Light Naphtha Research Articles

The Oligomerization of Olefin Hydrocarbons in Light FCC Naphtha on Ion Exchange Resin Catalyst

In our experimental work our aim was the investigation of the possibility to convert olefin hydrocarbons of a light FCC naphtha fraction with oligomerization. In this framework, we studied the production possibilities of higher carbon number isoolefin rich motor fuel blending components, with oligomerization of the C4-C6 olefin content of the feedstock on water-containing acidic ion exchange resin catalysts. From the studied catalysts the ion exchange resin showed the highest oligomerization activity: the conversion of the olefins was 90.9 % and the share of oligomer products was 29.0 %. After hydrogenation of the C8-C16 isoolefin mixture, the octane number of gasoline product is around 100, the JET product has high energy content and low crystallization point, the cetane number of gas oil product is high and it has a good CFPP (cold filter plugging point). So with these two catalytic steps valuable products can be produced from light olefin-containing refinery by-products.

Investigation of Isomerisation of Light Naphtha Fractions

Investigation of Isomerisation of Light Naphtha Fractions

Hydrothermal liquefaction of freshwater and marine algal biomass: A novel approach to produce distillate fuel fractions through blending and co-processing of biocrude with petrocrude

Biocrude was produced from Tetraselmis sp. – a marine alga and Arthrospira platensis – a fresh water alga using hydrothermal liquefaction (HTL) process. Considering the constraints in cultivating algae for replacing 100% petrocrude, this study evaluated the option of blending and co-processing algal biocrude with petrocrude. Biocrudes obtained from algal strains cultivated in fresh water and sea water were blended with petrocrude at 10% concentration and the characteristics were studied using FT-IR and CNS SIMDIST. True Boiling Point (TBP) distillation was carried out to assess yields and properties of distillates of blended biocrudes. Biocrudes obtained from both algae were light crudes and the blended crudes recorded distillate yields of 76–77wt%. The yield of light naphtha fraction of biocrude blends was 29–30%; whereas the yield of diesel fraction was about 18%. This study proposes blending and co-processing of algal biocrude with petrocrude to produce drop-in biofuels.

Simulation of hydrodesulfurization unit for natural gas condensate with high sulfur content

The natural gas condensates are composed of various components of hydrocarbons and some contaminants such as hydrogen sulfide, thiols (mercaptans), and aromatics. Thus, the natural gas condensates could be considered as a fuel resource. This study concerned the simulation of an Ultra-Deep Hydrodesulfurization (UDHDS) unit plus a distillation section to treat a combination of gas condensate and disulfide oils (DSO) and produce clean fuel cuts. Gas condensate of South Pars field of Iran with high sulfur content was applied to obtain clean fuel cuts. In order to reduce the sulfur content of this stream to less than 10 ppmw as sulfur, a UDHDS unit was simulated using Aspen HYSYS software package. The clean gas condensate leaving the UDHDS unit (with sulfur content <10 ppmw) contains complex mixtures of hydrocarbon components called petroleum cuts which are identified by their boiling points ranges. To obtain the narrow fractions of butane, light naphtha, heavy naphtha, kerosene, and gasoil, a fractional distillation system was simulated. The simulation results revealed that the top products of distillation column, namely butane, light naphtha, and heavy naphtha were sulfur free and the sulfur contents of kerosene and gasoil cuts were 12 and 27 ppmw as sulfur, respectively.

Cleaner alternative liquid fuels derived from the hydrodesulfurization of waste tire pyrolysis oil

Waste tires are attractive sources for alternative energy due to their long hydrocarbon chains with a high heating value. However, the condensed (volatile portion) pyrolysis oil derived from waste tires contains a relatively large level of sulfur compounds (1.15wt%), which is not appropriate for use in combustion engines. Therefore, this research aimed to improve the waste tire pyrolysis oil (WTPO) via hydrodesulfurization (HDS) catalyzed by molybdenum (Mo), nickel–Mo (NiMo) or cobalt–Mo supported on alumina (γ-Al2O3). The maximum % sulfur removal (87.8%) was achieved when the reaction was performed at 250°C for 30min using a 2wt% NiMo/γ-Al2O3 catalyst loading based on the WTPO content and 20bar initial hydrogen pressure. The amount of sulfurous compounds in the waste tire pyrolysis oil was determined using gas chromatography spectroscopy equipped with a flame photometric detector (GC–FPD). The HDS of the WTPO was effective to reduce the sulfurous compounds, especially thiophene and its derivatives. The results from the simulated distillation gas chromatography (GC–SIMDIS) showed that the hydrodesulfurized WTPO (HDS-WTPO) was mainly composed of a light naphtha fraction (ca. 69%). The heating value of the HDS-WTPO (44MJ/kg) was similar to those for commercial diesel (45MJ/kg) and gasoline (gasohol) fuels (47MJ/kg).

