Hydrocarbon Fractions Research Articles

Hydrocarbon selectivity enhancement through catalytic fast co-pyrolysis of almond shell and plastic blends

BackgroundThe aim of this article is to explore possible pathways for the synergistic optimization of bio-oil by the catalytic fast co-pyrolysis of almond shell (AS) and plastic residues (polyethylene, PE, and polystyrene, PS). Pyrolysis was carried out at 650 °C at a heating rate of 20 °C/ms at a residence time of 20 s. Hydrogen from the plastic promoted the decarboxylation of acids and decarbonylation of carbonyls and sugars from biomass waste.ResultsCo-pyrolysis results showed a fall in oxygen in the AS/plastics blends, whereas carbon yields increased as did the calorific value of the oil. As expected, AS/PE blends enhanced production of hydrocarbon fractions, especially olefins, with yields reaching 81.1%, whereas AS/PS blends enhanced formation of aromatic compounds. HZSM-5 assisted the increase of monocyclic aromatics content in AS/PE blends. AS/PS blends favoured the increased of aromatics (45% of total hydrocarbons for 1:2 AS/PE-HZ). For AS/PS-HZ blends toluene was enhanced as was the production of 1,3,5-cycloheptatriene.ConclusionsThese findings helped to gain a great insight into how catalytic co-fast pyrolysis of feedstocks can enhance the formation of value-added products, promoting their economic potential for agricultural exploitations.Graphical

On the soot formation characteristics of an ammonia-ethylene counterflow diffusion flame based on the orthogonal decoupling method

Ammonia is regarded to be one of the most competitive fuels for achieving carbon neutral due to its carbon-free properties. In this work, the effects of adding ammonia (NH3) to the fuel stream of an ethylene counterflow diffusion flame on the soot formation characteristics were numerically investigated. The orthogonal decoupling method was used to completely separate the dilution, chemical and thermal effects of the added NH3 by introducing two different virtual NH3. The influence of these effects and their interactions were explored by the range analysis, respectively. The results show that the soot volume fraction (SVF) of the flame decreases under the dilution, chemical and thermal effects of NH3, with the dominated effect being the chemical effect, followed by the dilution effect, and the least is the thermal effect. Besides, the chemical-thermal interaction also has an important impact on the SVF. The increase of SVF is dominated by the HACA surface growth, while the decrease of that is dominated by the OH oxidation. The HACA surface growth reaction is inhibited under the three effects of NH3 addition mainly due to a lower concentrations of C2H2 and H radical. The number density of soot increases under the chemical effect, while decreases under the dilution effect. The mole fractions of polycyclic aromatic hydrocarbons (PAHs) reduces under these three effects, leading to a lower inception rate, which in turn has a significant effect on the number density of soot.

Optimization of Polypropylene Waste Recycling Products as Alternative Fuels through Non-Catalytic Thermal and Catalytic Hydrocracking Using Fresh and Spent Pt/Al2O3 and NiMo/Al2O3 Catalysts

In this work, the conversion of waste polypropylene to alternative fuels (liquid and gas) was performed through non-catalytic thermal and catalytic hydrocracking over NiMo/Al2O3 and Pt/Al2O3 catalysts. The process was carried out in an autoclave batch reactor at a temperature of 450 °C and a pressure of 20 bar, which were selected based on experimental optimization. The spent catalyst was also successfully regenerated at 700 °C under a hot airflow. Experiments were conducted to determine the optimum conditions to completely separate the deactivated catalyst from the solid residue easily. The regenerated catalyst was reused to facilitate the economic cost reduction of the process. The reactivated catalysts have almost the same catalytic properties as the fresh catalysts; this was confirmed by several characterization techniques, such as TGA, XRD, SEM, EDX, BET and FTIR. The produced liquids/gases were quantified and classified into their fractions by the number of carbon atoms and gasoline to diesel ratio using GC/MS. The viscosity, density, API gravity, pour point and flash point of oil cuts were also investigated to evaluate the quality of the resulting liquid from the reactions. The NiMo/Al2O3 catalyst gave the highest liquid hydrocarbons yield of 86 wt%, while the highest weight products of gasoline range hydrocarbon fractions of 49.85 wt% were found over the Pt/Al2O3 catalyst. Almost the same catalytic behavior was found with the regenerated catalysts compared to the fresh catalysts. However, the highest gaseous products at 20.8 wt% were found in the non-catalytic thermal products with an increase in the diesel fuel range of 80.83 wt%. The kinetic model was implemented using six lumps and fifteen reactions, and the apparent activation energies for the gasoline and diesel fractions were calculated. In general, all primary and secondary reactions show greater activation energy values on the Pt/Al2O3 catalyst than on the NiMo/Al2O3 catalyst.

