/PP increased, the yield of oil phase product, coke, and solid decreased, and the yield of gas phase increased significantly. At the blending ratio of 75% PP, the concentration of oxygenates in the oil was reduced to 2.9% and that of aromatic hydrocarbons increased to 97.1%. Increasing the reaction temperature from 500 °C to 700 °C increased the yield of aromatic hydrocarbons further to 98.1%. Catalyst regeneration decreased the acidity of the HZSM-5 catalyst, resulting in a slight decrease in the deoxygenation and aromatization effects. The results showed that PP is an effective hydrogen donor in the catalytic deoxygenation and aromatization process; the hydrogen provided enhanced the adsorption of phenols produced by the pyrolysis of PC on HZSM-5 and their direct deoxygenation to form new aromatic hydrocarbons.

Comparative study on the coking characteristics of two low-asphaltene heavy oils and their main fractions

Heavy oil coking is an important process for in situ combustion. The coking characteristics of two low-asphaltene heavy oils from Fengcheng (FC) and Hongqian (HQ) oilfields, which are different in viscosity, density, and composition, were studied in a fixed bed reaction system in pyrolysis and oxidizing atmospheres. FC heavy oil showed a 35% higher coke yield than HQ heavy oil, and the coke oxidation activity was worse, whereas the coke elemental compositions and heat values were similar for both cokes. Kinetic analysis of coke oxidation showed that both cokes from FC and HQ oils had similar activation energies, 124 kJ/mol for cokes from oil pyrolysis and 138 kJ/mol for cokes from oil oxidation, but their active site numbers are different. The coking characteristics of two oils' main fractions (saturates, aromatics, and resins) were studied and compared. In the inert atmosphere, the main coking fraction was resins with a coke yield of 17%, whereas all three fractions produced coke in the oxidizing atmosphere. The coke yields of saturates, aromatics and resins were around 7%, 25% and 57% in oxidizing atmosphere, respectively. There was a small difference in the coke yields of the same fraction from the two heavy oils. Saturates and aromatics from the FC heavy oil showed a 20–30% higher coke yield than the same fractions from HQ oil because of the different contents of low-boiling-point components. After removing the influence of low-boiling-point components, the coke yield of the heavy oil could be predicted by a weighted average method based on the main fraction contents and their coke yields. Upon comparing the coke produced by different fractions, the coke from saturates showed better oxidation activity than that from aromatics and resins. The oxidation activities of coke produced by FC aromatics, HQ aromatics, and HQ resins were similar, but that of coke produced by the FC resins was worse. FC oil coke was less reactive than HQ oil coke probably due to the high resin content of FC heavy oil and the low oxidation activity of the coke from its resins.

Influence of Parameters of Delayed Coking Process and Subsequent Calculation on the Properties and Morphology of Petroleum Needle Coke from Decant Oil Mixture of West Siberian Oil

This paper includes the results of studies of the temperature effect in the range of 480–510 °C at an excess pressure of 0.35 MPa, as well as the effect of excess pressure from 0.15 to 0.55 MPa at a temperature of 500–510 °C, during the delayed coking of a decant oil obtained from a mixture of West Siberian oils and subsequent calcination in an inert atmosphere of nitrogen at 1100 °C on the microstructure and properties of the needle coke. Properties such as absolute density, volatile-matter yield, ash, sulfur, and trace element contents were analyzed to evaluate the quality of the “green” and calcined coke. The microstructure of the obtained coke was analyzed by means of X-ray diffraction, for which the evaluation criteria were the interplanar spaces d002 and d100, as well as the crystallite sizes Lc and La. The scanning electron microscopy method was used to confirm the results of the formed structure of petroleum coke analysis obtained earlier. The calcined samples were assigned to needle cokes with stringy-circular flow domain anisotropy.

