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Canola hull, meal and straw are abundantly available as low-value agricultural residues in Canada. These lignocellulosic feedstocks have the potential for the generation of biofuels as alternatives to fossil fuels. Supercritical water gasification is an emerging hydrothermal process for the conversion of recalcitrant biomasses into value-added hydrogen with the application of water beyond its critical temperature and pressure. This study focuses on the comparative investigation of supercritical water gasification of canola residues for H 2 production through optimization of process temperature (350–500 °C), reaction time (20–80 min) and feedstock concentration (10–25 wt%) at a constant pressure of 23–25 MPa. Supercritical water gasification of canola straw resulted in a high H 2 yield of 7.1 mmol/g to 6.2 mmol/g of H 2 from canola hull and 5.5 mmol/g of H 2 from canola meal at a temperature, reaction time and feedstock concentration of 500 °C, 40 min and 20 wt%, respectively. Furthermore, H 2 yield and total gas yield from canola straw were maximized to 8.1 mmol/g and 29.7 mmol/g at the optimized supercritical water gasification conditions of 500 °C, 60 min and 10 wt%. Hydrochar obtained at high gasification temperatures also revealed aromatic carbon structures and thermal stability due to dehydrogenation, decarboxylation, deamination and aromatization. The overall results demonstrated the potential of supercritical water gasification as an evolving hydrothermal process to convert lignocellulosic biomass into high-value H 2 -rich gas. [Display omitted] • A comparative study of hydrothermal gasification of canola residues was performed. • Temperature, reaction time and feed concentration were optimized for H 2 production. • H 2 yield varied as canola straw (7.1 mmol/g) > hull (6.2 mmol/g) > meal (5.5 mmol/g). • Hydrochar at high temperatures revealed high aromatic carbon and thermal stability. • Water-gas shift, methanation and hydrogeneration affected H 2 , CO, CO 2 and CH 4 yields. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hydroprocessing of oleic acid was done to produce aviation turbine fuel range hydrocarbons. • Sn(1)-Fe(3)-Cu(13)/SiO 2 -Al 2 O 3 was identified as the most promising catalyst. • Catalyst with high oxophilic reduced iron has a positive influence on product selectivity. • Catalyst with high surface area and greater pore volume resulted in high catalyst productivity. • Catalyst with weak metal–support interaction was highly productive for aviation turbine fuel. In this work, the synergistic effects of 1 wt.% Ti, 1 wt.% Zr, and Sn in the range of 0.5−2 wt.% on Fe(3)-Cu(13)/SiO 2 -Al 2 O 3 catalyst were ascertained through extensive characterization and their subsequent evaluation for the production of aviation turbine fuel range hydrocarbons (C 8 -C 16) via hydroprocessing of oleic acid. The largest surface area (571 m2/g) and pore volume (0.65 cm3/g) were obtained from the N 2 physisorption analysis of 1 wt.% Sn-promoted catalyst (E). Cu 2 O and CuO were identified in the X-ray diffractograms (XRD) of all the catalysts except for catalyst E, which revealed only the peaks of Cu 2 O owing to the small particle size of CuO below the threshold of detection of XRD. X-ray photoelectron spectroscopy (XPS) analysis revealed the presence of both oxidized and reduced phases of Cu, Fe, Ti, Zr and Sn in their respective catalysts, with the highest and lowest atomic compositions of reduced Fe and CuO, respectively, detected in catalyst E; corroborating findings from XRD analyses. The relatively homogeneous dispersion of phases present in catalyst E (revealed by its smallest crystallite size of 5.1 nm) was also evidenced by the weakest metal-support interaction from the H 2 -TPR analysis of the same catalyst. Hydroprocessing of oleic acid using catalyst E at 320 °C under H 2 pressure of 2.1 MPa and reaction time of 8 h resulted in the highest aviation turbine fuel range hydrocarbons selectivity of 76.8 % and yield of 71.7 %. This was due to its high metal dispersion, desirable textural properties and high oxophilic reduced iron content. [ABSTRACT FROM AUTHOR]

[Display omitted] • Developed bifunctional mesoporous catalysts of Pt/Al-TUD-1 for hydroisomerization. • F-T wax with C 8 -C 44 n-paraffins was hydrorefined into jet fuel with a yield of 63%. • Pt/Al-TUD-1 was tailored with a suitable Brønsted acidity for jet fuel isoparaffins. TUD-1 supported bifunctional platinum catalysts were prepared and characterized for structural and textural properties, acidity, and platinum dispersion. The acidity of TUD-1 was varied by isomorphous substitution of Al and Ti in the framework. The TUD-1 supports possess a three-dimensional amorphous structure as shown by XRD. BET-N 2 adsorption and pyridine FTIR studies revealed that the incorporation of Al in the TUD-1 framework enhances the surface area and generates Brønsted acidity. The catalysts were screened for hydrorefining of Fischer-Tropsch wax with C 8 -C 44 n-paraffins. The catalysts prepared with Si-TUD-1 and Ti-TUD-1 supports were not active for hydrocracking and hydroisomerization due to the absence of Brønsted acid sites, which was verified by pyridine FTIR. Increasing the amount of Al in the framework gradually increased the Brønsted acid sites and thus promoted hydrocracking and hydroisomerization of F-T wax. Pt/Al-TUD-1 catalyst with a Si/Al ratio of 10 produced more jet fuel range hydrocarbons. Hydrorefining of F-T wax was evaluated over an optimal Pt/Al-TUD-1 (Si/Al = 10) catalyst at different pressures and temperatures. Hydroisomerization was favored at low hydrogen pressure. Increasing the temperature shifted the hydrocarbon distribution more towards gasoline due to severe cracking. The temperature of 330 °C and a hydrogen pressure of 5 MPa were found to be optimum to produce jet fuel range hydrocarbons that meet the ASTM specification of cold flow properties. This study proves the feasibility of the production of renewable jet fuel that is directly compatible with fossil-based aviation engines, through hydrorefining of F-T waxes using a mesoporous bifunctional catalyst. [ABSTRACT FROM AUTHOR]

