Parr Reactor Research Articles

Synthesis of NiZn-based paddle-wheel metal-organic framework and its use as a catalytic precursor for ethylene dimerization

A bimetallic pillared-layered MOF based on Ni and Zn with improved catalytic activity was synthesized and applied in the ethylene oligomerization reaction. According to the XANES spectra, the MOF possesses Ni in the 2+ oxidation state, a well-known active catalytic precursor in oligomerization systems. In addition, Ni and Zn oxide or metallic species were not identified, indicating the absence of impurity phases. µ-XRF and SEM-EDS techniques showed the homogeneous distribution of Ni and Zn species across the SBUs of the bimetallic MOF. Ni/Zn-MOF was applied in the ethylene oligomerization reaction using EASC as the co-catalyst, and the results were compared to its monometallic counterpart Ni-MOF. The bimetallic material Ni/Zn-MOF obtained a TOF corresponding to 135 ×103 h−1, which accounts for a 60 % increase in the catalytic activity achieved by Ni-MOF (85 ×103 h−1) under 15 bar of ethylene in a Parr reactor. Moreover, the results obtained in this work are remarkable compared to literature reports for Ni-based MOFs, demonstrating that the co-catalyst employed plays an important role in the catalytic activity. However, Ni/Zn-MOF showed a lower selectivity to α-C4 oligomers (36 %) against 58 % obtained by Ni-MOF. According to the reuse tests conducted, the bimetallic MOF can be reused for up to two reactions (under 5 bar ethylene in a glass reactor), although presenting a considerable loss in activity due to the formation of metallic Ni.

Effects of crystallization temperature on structure and digestibility of spherulites formed from debranched high-amylose maize starch

High-amylose maize starch (69.3 % amylose) was debranched to increase the level of linear molecules and enhance the formation of spherulites. Debranched high-amylose maize starch (25 %, w/w) was heated to 180 °C in a Parr reactor followed by crystallization at different temperatures between 25 and 150 °C. The objectives of this study were to investigate the effects of crystallization temperature on the yield, morphology, structure, crystallinity, and digestibility of the spherulites formed. When the crystallization temperature was 150 °C, spherulites with negative birefringent sign were formed. High crystallization temperature caused molecular degradation and the degree of degradation was severe at 150 °C, resulting in relatively short chain amylose (DP < 150). When crystallized at 25 to 120 °C, spherulites with strong positive birefringence were produced. The long chain amylose was attributed to the positive birefringence. All spherulites had a predominant B-type crystalline structure. The spherulites with negative birefringence showed a lower degree of crystallinity and lower resistance to enzyme digestion, but all the spherulites with positive birefringence had a high resistant starch content (89–94 %). α-Amylase was not able to penetrate inside the spherulites as revealed by the confocal laser scanning microscopic images.

Enzymatic hydrolysis lignin and kraft lignin from birch wood: a source of functional bio-based materials

In the pursuit of sustainable biomass utilization, this study investigates the hydrothermal treatment of birchwood and its subsequent impact on enzymatic hydrolysis lignin (EHL). Additionally, birchwood undergoes processing with NaOH (4% w/w) within a Parr reactor to precipitate lignin from the black liquor, resulting in lignin-rich substrates (LRSs) which are then subject to thorough characterization. Notably, EHL produced after hydrothermal pretreatment at 190 °C exhibits the highest lignin content at 67%, while kraft lignin (KL) obtained at 140 °C (pH 1.5) produces 65% lignin content. Among these LRSs, the KL sample produced at 190 °C (pH 4) stands out, displaying a robust aromatic skeletal structure and an abundance of methoxyl groups, primarily owing to its high purity. Furthermore, for these LRSs' it is shown that chemical configuration influences their thermal behaviour, allowing the lignin to be tailored for diverse applications, from low melting point materials to carbonaceous materials capable of withstanding temperatures exceeding 700 °C. This comprehensive understanding of the chemical, thermal, and physical attributes of LRSs not only enriches our knowledge of lignin-rich substrates but also paves the way for the development of sustainable bio-based materials, marking a step towards sustainable materials development.