Analysis of Numerical Simulation on Combustion of Different Fuels in Float Glass Furnace

The feasibility and reliability of numerical simulation model and calculation method are verified by comparing the simulation results with the relevant data collected during the operation of the furnace in the actual plant. Under the condition of constant thermal power of the furnace, the combustion status, temperature distribution and nitrogen oxides formation in combustion space of the furnace are simulated and studied when the fuel is heavy oil and petroleum coke respectively. The study found that large-scale transverse circumfluence is formed in the refining zone in the back of the furnace and the temperature system is stable and consistent whether the fuel is heavy oil or petroleum coke. When the fuel is petroleum coke, the combustion in the furnace is more intense and the temperature of the batch is higher, but the crown is eroded more strongly by high temperature flow. When the fuel is heavy oil, the scope of the high temperature zone whose temperature is higher than 2073K is wider, and the temperature of the glass level and the crown in the furnace is slightly higher, but the production of nitrogen oxides with burning heavy oil is much more than that of burning petroleum coke.

Flow Field Characteristics in the Combustion Space of a Float Glass Furnace with Co-combustion of Heavy Oil and Petroleum Coke

A numerical simulation was carried out for the combustion space of a float glass furnace in which the heavy oil and petroleum coke were co-fired. The characteristics of gas flow in the combustion space and its influence on the temperature distribution were analyzed. The research shows that after the combustion air coming from inlet 2 to inlet 6 respectively enters the flame space, it flows toward the outlet, and forms a relatively straight “flame” after the fuel is completely burned, eventually forming five high-temperature zones with wide coverage; when the flue gas generated by the combustion reaches the outlet, a part of the flue gas from inlet 2 to inlet 4 is deflected to the left, and a recirculation zone is formed above the batch material zone at the left end, and the O2 is diluted, so that the fuel at No. 2 zone is not sufficiently burned, resulting in a temperature region being significantly lower than other regions; A part of the flue gas at No. 5 and No. 6 is deflected to the right, forming a recirculation zone above the clarification zone at the right end, so that the combustion at No. 7 is insufficient, resulting in a lower temperature zone at that place, but the influence is weaker than that at No. 1, so the temperature peak at No. 7 is slightly higher than that at No. 1.

Unraveling economic and environmental implications of cutting overcapacity of industries: A city-level empirical simulation with input-output approach

On a way towards transition to greener and more intensive development patterns, many Chinese cities are ambitiously prompting cutting overcapacity as a primary task of supply-side reform. However, the impacts of cutting overcapacity of industries on economic development and environmental quality still remain unrevealed clearly. In this study, a dynamic input-output simulation model is developed by integrating supply and demand balances of material and value with industrial capacity and applied to Tangshan City, which is typically implementing cutting overcapacity against four key sectors (oil processing and coking, cement, iron and steel, and power and heat). Three scenarios are set for analyzing changes in capacity and pollutant (SO2, NOx and particulate matter) emission mitigation during 2017–2025 through mutual comparisons. Changes in capacity of four key sectors as well as gross regional product are simulated. Industrial structure will be reshaped with most notable changes in service industry and iron and steel industry. Critical industrial chains are traced for manifesting to what extent cutting overcapacity will influence the sectors closely interacted with the key sectors. Remarkable mitigation of emissions and concentration contribution can be contributed by cutting overcapacity with accumulative mitigated emissions of the pollutants as 0.48, 1.09 and 0.79 Mt, respectively. As a first attempt on combining input-output analysis with research on industrial capacity and on investigating environmental impacts of cutting overcapacity, this study is expected to provide reference to pertinent policy-making with regard to sound capacity regulation of industries.

