Yield Of Liquid Hydrocarbons Research Articles

Kinetic analysis of hydrocarbon generation based on saline lacustrine source rock and kerogen samples in the western Qaidam Basin, China

Tertiary carbonate rocks from the Qaidam Basin in China are typical plateau saline lacustrine source rocks. Despite the fact that this set of source rocks has a relatively low abundance of organic matter (major frequency of total organic carbon, 0.4–0.6%), the organic matter has a high hydrocarbon conversion rate and commonly forms low-maturity oil. In this study, a comparative analysis was conducted on Tertiary source rock and kerogen samples from the Qaidam Basin using a kinetic experiment of hydrocarbon generation. The objectives of the study were to investigate the mechanism of hydrocarbon generation from source rock to low-maturity oil and the catalysis of kerogen pyrolysis by minerals. The results showed that both the source rock and kerogen samples reached a maximum liquid hydrocarbon yield during the low-maturity stage. Eighty percent of the hydrocarbons were expulsed before the Easy Ro reached 0.8%. Special algal parent materials in the saline lacustrine basin could be the primary cause that leads to generating low-maturity oil. Compared to the kerogen samples, the source rock was more prone to hydrocarbon generation via pyrolysis. The latter had a higher liquid hydrocarbon yield per unit organic matter and a lower activation energy; thus, it entered the hydrocarbon generation threshold earlier. The key factor for the aforementioned differences might be catalysis by minerals (particularly carbonate minerals) and the presence of soluble organic matter in the source rocks.

Comparative study of nano iron catalysts in the presence of the crude polymer matrix and their cross link polymer in the Fischer-Trophsch synthesis

A new metal-polymer catalyst in a stable colloidal system, were prepared. Iron-paraffin catalysts, nano sized particles, with different polymers have been matrixes were used to examine the effects of polystyrene and their derivatives on chemical/structural properties through Fischer–Tropsch synthesis (FTS) and the yield as well. Nano size iron-containing particles distributed are suspended in the hydrocarbon medium of the slurry-reactor were found to have great impact and high percent conversion of CO to more than 70%. Polystyrene derivatives found to interact with Fe species by the formation of Fe3O4 oxide and amorphous hydrolyzed δ-FeOOH which were formed at the given conditions. All catalysts with a polymer found to have a bimodal distribution particle. In structural aspects, polystyrene derivatives increases the dispersion of Fe species and inhibits the coagulation of active iron particles, and on other hand, the chemical and structural effects would cause the increase of the FTS efficiency towered the selectivity of heavy hydrocarbons and olefins during the FTS. The state of iron and polymer-paraffin matrix were examined utilizing XRD and AFM techniques which showed the forms of ground state of iron as Fe3O4 oxide and amorphous hydrolyzed δ-FeOOH were exists. When the polystyrene derivatives are introduced, the proportion of amorphous paraffin found to be less than that in a crystalline state. The maximum conversion of CO (71%) and the yield of liquid hydrocarbons (63g.m-3) based on a cross-link polymer such as a polystyrene divinylbenzene (PS-DVB) used. A very interesting fact that the risen temperature found to have a small decrease in selectivity and an increase in conversion efficiency, this was observed in all reactions.

Methanol to Gasoline over ZSM-5 Zeolite Treated with Alkaline Mixture with Different Ratios of TBA+/OH–

The influence of ZSM-5 (SiO2/Al2O3 = 50) treatment with a tetrabutylamine hydroxide (TBAOH)/NaOH mixture having different mole ratios on its physicochemical properties and catalytic performance in the reaction of methanol to gasoline (MTG) was investigated. It was found that, with increasing ratio TBA+/OH–, the crystallinities, micropore surface areas, micropore volumes, the amounts of strong acid sites and Bronsted acid sites gradually increased, and the mesopore volumes decreased. The treatment with pure TBAOH (TBA+/OH– = 1.0) ensured the formation of narrow and uniform intracrystalline mesoporosity and the large amounts of strong or Bronsted acid sites on the zeolite, which contribute to the highest liquid hydrocarbon yield in the reaction of MTG.