Degradation of crude oil by the microbial populations of Lagos and Ologe lagoon waters

Introduction: hydrocarbon contamination of surface waters as a result of anthropogenic activity poses threat to ecosystems and counter their beneficial uses. Some indigenous microbial communities have the potential to purify such waters unaided. Aims: To show the biodegradative potential of microbial communities in Lagos and Ologe Lagoons during minimal pollution with crude oil. Materials and Methods: The total heterotrophic bacteria and hydrocarbon utilising bacterial and fungal populations were estimated from Lagos and Ologe lagoon water samples contaminated with 1% crude oil over 42-day incubation period by plate count and vapour-phase transfer techniques. Residual hydrocarbons were determined by Gas chromatography. Results: The predominant bacterial genera identified from the lagoons include Enterobacter, Klebsiella and Proteus, while Escherichia, and Morganella. Aspergillus and Mucor were the predominant fungal genera in both waters. The hydrocarbon degradation rate in the Lagos Island microcosm was 65.391±0.370 mg/l/d, degradation rate constant 0.05±0.01 /d, half-life 9.559±0.093 /d and percentage degradation of 95.315 ± 0.134. Corresponding values in the Ologe water were 61.190± 8.542 mg/l/d, 8.725 ±0.389 /d, 0.055±0.003/d and 96.345±0.488 respectively. There was almost complete disappearance of the various fractions of the oil in the two samples. The microbial communities from both lagoons effectively utilised majority of the hydrocarbon fractions after 42 days where 66.890±1.075 and 100±000 were recorded for benzene, toluene had 100±000 percent degradation, anthracene 96.755±0.119 and 99.726±0.026, and pristane had 91.674±0.222 and 99.943±0.015 while phytane had 96.44±0.058 and 99.670±0.104 respectively. Conclusion: Efficient biodegradation of moderate contamination crude oil could be achieved by indigenous microbial flora present in Lagos and Ologe lagoon waters.

On the products from the pyrolysis of heavy fuel and vacuum residue oil

Incorporating unconventional fuel sources into the global energy mix is necessary to meet increasing energy demand. One attractive option is the gasification of residual fuels, such as heavy fuels, which produce clean combustible gases. Pyrolysis is the first step in the gasification process, so its understanding can help in the development of the gasification process. The information on the pyrolysis products can serve the development of chemical kinetics mechanisms for gasification of heavy fuels for their efficient utilization. In this study, pyrolysis of heavy fuel oil (HFO) and vacuum residue oil (VRO) is reported. The pyrolysis experiments were conducted in a wide temperature range of 400–1000 °C in a customized tubular furnace-based reactor and products were collected. Both liquid and gaseous products were characterized using a gas chromatography (GC)-mass spectrometry (MS)-flame ionization detector (FID) and Fourier transform–ion cyclotron resonance–mass spectrometer (FT-ICR MS) to understand the presence of different types of compounds. The identified compounds in the liquids were classified as benzene derivatives, naphthalene derivatives, polycyclic aromatic hydrocarbons, saturated and unsaturated hydrocarbons and sulfur-containing compounds. The presence of lighter hydrocarbon fractions in HFO acts as a hydrogen donor and resulted in the formation of more saturated hydrocarbons compared to VRO under pyrolysis conditions. Compounds present in the heavy fraction (with high molecular weight) which could not be analyzed and identified in liquid samples using GC-MS/FID were analyzed using FT-ICR MS. Elemental analyses of solid residues obtained from pyrolysis were also performed. Twenty lighter hydrocarbons ranging from C1-C5 were identified and quantified in the pyrolysis vapors of both fuels.