THE CURRENT STATE OF RESOURCE AND ENERGY SAVING IN THE TECHNOLOGY OF PRODUCTION OF CARBON-BASED FILLER OF ELECTRODE PRODUCTS (REVIEW)

Advantages of application of electrocalciners to production of carboniferous fillers of the electrode industry are considered. The analysis of designs of electrocalciners is made, their advantages and disadvantages are given, and also the physical processes happening in them are described. The critical analysis of theoretical and experimental methods of research of physical processes at heat treatment of carboniferous materials in electric furnaces is carried out. It is shown that for development of resource-power effective technical solutions on modernization of the production technology of fillers in electrocalciner it is expedient to combine methods of mathematical modeling with separate pilot studies on the industrial equipment. It is shown that industrial using of resource-power effective technical solutions on modernization of the production technology of fillers in electrocalciner allows to receive the following indicators of efficiency: for anthracite calcinating electrocalciners the resource of work increased from 1 month to 6 months, and specific expenses of the electric power decreased by (50–100) kW·h/t; for graphitizing of oil coke electrocalciners the resource of work increased from 2 days till 1 year, and specific expenses of the electric power decreased more than by 1600 kW·h/t in comparison with classical technology. Bibl. 37, Fig. 7, Tabl 1.

An efficient method of foundry and metallurgical coke quality improvement

At foundry coke production, introduction into a coal burden comparatively small amount of non-sintering carbonaceous additives is one of effective methods of the coke mechanical, physical and chemical properties intended control. A review of industrial tests on coal burdens coking with different thinning additives, carried out at coking plants of Western Siberia and the Urals, presented. Coke dust of coke dry quenching facility was used as additives, as well as oil-coke and semi-coke fines, and rubber crumb. Under industrial conditions of JSC “Altaj-koks” and JSC “Koks” coke dust of coke dry quenching facility was tested as a thinning additive. After introduction into the burden of 1.6–3.0% of coke dry quenching facility dust, the coarseness and mechanical strength of foundry coke increased. The industrial burden coking with oil-coke fines was accomplished at JSC “Altajkoks” Nos 1 and 2 coke-oven batteries. Oil-coke fines in the amount of 5% was added to a burden (у = 15–16 mm) without change of coking regime (the period of coking is 15–16 h). Strength of foundry coke (М40) increased by average 0.5%, of BF coke – by 1.2%, ash content decreased by 0.3%, sulfur content increased by 0.03–0.06%, reaction ability decreased by 19% (rel.). At the OJSC “Gubakhinsky koks” it was determined by industrial tests, that it is possible to produce a metallurgical coke, meeting requirements of non-ferrous metallurgy, providing up to 5% of oil-coke fines are added instead of the same amount of low-sintering coals. VUKHIN’ studies showed, that still higher effect in improving foundry and BF coke quality can be reached by introducing into the coal burdens “modified” oil coke up to 50% as a coking additive. During industrial tests at JSC “Altaj-koks” semi-coke fines were introduced into production burden instead of KCH coal in the amount of 3–7%. At its utilization a burden crushing degree decreased down to 76.5%, dust content (class 0.5–0 mm) decreased down to 39.1%, its bulk density increased up to 780 kg/m3 . At that the coke mechanical strength corresponds to that for coke made of industrial burden, and its coarseness increased. Results of successful industrial tests of foundry coke made of burdens with coke dry quenching facility dust and oil coke fines at smelting in cupola gray cast iron and malleable cast iron.

Modeling and Design Improvement of a Scrubber for Cooling of Flue Gas During Combustion of Fuel Oil and Petroleum Coke at Thermal Power Plants

Scrubber operations were studied using the Flow Vision software system, which made it possible to obtain a picture of the distribution of velocity, temperature, and pressure fields of the flue gas inside the scrubber, and estimate the operation of the gas distributors and intake equipment based on the standard deviation of the modulus of the axial speed. Based on the analysis that was conducted, design changes were adopted that are based on the design of flue gas cooling scrubber by refinement of the ammonia-sulfate desulfurization process.

Оценка влияния методики калькулирования себестоимости продукции нефтепереработки на цену нефтяного кокса

В статье рассматривается проблема определения себестоимости и цены нефтяного кокса, получаемого в процессе замедленного коксования, за счет применения действующей методики калькулирования себестоимости продукции в нефтеперерабатывающей промышленности.