Energy Valorization by Continuous Pyrolysis of Straight Vegetable Oils (SVOs)

Researches have been undertaken to find a form of valorization of the surplus production of vegetable oils in C&#244te d’Ivoire for their use as a substitute diesel. The first tests of the use of crude oils-diesel blends by the company Palmindustrie faced enormous difficulties. We have therefore undertaken a campaign of pyrolysis of Tropical Straight Vegetable Oils: palm, copra, peanut, cotton, cabbage palm and shea, between 400°C and 600°C under atmospheric pressure. A silica support was used in co-catalysis either with water or with methylcyclohexane, which is a model compound of cetanes contained in gas oil. This compound has the advantage, unlike the gas oil itself, of not masking the peaks of the pyrolysis recombinates of oils in the chromatograms. The condensed organic phase consists mainly of hydrocarbons including paraffins, olefins, alkylbenzenes and styrenes. The yields of liquid hydrocarbons vary between 72% and 86%. A comparative study of coke precursors and gas production was carried out. A discussion on the parameters to be considered for a large-scale implementation was undertaken.

Hydroconversion of rapeseed oil to hydrocarbons in the presence of MFI/MCM-41 micro–mesoporous materials synthesized by the hydrothermal microwave method

Catalysts containing an MFI zeolite and an MFI/MCM-41 composite synthesized by the hydrothermal microwave method have been first studied in rapeseed oil hydroconversion. Catalysts provide the production of valuable petrochemicals, namely, high-octane components of motor fuels and С2–С4 olefins. Synthesized MFI zeolite mostly catalyzed the formation of aromatic hydrocarbons (ArH); incorporation of this zeolite into the matrix of mesoporous silicate MCM-41 leads to a decrease in the ArH content in the liquid hydrocarbon products owing to an increase in the yield of liquid aliphatic hydrocarbons. Promotion of the MFI zeolite synthesized by the hydrothermal microwave method with zinc ions leads to the formation of a catalyst providing the formation of liquid products consisting of ArH.

Synthesis and catalytic performance of bimetallic NiMo- and NiW-ZSM-5/MCM-41 composites for production of liquid biofuels

This work presents a synthesis of bimetallic NiMo and NiW modified ZSM-5/MCM-41 composites and their heterogeneous catalytic conversion of crude palm oil (CPO) to biofuels. The ZSM-5/MCM-41 composites were synthesized through a self-assembly of cetyltrimethylammonium bromide (CTAB) surfactant with silica-alumina from ZSM-5 zeolite, prepared from natural kaolin by the hydrothermal technique. Subsequently, the synthesized composites were deposited with bimetallic NiMo and NiW by impregnation method. The obtained catalysts presented a micro-mesoporous structure, confirmed by XRD, SEM, TEM, EDX, NH3-TPD, XRF and N2 adsorption-desorption measurements. The results of CPO conversion demonstrate that the catalytic activity of the synthesized catalysts decreases in the series of NiMo-ZSM-5/MCM-41 > NiW-ZSM-5/MCM-41 > Ni-ZSM-5/MCM-41 > Mo-ZSM-5/MCM-41 > W-ZSM-5/MCM-41 > NiMo-ZSM-5 > NiW-ZSM-5 > ZSM-5/MCM-41 > ZSM-5 > MCM-41. It was found that the bimetallic NiMo- and NiW-ZSM-5/MCM-41 catalysts give higher yields of liquid hydrocarbons than other catalysts at a given conversion. Types of hydrocarbon in liquid products, identified by simulated distillation gas chromatography-flame ionization detector (SimDis GC-FID), are gasoline (150–200°C; C5–12), kerosene (250-300°C; C5–20) and diesel (350°C; C7–20). Moreover, the conversion of CPO to biofuel products using the NiMo- and NiW-ZSM-5/MCM-41 catalysts offers no statistically significant difference (P> 0.05) at 95% confidence level, evaluated by SPSS analysis.

