Light Oil Fractions Research Articles

Influence of thermal pretreatment on pyrolysis of lignite

The effects of thermal pretreatment on pyrolysis behavior of Shengli lignite were investigated in a fixed bed reactor. In comparison with raw coal, the thermally pretreated coal has lower content of hydroxyl group and lower ratio of aromatic-H to aliphatic-H. The yield of pyrolysis water is lowered after thermal pretreatment in N2, N2+O2 and CO2 atmospheres. The pretreatment also causes a higher CO2 content in pyrolysis gas, which thus lowers the heating value of the gas. Pretreating the coal in superheated steam raises the tar yield by 3–4 weight percentage points, and the composition of tar varies with the atmosphere and temperature of the pretreatment. The light fraction (with boiling points below 360°C) increased by 27 weight percentage points by pretreatment in 200°C -steam. The pretreatments at 200°C and 250°C in the mixture of steam and simulated flue gas elevate the light oil and phenol oil fractions in tar by 60 and 42 weight percentage points, respectively.

Gaseous Products from Scrap Tires Pyrolisis

Gaseous Products from Scrap Tires Pyrolisis In European Union 75% of used tires should be recycled. The most common method of used tires disposal, is burning in cement kilns, which does not solve the problem. Pyrolysis process can be an alternative way of utilization of tires. The aim of the researches was to check the influence of pyrolysis products (gas and oil fractions) on environment. Samples from pyrolysis process, like light oil fractions or pyrolysis gases were analyzed using gas chromatography. The pyrolysis installation should be hermetical, because of the PAHs which were detected in a light fraction of oil. In exhaust gases BTEX and PAHs were not detected.

Visual in-situ monitoring of the behavior and phase states of water-hydrocarbon inclusions at high temperatures and pressures

Experiments aimed at examining interactions between hydrothermal solutions and caustolithic rocks, oil, and its major fractions were carried out to obtain model water-hydrocarbon fluids (WHCF) and study their behavior and phase states at high P-T parameters. Simultaneously we experimentally synthesized and grew quartz crystals with inclusions as the major source of information on the behavior and phase state of the model WHCF. The inclusions were then examined with the application of conventional and local IR spectroscopy, gas and liquid chromatography, fluorescent and X-ray diffraction analysis, and the microthermometry of fluid inclusions. Interactions between hydrothermal solutions and caustolithic rocks were proved to result in the synthesis of an oil-like liquid, gaseous hydrocarbons (mostly methane), and solid bitumen. The behaviors and phase states of WHCF generated at temperatures below 260–320°C and above 330–500°C (under saturated vapor pressure and higher) were proved to be different, with these differences predetermined by oil cracking in hydrothermal solutions at temperatures above 330°C (particularly at 350–500°C) with the synthesis of predominantly light and intermediate hydrocarbon fractions. As the temperature was increased, the WHCF generated at temperatures of 260–320°C were transformed into two-phase oil-water fluids without free gas. In contrast to them, the heating of the fluids generated at 330–500°C first resulted in two-phase gas-liquid fluids with light oil fractions dissolved in them. As soon as the critical point (370–380°C) was reached, these fluids passed into a homogeneous supercritical state. The content of oil dissolved in hydrothermal weakly alkaline and alkaline solutions (visual estimations at temperatures of 260–400°C and pressures up to 90 MPa; the inclusions decrepitated at higher pressures) increased from a few hundredths and a few tenths of a percent to 8–10 vol % or, upon oil cracking at 380–450°C, to 20–30 vol % and more.

Ralstonia sp. U2 naphthalene dioxygenase and Comamonas sp. JS765 nitrobenzene dioxygenase show differences in activity towards methylated naphthalenes

