Browsing by Author "Jande, Yusufu A. C."

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    Biomass-based carbon electrode materials for capacitive deionization: A review
    (Springer Nature, 2019) Elisadiki, Joyce; Kibona, Talam Enock; Machunda, Revocatus L.; Saleem, Muhammad Wajid; Kim, Woo-Seung; Jande, Yusufu A. C.
    Capacitive deionization (CDI) is a promising water purification technology which works by removing salt ions or charged species from aqueous solutions. Currently, most of the research on CDI focuses on the desalination of water with low or moderate salt concentration due to the low salt adsorption capacity of the electrodes. The electrosorption capacity of CDI relies on the structural and textural characteristics of the electrode materials. The cost of electrode materials, the complicated synthesis methods, and the environmental concerns arising from material synthesis steps hinder the development of large-scale CDI units. By considering the good electrical conductivity, high specific surface area (SSA), porous structure, availability, mass production, and cost, porous carbon derived from biomass materials may be a promising CDI electrode material. This review presents an update on carbon nanomaterials derived from various biomasses for CDI electrodes. It covers different synthesis methods and the electrosorption performance of each material and discusses the impact of the SSA and porous structure of the materials on desalination. This review shows that a variety of biomass materials can be used to synthesize cost-effective CDI electrode materials with different structures and good desalination performance. It also shows that diverse precursors and synthesis routes have significant influences on the properties and performance of the resulting carbon electrodes. Additionally, the performance of CDI does not depend only on BET surface area and pore structure but also on the applied voltage, initial concentration of the feed solution, and mass, as well as the capacitance of the electrodes.
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    Catalytic supercritical water gasification of biomass waste using iron-doped alkaline earth catalysts
    (Springer, 2022) Bakari, Ramadhani; Xiao Huang, Thomas Kivevele; Jande, Yusufu A. C.
    The objective of this study is to optimise the process of supercritical water gasification of rice husk biomass utilising a low-cost catalyst made from alkaline-earth materials. The interactions between catalyst loading and Fe content on gasification yield were investigated using response surface methodology. The catalyst characterisation findings revealed that the catalysts’ predominant reactive site is on iron oxide, calcium ferrite, and calcium oxide. Under all the conditions tested, the manufactured catalyst was highly active in promoting char gasification, gas volume, and gasification efficiency whilst the tar yield was substantially elevated. The maximum gasification efficiency of 69.57%, gas yield of 402.8 mL/g biomass, char yield 24.68 wt%, and gravimetric tar yield of 57.5 mg/g were obtained under the catalytic conditions of 15% catalyst loading with 5%Fe/limestone, 492 °C, 120-min residence time, and 9.5 wt% feed concentrations. Thus, the manufactured catalyst showed a potential for optimising gasification outputs.
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    Sub- and supercritical water gasification of rice husk: parametric optimization using the I-optimality criterion
    (American Chemical Society, 2021) Bakari, Ramadhani; Kivevele, Thomas; Huang, Xiao; Jande, Yusufu A. C.
    In this study, rice husk biomass was gasified under sub- and supercritical water conditions in an autoclave reactor. The effect of temperature (350–500 °C), residence time (30–120 min), and feed concentration (3–10 wt %) was experimentally studied using the response surface methodology in relation to the yield of gasification products. The quadratic models have been suggested for both responses. Based on the models, the quantitative relationship between various operational conditions and the responses will reliably forecast the experimental outcomes. The findings revealed that higher temperatures, longer residence times, and lower feed concentrations favored high gas yields. The lowest tar yield obtained was 2.98 wt %, while the highest gasification efficiency and gas volume attained were 64.27% and 423 mL/g, respectively. The ANOVA test showed that the order of the effects of the factors on all responses except gravimetric tar yield follows temperature > feed concentration > residence time. The gravimetric tar yield followed a different trend: temperature > residence time > feed concentration. The results revealed that SCW gasification could provide an effective mechanism for transforming the energy content of RH into a substantial fuel product.