Upgrading of Bio-Oil Aqueous Fraction by Dual-Stage Hydrotreating–Cocracking with Methanol

Upgrading of the bio-oil aqueous fraction (BAF) for liquid hydrocarbon production was studied in this work. Hydrotreating pretreatment and methanol cocracking were combined as a dual-stage hydrotreating–cocracking process to overcome the severe coking problem caused by the hydrogen-lacking property of BAF. The influences of hydrotreating temperature, reaction pressure, and BAF/methanol ratio in feedstock were investigated. It was found that the hydrogenation efficiencies of phenols in BAF were elevated with increases in hydrotreating temperature and reaction pressure, which were important for maintaining cracking catalyst activity. However, a too high hydrotreating temperature significantly enhanced the gasification reaction and led to reduction in the final liquid hydrocarbon yield. Meanwhile, an excessively high BAF/methanol ratio obviously accelerated the deactivation of the cracking catalyst. The comparison of different cracking processes showed that dual-stage hydrotreating–cocracking was the most su...

Effect of ZSM-5 crystal size on its catalytic properties for conversion of methanol to gasoline

Four-sized monodispersed ZSM-5 crystals, being 70, 200, 400 and 650 nm, were hydrothermally synthesized by changing the H2O/Si molar ratio in the synthesis gel, and characterized with XRD, TEM, BET and NH3-TPD techniques. The crystal size effect of ZSM-5 on its catalytic performance for conversion of methanol to gasoline (MTG) was investigated. It was shown that the external surface area of the sample decreased with its crystal size, while the acid site amount firstly increased, and then kept almost constant. Nevertheless, 650 nm ZSM-5 crystals attaching small particles exhibit large external surface area and strong acidity. The catalytic stability and the liquid hydrocarbon yield decreased with increasing crystal size. The sample with a crystal size of 70 nm shows a catalytic lifetime of 96 h and a gasoline yield of 30.8%. The large external surface area and relatively strong acidity endow the sample with a crystal size of 650 nm also has a catalytic lifetime of 91 h, indicating that synthesis of large ZSM-5 crystals with small crystallites adhered to their surface could be a potential way to improve the catalytic performance.

Catalytic Conversion of Biomass-Derived Ethanol to Liquid Hydrocarbon Blendstock: Effect of Light Gas Recirculation

We describe a light gas recirculation (LGR) method to increase the liquid hydrocarbon yield with a reduced aromatic content from catalytic conversion of ethanol to hydrocarbons. The previous liquid hydrocarbon yield is ∼40% from one-pass ethanol conversion over the V-ZSM-5 catalyst at 350 °C and atmospheric pressure, where the remaining ∼60% yield is light gas hydrocarbons. In comparison, the liquid hydrocarbon yield increases to 80% when a simulated light gas hydrocarbon stream is co-fed at a rate of 0.053 mol g–1 h–1 with ethanol as a result of the conversion of most of the light olefins. The LGR also significantly improves the quality of the liquid hydrocarbon blendstock by reducing the aromatic content and overall benzene concentration. For 0.027 mol g–1 h–1 light gas mixture co-feeding, the average aromatic content in liquid hydrocarbons is 51.5% compared to 62.5% aromatic content in the ethanol only experiment. The average benzene concentration decreases from 3.75 to 1.5%, which is highly desirable ...

Effect of Particle Morphology for ZSM-5 Zeolite on the Catalytic Conversion of Methanol to Gasoline-Range Hydrocarbons

ZSM-5 zeolite composed of nano-sphere or nano-rod crystallites were prepared to compare with micron-sized ZSM-5. These samples have different morphologies but similar acid properties, which could diminish the effect of acid properties to study the morphology effect of ZSM-5 particles on MTG reaction. It was found that nano-sphere crystallite aggregate ZSM-5 presented larger external surface and mesopore volume than micron-sized ZSM-5 and nano-rod crystallites aggregate ZSM-5, increasing both acid sites accessibility and diffusion properties. Add that into the consideration with the weak acidity, nano-sphere crystallite aggregated ZSM-5 exhibited high liquid hydrocarbon yield, slow deactivation process and high selectivity to aromatics and iso-paraffins.