Impact of formulation on solid oxygen-entrapping materials to overcome tumor hypoxia.

Tumor hypoxia, resulting from rapid tumor growth and aberrant vascular proliferation, exacerbates tumor aggressiveness and resistance to treatments like radiation and chemotherapy. To increase tumor oxygenation, we developed solid oxygen gas-entrapping materials (O2-GeMs), which were modeled after clinical brachytherapy implants, for direct tumor implantation. The objective of this study was to investigate the impact different formulations of solid O2-GeMs have on the entrapment and delivery of oxygen. Using a Parr reactor, we fabricated solid O2-GeMs using carbohydrate-based formulations used in the confectionary industry. In evaluating solid O2-GeMs manufactured from different sugars, the sucrose-containing formulation exhibited the highest oxygen concentration at 1 mg/g, as well as the fastest dissolution rate. The addition of a surface coating to the solid O2-GeMs, especially polycaprolactone, effectively prolonged the dissolution of the solid O2-GeMs. In vivo evaluation confirmed robust insertion and positioning of O2-GeMs in a malignant peripheral nerve sheath tumor, highlighting potential clinical applications.

Extraction and characterisation of lignin from residues of Mexican Ocote pine (Pinus montezumae Lamb.) for biofuel production

The objective of this research was to extract lignin from residual lignocellulosic biomass of Ocote pine softwood (Pinus montezumae Lamb.) in the south-southwestern region of the Mexican Republic and to determine its potential as raw material to obtain biofuels. The lignin obtained was characterised by Fourier Transform Infrared (FT-IR) spectroscopy, Thermogravimetric Analysis (TGA), Higher Heating Value (HHV) analysis and elemental analysis. The Kraft process was applied for biomass delignification because it is most commonly used in the paper industry worldwide, using sodium hydroxide (NaOH) and sodium sulphide (Na2S) to extract the lignin from the fibres of the forest residues (sawdust and bark) in a 600 mL Parr reactor. The lignin extracted from pine sawdust obtained a better calorific value (28.75 MJ kg−1) than that recovered from the bark (23.61 MJ kg−1). The yield of lignin obtained from 50 g of bark, 5 g, was higher than that obtained from 50 g of sawdust, 2 g. The obtained lignin can be further processed to generate higher value-added products such as liquid biofuels.

Two-step physico-biological production of xylooligosaccharides from sugarcane leaves

The production of xylooligosaccharides (XOS) from sugarcane leaves (SCL) presents high potential to the nutraceutical industries as SCL are cheap and readily available. In this study, a two-step process using hydrothermal pretreatments and enzymatic hydrolysis are developed and optimized for XOS production to obtain high conversion yield and product specificity. Two operation methods for hydrothermal pretreatments, parr reactor, and microwave reactor were compared to extract xylan from SCL. Two hemicellulose enzymes, hemicellulase Amano and xylanase (X2753) were then tested for enzymatic hydrolysis of extracted xylan to XOS. Conditions with high conversion yield after pretreatments were found at 180 °C for 30 min (parr reactor) and 800 W for 8 min (microwave reactor): producing 4.95 mg/mL (22.11 %w/v) and 3.49 mg/mL (15.61 %w/v) XOS respectively. Subjection of derived liquor from hydrothermal pretreatment to enzymatic hydrolysis produced a maximum of 9.42 mg/mL (41.87 %w/v) and 7.81 mg/mL (34.71 %w/v) of XOS for hemicellulase Amano and xylanase (X2753) respectively. The hemicellulase resulted in XOS with degree of polymerization (DP) of 2–5 for the various pretreatment conditions whereas xylanase yielded XOS of DP 2 to 4. However, a negative effect on enzymatic hydrolysis was observed for microwave-assisted pretreated samples. This study revealed that combination of physico-biological methods on SCL could result in high XOS yield with distinct degree of polymerization.

