Distillation Range Research Articles

A Rapid Analysis Method for Determination of Hydrocarbon Types in Aviation Turbine Fuel by Gas Chromatography-Mass Spectrometry.

A rapid analysis method for determination of hydrocarbon types in aviation turbine fuel was investigated in this study. A kind of reversible adsorption material packed as an unsaturated trap was used to separate saturated hydrocarbons and unsaturated hydrocarbons in the GC-MS system. No manual process or organic reagent was needed during the entire analysis process. The contents of 13 kinds of hydrocarbons, including paraffins, monocycloparaffins, dicycloparaffins, tricycloparaffins, monoolefins, cycloolefins, alkylbenzenes, CnH2n-8 aromatics, CnH2n-10 aromatics, naphthalenes, CnH2n-14 aromatics, CnH2n-16 aromatics, and CnH2n-18 aromatics were calculated by the characteristic mass fragments detected by MS with the modified matrices of ASTM D2425. The overall analysis time was less than 10 min. The precision of this test method has been conducted with 8 laboratories attended and 16 samples analyzed. The performance of this new method was demonstrated by comparing the results tested by ASTM D1319, ASTM D2425, and ASTM D6379. This rapid analysis method can provide hydrocarbon compositions of aviation turbine fuels or other liquid hydrocarbon samples within the same distillation range.

Wax Deposition of Diesel Oil and Consequent Contamination of Gasoline in Sequential Transportation of Product Oil Pipeline

Wax deposition of diesel oil and contamination of gasoline by diesel wax deposit is a severe problem in sequential transportation of product oil in pipes. However, it has long been neglected by the pipeline transportation industry. In response, this work aims to present a unique perspective on wax deposition of diesel oil and consequent contamination of gasoline. A cold finger apparatus was designed and constructed. Model oil composed of diesel and refined wax was prepared for wax deposition. Shear dispersion was excluded for wax deposition of diesel oil. Moreover, dissolution experiments of diesel wax deposit in gasoline were conducted. It was found that the dissolution rate increases with oil temperature and decreases with cold finger temperature and shear stress. Analysis on gasoline quality after diesel wax deposit dissolution indicated that contamination of gasoline caused by diesel wax deposit severely deteriorates its distillation range, but the octane number remains acceptable. This work features an interesting investigation on the wax-deposition mechanism of diesel oil, dissolution characteristics of diesel wax deposit, as well as quality deterioration of subsequent gasoline. It would be helpful in scheduling a product oil-transportation program.

Properties That Potentially Limit High-Level Blends of Biomass-Based Diesel Fuel.

While today's biomass-based diesel fuels are used at relatively low blend levels in petroleum diesel, decarbonization of the heavy-duty trucking and off-road sectors is driving increasing use of higher level blends and the combination of hydroprocessing-derived renewable diesel (RD) with biodiesel (fatty acid methyl esters) to create a 100% renewable fuel. However, little data are available on the properties of biodiesel blends over 20 vol % into RD or conventional diesel, despite the potential for properties to fall well outside the normal range for diesel fuels. Here, we evaluate the properties of 20-80% blends of a soy-derived biodiesel into RD and petroleum diesel. Properties measured were flash point, cloud point, cetane number, surface tension, density, kinematic viscosity, distillation curve, lower heating value, water content, water solubility in the fuel, lubricity, and oxidation stability. Density and viscosity were measured over a wide temperature range. A key objective was to reveal properties that might limit blending of biodiesel and any differences between biodiesel blends into RD versus petroleum diesel and to understand research needed to advance the use of high-level blends and 100% renewable fuel. Properties that may limit blending include the cloud point, viscosity, distillation curve, and oxidation stability. Meeting cloud point requirements can be an issue for all distillate fuels. For biodiesel, reducing the blend level and use of lower cloud point hydrocarbon blendstocks, such as No. 1 diesel or kerosene, can be used in winter months. Alternatively, a heated fuel system that allows for starting the vehicle on conventional diesel before switching to pure biodiesel (B100) or a high-level blend has been successfully demonstrated in the literature. Some biodiesels can have kinematic viscosity above the upper limit for diesel fuels (4.1 mm2/s), which will limit the amount that can be blended. Biodiesel boils in a narrow range at the very high end of the No. 2 diesel range. Additional research is needed to understand how the high T90 of B100 and high-level blends and the very low distillation range of B100, some RD samples, and high-level biodiesel blends impact lube oil dilution, engine deposits, and diesel oxidation catalyst light-off. Blending with No. 1 diesel or kerosene or biodiesel-specific engine calibrations may mitigate these issues. Oxidation stability of higher level blends is poorly understood but may be addressed through the increased use of antioxidant additives. Finally, high-level biodiesel blends and B100 will have significantly higher density, viscosity, and surface tension compared to conventional diesel. In combination with the high boiling point, these properties may impact fuel spray atomization and evaporation, and additional research is needed in this area.