Pore fabrication of nano-ZSM-5 zeolite by internal desilication and its influence on the methanol to hydrocarbon reaction

A nano-ZSM-5 zeolite with average crystal size of 100nm was modified by internal desilication in NaOH solutions and exhibited great improvements in the catalyst lifetime and the yield of liquid hydrocarbons for the conversion of methanol to hydrocarbons (MTH). The microstructures of the treated nano-ZSM-5 zeolites were characterized by N2 adsorption, XRD, ICP-AES, TEM, TG and NH3–TPD techniques. It was found that the mesopores were introduced into nano-ZSM-5 crystals and the external surface area was increased from 72 to 115m2g−1 by internal desilication. With the increase of the treating time, these mesopores grew larger and more crowded, and subsequently they were connected with each other forming bigger cavities. Finally, a hollow structure was presented for nano-ZSM-5 crystals. Although great changes have been made in pore structure by this internal desilication, the specific MFI structure of the nano-ZSM-5 was still well maintained and the acidity was also obviously increased. This result was quite different from that obtained from desilication on the micro-ZSM-5. MTH reaction over treated nano-ZSM-5 catalyst was carried out in a fixed-bed tubular reactor at 400°C and WHSV of 4.7h−1 under 1MPa. The catalyst lifetime and the total production of the liquid hydrocarbon were increased by a factor of 2.2 and 2.5, respectively, as a consequence of the pore fabrication and the increased acidity. Production of light hydrocarbons was increased with increasing treating time of nano-ZSM-5. However, one thing to note is that the acidity of nano-ZSM-5 is vulnerable to damage during reaction and hydrothermal treatment process. Its regenerability and hydrothermal stability are not very satisfactory. More work is needed to improve the stability of acidity structure under the hydrothermal environment.

Fischer–Tropsch synthesis with cobalt catalyst and zeolite multibed arrangement

The role of zeolite in transformations of hydrocarbons produced from CO and H2 over a Fischer–Tropsch cobalt catalyst under the conditions of multibed arrangement of the cobalt catalyst and the zeolite has been determined. Hydrocarbon conversion over the HBeta zeolite occurs via the bimolecular mechanism, as evidenced by a low methane yield and a high yield of unsaturated gaseous and liquid hydrocarbons. The conversion over the CaA zeolite obeys the unimolecular mechanism, as evidenced by the formation of increased amounts of methane and saturated gaseous C2–C4 hydrocarbons.

Influence of the conditions of hydrogenation treatment of black oil on the yield and properties of the products obtained

The conversion of black oil in hydrogen (hydroconversion) and nitrogen (pyrolysis) media was studied. The influence of the hydrogen pressure and temperature of the hydrotreating of black oil on the yield and properties of the resulting liquid hydrocarbons was examined. Hydrogen actively participates in the conversion of kerogen (major organic component of black oil), which leads to an increase in the conversion of the organic matter, to an increase in the yield of liquid hydrocarbon products, and to improvement of their quality, compared to pyrolysis. The highest conversion of organic carbon (91.7%) and the maximal yield of liquid hydrocarbons (30.7 wt %) were reached in a hydrogen medium at a pressure of 10.0 MPa and a temperature of 400°C.

Conversion of C19–C38 n-paraffins into components of kerosene and diesel fuels on Pt-containing amorphous aluminosilicate

The behavior of Pt-containing catalysts based on mesoporous amorphous aluminosilicate in the process of hydroconversion of C19–C38n-paraffins with the goal to produce diesel and kerosene fractions with improved cold flow properties was investigated. These systems were characterized by high efficiency and selectivity in the process of producing diesel and kerosene fractions. A 91% degree of conversion was achieved with a yield of liquid hydrocarbons of 76% (320°C, volume feed rate 0.5 h–1, molar ratio hydrogen: feed = 600: 1, pressure 50 atm). The initial freezing point of the isolated kerosene fraction was below minus 50°C, and the cold filter plugging point of the diesel fraction was minus 34°C.

