Biomass-based Carbon for Hydrogen Storage

引言当今，由于气候变化和能源危机的加剧，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。专家们已经设法将氢储存在地下洞穴、压力罐和液态氢中。然而，这些存储系统遭受若干挫折，诸如有限的存储容量、低能量效率、高成本和安全问题。为了克服上述挫折，在环境条件下提供大重量容量的可靠、安全和有效的替代技术至关重要。因此，由于氢气按需快速释放，天然丰富的原料，以及良好的再生记录，多孔碳储氢被认为是一种有前途的技术。尽管出现了碳材料储氢能力的有希望的报告，但还没有材料达到美国能源部制定的市场标准。迄今为止，已经做出了前所未有的努力来最大化多孔碳在环境条件下的氢吸附潜力。在这些方法中，氢溢出和杂原子掺杂被认为提高了碳基材料在环境条件下的储氢潜力。报道显示，由于氢溢出效应，金属掺杂的多孔碳揭示了氢吸收能力的显著改善。本项目将深入分析钨金属修饰和杂原子掺杂对不同生物质基碳（如废咖啡、坚果壳和玉米芯）储氢潜力的协同效应。主要目标是：A.合成不同生物质活性炭用于储氢。B。通过掺杂过渡金属和杂原子来提高多孔碳的吸氢能力。对多孔炭的形貌、孔隙率、织构、热稳定性和重复使用性进行表征和分析。开发生物质衍生碳的吸附等温线、动力学和热力学性质的数学模型。多孔碳合成过程和氢气吸附首先，生物质前驱体将用蒸馏水洗涤并在热空气烘箱中干燥。然后，将干燥的生物质前体在水平电炉中热解，并在氩气流中加热至400和450 ℃。然后，将浸渍的样品浸渍到氢氧化钾中并转移到水平电炉中，并在800和850 ℃的温度下活化。最后，将活性炭样品用蒸馏水洗涤并干燥。然后将制备的多孔碳掺杂不同的过渡金属（Ni、Pt、Ni）和杂原子（N2、B、O2）。多孔碳的氢吸附实验和表征为了评估多孔碳的氢吸附潜力，将使用测压/Sievert方法。然后，用过的活性炭将在几个循环中重复使用，以测试多孔炭的再利用。合成的多孔碳将使用不同的表征技术，如近似和元素分析，表面形态，纹理特性，能量色散X射线光谱，傅里叶变换光谱，热重和差热分析进行表征。该项目被认为对开发用于环境操作条件应用的新型碳储氢材料以实现氢基经济做出了重大贡献。

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.