Non-Oxidative Ethane Dehydrogenation in a Packed-Bed DBD Plasma Reactor

Plasma-assisted conversion of ethane (C2H6) can produce value-added chemical building blocks using green electricity. Here we employ a simple packed-bed coaxial dielectric barrier discharge (DBD) reactor to convert C2H6 at mild operating conditions unattainable by conventional thermocatalysis. Ethylene (C2H4), acetylene (C2H2), and methane (CH4) are the main products along with small fractions of C3 and C4 hydrocarbons. Interestingly, the C2H4 selectivity is primarily correlated to C2H6 conversion, dominated by electron dissociation and recombination reactions irrespective of the dielectric properties of the packed bed material (SiO2, Al2O3, ZrO2, TiO2, and BaTiO3), packing material size, supplied power, and C2H6 concentration. While a distortion of the electric field and discharge propagation results in varying dissipated power as materials change, the C2H4 energy yield remains constant. The particle size appears to affect conversion mainly due to pressure alterations. Pd/SiO2 catalyst can change the selectivity, favoring saturated species by expending hydrogen.

Bioremediation study of a hydrocarbon-contaminated soil by profiling aromatic and aliphatic chains

Efficient decontamination of oil contaminated soils is not always easy, especially when the contamination is aged. In this work, we have opted for bioremediation techniques, with a low environmental impact, whose treatments were selected according to the area and soil to be treated. Thus, an industrial area, which had had fuel oil spills for decades, was our decontamination target, using bioremediation techniques that included bioaugmentation with bacteria (autochthonous bacterial consortium), phytoremediation with a plant (Medicago sativa L.) and bioaugmentation with a fungus (Pleurotus ostreatus). These treatments were tested alone and in combination to observe any possible synergies. The evaluation of these treatments for the degradation of the total aliphatic and aromatic fractions of total petroleum hydrocarbons (TPH), showed a higher efficiency (18–48 %) in the degradation of the aliphatic fractions for all the treatments compared with natural attenuation (11 %). By contrast, lower efficiencies were obtained for the aromatic fractions (0–35 %) compared with natural attenuation, which did not decrease. The removal of these fractions was only effective in the combined treatment using all three organisms: the plant, the bacteria, and the fungus, where the bioaugmentation enhanced the plant-microorganism interaction in the root system. The selection of the biological treatments to a specific contaminated site and the evaluation of decontamination by the aromatic and aliphatic chain profiles, leads to a better understanding of the degradation of the different fractions of fuel.

Bacterial community dynamics and associated genes in hydrocarbon contaminated soil during bioremediation using brewery spent grain.

Brewery spent grain (BSG) has previously been exploited in bioremediation. However, detailed knowledge of the associated bacterial community dynamics and changes in relevant metabolites and genes over time is limited. This study investigated the bioremediation of diesel contaminated soil amended with BSG. We observed complete degradation of three total petroleum hydrocarbon (TPH C10-C28) fractions in amended treatments as compared to one fraction in the unamended, natural attenuation treatments. The biodegradation rate constant (k) was higher in amended treatments (0.1021k) than in unamended (0.059k), and bacterial colony forming units increased significantly in amended treatments. The degradation compounds observed fitted into the elucidated diesel degradation pathways and quantitative PCR results showed that the gene copy numbers of all three associated degradation genes, alkB, catA and xylE, were significantly higher in amended treatments. High-throughput sequencing of 16S rRNA gene amplicons showed that amendment with BSG enriched autochthonous hydrocarbon degraders. Also, community shifts of the genera Acinetobacter and Pseudomonas correlated with the abundance of catabolic genes and degradation compounds observed. This study showed that these two genera are present in BSG and thus may be associated with the enhanced biodegradation observed in amended treatments. The results suggest that the combined evaluation of TPH, microbiological, metabolite and genetic analysis provides a useful holistic approach to assessing bioremediation.

Occurrence and concentrations of organic micropollutants (OMPs) in highway stormwater: a comparative field study in Sweden

This study details the occurrence and concentrations of organic micropollutants (OMPs) in stormwater collected from a highway bridge catchment in Sweden. The prioritized OMPs were bisphenol-A (BPA), eight alkylphenols, sixteen polycyclic aromatic hydrocarbons (PAHs), and four fractions of petroleum hydrocarbons (PHCs), along with other global parameters, namely, total organic carbon (TOC), total suspended solids (TSS), turbidity, and conductivity (EC). A Monte Carlo (MC) simulation was applied to estimate the event mean concentrations (EMC) of OMPs based on intra-event subsamples during eight rain events, and analyze the associated uncertainties. Assessing the occurrence of all OMPs in the catchment and comparing the EMC values with corresponding environmental quality standards (EQSs) revealed that BPA, octylphenol (OP), nonylphenol (NP), five carcinogenic and four non-carcinogenic PAHs, and C16-C40 fractions of PHCs can be problematic for freshwater. On the other hand, alkylphenol ethoxylates (OPnEO and NPnEO), six low molecule weight PAHs, and lighter fractions of PHCs (C10-C16) do not occur at levels that are expected to pose an environmental risk. Our data analysis revealed that turbidity has a strong correlation with PAHs, PHCs, and TSS; and TOC and EC highly associated with BPA concentrations. Furthermore, the EMC error analysis showed that high uncertainty in OMP data can influence the final interpretation of EMC values. As such, some of the challenges that were experienced in the presented research yielded suggestions for future monitoring programs to obtain more reliable data acquisition and analysis.