Steady‐state and dynamic control of hydrocracking tail oil distillation process for high‐valued products

AbstractThe maximum utilization of hydrocracking tail oil becomes increasingly important for petrochemical industry. The aim of this work is to develop optimized distillation processes to achieve various high‐valued qualified oil products from hydrocracking tail oil. Six different oil products is produced and the steady‐state distillation process, which aims to fractionate six qualified narrow distillates is established. The algorithm method incorporating divided‐wall column (DWC) configuration was introduced into the steady‐state design. Compared with traditional separation sequences, the DWC configuration leads to an energy‐saving potential up to 11.17%. Furthermore, effective dynamic control strategies were proposed, demonstrating precise and efficient control performance. In the presence of a 15% feed disturbance, the dynamic control structure is capable of maintaining the product distillation range near the set value. This comprehensive study provides a thorough investigation into the efficient utilization of hydrocracking tail oil, establishing a robust theoretical foundation for its industrial application.

Catalytic pyrolysis of vegetable oils over NbOPO4 for SAF and green diesel production

Drop-in biofuels for aviation have been pointed out as a sustainable alternative for reducing the emission of greenhouse gases. These fuels are hydrocarbons and have a performance and composition similar to fossil fuels. Developing conversion routes for their production has stimulated different research projects and is considered one of the most challenging areas in biofuels research. In the present study, the liquid phase was analyzed and the biohydrocarbons were obtained from vegetable oils in the distillation range of gasoline, diesel, and aviation kerosene using NbOPO4 as a catalyst in the pyrolysis process. This catalyst was characterized by XRD and gas adsorption/desorption methods (BET, BJH, and TPD). The fatty materials' simultaneous deoxygenation, cracking, and partial isomerization reactions were performed at 350 °C under N2 atmosphere (10 bar), with up to 95% conversions. Considering the overlap of carbon chains in the fuel ranges, this study demonstrates that it is possible to obtain up to 21%, 83%, and 80% of biogasoline, Sustainable Aviation Fuel (SAF), and green diesel, respectively. The products were characterized by infrared spectroscopy and gas chromatography coupled with mass spectrometry. The freezing temperatures of the products without any purification treatment and their mixtures with fossil kerosene were measured by DSC. The SAF obtained after the distillation step, presented a freezing point of − 47 °C, in agreement with the standard ASTM 7566. This innovative, sustainable, and low-cost process is promising for industrial use, mainly because hydrogen was not used, and reactions were performed in a one-pot procedure.

Defect detection method for key area guided transmission line components based on knowledge distillation

Introduction: The aim of this paper is to address the problem of the limited number of defect images for both metal tools and insulators, as well as the small range of defect features.Methods: A defect detection method for key area-guided transmission line components based on knowledge distillation is proposed. First, the PGW (Prediction-Guided Weighting) module is introduced to improve the foreground target distillation region, and the distillation range is precisely concentrated in the position of the first k feature pixels with the highest quality score in the form of a mask. The feature knowledge of defects of hardware and insulators is used as the focus for the teacher network to guide the student network. Then, the GcBlock module is used to capture the relationship between the target defects of the hardware and the transmission lines in the background, and the overall relationship information of the image is used to promote the students’ network to learn the teacher’s network perception ability of the relationship information. Finally, the classification task mask and regression task mask generated by the PGW module, combined with the overall image relationship loss, form a distillation loss function for network training to improve the accuracy of students’ network detection accuracy.Results and Discussion: The effectiveness of the proposed method is verified by using self-build metal fittings and insulator defect data sets. The experimental results show that the student network mAP_50 (Mean Average Precision at 50) in the Faster R-CNN model with the knowledge distillation algorithm added in this paper increases by 8.44%, and the RetinaNet model increases by 2.6%. The Cascade R-CNN model improved by 5.28%.