Parametric Identification of a Countercurrent Aqueous Hydrolysis Process for the Production of Glycerine under Higher Pressure and Temperature

AbstractGlycerine is produced by aqueous hydrolysis of tallow fat in the Twitchell process under high pressure (40–60 bar) and temperature (250–270 °C). An effort was made to improve the degree of hydrolysis under optimal operating conditions by varying the feed ratio in a 20‐L Parr reactor. The 1:4 blend of water/tallow at 256 °C and 60 bar was recorded as optimal operating conditions (non‐catalytic), yielding a degree of hydrolysis of 98.4 %. A survey shows that there is a need to find alternate operating control strategies for achieving better efficiency and safe operation. Material and energy balances across the countercurrent hydrolysis tower were developed to calculate the glycerine and free fatty acids in the raffinate and extract phases, using the first principle for dynamic analysis. The model equations were validated and used to identify simple model structures suitable for designing model‐based strategies to control the process temperature in the extraction process.

Valorization of rice husk by hydrothermal processing to obtain valuable bioproducts: Xylooligosaccharides and Monascus biopigment

Rice husk is a readily available residue which can be used for producing bioproducts in a biorefinery context. In this study, the hemicellulose fraction was hydrolyzed in a hydrothermal process to produce xylooligosaccharides (XOS), whereas the cellulosic hydrolysate was used for red pigment production by Monascus ruber Tieghem IOC 2225. The highest XOS (X2-X4) production (24 g per 1 kg of rice husk) was achieved at 180 °C for 68 min in a non-stirred Parr reactor (50 mL). Subsequently, using a stirred parr reactor (1 L) at 180 °C for 60 min, 40 g of XOS (42% of xylobiose, 35% of xylobiose, 13% of xylotriose, 7% of xylotetraose, and 3% of xylopentaose) per 1 kg of rice husk were obtained. The XOS was then purified by using ultrafiltration (UF) with two diafiltration membranes at 6.5 pH, recovering approximately 92% of total XOS. Further purification was conducted with nanofiltration (NF) at 3.8 pH, recovering approximately 86.4% of XOS in the retentate. This process yielded XOS with a purity of 77%. Additionally, the enzymatic process yielded 132 g/kg of sugar, and the hydrolysate was used to produce 2.1 UA490nm of red pigment by fungi after 7 days.

The effect of the support nature and palladium dispersion on activity and selectivity of the palladium catalyst in hydrogenation of sunflower oil

Samples of the powdered catalysts Pd/C and Pd/Ox, which were synthesized by depositing 0.5 and 1.0 wt.% Pd on carbon materials (Sibunit 159k, thermal black Т-900, Vulcan XC-72R) and oxide supports (Ox: γ-Al2O3, Cr2O3, Ga2O3, TiO2, Ta2O5 and V2O5, and kieselguhr FW-70), were studied. Their catalytic properties were investigated in the partial hydrogenation of sunflower oil. Comparative testing of the catalysts was performed in the kinetic mode using a static Parr reactor to estimate their activity and trans-isomerization selectivity. The effect of the average size of supported palladium particles (dCO) on the indicated characteristics in a wide range of dCO values was discussed.

Catalytic Hydrodeoxygenation of Vanillin, a Bio-Oil Model Compound over Renewable Ni/Biochar Catalyst