Methylsubstituted naphthalenes constitute a significant part of light gas oil fractions (LGO). These are toxic compounds with low fuel value, and can potentially be enzymatically modified to increase the fuel value and at the same time reduce toxicity. The first step in the biodegradation of naphthalene involves dioxygenation of the aromatic ring catalysed by naphthalene dioxygenase (NDO). Here we show that recombinantly produced NDO from Ralstonia sp. U2 and the related nitrobenzene dioxygenase (NBDO) from Comamonas sp. JS765 can use several mono-, di-, tri-, and tetramethylated naphthalenes as substrates. For the majority of the substrates both enzymes catalyse the formation of a mixture of mono- and dioxygenated products, and it is only dioxygenated products that are likely to be processed further, leading to ring cleavage. In some cases, like for 1-methylnaphthalene, NDO mainly generates the monooxygenated form, while with NBDO, the dioxygenated form dominates. In other cases, as for 1,4-dimethylnaphthalene, the monooxygenated product dominates with NDO, whereas NBDO generates similar amounts of both forms. Presumably, the best future strategy for bioconversion of methylated naphthalenes in LGO is to develop engineered enzyme that are optimised with respect to the specific composition of naphthalene derivatives found in a given product.

Graph-Based Method for the Automated Calculation of Thermochemical Properties of Components and Intermediate Species in the Hydroprocessing of Light Oil Fractions

A method based on graph theory has been formulated to estimate some key thermochemical properties commonly utilized in modeling acid-catalyzed transformations of hydrocarbons at the elementary step...

Histopathological liver alterations in juvenile rabbit fish ( Siganus canaliculatus) exposed to light Arabian crude oil, dispersed oil and dispersant

With the heavy transport of crude oil there is an increasing risk of a major oil spill in the Gulf waters; however, there have been few studies on the impact of oil spills and subsequent remedial action on Gulf fish. The aim of the experiment was to investigate the effects of acute exposure to water soluble fraction (WAF) of light Arabian crude oil, dispersed oil and dispersant on the liver of the juvenile rabbit fish ( Siganus canaliculatus), observing several histopathological biomarkers of the liver at different time points and different doses. The concentrations used (3–100 percent WAF) simulated a range of possible oil pollution events. The main alterations observed in this study include hepatocyte swelling and cytoplasmic vacuolisation, megalocytosis, coagulative dispersed necrosis, lymphocytic infiltration, melanomacrophage aggregates, spongiosis hepatis, pericholangiitis, and bile stagnosis. Treated livers showed significantly higher total index values than the control group ( p<0.01). According to the total liver index, liver exposed to WAF, dispersed oil or dispersant showed significant histopathologic alterations compared with the control fish (Mann–Whitney U-test; p<0.01). Components of the total liver index, (circulatory, degenerative, proliferative, and inflammatory changes) differed significantly from the control groups. There was a significant correlation between exposure time and the total liver index values and the different reaction pattern indexes of treated fish (Spearman correlation; p>0.05). The present study indicates that dispersed oil is not more toxic, to livers of juvenile rabbit fish, than crude oil or dispersant.

In vivo effects of the soluble fraction of light cycle oil on immune functions in the European sea bass, Dicentrarchus labrax (Linné)

Hydrocarbons are major contaminants that may affect biota at various trophic levels in estuaries and coastal ecosystems. The effects of accidental pollution by light cycle oil (LCO), a refined product of heavy fuel oil, on bioaccumulation, depuration processes and immune-related parameters in the European sea bass, Dicentrarchus labrax, were investigated in the laboratory after 7 days of exposure and a 2-week recovery period. Exposure of fish to the soluble fraction of LCO (1600 ng L −1) for 7 days led to the bioaccumulation of some polycyclic aromatic hydrocarbons (PAHs) in muscles: naphthalene, acenaphthene, fluorene, phenanthrene and anthracene. After 7 days of recovery period, half-elimination of naphthalene was reported in fish muscles due to facilitated diffusive loss by the epithelium and a faster elimination rate proven by the presence of a high level of naphthalene biliary metabolites. The other bioaccumulated molecules displayed a slower depuration rate due to their elimination by the formation of hydrophobic metabolites excreted through bile or urine. Three days after the beginning of the recovery period, each contaminated fish showed severe external lesions (tissue necrosis, suppurative exudates, haemorrhagic area). The hypothesis of a possible link with inflammatory phenomenon was supported by (i) an inversion of the leucocyte sub-population percentage, (ii) a significant up-expression in the spleen of the tumour necrosis factor alpha gene, (iii) a significant increase in ACH 50. Moreover, the lack of C3 gene regulation in the spleen suggested a non-renewal of this component. The reduction of phagocytic activity and lysozyme concentration reflected immune suppression. Finally, LCO toxicity in this fish was clearly demonstrated to be related to inflammatory reaction and immune depletion.