Hydrothermal liquefaction of starch using homogeneous and heterogeneous co-catalysts

We examined the hydrothermal liquefaction (HTL) of potato starch with K2HPO4, which dissolves in hot, compressed water, along with metal-containing co-catalysts, which present a separate solid phase in the reaction system. Co-catalytic HTL with K2HPO4 and either Mo2C or Co-Mo/γ-Al2O3 produced more biocrude than did HTL with no catalyst or either catalyst alone. The synergistic effect of co-catalysis was greatest when the masses of K2HPO4 and Co-Mo/γ-Al2O3 were equal. At this condition, HTL with the two catalysts produced a biocrude that contained more than 90% of the chemical energy originally in the biomass feedstock. This biocrude also had a larger portion (61 wt%) of desirable lighter components (volatilized below 343 ℃) than did the biocrudes from HTL with either catalyst individually at the same conditions (38 and 41 wt%). With the addition of catalysts, there was less aliphatic content in the biocrude, and more ethers and aromatics appeared. The use of K2HPO4 and Co-Mo/γ-Al2O3 together for HTL led to greater fractions of alcohols, aldehydes/ketones, hydrocarbons, and phenolic compounds in the biocrude. In addition, less of the organic carbon in the feedstock migrated to the aqueous products. We identify catalysis of different HTL pathways to account for the experimental observations.

Soot formation of renewable gasoline: From fuel chemistry to particulate emissions from engines

Renewable fuels are essential to meet climate protection goals, especially for decarbonizing the existing vehicle fleet. In addition, optimized and specially designed fuels allow emissions to be avoided before they occur. This paper presents fuel effects on emission characteristics of six chemically complex gasoline blends compliant with the DIN EN 228 standard and one ethanol/gasoline blend, focusing on particle emissions. First, the sooting propensity of the fuels was examined using different soot indices, such as the Particulate Matter Index (PMI), the Oxygen Extended Sooting Index (OESI), the Yield Sooting Index (YSI), and the soot threshold (φST), which is drawn on measurements of the particle number (PN) density in the exhaust gas of a laminar flat flame. Second, PN emissions (particle number concentration) from a production-calibrated turbo gasoline direct injection engine with four cylinders were investigated. Third, soot precursor chemistry was investigated using a laminar flow reactor at atmospheric pressure. Finally, correlations to fuels’ volatility and chemical characteristics were made for the complete data set. Based on the soot precursor chemistry in the homogeneous gas phase reaction, the analysis shows that engine PN emissions are primarily influenced by fuel chemistry for the investigated engine conditions. In particular, the composition of the hydrocarbon fraction is decisive, with the heavy C9+ aromatics and the upper distillate significantly influencing soot formation. In order to reduce PN engine emissions, future fuels should contain fewer soot-increasing hydrocarbon fractions.

Effect of time on alternative hydrocarbon production from waste PS with biodiesel of candlenut oil using catalytic cracking and Si/Al-Ceramic as catalyst

In the present study, the catalytic cracking process of polystyrene (PS) plastic waste and biodiesel of candlenut oil was carried out using Si/Al-ceramic catalyst with a mass ratio of 7:3 at 300 °C. This study aimed to investigate the effect of reaction time on the distribution of hydrocarbon fuel fractions produced. They are characterized by XRD, SEM-EDX, FTIR, and N2 gas adsorption-desorption. The products components of PS catalytic cracking were analyzed by gas chromatography-mass spectroscopy (GC-MS). The liquid fuel obtained was mixed with commercial fuel, Premium RON 88, and methyl tertiary butyl ether (MTBE) additive to determine its physicochemical properties and performance in a generator engine with gasoline-based fuel. The result showed that an increase in reaction time from 60 minutes to 120 minutes of PS cracking over Si/Al-Ceramic catalyst leads to the enrichment of long-chain hydrocarbon fraction (> C12) by 25.61% which is attributed to the formation of styrene dimer. The fuel has thermal efficiency of 26.49% with density of 0.7405 g/cm3, flashpoint of < -50 °C, calorific value of 9642.42 kcal/kg, and octane number of 92.2. These characteristics are in accordance with SNI 06-3506-1994 standard. Therefore, liquid fuel from catalytic cracking of polystyrene plastic wastes can be used as a potential alternative fuel in the gasoline range.