Effect of the SiO2/S coating and Sulfur/phosphorus-containing inhibitor on coke formation during light naphtha cracking

Effect of the SiO2/S coating and Sulfur/phosphorus-containing inhibitor on coke formation during light naphtha cracking

Simulation of Light Naphtha Isomerization Process

An approach to modeling the isomerization process implemented in the technological scheme with the maximum normal paraffins conversion was described. The comprehensive mathematical model was designed as a powerful tool for optimization. It is based on the influence of the feedstock composition for assessment of the current catalyst activity. According to the calculations, the optimal operating parameters are determined by the refined feedstock composition.

ChemInform Abstract: Zeolites as Catalysts in Oil Refining

AbstractReview: 50 refs.

Development of a rule to maximize the research octane number (RON) of the isomerization product from light naphtha

The isomerization process is a substantial technology to produce clean fuel from linear paraffinic species existing in light naphtha. We investigated the influence of hydrocracking reactions besides the other reactions on the research octane number (RON) of the isomerization product. A reaction network and a kinetic model including fifteen lumps and sixteen reactions were developed. Several experiments were carried out in a pilot plant to estimate kinetic parameters. The accuracy of the model was evaluated by comparing the model prediction with the experimental results. The maximum RON and process yield were strongly dependent on the temperature, hydrogen to hydrocarbon molar ratio (H2/Oil) and liquid hourly space velocity (LHSV). Also, increasing the reaction temperature compensated for the negative effects of raising the LHSV and H2/Oil in RON maximization. Moreover, we concluded that the hydro cracking reactions were very effective on RON, such that they can dominate the role of the other reactions. By sensitivity analysis in this research, a rule was obtained to declare the effect of operating condition on maximization of RON and the method of revamping of naphtha isomerization reactor.

Artificial Intelligent Modeling and Optimizing of an Industrial Hydrocracker Plant

The main objective of this study is the modelling and optimization of an industrial Hydrocracker Unit (HU) by means of Adaptive Neuro Fuzzy Inference System (ANFIS) model. In this case, some data were collected from an industrial hydrocracker plant. Inputs of an ANFIS include flow rate of fresh feed and recycle hydrogen, temperature of reactors, mole percentage of H2 and H2S, feed flow rate and temperature of debutanizer, pressure of debutanizer receiver, top and bottom temperature and pressure of fractionator column. The network was employed to calculate the flow rate of gas oil, kerosene, Light Naphtha (LN), and Heavy Naphtha (HN).Unseen data points were used to check generalization capability of the best network. There were good adjustment between network estimations and unseen data. Finally optimization was performed to maximize the production volume percent of gas oil, kerosene, HN and LN and to identify the sets of optimum operating parameters in order to maximize yields of mentioned product. Optimum conditions were found as feed flow rate of 90.9 m3/h, reactor temperature of 378.4 °C, hydrogen flow rate of 54.31 MSCM/h and LN (feed vol.%) of 9.34.

Simple Model for Predicting the Cutting Temperature between Light and Heavy Fractions in Fluid Catalytic Cracking Naphtha Selective Hydrodesulfurization Processes

In selective hydrodesulfurization processes for hydro-upgrading fluid catalytic cracking (FCC) naphtha with high olefin and sulfur contents, it is a common practice to split the feeding full-range FCC naphtha into a light fraction and a heavy fraction. This operation can effectively alleviate olefin saturation and thereby octane loss. Thus, the determination of a suitable cutting temperature plays a vital role in guaranteeing the success of the operation. Starting by fractionating two FCC naphthas into nine narrow cuts, this paper shows that, despite the great differences in the properties of the two FCC naphthas, both hydrocarbons and sulfides have almost the same distributions in the nine cuts. More importantly, it was observed that the distribution of sulfides in the narrow cuts is irrelevant to their true boiling points because of the formation of azeotropes between sulfides and hydrocarbons. On the basis of these findings, a simple model for estimating thiophene content in light FCC naphtha and, ther...