Biodiesel Production by Pyrolysis from Waste Animal Fats

The biodiesel has attracted attention as an alternative fossil fuel. Generally, the biodiesel is fatty acid methyl esters obtained from triglycerides which are the principal ingredients of oils and fats. The plantation vegetables of biodiesel raw materials are grown in Europe and America. On the other hand, it is necessary to use waste cooking oils in Japan where the cultivated acreage is narrow. The flee fatty acids are included in waste cooking oils decrease the biodiesel yield. Moreover, the long chain saturated compounds of animal fats in waste cooking oils lower the low temperature property of the obtained biodiesel. The pyrolysis of waste cooking oils was examined in order to apply to the manufacturing method of the biodiesel. As the results, it was cleared that the triglyceride generates the fatty acids by the ester bond decomposition at 360-390°C. Next, the fatty acids decompose and the short chain hydrocarbon is generated. Moreover, the hydrocarbon of the light oil fraction is obtained by the decarboxylation of the hydrocarbon at 420°C. At this time, the yield and the selectivity of the light oil fraction can be improved when the activated carbon supported palladium is added as a catalyst. The obtained light oil fractions had a good low temperature property.

Adsorption Kinetics and Capacity of Fatty Acid-Modified Banana Trunk Fibers for Oil in Water

Oil spill leaves detrimental effects to environment, living organisms, and economy. As such, it is of considerable interest to find an effective, simple, and inexpensive method to treat this calamity. This work reports the use of banana trunk fibers (BTF) modified with oleic acid, stearic acid, castor oil, and palm oil for oil spill recovery. The maximum sorption capacity, effect of oil to water ratio, effect of light oil fractions, and effect of dissolved organic compounds in weathered oil-contaminated seawater were studied. It is found that BTF treated with oleic acid exhibited the best sorption capacity for engine oil, dissolved organic compounds in weathered oil, and light oil fractions. The equilibrium process was described well by the Freundlich isotherm model, and the kinetic studies show good correlation coefficients for a pseudo-second-order kinetic model.

In vivo effects of LCO soluble fraction on immune-related functions and gene transcription in the Pacific oyster, Crassostrea gigas (Thunberg)

The effects of a soluble fraction of light cycle oil (LCO) on haemocyte parameters, phenoloxidase (PO) activity and mRNA expression of immune-related genes, in the Pacific oyster, Crassostrea gigas, were tested after seven days of exposure and two weeks of recovery period. Five polycyclic aromatic hydrocarbons (PAHs) out of ten detected in tank water had bioaccumulated at the end of the contamination period. The concentration of PAHs in oyster tissues decreased during the recovery period and 14 days after the exposure, 69% of bioaccumulated PAHs were detected in contaminated oysters. The exposure induced severe oyster mortality (21%), external and internal green colouration of the shell and a significant decrease of PO activity. The mRNA expression of several genes was altered. As a conclusion, a modulation of immune-related parameters was demonstrated using three different approaches, namely cellular (flow cytometry), biochemical (spectrophotometry) and genomics (gene transcription) in oysters after contact with soluble fraction of LCO.

Effects of water activation of crumb rubber on the properties of crumb rubber-modified binders

Hot water activation of crumb rubber has been suggested as a method of improving compatibility between crumb rubber and asphalt binder. This procedure removes light oil fractions present in the crumb rubber particles, thus decreasing segregation occurring between rubber particles and binder. For this research, a PG 64-22 binder was modified with four different crumb rubber sources at concentration of 15% by weight of binder. Binder properties were evaluated for virgin binders, water-activated crumb rubber-modified (CRM) binders, and for non-activated CRM binders. CRM surface morphologies were studied using a scanning electron microscope, molecular size distributions of modified binders were determined using gel permeation chromatography, while storage stability was evaluated by cigar tube testing. Rheological properties of the CRM binder were investigated; improved phase separation properties were observed following water activation, however, these improvements did not result in improved rheological properties of the activated CRM binder.