Study of a light hydrocarbon fraction spill migration that occurred in an area of the Mexican southeast using computational fluid dynamics

The present work aimed to study, predict and understand benzene migration that occurred during an industrial spill using numerical simulation by computational fluid dynamics. Advection, diffusion and adsorption were the main mechanisms considered that governed the spill incident. The incident occurred due to a fracture under a fuel oil storage tank. The tank was located on a hill 18m high, and the initial value of benzene concentration (soil saturation) was 60ppm. When the spill was discovered, samples in the affected zone were taken using an experimental design. Many samples showed a greater concentration of benzene than allowed by Mexican Official Standards (MOSs) (15ppm). The concentrations found 100m away from the spill were around 60 to 15ppm. Due to the spill being under the tank, it was difficult to discover. The numerical simulation provided an estimate that the spill started around 2years ago. The type of soil in the afflicted zone is rocky, and, consequently, it is difficult to estimate how long it will take to reach the concentration allowed by the MOSs, but the numerical simulation predicts that this concentration will be reached in 14years. Experimental values of the spill contaminant concentration were statistically similar to the CFD estimated data (p < 0.05).

Повышение эффективности систем улавливания паров нефти при товарно-транспортных операциях на нефтеналивных терминалах

In this paper the problem of losses from evaporation of light fractions of hydrocarbons during loading operations of tanker fleets vessels is considered. It was found that there is no unified approach to modeling the system “tanker – gas phase pipeline – vapor recovery units” in open sources. The absence of a generally recognized model makes it impossible to scientifically justify the application of instruments to reducing losses and the development of corresponding measures. In work it is showed that the dynamics of growth of pressure in the inner tanker capacity is described by a differential equation, considering for non-stationary essence of the process. This equation is converted to a non-dimensional form and investigated in relation to the similarity criteria of this system. This research has allowed to establish unambiguously the general character of pressure changes in the inner tanker capacity, and to predict the peak values of its growth at the initial stage of the loading operation. The obtained equations were tested on real tanker loading data and showed satisfactory convergence with the experimental data. At different stages of the loading opera-tion the component composition of vapor changes, which is shown by chromatographic analysis of the gas mixture. With the availability of a model of hydrocarbon vapor displacement from the inner of tanker, it is possible to propose measures to minimize the negative impact on the environment and return valuable vapors of the product to the technological chain of transportation.

Catalytic pyrolysis of olive mill wastes towards advanced bio-fuels and bio-chemicals using metal oxide catalysts

Among the environmental challenges that Mediterranean countries have to address are the abundant amounts of olive mill wastewater (OMWW) produced by olive oil agro-industry, such as those found in Greece and Tunisia, which lead to significant land and water pollution. The most common disposal method of olive mill wastewater, includes storage ponds, where most of the water is evaporated, while the residual sludge (olive mill wastewater sludge, OMWWS) is sent to landfills. Fast pyrolysis of OMWWS was investigated as an alternative approach of valorizing this waste, leading to the production of high heating value biofuel (bio-oil). Extraction of polyphenolic compounds with bioactive properties from OMWWS was additionally explored in order to provide further added value to OMWWS, considered as a source of bioactively important polyphenolic compounds, prior its use as pyrolysis feedstock towards the production of green fuel. Pyrolysis of the treated OMWWS (after extraction) led to a considerable reduction of the bio-oil yield, however in both cases the bio-oil produced exhibits a very interesting composition (predominance of aliphatic hydrocarbons and small fractions of aromatic hydrocarbons and phenols) and sufficiently low oxygen content. Exploring the effect of either an acidic (ZSM-5) or a basic (MgO) catalyst on the yield and composition of the bio-oil produced during the catalytic pyrolysis of OMWWS we observed that yield and quality of the produced bio-oils strongly depended on the catalyst used. Thus, acidic ZSM-5 zeolite catalyzed cracking and aromatization reactions, resulting in a bio-oil enriched in aromatics, while basic MgO catalyzed decarboxylation of fatty acids yielding a bio-oil composed mostly of aliphatic hydrocarbons. In addition, Co-promoted catalysts (5% Co either on ZSM-5 or MgO) led to additional variation of bio-oil quality, mostly enhancing ketonization reactions. The effect of a series of Fe and Mn oxide catalysts, based on alumina, silica and magnesia supports, was also studied for the catalytic pyrolysis of OMWWS, mainly focusing on using low-cost catalytic materials. In addition, ferric oxide, aluminum oxide, magnesium oxide, and silicon oxide, are among the major components of red mud, an effective catalyst used in the pyrolysis of OMWWS. All of these Fe- or Mn- materials exhibit very promising in situ upgrading of pyrolysis vapors (retaining organics’ yield and improving produced bio-oil). Most of these materials also tend to favor ketonization reactions, a more or less preferred route among the studied catalysts, which seems to mainly relate with their multifunctional (both acidic and basic) character.