This study aims to examine the hydrodeoxygenation (HDO) of vanillin, an oxygenated phenolic compound present in bio-oil, into creosol. Biochar residue generated when wood is slowly pyrolyzed is utilized as a catalyst support. To improve biochar’s physicochemical properties, H2SO4 (sulfuric acid) and KOH (potassium hydroxide) are used as chemical activators. By means of a wet impregnation method with nickel salt, an Ni/biochar catalyst was prepared and utilized in the HDO of vanillin using a 100 mL Parr reactor, catalyst loading 0.4–0.8 g, temperature 100 °C to 150 °C, hydrogen (H2) pressures of 30 to 50 bar, and a stirring rate of 1000 rpm. The prepared catalysts were characterized with the nitrogen-sorption isotherm technique, carbon dioxide temperature-programmed desorption (CO2-TPD), scanning electron microscopy (SEM) coupled with energy dispersed X-ray analysis (EDX), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). Based on chemical treatment, Ni/biochar (KOH) pore sizes were found to be dominated by mesopores, with a surface area increase of 64.7% and a volume increase of 65.3%, while Ni/biochar (H2SO4) was mostly microporous and mesoporous, with an area increase of 372.3% and a volume increase of 256.8% in comparison to Ni/biochar (74.84 m2g−1 and 0.095 cm3g−1). Vanillin conversion of up to 97% with 91.17% selectivity to p-creosol was obtained over Ni/biochar catalyst; in addition to being highly selective and active for p-creosol, a plausible fuel, the catalyst was stable after four cycles. Chemical treatments of the biochar support resulted in improved physicochemical properties, leading to improved catalytic performance in terms of vanillin conversion and p-creosol yield in the order Ni/biochar (H2SO4) &gt; Ni/biochar (KOH) &gt; Ni/biochar.

Fractionation of Yellow Thatching Grass (Hyparrhenia filipendula) for Sugar Production Using Combined Alkaline and Deep Eutectic Solvent Pretreatment

PurposeBiomass pretreatment followed by enzymatic hydrolysis is one of the most viable ways to obtain sugars from biomass. In this work, the effect combined alkaline pretreatment and Deep Eutectic Solvent on enzyme hydrolysis of Hyparrhenia filipendula by cellulase is investigated. There is no previously reported literature on this substrate and the authors aim to establish baseline values for further research in the utilization of Hyparrhenia filipendula.MethodsThe yellow thatching grass (Hyparrhenia filipendula) was fractionated with a combination of alkaline and Deep Eutectic Solvent to increase sugar recovery. An alkaline solution of 10 wt % (w/v) of Sodium Hydroxide (NaOH) was used for the first stage of pretreatment at 100 °C for 4 h. Three DES, namely, Choline chloride (ChCl): urea; ChCl: glycerol; and Ethylene glycol: Citric acid at 1:2 molar ratio each, were heated to 80 °C until a clear solution was formed. The DESs were used for the second stage of pretreatment at 110 °C for 6 h in a Parr reactor. During the pretreatment, a solid: solvent ratio of 1:10 was used for the first and second stages of pre-treatment. Enzymatic hydrolysis was accomplished with a cellulase enzyme blend, Cellic CTec2, in a 50 mM sodium citrate buffer (pH 4.8) at 50 °C using a shaking incubator at a speed of 150 rpm. A solid loading of 2% and enzyme dosage of 50 g/100 g cellulose in the sample was used for all the experiments. Furthermore, samples were withdrawn every 24 h for 7 days and analyzed for glucose and xylose using High-Performance Liquid Chromatography (HPLC).ResultsA high delignification of 90% and hemicellulose removal of 70% was achieved with a combination of Alkali and ChCl: Urea pretreatment. Subsequently, the highest glucose and xylose conversion of 90% and 92% were observed, respectively, with the same sample. Additionally, the highest glucose yield achieved was 25 gL−1 from the combined alkaline/ChCl: Glycerol treated sample after 120 h. Moreover, the highest xylose yield was 3 gL−1 from the raw sample, the NaOH- pulped sample, and the ChCl: Glycerol-treated sample.ConclusionThe results from this study demonstrated that the solvents used for fractionating biomass have a significant effect on the sugar recovery during enzymatic hydrolysis. Also, the pretreatment with a combination of NaOH and DES of ChCl: Glycerol was the most effective for the recovery of glucose and total sugar. In conclusion, yellow thatching grass is a promising substrate for bio-refineries. However, the ideal conditions for enzyme hydrolysis should be investigated further to promote its utilization for value-added products.Graphical Abstract