Development of a Skeletal Mechanism of a Four-Component Diesel Surrogate Fuel Using the Decoupling Method.

Alkylcyclohexanes with a long alkyl chain account for more than 30% of diesel fuel but seldom used in the oxidation mechanism of diesel surrogate fuel due to the lack of a reduced skeletal mechanism. Hence, a four-component diesel surrogate fuel was developed with n-butylcyclohexane (NBCH) as the representative of alkylcyclohexanes with a long alkyl chain in real diesel. The surrogate fuel can reproduce the physicochemical characteristics of real diesel, especially the distillation range. The reduced mechanism of NBCH was developed, and the skeletal mechanism of the surrogate fuel was formulated including 80 species and 251 reactions based on the decoupling method. The mechanism was validated under a wide range of conditions with the experimental results of ignition delay time (IDT), laminar flame speed, and species concentrations of both pure components and diesel. The accuracy of the mechanism on the spray and ignition performance was further validated against the experimental data obtained in a constant volume combustion chamber system. The calculated results showed a satisfactory agreement, in which the maximum error of flame lift-off length is 7.82 mm and that of IDTs is 0.16 ms. It was proven that the mechanism is suitable to reproduce the physicochemical properties of diesel and further predict the diesel spray and ignition performance.

Maximizing Sustainable aviation fuel usage through optimization of distillation cut points and blending

Sustainable aviation fuel pathways do not generally yield selective synthetic blend components in the aviation turbine fuel distillation range. Here we discuss a methodology for maximizing the sustainable aviation fuel yield from a pathway and the respective blend ratio with a petroleum-derived fuel by varying distillation cut points. These cut points are typically unique for each combination of feedstock and conversion technology and are essential independent variables for fuel finishing. The resultant cut point variations create a Pareto front, illuminating a competition between yield and blend ratio limits, i.e., the boundary where key operability properties are on the specification limit. Computational and experimental examples are given herein. In the computational case, eight bulk properties are calculated for a surrogate composition to simultaneously predict the competition between distillation yield and blend limit, with 10 points along the Pareto front experimentally verified. In the experimental optimization example, this methodology has been applied to an actual product stream currently under development. Relative to a third-party distillation cut recommendation, the method here yielded 37 %v more renewable carbon into the SAF fraction, while also affording a greater margin to property specification limits. This article shares the optimization process which can impact SAF qualification, the relative corresponding diesel and gasoline fractions, and business strategy.

Structural characterization and transformation of nitrogen compounds in waste tire pyrolysis oils

The waste tire pyrolysis oil (WTPO) has been widely concerned because it's a promising recycling method of waste tires. However, the high content of nitrogen in WTPO is unfavorable to its application. In this work, nitrogen compounds in the full distillation range of a waste tire pyrolysis oil were characterized by gas chromatograph-nitrogen chemiluminescence detector (GC–NCD), gas chromatograph-mass spectrometry (GC–MS) and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). In the gasoline fraction of WTPO, the most abundant nitrogen compounds were benzonitrile, aniline and small molecule nitriles. In the diesel fraction of WTPO, the most abundant nitrogen compounds were benzothiazole, quinoline derivatives, p-phthalodinitrile, benzonitrile derivatives, hexadecanenitrile and octadecanenitrile. In the heavy fraction of WTPO, significant amounts of NxOy (x = 2–3 and y = 1–2) species were discovered after the separation of solvent dissolution and solid phase extraction. The molecular structures of these NxOy species were determined as amide derivatives of diphenylamine by tandem mass spectra of FT-ICR MS. Therefore, the origin of nitriles in the light fractions of WTPO was suspected as the pyrolysis of these amides in the heavy fractions. Finally, the nitrogen transformation during the pyrolysis of waste tires was suggested based on the results of quantum chemistry simulations. These results would be helpful for the treatment and removal of these undesirable nitrogen compounds in WTPO.