The role of porosity and acidity in the catalytic upcycling of polyethylene

Plastics have become fundamental and widespread materials in our everyday life. Nowadays, the most demanded plastics are polyolefins, accounting for nearly half of the Global plastic production. However, the end-of-life disposal of these materials is an issue inevitably connected to their increased production. Among chemical recycling techniques, the most thoroughly investigated process is the catalytic pyrolysis, showing a vast panorama of different set-ups optimized for the major production of either gaseous or liquid compounds. In this contribution a series of mesoporous silica-based materials, either pure SiO2 or substituted with Zr and Al, were systematically synthetized varying both porous framework and surface acidity, in the attempt of rationalizing the effect of each parameter (deeply characterized by physico-chemical methods) on the catalytic pyrolysis of linear low-density polyethylene (LLDPE). The synthetized materials together with some zeolites and aluminas reference samples were tested towards LLDPE degradation in a batch reactor set-up optimized for the formation and accumulation of the gaseous compounds, coupled with IR spectroscopy for in situ monitoring the evolution of the most abundant species (mostly propylene and branched C4-C6 olefins, together with a minor fraction of ethylene and short hydrocarbons). This work points out the necessity of the presence of Brønsted acid sites for a good activity (in terms of both the yield of gaseous products and lowering of the process temperature), but it also reveals a non-negligible role of the Lewis acid sites and it warns about the importance of controlling not only the amount of acid sites but also their strength.

Assessment of Hydrocarbon Potential Conversion in Source Rocks in the Southwestern Flank of the Korotaikha Depression, Timan–Pechora Basin

The 1-D burial and thermal history of the Korotaikha depression in the Timan–Pechora basin was numerically simulated for the sedimentary sequences of three wells: Korotaikhinskaya 1, Labogeyskaya 15, and Khavdeiskaya 1. This made it possible to numerically assess the conversion history of the hydrocarbon (HC) potential of source rocks in the southwestern flank of the Korotaikha depression in the northeastern Timan−Pechora basin. The modern modified kinetic spectrum of vitrinite maturation was used in calculations of the vitrinite reflectance to clarify the thermal history of the sedimentary cover of the study area. The occurrence of episodes of hydrothermal activity follows from comparison of the calculated and measured values of the vitrinite reflectance and explains the jumps in the maturity of organic matter at the boundaries of the unconformity of Quaternary and Triassic sediments, as well as the Permian and Carboniferous sediments. The simulations suggest a high conversion of the initial HC potential of the source rocks of the Silurian and Domanic horizons, Tournaisian, and Visean ages in the Korotaikhinskaya and Labogeiskaya areas and moderate generation in the Havdeyskaya area. The simulation shows that the high grades of the catagenesis (MC5 and higher) of the main source rocks and the significant role of secondary cracking of liquid HC fractions in the central part of the Korotaikha depression (wells Korotaikhinskaya 1 and Labogeyskaya 15) suggest that the possible HC accumulations should contain only gas. Accumulations in the southern part of the depression (Khavdeiskaya area), where secondary cracking was minimal and source rocks occur within the oil window, should contain both oil and gas (due to Permian rocks with terrigenous organic matter).

