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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]

In order to study the availability of canola residue for biosorption of acid orange 7 (AO7) from aqueous solution, batch experiments were performed for thermodynamic and kinetic studies. Physical characterization of canola samples was determined by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, and Brunauer–Emmett–Teller. The equilibrium adsorption data were analyzed using Langmuir and Freundlich isotherms. Langmuir isotherm was well fitted with the experimental adsorption data. Kinetic analysis were performed using pseudo-first order, pseudo-second-order and intra-particle diffusion models. The kinetic analysis indicated that the adsorption kinetic data of AO7 fit better to the pseudo-second-order kinetic model. In addition, the existence of three steps were observed during the adsorption experiment. The first stage represented the transport of AO7 molecules from the surface to pores of the adsorbent external structure. The second stage showed invasion of the molecules into the internal structure of the adsorbent. The adsorption of the molecule on the interior surface of the adsorbent was the last step. The thermodynamic data obtained at different temperatures were used to calculate standard free energy changes (∆G°), standard enthalpy change (ΔH°), and standard entropy change (ΔS°). All ΔG° values are ranged from –4.987 to –0.045 kJ/mol; ΔH° and ΔS° values of canola biomass were 29.62 kJ/mol and 0.107 J/mol K, respectively. Based on the calculation, adsorption of AO7 onto canola biomass was a spontaneous and endothermic process. [ABSTRACT FROM AUTHOR]

• Examined SOC priming via 13C-canola or wheat residue under tillage-based farming. • Canola vs. wheat residue return caused greater SOC priming in till vs. no-till farming. • Residue return in the farming systems enhanced nutrient release (Luvisol > Vertisol). • Canola vs. wheat residue caused greater release of available N, P & S from the soils. • Net available N, P & S release via residues was greater in the till vs. no-till farming. Understanding the legacy effect of tillage-based farming systems on soil organic carbon (SOC) mineralisation and nutrient [nitrogen (N), phosphorus (P) and sulphur (S)] supply after crop residue input is critical to appropriately manage plant available nutrients at the farm scale. To enhance this understanding, crop residues [canola (Brassica napus : δ13C 124‰) or wheat (Triticum aestivum : δ13C 461‰)] were added to Luvisol and Vertisol from two long-term (16–46 years) field experiments and incubated under a controlled environment for 126 days. The practices in the Luvisol were conventional tillage (CT) and reduced tillage (RT) under mixed crop-pasture rotation, and no-till (NT) under continuous cereal-cover crop rotation. The practices in the Vertisol were CT and NT under wheat-wheat rotation. The residue input significantly stimulated SOC mineralisation via "positive priming", which was greater (p < 0.05) in the CT than RT/NT in the Luvisol only. The SOC mineralised after 126 days was 3.1–4.2 and 1.6–2.5 times higher in the canola and wheat residue-amended soils, respectively, than the unamended soils. Although the CT or RT versus NT had higher net N availability in the Luvisol only, the residue input did not increase plant available N in both soils, possibly due to stronger residue-induced N immobilisation than mineralisation. The results showed a significant release of available P and S in both residue-amended soils (canola > wheat) after 26–50% of residue-C was mineralised over 126 days, and the Vertisol had greater net available P than Luvisol. Our results suggest that considerable quantities of available P and S may release from the soil reserves via SOC priming, and possibly via dissolution/desorption reactions in the soils, in addition to their direct release from the residues. In conclusion, crop residue input to historical farming systems enhanced the supply of available P and S, which varied with tillage, crop residue and soil type. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Canola oil factory residue was investigated as potential pyrolysis feedstock. • Residue has higher volatile matter, lower moisture content than other biomasses. • Distributed activation energy model applied to canola residue pyrolysis. • Evolved gas analysis showed CO 2 emission increased with temperature. • Thermodynamic and kinetics analysis suggested pyrolysis optimized ∼450 °C. Abstract The identification of biomasses for pyrolytic conversion to biofuels depends on many factors, including: moisture content, elemental and volatile matter composition, thermo-kinetic parameters, and evolved gases. The present work illustrates how canola residue may be a suitable biofuel feedstock for low-temperature (<450 °C) slow pyrolysis with energetically favorable conversions of up to 70 wt% of volatile matter. Beyond this point, thermo-kinetic parameters and activation energies, which increase from 154.3 to 400 kJ/mol from 65 to 80% conversion, suggest that the energy required to initiate conversion is thermodynamically unfavorable. This is likely due to its higher elemental carbon content than similar residues, leading to enhanced carbonization rather than devolatilization at higher temperatures. Evolved gas analysis supports limiting pyrolysis temperature; ethanol and methane conversions are maximized below 500 °C with ∼6% water content. Carbon dioxide is the dominant evolved gas beyond this temperature. [ABSTRACT FROM AUTHOR]