Hydrodynamics and mass transfer study of oil-water micro-emulsion in a three phase external loop airlift reactor

In this study, the impact of operating conditions, liquid properties and loading of a solid phase on the hydrodynamics and mass transfer coefficient in an airlift reactor with an external loop was investigated. The gas phase sparged through the reactor was air. Oil-in-water micro emulsions containing diesel, kerosene, heavy naphtha and light naphtha made up the liquid phase with an oil concentration of 5%. The impact of the solid phase was studied with solid loadings of 0, 0.25 and 0.5 wt%. The results showed that light naphtha which had the lowest density, viscosity and surface tension had the highest mass transfer and gas holdup and the lowest liquid circulation velocity. Solid addition decreased the gas holdup and mass transfer while increasing the liquid circulation velocity. This effect was considerable on the parameters above. In addition, a correlation based on dimensionless numbers was gained to predict the Sherwood number. Good agreement was observed between the correlated and experimental values.

Advances in the aqueous-phase hydroformylation of olefins from a refinery naphtha cut: The effect of monoethanolamine in the catalytic activity of the Rh/TPPTS system

In the present work we report the effect of monoethanolamine (MEA) in the biphasic hydroformylation of the olefin content in a real light naphtha cut from “El Palito” refinery in Venezuela using the Rh/TPPTS system. It was found that the MEA increased dramatically the solubility of a 1:1 mixture of H2:CO up to 27% compared with pure water which resulted in a 10 fold increase in the reaction rate. There was spectroscopic evidence of the coordination of the MEA to the rhodium centre. This accelerated reaction allowed for the redesign of a pilot-scale naphtha hydroformylation plant with 55% smaller reactors. The aldehydes obtained were predominantly C7 branched with high octane-value, evidencing that the biphasic reaction is a green technological alternative to the toxic additive currently use in gasoline formulations such as TAME and MTBE.

Zeolites as catalysts in oil refining

Oil is nowadays the main energy source and this prevalent position most probably will continue in the next decades. This situation is largely due to the degree of maturity that has been achieved in oil refining and petrochemistry as a consequence of the large effort in research and innovation. The remarkable efficiency of oil refining is largely based on the use of zeolites as catalysts. The use of zeolites as catalysts in refining and petrochemistry has been considered as one of the major accomplishments in the chemistry of the XXth century. In this tutorial review, the introductory part describes the main features of zeolites in connection with their use as solid acids. The main body of the review describes important refining processes in which zeolites are used including light naphtha isomerization, olefin alkylation, reforming, cracking and hydrocracking. The final section contains our view on future developments in the field such as the increase in the quality of the transportation fuels and the coprocessing of increasing percentage of biofuels together with oil streams. This review is intended to provide the rudiments of zeolite science applied to refining catalysis.

Role of support in deoxygenation and isomerization of methyl stearate over nickel–molybdenum catalysts

Microporous SAPO-11 and highly ordered mesoporous AlSBA-15 with different aluminum contents (with Si/Al ratio of 5 and 10) were synthesized. Thus prepared samples were characterized by BET, pyridine-FTIR and NH3-TPD to investigate their structural and acidic properties. The samples were then transformed into bifunctional catalysts by loading with molybdenum and nickel. Their activities were tested in the hydroconversion of methyl stearate using a fixed bed flow reactor system. The sulfided NiMo catalysts exhibited high conversion and deoxygenation activities. High isomerization activities observed for both NiMo/SAPO-11 and NiMo/AlSBA-15 catalysts, similar to the isomerization of light naphtha, was attributed to the acidity of supports. However, the acidity of supports was not the only factor influencing the isomerization of long chain molecules. AlSBA-15 had a large specific surface area that contained more acidic sites inside of its channels, promoting the formation of cracking products; SAPO-11 had a suitable pore size and contained fewer acidic sites inside the pore channels, promoting the formation of mono-branched isomers while suppressing cracking reactions.