Tannin extracts as a preservative for pine thermo-mechanically densified wood

Thermo-mechanical densification modifies wood to produce a more dense and resistant lignocellulosic material and may degrade extractives that contribute to the increased susceptibility of wood to attack by xylophagous organisms. This study evaluated the efficiency of tannin extracts of Acacia mearnsii in the treatment of thermo-mechanical densified pine wood in relation to physical, mechanical, and biological resistance (Cryptotermes brevis) properties. Pinus elliottii samples were pretreated with oxalic acid in a Parr reactor, then treated by diffusion in tannin solutions at concentrations 5, 10, and 15%, and finally hot pressed. The apparent density of the modified wood was 87.8% greater than that of the in natura wood (control) with tannins at 15%. The mechanical strength increased, especially the parallel compressive strength, which had an average increase of 169% for the wood with tannins at 10 and 15%, compared with the in natura wood. There was an increase in termite mortality and a reduction in damage for the modified wood treated with 15% tannins, obtaining the best results in mechanical and biological resistance and for the physical parameters. Thermal densification pine wood and preserved with tannin extractives proved to be a potential alternative as a high performance material.

Development of Next Generation EV Coolant

Research indicates that there are two approaches to Electric Vehicle (EV) liquid cooling: direct and indirect. Direct liquid cooling involves direct contact between the coolant and the battery pack. Indirect liquid cooling requires a medium in between the battery pack and the coolant, preventing direct contact. Many prominent EV manufacturers have adopted indirect liquid cooling for example Tesla, and GM in North America. Currently, shelf coolants used for Internal Combustion Engines (ICE) are being used in many EV vehicles for indirect cooling. One of the challenges is absence of ASTM test methods for evaluating EV coolants. Some operators have used copper wires for generating deposits by employing voltage to test low conductivity EV coolants. Dober long ago realized that copper and aluminum will be the main components of EV engines hence used copper wire under high temp and pressure to show differentiation among coolants. The present paper focuses on Dober-in-house test Parr reactor methodology for comparing electrical conductivities, pH and additive depletion of various coolants thereby showing meaningful trends with time and temperature. This ultimately helps in developing new generation EV coolants. It is concluded that low electrical conductivity along with robust corrosion inhibition package is needed for optimum performance of EV coolants.

Lignin Ammoxidation: Synthesis of Nitrogen Releasing Soil Conditioning Products from Waste Pulp Liquor and Their Pot Trial Evaluation

PurposeLignin is a precursor of humus, and a by-product of the pulp and paper industry. This study investigated the synthesis of soil conditioning materials from industrial lignins (kraft, soda and sulphite), through ammoxidation.MethodThe industrial lignins were characterized and ammoxidized in a 1 L Parr reactor at 80 °C, 10 barg, for 4 h, with 7 wt% ammonia and 10 wt% lignin in the reaction mixture. A plant trial assessment of the products was conducted over four weeks.ResultsN-lignins with C/N ratios of 12.30, 15.81, and 14.64 were obtained from kraft, soda and sodium lignosulfonate against a standard requirement of a C/N < 20. However, an oxidation step with 5% hydrogen peroxide was required (prior to ammoxidation) because the criterion for N-lignins (C/N < 20) could not be met under standard reaction conditions. In the plant trial, N-modified kraft (3.50 t/ha) and soda lignin (3.21 t/ha) recorded crop yields that were 71% and 57% higher than the control (2.04 t/ha), respectively. The sodium lignosphonate, while it met the requirements for use as a soil fertilizing material in terms of nitrogen content, resulted in complete crop failure. Further characterization showed it had a high pH (8.81 pH) and a high salt index (63.62%) due to the pulping technique used in its isolation.ConclusionKraft and soda lignins could be successfully ammoxidized to synthesize N-lignins that are suitable for use as soil conditioning materials.Graphical Abstract