Torrefied pellets have gained more commercial importance due to their excellent performance in combustion, co-firing and gasification. The present investigation provides a conceptual design for torrefied fuel pellets production via combined torrefaction and pelletization technologies with and without additives. The entire design contains torrefaction unit, grinding, preparation of pellet formulation, pelletizing, and finally cooling of pellets. Two scenarios, scenario 1 (pelletization of torrefied biomass with additives) and scenario 2 (pelletization of torrefied biomass without any external additives) were tested and compared. The economic analysis suggests that both scenarios are profitable. Both scenarios were simulated using Aspen plus™, and economic feasibility was estimated using a complete cash flow analysis for a base case plant with 40,080 tonne/y capacity. For both cases, a discounted cash flow is a useful tool for estimating the minimal selling price for torrefied pellets as well as the capital investment, production cost and operating costs. The cost of the reactor used for torrefaction was found to be the most important component of combined torrefaction and pelletization system. The lowest selling price of generated torrefied pellets was found to be $103.4 and $105.1 per tonne at the plant gate for scenarios 1 and 2, respectively. Sensitivity analysis shows that, among all variable costs, labor cost has the highest influence on both net present value (NPV) and minimum selling price (MSP) in making pellets for both the scenarios. Furthermore, the internal rate of return was found to be25% and 22% at 10% discounted cash flow rate for scenarios 1 and 2, respectively. The framework that was created was found to lessen over-dependence on wood or fossil fuels and facilitate the promotion of bioenergy in rural areas., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

In this study the effect of different nitrogen source substrates on the amount of chitosan production by Aspergillus niger was investigated. A. niger PTCC 5012 from the Persian Type Culture Collection (PTCC) was grown on soy bean, corn seed and canola residues at 30 °C for specified cultivation days under sterilized conditions. Chitosan was extracted from the fungal mycelia using hot alkaline and acid treatment. The results were shown that soy bean residue at moisture of 37% and 8.40.26 % of nitrogen content produced the highest amount of chitosan (17.0530.95 g/kg of dry substrate), after 12 days of incubation. Corn seed residue produced very low amount of chitosan (1.90.4 % of nitrogen content). The chitosan was analyzed by FTIR spectroscopy and its spectrum was recorded.

[Display omitted] • Canola residue pellets were gasified at 650–850 °C with an equivalence ratio of 0.2–0.4. • Highest syngas yields were obtained from gasification at optimal temperature (800 °C) and equivalence ratio (0.4). • Torrefaction and densification significantly improved the gas yields and quality. • Syngas from torrefied pellets had a greater lower heating value (1828–2396 kJ/Nm3). • Tar content from gasification reduced remarkably due to torrefaction of pellets. In this study, steam gasification of pellets prepared from canola residue was carried out at varying temperatures (650–850 °C) and equivalence ratio (0.2–0.4). The optimal gasification temperature and equivalence ratio, based on syngas yield and its fuel quality, were found to be 800 °C and 0.4, respectively. Torrefaction and densification of canola residue significantly improved syngas yield. Torrefied pellets were obtained from torrefaction of canola residue at a microwave power, residence time and feeding load of 250 W, 10 min and 90 g, respectively. Pellets prepared with different bio-based additives were gasified to compare the effects of binder in gas compositions. The highest total gas yield (24.4 mol/kg), syngas yield (22.1 mol/kg), carbon conversion efficiency (85.1%), lower heating value of gases (2396 kJ/Nm3) and gas energy recovery (29.2%) were reported from the gasification of torrefied canola residue pellet at optimal conditions. Tar yield decreased significantly when torrefied pellets were gasified. A comprehensive characterization of biochar and tar produced from gasification of raw and torrefied canola residue pellets was performed to determine their potential applications. The formation of aromatic carbon structures in biochar produced at higher gasification temperatures was noticed through FTIR spectroscopy. The aromaticity of biochar also resulted in its greater carbon content, heating value and thermal stability as evident from ultimate and thermogravimetric analyses. Tar obtained from gasification of canola residue pellets contained depolymerized products such as organic acids, phenolics, aldehydes, ketones, ethers and esters. [ABSTRACT FROM AUTHOR]