Quality Improvement of Heavy Gas Oil with Hydroprocessing

Quantity requirement for diesel fuel of low sulphur and aromatic content is increasing worldwide; meantime the quality of available crude oils has declined causing challenges in hydroprocessing of gas oils. Results of quality improvement of heavy gas oil are presented, it was carried out in one stage on NiMo/Al2O3 catalyst and in two stages on NiMo/Al2O3 and PtPd/USY-zeolit catalysts. In one stage hydroprocessing sulphur and polyaromatic contents of the products  met the requirements of the standard only if strict process parameters were applied which resulted in operation problems and product loss, moreover the advantageous process parameters of hydrodesulphurization and hydrodearomatization did not coincide. In two stages hydrotreating a partially hydrogenated product obtained on NiMo catalyst was further hydroprocessed on PtPd/USY at moderate process conditions. Results showed that the advantageous process parameters for reduction of sulphur and aromatics coincided. Quality parameters of products regarding to aromatics met not only the requirements of the standard but the stricter requirements of engine manufacturers also

Application Possibilities of Zeolite Catalysts in Oligomerization of Light Olefins

In recent decades, the application of more zeolite-type catalysts has been studied in oligomerization reaction. In the oligomerization process various boiling-range isoolefins can be produced which can be hydrogenated to isoparaffins. The oligomerization of olefins in the light FCC gasoline-matrix in the presence of zeolites has not yet been reported. Therefore, our objective was to select a catalytic system that is suitable for producing isoolefin mixtures from the referred feedstock. The activity of the studied catalytic systems was similar, but with the use of the two layered bed the share of oligomers in middle distillate boiling point range was doubled. In the favourable reaction conditions (two layered bed, T: 270 °C, P: 40 bar, LHSV: 1.0 h-1) such isoolefin mixtures can be produced from which after hydrogenation excellent, environmentally friendly gasoline, JET, and diesel gas oil blending components can be obtained

Kinetic Model Development of the Oligomerization of High Olefin Containing Hydrocarbon By-products to Clean Engine Fuels on Amberlyst Catalyst

Nowadays, since the demand for engine fuels is continuously changing, in petroleum refineries, increasing the flexibility of gasoline/middle distillate is still an important issue, e.g. by oligomerizing light olefins (3–6 carbon atoms). The aim of our work was to develop a valid kinetic model based on the extended Eley-Rideal mechanism to describe the oligomerization of the olefin content of light naphtha by fluidized catalytic cracking (FCC) on an ion-exchange resin. Experiments were carried out in a fixed-bed tubular reactor at temperatures of between 80 and 130 °C with liquid hourly space velocities (LHSV) of between 0.5 and 2.0 1/h using Amberlyst® 15 as a catalyst. The oligomerization process was characterized based on the composition of products determined by gas chromatography. The conversion of olefins and the selectivity of the oligomerization reactions forming C8-11 and C12+ hydrocarbons (C8-11 and C12+ selectivity; unit: relative %) were dependent on factors that determine the reactor performance in order to identify the kinetic model parameters. Given that the developed reactor model described the measured data reasonably accurately, it can be used in terms of the optimal design of an industrial oligomerization reactor

Isomerization of paraffin mixtures produced from sunflower oil

The importance of biofuels becomes more acute, especially in the European Union. Beside them, the bio gas oil is a promising product that is a fuel with high isoparaffin content in the gas oil boiling range, which can be produced by the catalytic hydrogenation of different triglycerides. In this paper the isomerization of different intermediate products obtained over different hydrogenation catalysts and having high n-paraffin content was studied on SAPO-11 catalyst at 300–380 °C temperature, 20–80 bar pressure, 0.5–3.0 h-1 of liquid space velocity and 400 Nm3 /m3 of H2/feed ratio. It was found that the oxygen containing intermediate products significantly changed the degree of isomerization, but the hydrocarbon composition and the aromatic content of the n-paraffin mixtures had no noticeable effect on the conversion. During the experiments excellent quality diesel gas oil blending components were produced with high i-paraffin content and they were practically free of heteroatom conten