Conversion of Bio-syngas to Liquid Hydrocarbon over CuCoMn-Zeolite Bifunctional Catalysts

A series of bifunctional catalysts composed of a component for higher alcohol synthesis (CuCoMn oxides, CCM) and an acidic zeolite (SAPO-34, ZSM-5, Y, MCM-41) were prepared for production of liquid hydrocarbon directly from a bio-syngas through a one-stage process. The effects of zeolite type, zeolite content, Si/Al ratio and preparation method on catalyst texture and its reaction performance were investigated. Higher selectivities and yields of liquid products were obtained by using bifunctional catalysts. The yields of liquid hydrocarbons decreased in the order CCM-ZSM-5>CCM-SAPO-34>CCM-Y>CCM-MCM-41. CCM-ZSM-5 (20wt%, Si/Al=100) prepared by coprecipitation method displayed the optimal catalytic performance with the highest CO conversion (76%) and yield of liquid products (30%). The catalysts were characterized by N2 adsorption/desorption, NH3-TPD, XRD, and H2-TPR analysis. The results showed that higher specific surface areas and pore volumes of bifunctional catalysts were achieved by adding zeolites into CuCoMn precursors. Medium pore dimension and moderate acidity in CCM-ZSM-5 were observed, which probably resulted in its excellent reaction performance. Additionally, a higher number of weaker acid sites (weak and/or medium acid sites) were formed by increasing ZSM-5 content in CCM-ZSM-5 or decreasing Si/Al ratio in ZSM-5. It was also seen that metal dispersion was higher and reducibility of metal ions was easier on the CCM-ZSM-5 catalyst prepared by coprecipitation. The higher alcohols-to-hydrocarbon process provides a promising route to hydrocarbon fuels via higher alcohols from syngas or biobased feedstocks.

Study on mild cracking of polyolefins to liquid hydrocarbons in a closed batch reactor for subsequent olefin recovery

The polyolefins mild cracking experiments have been carried out in a closed batch reactor under inert nitrogen atmosphere over a temperature range from 370 °C to 420 °C and the characterization of the mild cracking products has been investigated. The objective of this work is to study the cracking mechanism and reaction path for the mild cracking of polyolefins with lower heating rate (the isothermal and non-isothermal process), and to find the appropriate operating conditions (temperature and residence time) for optimal yield of liquid hydrocarbons (oils/waxes) as the suitable feedstock of olefin recovery. The advantages of this work can be summarized as high yield of light fraction, low aromatics content and mild cracking conditions. More viscosity-reducing and less volatiles-loss can be simultaneously achieved in mild cracking of polyolefins by selecting the reasonable residence time-temperature combination. The results confirm that chain scission reactions are significantly predominant in these experimental conditions. Intramolecular hydrogen transfer and intermolecular hydrogen transfer, which are responsible for the reduction in molecular weight of liquid products, can be improved in lower temperature and longer residence time, and intermolecular hydrogen transfer can also be enhanced in the PE/PP mixture cracking. For polyolefins mixture cracking, the cracking temperature can be reduced about 20 °C, or the cracking time can be shortened significantly, and so utilizing the whole polyolefins mixture without a need of further separation is very desirable in the chemical recycling.

Development of NiCu Catalysts for Aqueous-Phase Hydrodeoxygenation

Herein, we report on the development of supported Ni and Raney Ni catalysts doped with Cu for the hydrothermal hydrodeoxygenation (HDO) of o-cresol. Raney Ni catalysts doped with >10 wt % Cu show a significant reduction in gasification activity and produce a higher yield of liquid products than the unmodified Raney Ni catalyst. Adding Cu did not, however, increase the yield of the desired HDO products, liquid hydrocarbons. The addition of acid sites to the catalysts, by supporting Ni and NiCu on Al2O3 and by calcining the Raney Ni to produce Al2O3 within the catalyst, however, did significantly increase the HDO activity of the catalysts such that yields of liquid hydrocarbons exceeded 60%. Two catalysts, a novel calcined 5% Raney NiCu catalyst and a NiCu/Al2O3 catalyst, produced the highest liquid hydrocarbon yields to date (∼70%) for stable, non-noble metal, hydrothermal HDO catalysts.