A unified plant for trapping light oil fractions

A unified plant has been developed for trapping light oil fractions, which allows one to introduce a universal technology for collecting oil-associated gas from tanks and separators in the last stage of gas separation, which raises the performance in preparing the oil as a result of more effective separation of the gas from the oil, while reducing the separation pressure, and also reducing the capital and working costs.

Oxidative Processing of Light Oil Fractions. A Review

The review and analysis of oxidation processes necessary for quality improvement of oil fractions boiling to 623 K have been carried out. Different oxidative technologies for crude oil processing have been examined. Their advantages and disadvantages have been shown.

Pyrolysis of mixed plastics for the recovery of useful products

Thermal and catalytic pyrolysis of polystyrene (PS) with low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), poly-ethylene terephthalate (PET) plastics were carried out in a 25 cm 3 stainless steel micro reactor at around 430–440 °C under 5.5–6.0 MPa of N 2 gas pressure for 1 h. Three reactions of each plastic with PS were conducted in the ratio of 1:1, 1:2 and 1:3. The amount of PS was varied to explore its role and reactivity. In all coprocessing reactions, ratio 1:1 afforded the best yields in the form pyrolytic oils. SIM distillation of hexane soluble portion showed that the low boiling fractions were not found and fractions were obtained only after 96 °C + boiling point. It could be due to the vaporization of high volatile components. In most of the binary pyrolysis, light cycle oil (LCO) fractions have low recovery than heavy cycle oil (HCO). GC identified some very important chemical compounds present in the liquid products obtained from the pyrolysis of mixed plastics. The results obtained from this study have shown usefulness and feasibility of the pyrolysis process of the mixed plastics as an alternative approach to feedstock recycling.

Hydroprocesssing of light gas oil — rape oil mixtures

Two series of experiments of hydroprocessing of light gas oil - rape oil mixtures were carried out. The reactor feed was composed of raw material: first series — 10 wt.% rape oil and 90 wt.% of diesel oil; second series — 20 wt.% rape oil and 80 wt.% of diesel oil. Hydroprocessing of both mixtures was performed with the same parameter sets, temperature (320, 350 and 380 °C), hydrogen pressure 3 and 5 MPa, LHSV = 2 h − 1 and hydrogen feed ratio of 500 Nm 3/m 3. It was stated that within limited range it is possible to control vegetable oil hydrogenolysis in the presence of light gas oil fraction (diesel oil boiling range) through the proper selection of the process parameters. Hydrogenolysis of ester bonds and hydrogenation of olefinic bonds in vegetable oils are the main reactions in the process. Basic physicochemical properties of the obtained hydroprocessed products are presented.

Analysis and Simulation of Steam Distillation Mechanism during the Steam Injection Process

Steam distillation could improve the oil recovery efficiency during the steam injection enhanced oil recovery process. Because of its immense effects on oil recovery, it is important to investigate the main parameters of steam distillation as well as the effects of oil and reservoir properties during this thermal process. In this work, the simulation of batch steam distillation is performed on 18 sets of crude oil found in the literature. The developed model is highly compatible with respect to the input oil properties that can also characterize the oil with minimum entry. The calculated distillates were compared to the experimental data, and the results show an average relative error of 13.74% for 15 sets of crude oil data, each calculated at 20 different points. According to this study, the superheat conditions of steam and the amount of light oil fractions have the greatest effect on the distillation yields, while the steam saturation conditions have less considerable effects. It was also found that th...

Investigation of the Heterogeneous Catalytic Transformation of Vegetable Oil/Gas Oil Blends

The applicability of vegetable oils (tryglycerides) and their derivates is well-known for a long time. The main goal (to produce fuels from non-fossil based energy source) has been extended with the global aims of reducing the environmental pollution. Therefore the main objective now is to produce, store, transport and use fuels with lower emission levels. Until the last couple of years the vegetable oils were mostly transesterified catalytically to biodiesel to produce fuels. Because of the numerous disadvantages of biodiesel production and application the alternative chemical transformations of triglycerides were started to be studied intensively. One of the best alternative is to convert the vegetable oils (or other materials containing triglycerides) and/or their blends with gas oil to hydrocarbons rich in paraffins. These compounds can be applied in Diesel-engines directly or blended with petroleum-based gas oil. In our experimental work we examined the heterogeneous catalytic conversion of light gas oil fraction containing 10% sunflower oil on transition metal/Al2O3 catalyst. Our objective was to study the effect of the operating parameters to the yield of liquid organic products, to the yield of the fraction of gas oil boiling point range and to the product properties. Based on our results it can be concluded that with the catalytic hydrogenation of the feedstock containing 10% sunflower oil products with excellent properties can be produced with high yield. The product gas oil had ³10 mg/kg sulphur and nitrogen content, lower than 10% total aromatic content and ³-5 °C cold filter plugging point. The cetane number of the products was significantly higher than the limit (51) of the EN 590:2004 standard.