Storage Stability of Gas Oils Containing Waste Originated Biocomponent

Nowadays in Europe the demand for diesel fuel is continuously growing, while the demand for gasoline decreases slightly. Currently, the biodiesel is the biofuel which is blended into the gas oil with the highest amount in case of Diesel engines, which can be produced from different, even waste-derived triglycerides (with transesterification with alcohol). Due to the adverse properties of biodiesel the storage stability of biodiesel/diesel blends has to be examined in detail.In our experimental work we investigated the changes in the qualities of biodiesels produced from vegetable oil which contained various waste cooking oil (waste-derived component) share (10, 30, 50%), and its 7 and 10% blends with gas oil in case of long-term (more than 130 weeks) storage. We found that with increasing the proportion of used cooking oil in the vegetable oil used as raw material for biodiesel, the oxidation reactions took place in a greater degree. Biodiesel made from vegetable oils containing 10% used cooking oil was the most applicable for blending; in case of using higher proportion it is very necessary to use a further amount of antioxidant additives to minimize the degradation

Reduced aromatic jet fuels

At present time growing demand and more sever quality specifications are observed for the jet fuels. The reasons of these are the growing aviation and the more conscious environmental requirements. The expansion of aviation featured the last two decades, especially the 2% at the beginning of the reviewed period approaches 15%, if we calculate in the point of passenger kilometers the driven passages with vehicles, buses, railroads and jets. It can not be left from focus that aviation generates only 2% of the CO2 emission of the world. This value can grow only for 3% to 2050, moreover it generates 12% of the CO2 emission of the full transportation section, for comparison the public way transport generates 76% of the CO2 emission. One of the greatest problems is the jets that fly at one time more than 1500 kilometers, because aviation produces 80% of the greenhouse gases. But there are no other alternatives for bridging these distances in the transport section. The quality of the jet fuels is improvable with reducing their sulphur- and aromatic content. The hydrogenation of the aromatic content of the jet fuels to naphtenic hydrocarbons can produce products that are environment-friendly, they have high energy content, lower density, which contributes to satisfying the growing demands. Our aim was to study the possibilities of producing low sulphur and aromatic content jet fuels in a catalytic way. On a transient metal catalyst we studied the possibilities of quality improving of Russian crude oil based petroleum fraction depending on the change of the operating parameters (temperature, pressure, liquid hourly space velocity, volume ratio). With 1800 mg/kg sulphur content petroleum on the NiMo/γ-Al2O3 catalyst we carried out the experiments at 200–340°C, 20–50 bar pressure, 1.0–3.0 cm3 /cm3 h liquid hourly space velocity and 200-400 Nm3 /m3 hydrogen/hydrocarbon ratio. Based on the quality parameters of the liquid products we found that we made from the Russian based petroleum in the adequate technological conditions products which have lower sulphur content than 10 mg/kg and which have reduced aromatic content, so these are excellent jet fuels, and their stack gases damage the environment less. We blended bioparaffins to the products of the catalytic experiments. We reached products with lower aromatic content than 5%

Investigation of storage stability of biodiesels

The production and application of fuels from agricultural origin have emerged into focus in the last couple of years. A number of environmental, political and economical factors has confirmed and strengthened this process. The main reason of this tendency is the energy policy of the European Union, namely to reduce the green house gas emission of fuels, to decrease the significant dependence of EU on import energy and crude oil and to support rural development. To achieve these objectives, the European Union created the 2003/30/EC and 2009/28/EC directives, which regulate the application of biomass derived fuels. The main purpose is to promote the use of biofuels in transportation by recommending and specifying the share of the bio-components. This proposed value (10 energy % share of biofuels in the transport sector by 2020 in the EU) can be reached by the conversion of different triglyceride-containing biofeedstocks (e.g. vegetable oils, used frying oils, animal fats, algae oils, brown grease, etc.) to different biofuels or blending components. Nowadays FAME (Fatty Acid Methyl Esters), called as first generation biofuel, is mostly used as diesel bio blending component. But this biofuels due to its chemical structure the presence of the double bond in the molecule have a high reactivity with the oxygen, especially when it placed contacting air. That is why the long term storage stability of biodiesel is an important issue. The aim of our research work was to investigate the long term storage stability of biodiesel samples originated from different feedstock. The effects of the real storage conditions on the properties (induction period, acid value, iodine value, density, water content and kinematic viscosity) of the different biodiesels were investigated. Results showed that the acid number and the water content increased, while the induction period and the iodine number decreased with increasing storage time of biodiesel samples