Fast three-dimensional heat transfer model for computing internal temperatures in the bearing housing of automotive turbochargers

Each of the elements that make up the turbocharger has been gradually improved. In order to ensure that the system does not experience any mechanical failures or loss of efficiency, it is important to study which engine-operating conditions could produce the highest failing rate. Common failing conditions in turbochargers are mostly achieved due to oil contamination and high temperatures in the bearing system. Thermal management becomes increasingly important for the required engine performance. Therefore, it has become necessary to have accurate temperature and heat transfer models. Most thermal design and analysis codes need data for validation; often the data available fall outside the range of conditions the engine experiences in reality leading to the need to interpolate and extrapolate disproportionately. This article presents a fast three-dimensional heat transfer model for computing internal temperatures in the central housing for non-water cooled turbochargers and its direct validation with experimental data at different engine-operating conditions of speed and load. The presented model allows a detailed study of the temperature rise of the central housing, lubrication channels, and maximum level of temperature at different points of the bearing system of an automotive turbocharger. It will let to evaluate thermal damage done to the system itself and influences on the working fluid temperatures, which leads to oil coke formation that can affect the performance of the engine. Thermal heat transfer properties obtained from this model can be used to feed and improve a radial lumped model of heat transfer that predicts only local internal temperatures. Model validation is illustrated, and finally, the main results are discussed.

Design and dispatch optimization of a solid-oxide fuel cell assembly for unconventional oil and gas production

This paper presents design and dispatch optimization models of a solid-oxide fuel cell (SOFC) assembly for unconventional oil and gas production. Fuel cells are galvanic cells which electrochemically convert hydrocarbon-based fuels to electricity. The Geothermic Fuel Cell (GFC) concept involves utilizing heat from fuel cells during electricity generation to provide thermal energy required to pyrolyze kerogen into a mixture of oil, hydrocarbon gas and carbon-rich shale coke. We formulate a continuous, non-convex nonlinear program (NLP) in A Mathematical Programming Language (AMPL) to analyze the techno-economic characteristics of the GFC system. The problem is separated into a design model $$({{\mathcal {D}}})$$ and a dispatch model $$({{\mathcal {O}}})$$ . The GFC design problem determines the size and configuration of a single heater well. Specifically, we optimize the heater length and number of SOFC stacks in each assembly such that the maximum volume of oil shale is heated per well. Using the resulting design from $$({{\mathcal {D}}})$$ , the dispatch model $$({{\mathcal {O}}})$$ determines daily GFC operating conditions through variation in electric current, fuel utilization, and stoics of excess air. We optimize the system operating costs and the combined-heat-and-power efficiency, subject to geology heating demands, auxiliary component electric power demands and GFC system performance characteristics. Solutions to the design and dispatch problems are obtained using the IPOPT and KNITRO solvers. A case study shows that the optimal well-head cost of oil and gas produced using the GFC technology is about $39 bbl $$^{-1}$$ , which is comparable to that from other unconventional crude oil extraction techniques. The optimal dispatch strategy results in a maximum heating efficiency of 43% and a combined-heat-and-power efficiency of 79%. The Geothermic Fuel Cell’s performance is better than current in situ upgrading technologies that rely on electricity supplied from the grid at generation-and-transmission efficiencies near 33%.

On the possibility of carbonaceous dust waste use of prebaked anode production in silicon metallurgy

During the prebaked anodes production used in aluminium electrometallurgy a considerable amount of fine-dispersed waste with a carbon content of more than 90% is formed. Analytical studies of the waste properties such as chemical, particle size analysis, moisture content and some others have been conducted. Electro-paramagnetic resonance (EPR) method was used to study the structures of charcoal, oil coke and a sample of carbon-containing dust from mixing and pressing compartment of aspiration equipment. EPR results showed that the studied sample is similar in structure to natural traditional reductants (its EPR spectrum has a pronounced narrow Gaussian signal). This indirectly shows its satisfactory reactivity and can be recommended as an additive (in pelletized form) to the charge for the silicon production