Design of a special vent component for hydrogen-on-demand system

• Main Author: Lim, Sin Wei
• Other Authors: Chan Siew Hwa
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2020
• Subjects: Engineering::Aeronautical engineering
• Online Access: https://hdl.handle.net/10356/139086
• Institution: Nanyang Technological University

Due to the lack of energy resources and an increase in global warming, initiatives have been taken around the world to create cleaner energy sources. The fact that hydrogen fuel cells generate electricity with no pollutants or any of the greenhouse gases, mainly using only hydrogen and oxygen, they are of great appeal as a clean energy source. The use of hydrogen as a fuel for fuel cell has also attracted much attention since it can be derived from renewable sources, clean and non-toxic. Although hydrogen is the most abundant element in the universe, it is not readily available as a primary fuel source for use in fuel cell. Therefore, methods such as water electrolysis, thermochemical process, and hydrolysis of metal hydrides have been studied to produce pure hydrogen for application. Due to hydrogen’s low energy density and high flammability, proper storage is essential to prevent overpressure within the system since hydrogen produced has to be pressurized to increase its energy density. In this project, hydrolysis of sodium borohydride has been used to generate hydrogen gas using a mechanical system to automate the reaction of the chemicals. As the chemical reactions produce hydrogen gas and recyclable sodium metaborate (NaBO2), it is also crucial to ensure that the latter remains soluble for smooth solution discharge. Should there be any crystallization formed within the system, it may block the flow during refueling or cause transfer of solution issue during operation, affecting the effectiveness and lifespan of the hydrogen-on-demand system. Therefore, modifications have been suggested to improve the overall efficiency of the existing hydrogen-on-demand system by introducing new components such as a double function storage tank that condenses water from the moist hydrogen gas. From the results obtained, the double function storage tank is able to condense water, but the amount of water collected is not effective in keeping the product soluble at room temperature. It may be more effective if the temperature of the solution is elevated to increase the solubility of NaBO2.