Boosting the activity in the direct conversion of CO2/CO mixtures into gasoline using ZnO-ZrO2 catalyst in tandem with HZSM-5 zeolite

The direct production of C5+ hydrocarbons from CO2/CO mixtures with methanol as intermediate is an attractive alternative for the production of gasoline from CO2 and syngas derived from biomass. With this purpose, the performance of CuO-ZnO-ZrO2 (CZZ), In2O3-ZrO2 (IZ) and ZnO-ZrO2 (ZZ) metallic oxides was compared by using them in tandem with a HZSM-5 zeolite. The catalysts were analyzed by means of N2 adsorption-desorption, XRD, XRF, H2-TPR and NH3-TPD. Two series of runs were performed in a packed bed reactor: (i) the methanol synthesis with the metallic oxides as catalysts, at 250–430 °C; 50 bar; CO2/COx, 0–1; H2/COx, 3; space time 6 gcat h molC−1; and (ii) the synthesis of hydrocarbons with the tandem catalysts with a metallic oxide/zeolite mass ratio of 1/1, at 340, 380 and 420 °C; 30 and 50 bar; CO2/COx, 0.5 and 1; H2/COx, 3; space time 12 gcat h molC−1. The results were quantified in terms of yield and selectivity of the product fractions and CO2 and COx (CO2 + CO) conversion. The higher methanol yield attained with the CZZ catalyst for the CO + H2 feed and its mixing with CO2 was faded by the problem of its sintering above 350 °C (minimum temperature required for the extent of methanol conversion to hydrocarbons). The IZ and ZZ catalysts were active, selective to methanol and stable both in the methanol synthesis and when used in IZ/HZSM-5 and ZZ/HZSM-5 tandem catalysts. Excellent results were obtained with the latter, which resulted in a 20.7% yield of C5+ hydrocarbon fraction at 420 °C and 50 bar, with CO2 and COx conversion of 39.7% and 28.4%, respectively. This fraction corresponded to isoparaffinic gasoline, with isoparaffin yield (mainly C5 and C6) surpassing 20% and low concentration of aromatics (0.1%) that led to a Research Octane Number of 91.8. This composition results attractive for its integration into the refineries gasoline pool. Furthermore, the changes of the CO2/COx ratio in the feed barely affected the yield and composition of the gasoline obtained with the ZZ/HZSM-5 catalyst, stating its great versatility.

Spinning band distillation of biomass pyrolysis oil phenolics to produce pure phenol

Competitive pricing for biofuels will require the coproduction of biobased products and chemicals to improve the economic outlook of biorefineries. Phenolics have been eyed due to their natural abundance in bio-oils relative to petroleum, as well as their potential profit margins. In bio-oils, the wide product distribution (especially phenolics) prevents meaningful separation. We’ve shown previously that bio-oils with relatively low oxygen (<15 wt%) from advanced pyrolysis processes can be distilled and/or extracted, producing a fraction rich in phenol and cresols. To further improve separation, we utilized a spinning band column distillation system, designed to perform at 200 theoretical plates. Catalytic (HZSM-5) pyrolysis bio-oils from switchgrass biomass first underwent extraction directly, producing a phenolic fraction and a hydrocarbon fraction. Subsequently, the phenolic fraction underwent a preliminary flash distillation ahead of spinning band distillation, in order to remove residues. Spinning band distillation resulted in fractions with more than 80 wt% phenol (the balance o-cresol), which can be purified by recrystallization in pentane. Both GC/MS and NMR indicate phenol crystals were obtained at ∼92 wt% purity. To complete the biorefinery concept, the hydrocarbon fraction was distilled to obtain a fuel product and heavy polyaromatic residues. The residues were thermally treated to produce bio-pitch.

Influence of Acid Reagents on Oil Sediment Formation

The formation of oil sediment in highly paraffinic oil in the presence of carboxylic and naphthenic acids was studied. The influence of the concentration and composition of acids on the process of sediment inhibition and the concentrations of paraffins, resins, and asphaltenes in sediments was demonstrated. In the composition of sediments obtained from oil with the addition of acidic reagents, the amount of light n-alkanes increased and the fraction of higher molecular weight hydrocarbons decreased. The concentrations of aliphatic fragments and carboxyl groups in the resins of sediments obtained with the addition of acidic reagents decreased, and the aromaticity coefficient increased. Asphaltenes in the sediment were characterized by a decrease in the concentrations of aromatic structures and carboxyl groups.