Production and characterization of sunflower stalk biochar and ash: a study on batch versus semi-batch gasifier systems Adewale George Adeniyi, Taiwo Temitayo Micheal, Ebuka Chizitere Emenike, Omar H. Abd-Elkader, Kingsley O. Iwuozor, et al. International Journal of Chemical Reactor Engineering, 2025 This study is the first to compare batch and semi-batch gasifier systems for turning sunflower stalks into useful products, filling an important gap in our understanding of gasification technologies that use biomass fuel. This study investigated the production and characterization of biochar and ash derived from sunflower stalks using batch and semi-batch gasifiers. The conversion process, lasting 90 min, employed the top-lit updraft mechanism to generate sunflower stalk ash and biochar under both systems. The yields of batch-based samples were 34.60 % for biochar (BSB) and 19.40 % for ash (BSA), while semi-batch samples yielded 20.80 % (SSA) and 18.55 % (SSB). Elemental analysis revealed significant carbon enrichment from 44.2 % in raw feedstock to 85.4 % in semi-batch biochar, representing a 93 % increase in carbon concentration. The biochar produced in the batch gasifier exhibited a surface area of 364.127 m2/g, compared to 392.508 m2/g for the semi-batch gasifier biochar, as determined by BET analysis. Scanning Electron Microscopy (SEM) revealed a more porous structure in the semi-batch biochar. Fourier Transform Infrared Spectroscopy (FTIR) analysis identified both similarities and differences in the functional groups between the biochar and ash samples from both systems. Thermogravimetric analysis (TGA/DTA) showed a higher mass loss in the semi-batch ash (SSA) compared to the batch sample (BSA), indicating greater thermal stability in the batch biochar. These findings showed the potential of sunflower stalk biochar and ash for diverse applications such as soil improvement, pollutant removal, and energy conversion, while also providing insights into optimizing carbonization processes for enhanced material properties.
Characterization of groundnut shell biochar produced with different stainless steel combustion compartment volumes Oluwatoyin Rhoda Ayanwusi, Sulyman A. Abdulkareem, Taiwo Temitayo Michael, Kingsley O. Iwuozor, Ebuka Chizitere Emenike, et al. Biofuels Bioproducts and Biorefining, 2024 Biochar, a solid material derived from a thermochemical process, has received significant attention due to its usefulness in various sectors. Previous studies have been conducted to improve the properties and quality of this material by altering the thermochemical processes, treating the feedstock, hybridizing the feedstock, and so forth, but little has been done on the effect of varying the reactor's configuration. This research aims to study the effect of varying the stainless‐steel‐based combustion compartment volume of a biomass‐fueled top‐lit updraft gasifier on the groundnut shell biochar. The biochar yields for reactors ranged from 34.9% to 51.2%. The sample produced in the smallest combustion compartment volume showed the highest carbon content, according to energy dispersive X‐ray spectroscopy (EDX) analysis. Potassium, another major element, decreased as the combustion compartment was reduced. Scanning electron microscopy (SEM) analysis revealed that the biochar samples produced had an irregular shape and rough surfaces, and reducing the combustion compartment volume resulted in larger particles on the surface. Fourier transform infrared (FTIR) spectroscopy analysis showed similarities and differences in peaks observed for all the samples. The biochar samples produced can find applications in wastewater treatment, energy conversion and storage, and soil amendment, and the findings contribute to the design and optimization of biomass‐based gasifiers.
A Review on CO2 Capture over Novel Adsorbents: Progress in Robust Zeolite Adsorbent Development H. U. Hambali, T. Jimoh, T. L. Peng, A. A. Umar, B. T. Mutiullah, et al. Nigerian Journal of Technological Development, 2024 Indubitably, the combustion of fossils fuels has really hampered the preservation of the environment as it raises the content of CO2 in the atmosphere which consequentially results in global warming. Adsorption process remains the popular technique owing to its cost-effectiveness, faster reaction rates and flexible design. This review detailed the research progress in preparation of modified zeolite-based and novel adsorbents towards enhanced CO2 capture. In addition, the review presents an overview on available techniques of capturing CO2 and mechanism of reaction. Large surface area, distinctive mechanical characteristics and uniform dispersion of the exchangeable cations in the porous framework is prerequisite for high adsorption capacity and stability over zeolite materials. Novel nanostructured and polymeric zeolite composite materials seem promising because they offer solutions to energy-related problems while also contributing to environmental preservation. It is anticipated that this review could offer a conclusive roadmap in the pursuit of a cost-effective, industrially potent adsorbent suited for enhance CO2 capture.
Hydrothermic Reduction of Rutile-Ilmenite Mineral Producing an Oxyhydride η-Ti2FeO0.2H2.8: Towards In-Situ Hydrogen Production and Storage I. A. Mohammed, S. I. Mustapha, F. A. Aderibigbe, H. U. Hambali, A. M. Afolabi, et al. Nigerian Journal of Technological Development, 2024 As an alternative to the physical storage of hydrogen as compressed gas or liquid hydrogen requiring high-pressure tanks and cryogenic temperatures, the material-based storage of hydrogen in solids involves hydrogen uptake and release from the surface of adsorbents or within interstitials of hydrides. We report a hydrothermic reduction of rutile-ilmenite mineral into hydrogen-rich fibrous products, η-Ti2FeO0.2H2.8, in an ethanol-water system at 120°C for 4 hrs. As part of a project to generate hydrogen from water-ethanol system using advanced catalysts containing graphene oxide (GO) as carbon source, a system of 62.5 μg graphene oxide per g of rutile-ilmenite mineral was employed in a concentration of 50 mg/mL of ethanol-water solution. As well as in the original mineral, XRD of thermal annealed mineral between 500 and 800°C showed no hydride or phase change in rutile-ilmenite. With hydrothermal treatment of GO/rutile-ilmenite (50 mg/mL) in ethanol-water (1:1 v/v) at 120°C, a hydrogen-rich ferrotitanium hydride phase was formed, and there was a change in morphology from plate-like and granular particles into fibrous structures. Like the release of hydrogen by its ‘carriers’ (e.g., CaH2, NH4BH4, NaBH4, NH3, formic acid), it is anticipated that hydrogen was generated from the ethanol-water system in-situ, which reduced the rutile-ilmenite mineral into a hydride. EDX results showed that the reduction affected specifically the oxides of Fe and aluminosilicates in the mineral. The study demonstrated a possibility of in-situ hydrogen generation and storage via low-temperature graphene oxide hydrothermic reduction of rutile-ilmenite mineral in an ethanol-water system.