Properties of narrow cuts of hydrocracked kerosene for jet fuel

Hydrocracked kerosene represents an additional source of jet fuel in oil refineries. The objective of this study was to re-distill hydrocracked kerosene (distillation range of 155-211 °C) into narrow cuts (distillation range of 10 °C) and to determine the dependence of the critical parameters of jet fuel, i.e., density, aromatics, smoke, and freezing point on the mean boiling point (tmean) of these cuts, utilizing modern and well established analytical methods. Re-distillation yielded seven narrow cuts composed of hydrocarbons with maximally three different carbon numbers. The analyzed properties deteriorated significantly with increasing tmean of cuts. Already the cuts with tmean of 190 °C + did not meet the jet fuel specification for aromatics and the 210 °C + cut did not meet any of the studied properties. Aromatics were crucial in controlling the distillation range and this provided an explanation for why hydrocracked jet fuel can be produced only as a narrow fraction. Since a low freezing point characterized all narrow cuts, this property represents a crucial synergy of blending of the hydrocracked kerosene with a straight-run kerosene or SAF. Overall, we demonstrated that narrow-cut research provides new insights into the characteristics of the hydrocracked kerosene.

Relationship between aromatic hydrogen and aromatic carbon in straight run and converted oils

In the conversion of high boiling oil fractions, it is difficult to track compositional changes that affect the chemical nature of species. For reaction engineering, monitoring changes related to hydrogen transfer reactions and formation of aromatic species as thermal conversion progresses to coking is useful. Proton and carbon-13 nuclear magnetic resonance (1H and 13C NMR) spectrometry can measure the aromatic hydrogen and aromatic carbon content in oils of diverse origin and distillation range. 13C NMR analyses are more time consuming than 1H NMR analyses. The ability to calculate the aromatic carbon content of oils directly from measured aromatic hydrogen content is alluring and is reportedly feasible (Cookson, et al. Fuel 1986; 65:1247–1253). In this work previously reported 1H and 13C NMR data for different petroleum and coal derived oils were collated and supplemented with experimental measurements that included narrow cuts of straight run and refined oils, as well as bitumen-derived mixtures that were thermally converted at different levels of severity. It was found that aromatic carbon content, CAr, was only broadly related to aromatic hydrogen content, HAr. A wide range of values for CAr was possible for a specific value of HAr. The medium atmospheric equivalent boiling point temperature, T50, was a poor descriptor for indicating a directional change in the relationship between CAr and HAr, both for wide and narrow boiling range distillation fractions. An increase in heterocyclic aromatic content caused a decrease in the (H/C)Ar ratio, since heteroatoms in aromatics are mainly found in ring-edge and not in ring-junction positions. When the changes in HAr and CAr of different bitumen-derived materials with respect to thermal conversion severity were evaluated, it was found that changes in HAr and CAr were not in a fixed relation to each other.

Physicochemical characterization of levulinate esters with different alkyl chain lengths blended with fuel

AbstractDue to the advantages of cellulosic biomass, such as abundant reserves, renewable, and wide sources, the large‐scale development of lignocellulosic biomass fuels has the advantage of relieving energy pressure and promoting energy conservation and emission reduction, of which the levulinate esters are a potential biomass liquid fuel. In this study, different alkyl chain lengths of the levulinate esters were blended with 0# fossil diesel, and the physicochemical properties of the blended fuels, such as mutual solubility, density, distillation range, closed flash point, kinematic viscosity, cold filter plugging point, oxidation stability, and sulfur content and other physical and chemical properties were tested and investigated. The results showed that the longer the alkyl chains of the levulinate esters, the better their stability when mixed with 0# petrochemical diesel. And levulinate esters with short alkyl chains can be easily separated from blended fuels at low temperatures. The physicochemical properties of the blended fuels improved significantly with the increase of carbon chain length and levulinate esters content, low‐temperature flow characteristics, atomization characteristics of spraying, and safety of transportation and storage, and the physicochemical properties of levulinate blended fuels with long alkyl chains were more superior than shorter alkyl chains of the levulinate esters.