Fischer-Tropsch synthesis in the presence∣ of cobalt-containing composite materials based on carbon

The Fischer-Tropsch synthesis in the presence of composite materials prepared by the IR pyrolysis of polyacrylonitrile (PAN) with cobalt salts immobilized on it was studied. The catalysts were small granules containing PAN carbonization products and to 80% cobalt metal particles of size 10–17 nm. The synthesis was performed in flow reactors with a fixed bed and a catalyst bed suspended in a liquid at 2–3 MPa and 200–310°C. It was established that the activity of the catalyst depends on the nature of the cobalt salt used, the temperature of IR pyrolysis, and the synthesis conditions. The catalyst prepared with the use of cobalt carbonate exhibited the greatest activity. The yield of liquid hydrocarbons on it reached ∼70 g/m3 at ∼60% selectivity. It was found that the test composite materials were characterized by an extremely high productivity of 2–5 kg (kg Co)−1 h−1.

One-step hydrodeoxygenation of palm oil to isomerized hydrocarbon fuels over Ni supported on nano-sized SAPO-11 catalysts

Nano-sized SAPO-11s were hydrothermally synthesized with using di-n-propylamine (DPA) as structure-directing agent in mixed n-tetradecanoamine–n-propanol–H2O medium and the Ni/SAPO-11 catalysts were prepared by incipient wetness impregnation. The catalysts was characterized by XRD, SEM, BET, H2-TPR, NH3-TPD and TG techniques and their catalytic performance was tested in hydrodeoxygenation (HDO) of palm oil to hydrocarbon fuels. Surfactant n-tetradecanoamine could mediate the minimum SAPO-11 sizes into 20–50nm. As comparing to the commercial SAPO-11, the nano-sized SAPO-11s presented significantly enlarged surfaces and mesoporous volumes, which offered sufficient space and strong interactions for dispersing Ni. One-step HDO of palm oil demonstrated that the nano-sized SAPO-1 supported Ni catalysts showed the high yield (80%) of liquid hydrocarbons, high isomerization selectivity (80%) and excellent stability due to that the catalyst presented appropriate acidity, higher Ni dispersity, balance of metal (Ni) and acid (SAPO-11) functionalities and fast diffusion for bulky palm oil and products. These promotion effects observed over the nano-sized SAPO-11 supported Ni catalysts indicated the potential application in biorefinery of vegetable oils to hydrocarbon fuels.

Effect of Torrefaction on Bio-oil Upgrading over HZSM-5. Part 1: Product Yield, Product Quality, and Catalyst Effectiveness for Benzene, Toluene, Ethylbenzene, and Xylene Production

A three-step bio-oil production process involving torrefaction pretreatment (at 225, 250, or 275 °C with a 20 min hold time), pyrolysis (at 500 °C with two heating rates), and secondary catalytic processing over HZSM-5 (at 400, 450, or 500 °C) was studied to determine process effects, particularly of torrefaction, on the yield of liquid and aromatic hydrocarbons and the quality of upgraded bio-oil. When bio-oils derived from torrefied biomass were catalytically cracked, average yields (%, w/w of feed) of reactor char (100% reduction), catalyst coke (21.4%), and catalyst tar (8.1%) were significantly reduced relative to the best-case conditions using non-torrefied feedstock. The reduction in coke (%, w/w of feed) as a result of torrefaction was 28.5% relative to the respective control for slow-pyrolysis bio-oil upgrading and 34.9% for fast-pyrolysis bio-oil upgrading. The concentration of aromatic product (benzene, toluene, ethylbenzene, and xylene, i.e., BTEX) was highest at 95 g L–1 for upgraded (at 500 °C) fast-pyrolysis bio-oil derived from biomass torrefied at 275 °C. Catalyst effectiveness for BTEX production significantly increased with increased torrefaction and catalytic cracking temperatures.