High purity softwood lignin obtained by an eco-friendly organosolv process

Organosolv processes provide access to less degraded and higher purity lignins. However, these are rarely applied to softwood species with high lignin contents and complex condensed structures. We are presenting here the results of an optimized organosolv process, allowing for a high extraction yield of organosolv lignin from black spruce (Picea mariana), while preserving a good solid cellulose recovery. Optimized conditions are 70% ethanol liquor with a ratio of 1:10 (wood:liquor) and 5% FeCl3·6H2O as catalyst, treated in a Parr reactor for 90 min at 180 °C. The cellulosic pulp was then extracted with pure ethanol to recover the 2nd lignin. This 2nd lignin was darker in colour and denser than the 1st lignin obtained by precipitation from residual liquor. The other lignin properties were almost identical. The total lignin recovery averaged at 74% (with a purity of 97%), the highest result for lignin recovery from softwoods published so far.

Optimized Organosolv Pretreatment of Biomass Residues Using 2-Methyltetrahydrofuran and n-Butanol

Wheat straw and eucalyptus residues were pretreated in a biphasic system, constituted of butanol (n-butanol) or 2-methyltetrahydrofuran (2M-THF) and aqueous oxalic acid solutions. The pretreatments were carried out in a 300 mL Parr reactor (Autoclave Buchi Limbo-li®) with a solid load of 5 wt.%, the temperature in the range 140–180 °C, oxalic acid load from 0 to 10 wt.% and a duration of 30–90 min. The obtained slurry was then fractionated in three streams: the aqueous phase which contained solubilized hemicellulose, the organic phase which contained the solvated lignin, and the solid residue which contained cellulose. The solid was hydrolyzed using a commercial mix of enzymes to assess cellulose digestibility and glucose production. The pretreatment was optimized to maximize the purity of the cellulose and hemicellulose fractions and the glucose recovery as free sugar. The optimization was done by using an experimental design and response surface methodology. The mass flow details of the four optimized processes were obtained. In terms of biomass fractionation, butanol demonstrated significant advantages over 2M-THF in the same range of process conditions as shown by the recovery yield of free glucose which reached 98% of the theoretical value with butanol but was 67% with 2M-THF. Tests at low temperature and low enzyme loading highlighted the importance of the solvent choice over the operating conditions. 2M-THF showed interesting performances only in the delignification step, with 90% efficiency for the straw. Regarding the use of different feedstock, fractionation and recovery were generally higher for wheat straw than for eucalyptus wood residues.

Intensification of the steam stimulation process using bimetallic oxide catalysts of MFe2O4 (M\u2009=\u2009Cu, Co, Ni) for in-situ upgrading and recovery of heavy oil

In this study, bimetallic catalysts based on transition metals CuFe2O4, CoFe2O4 and NiFe2O4 are proposed for catalyzing aquathermolysis reaction during steam-based EOR method to improve in-situ heavy oil upgrading. All upgrading experiments were carried out under a nitrogen atmosphere for 24 h in a 300-ml batch Parr reactor at 250 and 300 °C under high pressure 35 and 75 bar, respectively. To evaluate the catalytic performance of the bimetallic catalysts used, comprehensive studies of changes in the physical and chemical properties of the improved oils, including the viscosity, elemental composition and SARA fractions of oils before and after upgrading processes were used. Furthermore, individual SARA fractions were characterized in detail by Gas Chromatography (GC), High-Performance Liquid Chromatography (HPLC) and Carbon-13 Nuclear Magnetic Resonance (13C NMR), respectively. The results showed that bimetallic catalysts have high catalytic performance at 300 °C for the upgrading of heavy crude oil in viscosity reduction, increasing the amount of saturates (especially alkanes with low carbon number) as a result of thermal decompositions of high molecular weight compounds like resin and asphaltenes leading to their increasing. Furthermore, the upgrading performance is reflected in the improvement of the H/C ratio, the removal of sulfur and nitrogen through desulfurization and denitrogenation procedures, and the reduction in polyaromatic content, etc. CoFe2O4 gives the best performance. Generally, it can be concluded that, used bimetallic based catalysts can be considered as promising and potential additives improving in-situ upgrading and thermal conversion the heavy oils.