Combustion and emission characteristics of diesel with different distillation ranges on the China-VI diesel engine

In this study, hydrocarbon compositions of two types of diesel with different distillation range indexes T90 and T95 were analyzed by gas chromatography-mass spectrometry combined with gas chromatography-field ionization-time of flight mass spectrometry (GC-FI TOF MS), to evaluate the effect on the combustion characteristics and exhaust emissions of three diesel engines. The diesel featured by lower T90 and T95 can improve diesel volatilization performance, shorten the ignition delay time and increase the engine combustion efficiency. The BSFC can be reduced by 0.7%, and the CO2 emission can be reduced by 0.69% (WHTC), and 0.94% (WHSC), respectively, as the increasing low carbon numbers of alkane (C8-C20), monocyclic cycloalkane (C7-C16), bicyclic cycloalkane (C9-C15) and tricyclic cycloalkane (C10-C19) and the decreasing of heavy components such as indane, indene, naphthalene, biphenyl, phenanthrene, etc. The diesel with lower T90 and T95 can reduce the original NOx emissions and the exhaust temperature after the vortex, then decrease the combustion temperature in the cylinder. Finally, tailpipe outlet NOx emissions of the China-VI diesel engine decreased by 7.64% (WHTC) and 12.93% (WHSC), respectively. Besides, the diesel with lower T90 and T95 can reduce the content of PAHs with π bonds, and generate a more uniform fuel–air mixture in the cylinder, thus achieving emission reduction of PM by 14.58% (WHTC) and 37.31% (WHSC), and PN reduction by 25.74% (WHTC) and 14.09% (WHSC), respectively.

Catalytic pyrolysis of holocellulose followed by integrated aldol condensation and hydrogenation to produce aviation fuel

The carbonyl platform compound from the catalytic pyrolysis of holocellulose was employed for the integrated aldol condensation and hydrogenation to produce hydrocarbons in the range of jet fuel. By the carbonylation of the pyrolysis vapor from holocellulose prepared from rape straw, bagasse and poplar (RS-Holo, BG-Holo and PL-Holo), it was revealed that BG-Holo rich in cellulose as the raw material presented the most production of carbonyl compounds including aldehydes and ketones. The optimal temperature for carbonylation of pyrolysis vapor from holocellulose was determined to be 400 °C, with the maximized carbon yield of carbonyls reaching 46.11%, which was boosted to the summit of 53.59% with more addition of ZrO2 catalyst. The integrated aldol condensation and hydrogenation were carried out using the catalytic pyrolysis bio-oil as the reactant over Ni/Mg-Al-O/AC bifunctional catalyst, with the highest carbon yield of hydrocarbons reaching 78.11%. The production mechanism of the final targeted alkanes was speculated, and it was discovered that ketones and aldehydes with short carbon chains are more prone to secondary condensation than those with long carbon chains, resulting in high-energy–density aviation fuel. Furthermore, the heating value of final oil was calculated based on an empirical formula, which was comparable to that of Jet A, meeting the standard of ASTM7566. The final oil’s distillation range distribution was simulated, and most of it fell in the range of aviation fuel. In this study, catalytic fast pyrolysis of holocellulose followed by integrated aldol condensation and hydrogenation was proved to be a promising way for producing aviation fuel.

Effects of Diesel Hydrocarbon Components on Cetane Number and Engine Combustion and Emission Characteristics

Commercial diesel consists of hundreds of hydrocarbons such as alkanes, cycloalkanes, and aromatics. The components of the fuel’s composition are what determine its physical and ignition properties, and their variations affect engine performance. In this study, n-heptane, n-dodecane, tetralin, and decalin were chosen as typical additives to blend with commercial diesel according to the China VI standard (Heavy Duty Diesel Vehicle Pollutant Emission Limits and Measurement Methods) in 20% and 50% volume fractions, respectively. The physical properties of the fuel blends, such as viscosity, density, cetane number (CN), and distillation range, were measured first. Then, the commercial diesel’s lower heat value was measured, and blended fuels were calculated accordingly. The CN of the blended fuel is tested by an Ignition Quality Tester (IQT), which is known as the derived cetane number (DCN). The results show that adding n-dodecane increases the value of DCN, while tetralin reduces the DCN, and n-heptane and decalin have negative effects. This study uses a type of WP12 diesel engine made by Weichai that meets China’s emission regulation 6. During the tests, the fuel injection strategy was kept as a pure diesel operation without any modifications. Compared with pure diesel operation, the bench test results show the following characteristics: the maximum torque output increased with increased decalin, followed by tetralin and n-dodecane, while n-heptane has a side effect compared to pure diesel operation. The addition of n-dodecane and n-heptane can reduce fuel consumption, while tetralin will increase it, and decalin has no obvious effect on fuel consumption. It was found that n-heptane increases HC and NOx emissions significantly. Furthermore, n-dodecane slightly increases CO, HC and NOx emissions. Decalin increases CO and HC emissions when mixed in a large proportion. In addition, tetralin causes a substantial increase in HC, CO and NOx emissions at medium and high loads.

