NOPR Collection:

Kinetic modeling in biofuel production: A critical review and roadmap for model selection

2026-09-02T05:01:34Z

Title: Kinetic modeling in biofuel production: A critical review and roadmap for model selection Authors: Chelak, Pankaj; Gupta, Renu; Bansal, Ajay; Mishra, Sanjeev Abstract: Kinetic modeling plays a central role in interpreting experimental behaviour and supporting reactor design in biofuel production systems. Commonly applied models range from empirical curve-fitting equations to mechanistically derived growth models, each constructed upon distinct theoretical assumptions. However, inappropriate model selection can compromise interpretability and predictive reliability beyond the experimental domain. Thus, kinetic model selection should be guided by scientific suitability rather than conventional or statistical convenience. This review provides a critical and comparative evaluation of kinetic models applied in biofuel production systems by comparing their mechanistic basis, parameter identifiability, data requirements, and extrapolation capability. Empirical models such as First-order, Logistic and Gompertz-type models are assessed for their descriptive accuracy but limited mechanistic insight. Growth-based models like Monod model capable of representing substrate consumptions, evaluated for their ability to represent biological and biochemical constraints, while highlighting persistent challenges related to data availability, parameter identifiability, and validation. More structured and hybrid approaches, such as Luedeking-Pirettype model examined for their ability to couple microbial growth and product formation under data-rich conditions. Systematic comparison shows that model suitability is governed primarily by research objective, system complexity, and experimental resolution rather than by conventional usage. On this basis, a decision-oriented framework is developed to guide context-specific kinetic model selection to enhance methodological rigor in biofuel process analysis Page(s): 503-514

Biomass-derived activated carbon from Cyperus pangorei for high-performance supercapacitor electrodes

2026-09-02T04:59:03Z

Title: Biomass-derived activated carbon from Cyperus pangorei for high-performance supercapacitor electrodes Authors: Maheswari, N; Nandhini, S Abstract: Activated carbon was successfully prepared from Cyperus pangorei through a simple and cost-effective thermal decomposition method using ghee as a carbonization aid. The obtained carbon was annealed at 500 °C for 3 h and characterized by scanning electron microscopy and Fourier transform infrared spectroscopy (FTIR). SEM analysis revealed aggregated carbon particles, while FTIR confirmed the presence of oxygen-containing surface functional groups. The electrochemical performance of the prepared carbon electrode was evaluated using cyclic voltammetry, galvanostatic charge-discharge, electrochemical impedance spectroscopy and cycling stability studies using PVA / Na2SO4 gel electrolyte within a potential window of 0–1.5 V. The electrode exhibited a maximum specific capacitance of 476 F g-1 and maintained excellent capacitive behaviour even at a high current density of 25 A g-1. The enhanced electrochemical performance is attributed to the combined contribution of electric double-layer capacitance and surface redox activity associated with oxygen-containing functional groups. The results demonstrate that Cyperus pangorei-derived carbon is a promising low-cost and sustainable electrode material for supercapacitor applications. Page(s): 515-522

Oil industry waste derived activated carbon for malachite green dye adsorption: Kinetic, isotherm, and thermodynamic study

2026-09-02T04:56:23Z

Title: Oil industry waste derived activated carbon for malachite green dye adsorption: Kinetic, isotherm, and thermodynamic study Authors: Sao, Ankita; S . Gaikwad, Mahendra Abstract: This study explores de-oiled rice bran (DORB), an agro-industrial by-product, as a precursor for the preparation of porous activated carbon. The study assesses the performance of the synthesized activated carbon (AC) in removing malachite green (MG) dye from aqueous solutions, with a focus on developing economically viable and sustainable adsorbents for wastewater treatment. AC was synthesized using a combined thermal and chemical modification process with H3PO4, eliminating the need for separate activation steps. This approach reduced preparation time and energy consumption. The resulting activated carbon possessed a surface area of 465 m2 g-1 and an average pore size of 5.0872 nm. Characterization was performed using SEM, FTIR, EDAX, and pHpzc techniques. The adsorption performance was studied under varying pH (3.0–9.0), initial MG concentration (10–50 mg L-1), adsorbent dosage (0.1–0.6 g), contact time (0–30 min), and temperatures (303–333 K). The adsorption behaviour followed the Freundlich isotherm model, and the kinetics were well described by the pseudo-second-order model. The highest adsorption capacity was 70.92 mg g-1. Thermodynamic analysis revealed spontaneous (ΔG<0), endothermic (ΔH>0), and favourable (ΔS>0) adsorption. Regeneration studies identified 0.2 M HCl as an effective solvent for De-oiled rice bran activated carbon (DORBAC) recovery. Page(s): 523-534

Synthesis and characterization of biomass-derived hard carbon for lithium-ion battery anode in electric vehicle applications

2026-09-02T04:54:16Z

Title: Synthesis and characterization of biomass-derived hard carbon for lithium-ion battery anode in electric vehicle applications Authors: Kuppuswamy, Rajasri; Singaravel, Dhipanaravind; Ashokan, Anbuchezian; Rajendran, Silambarasan Abstract: Development of sustainable and high-performance hard carbon anode for lithium-ion batteries (LIBs) using rice husk biomass have been performed in this study. The material was synthesized through pyrolytic carbonization followed by potassium hydroxide (KOH) activation to enhance structural and electrochemical properties. Characterization results confirmed the formation of an amorphous turbostratic carbon structure with a defect ratio (I_D/I_G) of 1.05, along with a high specific surface area of 185 m²/g and a pore volume of 0.21 cm³/g, which are significantly improved compared to nonactivated biomass-derived carbons. Electrochemical testing revealed a high initial discharge capacity of 320 mAh/g at 0.1 C, which is comparable to or slightly higher than conventional graphite anodes (~300 mAh/g). The material exhibited excellent cycling stability with over 90% capacity retention after 100 cycles and demonstrated a superior rate capability of 210 mAh/g at 2C, outperforming many reported biomass-derived hard carbons. Overall, improved performance is attributed to the synergistic effect of hierarchical porosity and surface functional groups introduced during activation. These results show that for advanced LIB applications, rice husk-derived hard carbon provides an affordable and scalable substitute for traditional anode materials. Page(s): 535-543