Process for producing high octane gasoline having lower benzene content and distillation end point with its environmental effect of engine exhaust emissions

In this research, a process is discussed for upgrading reformate and power former in Iraq’s Al-Doura refinery, by reducing the amount of benzene in the gasoline product with simultaneous reduction in the gasoline’s ASTM distillation end point. The process consists of fractionation of the reformate and power former to recover that fraction (90–180°C) of hydrocarbons. This was directly used as gasoline without further conversion. The heavy bottom fraction (180°C—EBP) consisting of the aromatic and non-aromatic hydrocarbons was recovered and used as antiknock additives to gasoline. The other fraction with (IBP—90°C) was used as feedstock to producing benzene by solvent extraction. The reformate and power former fractions (90–180°C) are blended with light straight run naphtha at ratio (75: 25) to producing gasoline as well as Al Doura gasoline. It was found that the amount of benzene was reduced from 1.41 wt % in the original pool to 1.37 and 1.31 in the alternative products. Engine emissions were also reduced when using the alternative products compared with original pool product.

The Influence of Oil-water Ratio on the Operation of an Airlift Reactor Containing Petroleum-based Micro-emulsion

Hydrodynamic and mass transfer coefficient in a split-cylinder airlift reactor for four different oil-in-water micro-emulsions containing kerosene, heavy naphtha, light naphtha, and diesel as oil-based with concentrations of 3%, 5%, and 7 % (v/v) were considered. The experimental results showed that with increasing the oil in water ratio, the gas holdup increased but liquid circulation velocity and oxygen transfer coefficient decreased. Light naphtha with the lowest surface tension and viscosity had the maximum mass transfer and gas holdup, and the minimum liquid circulation velocity, while diesel with the highest surface tension and viscosity had the minimum mass transfer and gas holdup and the maximum liquid circulation velocity.

Retrofit and Debottlenecking of Naphtha Splitter Process to Thermally Coupled Distillation Sequence with a Side Reboiler

The naphtha splitter process is a representative distillation processused in the refinery industry. To improve the fractionation of the naphtha boiling range derived from hydro-treatment, naphtha feedstock is sequentially separated into light naphtha, heavy naphtha, and light kerosene. Conventional naphtha splitting columns can be retrofitted to an advanced configuration requiring less energy consumption with consequently less CO2 emission. A systematic design for retrofitting naphtha splitting columns for the thermally coupled distillation sequence (TCDS) that addresses the bottleneck phenomenon by integration of existing shells was developed in this study. The results showed that the operating cost could be reduced drastically by novel combination of the TCDS and a side reboiler with minimal process modification.

Design and Optimization of Fully Thermally Coupled Distillation Scheme for the Naphtha Splitter Process

Naphtha feed stock is separated into light naphtha, heavy naphtha and light kerosene in sequence. Systems and methods of naphtha feed stock are destined for a conventional distillation sequence and the other applications with less energy consumption than conventionally possible, while producing less greenhouse gas emissions. In this work, the comparison between the conventional sequence and the fully thermally coupled distillation column or so-called dividing wall column was carried out based on the minimum vapor flow rate at infinite number of stages. The evaluation results showed that the dividing wall column can be effectively used to improve the performance of the naphtha splitter process. In this paper, the pseudo-components for defining a liquid fraction have been described through using a commercial process simulator. A response surface methodology was applied to the design of the dividing wall column. A less number of facilities are provided and correspondingly less capital investment as well as reduced operating cost can be achieved. Reducing CO2 emission is another benefit which is derived from the proposed sequence.

Development of Complex Mathematical Model of Light Naphtha Isomerization and Rectification Processes

The technique of developing a mathematical model of catalytic isomerization of light naphtha is stated Using experimental data from an industrial isomerization unit shows adequacy of the mathematical model to the real process. The paper presents a method for optimizing the operation of the plant together with catalytic isomerization unit and separation columns. Selection of optimal modes of separation columns allows achieving the desired flow separation between units, as well as extension of the life of the catalyst SI-2.