Hydrothermal liquefaction of microalgae under milder reaction conditions was studied for the production and characterization of high quality biocrude oil and hydrochar confirming its feasibility as sustainable biofuel source. The present study investigates the effects of solvents, temperature and time on the yield of biocrude oil. The comparatively higher yield of biocrude oil (47 wt%) obtained in methanol-water mass ratio of 0.75:0.25 also contained higher amount of ester components resulting in higher biocrude oil quality. Methanol-water co-solvent favored higher biocrude oil yield with lower nitrogen and oxygen contents as compared to pure water. Response surface methodology was applied to study the effects of temperature (222–322 °C), and reaction time (10–60min) at constant pressure of 11.5 MPa for methanol-water and biomass-solvent ratios of 0.75:0.25 and 1:5, respectively. The optimum yield of biocrude oil (57.8 wt%) and highest energy recovery (85.3%) was obtained with 75 wt% of methanol in water at 272 °C and reaction time of 35 min. Subcritical condition (temperature of 222 °C, pressure of 11.5 MPa) resulted in the highest hydrochar yield (19.5 wt%). Hydrochars were also characterized by CHNS, BET, FT-IR and TGA techniques to ascertain their prospective elemental composition, textural properties, functional groups as well as thermal stability. • Hydrothermal liquefaction of microalgae in methanol-water system was investigated. • Methanol-water (0.75:0.25 by wt.) system produced optimum bio oil yield of 57.8 wt%. • Addition of methanol in water in HTL lowered oxygen and nitrogen content in bio oil. • Highest hydrochar yield was obtained at 222 °C, 11.5 MPa and reaction time of 10 min. [ABSTRACT FROM AUTHOR]

Mesoporous supports with a π-acceptor were developed for adsorptive desulfurization of petroleum distillates. Pristine mesoporous Al 2 O 3 and Ti-substituted mesoporous Al 2 O 3 were synthesized and used as supports along with commercial γ-Al 2 O 3 for immobilizing ethylenediamine (EDA) linker followed by the π-acceptor, 2, 7-Dinitro-9-fluorenone (DNF). The adsorbents and supports were characterized using BET, FTIR, TGA techniques to ascertain their physicochemical properties. The extent of π-acceptor functionalization on supports was characterized using XRD, TGA and XPS techniques. Adsorbents were examined for the desulfurization of a model oil feed with 500 ppm of sulfur. The commercial γ-Al 2 O 3 -EDA-DNF adsorbent successfully removed 90.4 wt% of sulfur. The substitution of Ti in the framework of mesoporous Al 2 O 3 did not promote its desulfurization efficiency. The higher desulfurization activity of the commercial γ-Al 2 O 3 based adsorbent than that of others is attributed to its textural properties. [ABSTRACT FROM AUTHOR]

[Display omitted] • FTS performance of promoted iron catalysts supported on CNTs were investigated. • Hydrophobicity of catalysts was compared by the water contact angle measurement. • The carburization degree of catalysts was compared by XPS and XAS spectra. • COMSOL Multiphysics was used to simulate the FTS fixed-bed reactor. Light olefins and C 5+ are strategically important products of Fischer-Tropsch synthesis (FTS) over Fe catalysts. In the present work, FTS performance of 0.5K5Mo10Fe/CNTs (DOE 2) and 2 K0.5Mo30Fe/CNTs (DOE 5) catalysts was assessed in terms of CO conversion, C 5+ selectivity, and C 2 -C 4 selectivity under industrially relevant FTS conditions (H 2 /CO = 1.0; GHSV = 2000 h−1; T = 280 ℃; P = 4.13 MPa). The C 2 -C 4 selectivity increased in DOE 2 catalyst to 51.2% with respect to DOE 5 catalyst (2.9%). Meanwhile, the selectivity toward C 5+ hydrocarbons decreased from 93.1% in DOE 5 to 8.3% for DOE 2 catalyst. DOE 5 catalyst was more hydrophobic than DOE 2 as confirmed by the water contact angle measurement, lowering CO 2 selectivity and water gas shift rate. H 2 -TPR and CO 2 -TPD indicated an increase in reducibility and basicity of DOE 5 compared with DOE 2 catalyst, which enhanced iron carbide formation and chain growth probability. The highest amount of metallic Fe in DOE 5 calcined and spent catalysts obtained by XPS and XAS spectra also suggested higher degree of carburization in DOE 5. Additionally, COMSOL Multiphysics software package was employed to provide a 2-dimensional simulation of the FTS fixed-bed reactor. Simulation results were validated using the experimental data for FTS over DOE 2 and DOE 5 catalysts. Effects of temperature on CO conversion as well as distribution of H 2 , CO, and ethylene were discussed. The simulation illustrated the effects of the fixed-bed reactor wall on both velocity and temperature profiles. [ABSTRACT FROM AUTHOR]