PRODUCTION OF GASOLINE COMPONENTS IN ASEAN REFINERIES AND EFFECTS OF THE STRICTER FUEL QUALITY REQUIREMENT

Intensive implementation of the blue sky program in many countries imposed the use of reformulated gasoline with a very sophisticated specification. Motor gasoline is essentially a complex mixture of hydrocarbons distilled between 40 and 220 C, which consist of distillate fraction of crude oils and the conversion products of crude oil fractions. Small amounts of additives are also used to enhance various aspects of the performance of gasoline. In ASEAN refineries, over 740 MBPSD of feed- stock is processed which produce about 512 MBPSD of gasoline components. About 96 percent of the amount is processed in 39 units of the heterogeneous catalytic processes: i.e. cracking. reforming and isomerization, and the other 4 percent in 4 units of homogeneous catalytic processes: L.e. alkylation and polymerization. Volatility, octane number, hydroegtys4 com: position and impurity content are the most determinant criteria of the gasoline. In most spark-ignition internal combustion engines, the fuel is metered in liquid form through the carburettor or fuel injector, and is mixed with air and partially vaporized before entering the cylinders of the engine. Consequently. volatility, is and extremely important characteristic with respect to starting, driveability, vapor lock, dilution of engine oil fuel economy, and carburettor icing. To increase the octane level of gasoline an anti knock agent such as tetraethyl lead (TEL) or tetramethyl lead (TML) can also be used. Pres- sures to reduce atmospheric pollution are tending towards the reduction or elimination of lead from gasoline. Lead itself is known to be a poison and its presence in the exhaust gas is undesirable. Leudacts as a catalyst poison of catalytic converter installed to reduce carbon monaxide and hydrocarbon emission. Methyl tertiary butyl ether (MTBE) is one of the alternative to replace lead alkyls, and has been used as antiknock. Unleaded gasoline (ULG) has been introduced since 1990 in ASEAN Countries: The actual penetration of ULG utilization in the first half of 1998 are as follows : Brunei Darussalam 48.9 , Indonesia 0.6 %. Malaysia 80 %, Philippines 17.7 %, Singapore 81 %. and Thailand 100%. The passage of the Clean Air Act Amendment of 1990 in the USA has forced American refiners to install new facilities to comply with stricter specifications for fuels such as gasoline and diesel oil. Various terms in the models address quality of the gasoline blended, sulfur content, and total aromatics and olefins contents, RVP, the Tof distillation range, sulfur content, and oxygenated content. Specifications for the reformulated gasoline and the ASEAN commecial gasoline are presented. Driveability index (DI) has been standardized by ASTM D-4814-98a and in the near future this DI could be recommended in the specification for the reformulated gasoline. Reformu- lated gasoline can be blended from the high quality gasoline components. Volatitity (RVP. T T T and driveability index), octane number (RON, MON and octane distribution), and hydrocarbon compositions of the gasoline components, as well as the refinery configuration to improve the quality of the gasoline components, and the compositions of these improved gasoline components of reformulated gasoline production are briefly discussed in this paper.