Effect of Microwave Irradiation on the Catalytic Activity of Tetragonal Zirconia: Selective Hydrogenation of Aldehyde

Tetragonal zirconia was synthesized through microwave modified method and screened for the model reaction (hydrogenation of octanal to octanol) in self-design microwave reactor in a solvent-free system. The catalyst shows microwave cooperative activity with high selectivity toward desire products. The same reaction was also performed under conventional heating system in Parr reactor. The microwave protocol was found more effective in term of conversion and selectivity under optimal reaction conditions. The enhance activity is due to enormous reducing sites production on the surface triggered by microwave irradiation. Here, the mechanism of acidic site population on the surface was comprehensively investigated and correlated with catalyst efficiency. The gas chromatographic studies revealed the formation of octanol as a major product while other small peaks reflect the formation of byproducts C16 aldol, C16 α, β-unsaturated aldehyde and C24 acetal. Thus, the tetragonal zirconia can be used for the conversion of aldehyde to alcohol under microwave irradiation efficiently.

Effect of methane presence on catalytic heavy oil partial upgrading

In this work, several heavy crudes with wide viscosity range from 1200 to 120,000 cP at 15.6 °C were partially upgraded with a specially designed catalyst under CH4 atmosphere. All these reactions were conducted using a batch mode high temperature and high-pressure Parr reactor. This technique was proved to be suitable for the heavy oil feeds with varied properties, confirming its generality for industrial practice. Upgrading under CH4 demonstrated much better performance than that under N2 when the reaction conditions kept the same, confirming the role played by methane on facilitating heavy ends conversion during heavy oil partial upgrading. Furthermore, the effect of methane presence was further investigated through comparing with its N2 counterpart at the similar asphaltene conversion by tuning the reaction time and temperature. Although it is well expected that coke yield and gas yield increased yet liquid yield decreased along with upgrading reaction proceeding, the reaction under CH4 showed noticeably lower coke and gas yield while higher liquid yield than its counterpart under N2 at comparable asphaltene conversion, strongly indicating the methane’s effect on effective suppression of thermal over-cracking of heavy crude, which is beneficial for achieving more high value-added liquid products. Moreover, the properties of the oil products derived from different atmospheres including viscosity, density, TAN (total acidic number), AMW (average molecular weight) and sulfur content were studied and compared. All these indexes showed a decreasing trend with increasing asphaltene conversion. The values for viscosity, density and AMW were higher under CH4 than those under N2, while the TAN and sulfur content were lower when methane was present, implying the possible methane incorporation and its role played on promoting deoxygenation and desulfurization reactions. The research outcomes derived from this study further evidence the technical advantages of heavy crude partial upgrading under methane, thus providing a more cost-effective and environmentally friendly alternative to hydrotreating for processing heavy oil.

Obtaining hemicellulosic hydrolysate from sugarcane bagasse for microbial oil production by Lipomyces starkeyi.

The extraction of the hemicellulose fraction of sugarcane bagasse (SCB) by acid hydrolysis was evaluated in an autoclave and a Parr reactor aiming the application of the hydrolysate as a carbon source for lipid production by Lipomyces starkeyi. The hydrolysis that resulted in the highest sugar concentration was obtained by treatment in the Parr reactor (HHR) at 1.5% (m/v) H2SO4 and 120°C for 20min, reaching a hemicellulose conversion of approximately 82%. The adaptation of the yeast to the hydrolysate provided good fermentability and no lag phase. The fermentation of hemicellulose-derived sugars (HHR) by L. starkeyi resulted in a 27.8% (w/w) lipid content and YP/S of 0.16g/l.h. Increasing the inoculum size increased the lipid content by approximately 61%, reaching 44.8% (w/w). The hemicellulose hydrolysate from SCB is a potential substrate for L. starkeyi to produce lipids for biodiesel synthesis based on the biorefinery concept.