Investigation of catalytic conversion of Fischer-Tropsch wax on Pt/ALSBA-15 and Pt/beta zeolite catalysts

Because of the more serious problems with the environment (e.g. greenhouse effect) and the crude oil supply (e.g. import dependence) the use of fuels and lubricants produced from renewable feedstocks have come to the front nowadays. The Fischer-Tropsch wax (60–80% of the Fischer-Tropsch products) which is produced on synthesis gas from different sources (biological or waste), is a mixture of high molecular weight (C20-C60) n-paraffins, which are in solid state (high pour point) at normal conditions. The products (fuels and base oils) which can be produced from this paraffin mixture have high quality and have fewer negative effects on the environment (practically zero sulphur- and nitrogen content, low aromatic content, excellent application properties) thus they do not demand changes in the fuel supply infrastructure and in the engine constructions. The isomerization of high molecular weight n-paraffins can be effectively carried out on bifunctional catalysts. There are only a few indications about the application of metal catalysts on mesoporous carrier in the literature. Consequently our objective was to investigate some Pt/AlSBA-15 (SBA: Santa Barbara Amorphous) catalysts which have not been investigated in detail in this reaction system yet, and compare its properties with a Pt/beta zeolite catalyst which has been recommended for this reaction earlier. The applicability and catalytic activity of Pt/AlSBA-15 and Pt/beta zeolite catalysts of 0.5% platinum content for the selective isomerization of Fischer-Tropsch wax was investigated in the present experiment. The experiments were carried out in a high-pressure microreactor system in continuous operation and on a catalyst with steady-state activity. The main properties of the feedstock which was a mixture of paraffin produced by Fischer-Tropsch synthesis (the synthesis gas was produced from biomass) were: n-paraffin content (C18-C57): 97.4%, sulphur content: <5 mg/kg, pour point: 72 °C. In the experiment the following process parameters were applied: T = 275–375 °C, P = 40–80 bar, LHSV = 1.0–3.0 h-1, H2/hydrocarbon ratio: 400–800 Nm3 /m3 . The composition of the products was determined by gas chromatography. From the catalysts with different support the best results were gained on the catalysts with AlSBA-15 support, and with increasing temperature the yield of liquid products (C5+) decreased, but until 325 °C this value was above 93% in every case. In case of the beta zeolite high amount of cracking took place. Increasing the pressure shifted back the hydrocracking reactions (with the increasing number of moles) so it had a decreasing effect on the volume of the gas products and the lower contact time (higher liquid hour space velocity) had the same effect. In the gas products mainly branched isobutane was identified, which indicated that the cracking enacted partly after the isomerization reactions. The isoparaffin contents of the liquid products in the function of process parameters increased with increasing temperature and decreased with increasing pressure and LHSV in every case while other parameters were kept constant. Based on the isoparaffin contents of the different fractions it can be concluded that on Pt/AlSBA-15 catalyst at advantageous process parameter combinations (T = 300–325 °C (C11-C20)/ 275–300 °C (C21-C30), P = 40–80 bar, LHSV = 1.0–2.0 h-1) the catalyst was applicable to produce C11-C20 and C21-C30 fractions with high isoparaffin content (63.5–85.6% and 34.1–58.7%) with adequate yields (29.9–36.6% and 46.2–58.8%). We experienced that the gas oil fractions having the lowest pour point were obtained in the case of high concentrations of 5-methyl isomers. The C21-C30 fraction is a high viscosity index (VI ≥ 125) base oil. The selectivity of the target product fractions was high, and based on these facts the selective isomerization of the Fischer-Tropsch wax can be a new application area of the Pt/AlSBA-15 catalys