Biomass-based Carbon for Hydrogen Storage

前言当今，由于日益恶化的气候变化和能源危机，对替代能源的需求至关重要。氢气已成为绿色能源载体之一。然而，它的运输和储存一直是挑战。专家们已经成功地将氢气储存在地下洞穴、压力罐和液氢中。然而，这些存储系统面临着存储容量有限、能源效率低、成本高和安全问题等问题。要克服上述挫折，可靠、安全和高效的替代技术至关重要，这些技术可以在环境条件下提供巨大的重力测量能力。因此，由于氢的快速释放、原料的自然丰富性和良好的再生记录，多孔碳储氢被认为是一种很有前途的技术。尽管出现了关于碳材料储氢能力的有希望的报告，但目前还没有一种材料达到美国能源部设定的市场标准。到目前为止，人们已经做出了前所未有的努力来最大限度地提高多孔炭在环境条件下的吸氢潜力。在这些方法中，氢溢出和杂原子掺杂被认为可以提高碳基材料在常温下的储氢潜力。有报道表明，由于氢的溢出效应，金属掺杂的多孔炭的吸氢能力有了显著的提高。本项目将深入分析金属装饰和杂原子掺杂对废咖啡、坚果壳和玉米芯等不同生物质基碳的储氢潜力的协同效应。主要目标是：a.合成用于储氢的不同生物质衍生的活性碳。B.通过掺杂过渡金属和杂原子来提高多孔炭的吸氢能力。C.表征和分析多孔炭的形态、孔隙率、织构特性、热稳定性和可重用性。D.建立生物质碳的吸附等温线、动力学和热力学性质的数学模型。多孔炭的合成过程和氢吸附首先，生物质前驱体用蒸馏水洗涤并在热风炉中干燥。然后，干燥的生物质前体将在卧式电炉中热解，并在氩气中加热到400和450摄氏度。然后将炭化样品浸渍到氢氧化钾中，转移到卧式电炉中，在800℃和850℃下活化，最后用蒸馏水洗涤和干燥。然后将制备的多孔炭分别掺杂不同的过渡金属(Ni、铂、镍)和杂原子(N2、B、O2)。氢气吸附实验和多孔炭的表征将使用测压/Sievert方法来评估多孔炭的吸氢潜力。然后，废弃的活性碳将在几个循环中重复使用，以测试多孔炭的再利用。合成的多孔炭将用不同的表征技术进行表征，如物相和元素分析、表面形态、织构性质、能量色散X射线光谱、傅立叶变换光谱、热重分析和差热分析。该项目被认为对开发用于环境操作条件下的新型碳氢储存材料朝着实现氢基经济做出了实质性贡献。

IntroductionNowadays, due to the worsening climate change and energy crisis, the need for alternative energy sources is vital. Hydrogen has emerged as one of the green energy carriers. However, its shipment and storage have been the challenges. Experts have managed to store hydrogen in underground cavities, pressure tanks, and liquid hydrogen. However, these storage systems suffer from several setbacks such as limited storage capacity, low energy efficiency, high cost, and safety concerns. To overcome the above setbacks, reliable, safe, and efficient alternative technologies, which provide large gravimetric capacity at ambient conditions are crucial. Hence, due to the rapid release of hydrogen on demand, natural abundance of raw material, and the good track record of regeneration, hydrogen storage in porous carbons is regarded as a promising technology. Despite the emergence of promising reports of hydrogen storage capacities in carbon material, no material is yet to meet the market standards set by the US Department of Energy. To date, unprecedented efforts have been made to maximize the hydrogen adsorption potential of porous carbons at ambient conditions. Among these methods, hydrogen spillover and heteroatom doping are believed to improve the hydrogen storage potential of carbon-based materials at ambient conditions. Reports show that metal-doped porous carbon revealed a significant improvement in hydrogen uptake capacity due to the hydrogen spillover effect. This project will deeply analyse the synergistic effect of wmetal decoration and heteroatom doping on the hydrogen storage potential of different biomass-based carbons like spent coffee, nut shell, and corncob. The major objectives will be to:A. Synthesize different biomass-derived activated carbons for hydrogen storage. B. Enhance the hydrogen uptake capacity of the porous carbon by doping with transition metals and heteroatoms.C. Characterise and analyze the properties of the porous carbon for its morphology, porosity, textural properties, thermal stability, and reusability.D. Develop mathematical models of the adsorption isotherm, kinetic, and thermodynamic properties of biomass-derived carbon.Porous carbon synthesis procedure and hydrogen adsorptionFirst, a biomass precursor will be washed with distilled water and dried at hot air oven. Then, the dried biomass precursor will be pyrolyzed in a horizontal electric furnace and heated to 400 and 450 C in a stream of argon gas. Then, the carbonized samples will be impregnated into a potassium hydroxide and transferred to a horizontal electric furnace, and activated at a temperature of 800 and 850 C. Finally, the activated carbon samples will be washed with distilled water and dried. The prepared porous carbon will then be doped with different transition metals (Ni, Pt, Ni) and heteroatoms (N2, B, O2).Hydrogen adsorption experiments and characterization of porous carbonTo evaluate the hydrogen adsorption potential of the porous carbon the manometric/Sievert's method will be used. Then, the spent activated carbon will be reused repeatedly in several cycles to test the reuse of the porous carbon. The synthesized porous carbons will be characterized using different characterization techniques such as proximate and elemental analysis, surface morphology, textural properties, energy-dispersive x-ray spectroscopy, Fourier transform spectroscopy, thermogravimetric and differential thermal analysis. This project is believed to have a substantial contribution to the development of novel carbon hydrogen storage materials for ambient operating condition applications toward achieving a hydrogen-based economy.