PRODUCTION OF ENVIRONMENTAL FRIENDLY FUEL IN INDONESIAN REFINERY

Worldwide crude supplies are experiencing a mod- est trend toward heavier and high sulfur content. The average annual demand growth rate for light products (gasoline, kerosene and diesel oil) is higher than that for residual fuel oil, Therefore, converting additional bot- toms into light product by either thermal or catalytic pro- cesses will be needed. Vehicles and fuels have been developed simulta- neously and nowadays vehicles demand a very sophisti- cated fuel indeed. Environmental restriction, and efforts to minimize the pollutant problem by exhaust gases are causing design and changes in cars that in turn are hav- ing some effects on fuel quality. To reduce exhaust emission by fuel combustion, the specification of gasoline and diesel oil is now stricter. Various term in the models address qualities of the re- formulated gasoline, such as benzene, total aromatics and olefin content, RVP, the T of distillation range, sul- fur content, and oxygenate contents (Table 1)18.13.16). Diesel oil specification is limited as follows: aromatics, polyaromatics, sulfur content, T and cetane number (Table 2) (19.23,26) To improve the specification of commercial gasoline into the stricter specification of reformulated gasoline, refiners are forced in install new facilities to increase the production for high-octane mogas components. For the stricter diesel oil specification in the years 2000's, over 50% by volume of the total gas oil components (ex- cept hydrocracked gas oil) must undergo improvement by hydrotreating processes in order to achieve a suitable specification. In Indonesia, there are seven refineries with total crude oil capacity of 1,063 MBCD to produce fuel oils, lube base stocks and petrochemical products. Process- ing units and fuel oil production in Indonesia's refineries are given in Table 3 and 4, respectively. The production of gasoline and diesel oil components is review in this paper. Influence of hydrocarbon composition of those fuel components on their performances is discussed. A brief discussion is offered on the impact of the changing specification of gasoline and diesel oil on the refinery configuration.

PRODUCTION OF UNLEADED GASOLINE IN ASEAN COUNTRIES

Worldwide crude supply is experiencing a mod- est trend towards heavier and high sulfur content. The Middle East, being traditionally the world's ma- jor oil exporting region, will continue to be the princi- pal supplier of lower quality crude's in the future", For the period 1992-2005, the average annual demand growth rate for light products ( gasoline, kero- sene, diesel oil) is higher than for residual fuel oil21, These data clearly show that the need will continue for converting additional bottom fraction into light products, by both thermal or catalytic conversions. The passage of the Clean Air Act Amendement of 1990 in the USA has forced American refineries to install new facilities to comply with stricter speci- fications for fuels such as gasoline and diesel oil such as Asia-Pacific, California Air Resources Board (CARB) and European Commission (EC) [3.4. 5). Various terms in the models address qualities and the gasoline blended such as benzene, total aromatics and olefin contents, RVP, the T90 of distillation range, sulphur content, and oxygenates content. Comparison of fue l specifications between ASEAN countries and reformulated fuels and typi- cal compositions of gasoline and gas oil components for production of commercial unleaded gasoline is included in this report.

Calculation of reaction network and product properties of delayed coking process based on structural increments

The delayed coking reaction kinetic model based on the structure-oriented lumping method showed good accuracy in predicting the yield and composition of coking products at the molecular level. Based on the basic law that molecular structure determines molecular properties, the structural increment contribution method was constructed to expand the functions of established reaction kinetic model to predict the characteristic properties of coking gasoline and diesel products: distillation range, density, research octane number (RON) or cetane number (CN). The contributions of different structural increments of hydrocarbon molecules in gasoline to the RON and those in diesel to the CN could also be calculated by the model. The RONs of the hydrocarbon molecules decreased with the increase of R, and increased with the increase of br and me for the coking gasoline. The CNs of the paraffins molecules improved with the increase of R, but reduced with the increase of br and A6 for the coking diesel. The effects of all structural increments on the RON and CN could be quantitatively calculated through the established correlation formulas. The prediction of composition and properties of coking gasoline and diesel based on the model could guide the subsequent processing and process optimization of delayed coking plant.

Inference of reaction kinetics for supercritical water heavy oil upgrading with a two‐phase stirred reactor model

AbstractWe present the development and application of a two‐phase stirred reactor model for heavy oil upgrading in the presence of supercritical water (SCW), with coupled phase‐specific thermolysis reaction kinetics and multicomponent hydrocarbon–water phase equilibrium. We demonstrate the inference of oil and water phase kinetics parameters for a compact lumped reaction kinetics scheme through the application of this model to two different sets of batch reactor experiments reported in the literature. We infer that, although SCW can suppress the formation of newer polynuclear aromatics (PNA) from distillate range species, it is broadly ineffective in deterring the combination of pre‐existing PNA fragments in the oil feed. Quantification of the conversion to distillate liquids before the onset of coke formation helps arrive at a clear conclusion on whether the use of SCW in the batch reactor leads to better product outcomes for different oil feeds and operating conditions.