Production of oil with low organobromine content from the pyrolysis of flame retarded HIPS and ABS plastics

Pyrolysis of flame retarded plastics often leads to high concentrations of toxic organobromine compounds in the pyrolysis oil. In this work, we have investigated the pyrolysis of flame retarded high impact polystyrene (HIPS) and acrylonitrile–butadiene–styrene (ABS) over long residence times in a tube reactor with the aim of producing an oil that is free from organobromines. The tube reactor was fitted with a distillation column so that the pyrolysis products could be separated into heavy oil, middle distillate, light oil, and gases. The light pyrolysis products were characterised using GC–MS and GC-FID/ECD, while the total bromine content of the oils was determined by bomb calorimetery. The bromine content of heavy fractions and antimony content of all fractions of pyrolysis (light oil, middle distillates, heavy oil and char) was determined by inductively coupled plasma atomic adsorption spectroscopy (ICP-AAS). Heavy oil fractions were characterised using Fourier Transform-Infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy disperse X-ray analysis (EDAX), and gel permeation chromatography (GPC) techniques. It was found that the light oil produced by the pyrolysis of both flame retarded HIPS and flame retarded ABS mostly consisted of toluene, ethylbenzene, and cumene and had a relatively low bromine content, all of which was inorganic. The middle distillate oils produced by the same plastics had much higher bromine content, but the vast majority of the bromine was inorganic in the form of antimony bromide. The average molecular weights of heavy fractions were affected by the cracking temperature, while the structure of the mentioned fractions did not change considerably with temperature. Light oil fractions had very low amount of contaminants (bromine and antimony), while heavy oils contained them in enormous concentrations.

Factors Influencing the Quality of Pyrolytic Oil from Used Tires

Compared to middle oil and heavy oil, light oil has more extensive use in practice. Therefore, many factors that affect the light oil fraction of liquid produced during pyrolysis of waste tires were investigated with GC-MS, FT-ir, and chromatographic column as separated means. The results showed that carrier gas, flow rate, heating rate, and temperature all influence the percent of light oil. CO2 as carrier gas and fast flow rate can benefit to improve the yield of light oil, and fast heating rate cannot be favorable for the quality of oil. The components of the liquid composed of nearly 50% aromatic hydrocarbon, 19.06–24.66% alkanes, and distribution of polycyclic aromatic hydrocarbons (PAHs) as the function of temperature were also determined. Meanwhile, the depth of pyrolysis and relation of PAHs and possible reactions that occurred during pyrolysis were discussed.

Conversion of asphalt into distillate products

This paper reports the conversion of asphalt in a micro-autoclave under an inert atmosphere of nitrogen to lighter products. The influence of temperature, contact time and some catalysts, i.e. clay type; UTIMAC, HZSM-5 and sodium silicate, acidic type; phospho-tungstic acid, oxide type; ammonium hepta molybdate, silica gel, nickel oxide and alumina powder, chloride type; stannous chloride and aluminum chloride and modifiers like methyl iodide and coal, on the yield of liquid and gas products was studied. A marked effect of temperature on the yield of liquid as well as gas products was observed. Employment of clay type catalysts was found to be beneficial in term of yields of liquid products. Among the catalysts used; UTIMAC clay caused the maximum conversion to desired products. The other catalysts caused a decline in the yield of desired products because of coke formation due to condensation reactions catalyzed by these catalysts. The effect of concentration in the case of clay as catalyst was also studied, and synergistic effects were observed in terms of desired product yield. The study will be helpful in planning asphalt conversion processes into light oil fractions.