Presentation on theme: "Presented by Kareem El-Aswad on 12/4/2012 Article & Research by D. Mori & K. Hirose."— Presentation transcript:
Presented by Kareem El-Aswad on 12/4/2012 Article & Research by D. Mori & K. Hirose
Carbon emissions from factories and vehicles have harmed the environment in recent years. Excessive Amounts of energy consumption in gasoline (very inefficient energy output). Mobility requirements will increase in the future; therefore energy sources must be safe and clean. Due to these requirements, and the fact that relatively clean Hydrogen gas can be used, fuel cell technologies are an ideal solution! However…
Hydrogen gas (H 2 ) has an extremely low density; thus limiting how much can be stored in a vehicle. Hydrogen gas only has 1/10 th the energy as gasoline; which limits how far a vehicle can travel. Therefore, efficiency and the amount of storable hydrogen must be increased. However, since all of the hydrogen can’t be stored, it is required to either compress hydrogen gas or to absorb it into a form of solid material.
A new tank design that allows for maximum hydrogen gas efficiency must consider all the following: Material Density Heat Conductivity Volumetric Change Heat Absorption Gravimetric Density Hydrogen Uptake
A new vehicle must consider the following: Safety Performance Cost Technical adaptation Scalability
Three Main Proposals were tested & a hybrid was created using the following as a basis: High-Pressure Tank System Liquid Hydrogen Tank Hydrogen-Absorbing Alloy Tank
Most common tank used for on-road testing currently. Pressurized at MPa; although there is a tendency to use 70MPa so that more hydrogen gas is carried. Simple structure; easy to charge / discharge.
Uses V3 & V4 types of tanks. Natural gas tanks use V1 & V2. GFRP = Glass Fiber Reinforced Polymer. CFRP = Carbon Fiber Reinforced Polymer. CFRP is required in higher pressure tanks because it’s much stronger and more resilient.
Problems include: Pressure & hydrogen volume is non-linear. Doubling pressure only increase volume by 40-50%. Weight of the tank is still relatively heavy. Further testing for tank durability is required to make a lighter tank. Volume of the tank can’t be shrunken down even further due to physical properties (i.e. dramatic increase in pressure & lower vehicle range).
At 20K ( o C), hydrogen becomes a liquid. Capable of storing much more hydrogen due to significantly higher density than gaseous hydrogen. Liquids are potentially easier to handle and store. Tanks require a double wall to keep low temperatures insulated. Vacuum Multi-Layered Insulation (MLI) is used to prevent radiation and thermal intrustion.
Can utilize smallest tank size since it can store hydrogen more dense than liquid hydrogen. Absorbs up to 2.8% hydrogen. Reversible hydrogen charge and discharge capacities. Several critical issues: Low gravimetric density (% of hydrogen). Can’t handle large amount of heat. Inefficient hydrogen release in colder environments. Still largely in the experimental phase. Optimal materials have not even been determined yet, although various metal alloys are primarily used.
Designed to improve charge-discharge variables. 4x45L high-pressure tanks combined with high- pressure absorptive alloys (promotes high volumetric density) which absorbs 1.9% hydrogen. Metal hydride (Ti 1.1 CrMn) used. Cooling system (radiator or fan)
7.3 kg of hydrogen 35 MPa; 2.5x more than a typical 35 MPa tank. Can be charged with hydrogen up to 80% in 5 min. At -30 o C, still capable of supplying hydrogen. Can actually be applied to a vehicle(i.e. size and performance)
High-pressure hydrogen environment allows MH to absorb hydrogen quickly. This solves the issues with classical metal hydrides and creates a method of hydrogen storage for vehicles.
Comparison of high-pressure tank, hydrogen- absorbing alloy tank and high-pressure hydrogen- absorbing alloy tank system as follows:
Hybrid Containment is an effective hybrid of the simpler containment systems mentioned previously. There is a noted relationship between hydrogen uptake and ΔH, energy to take out hydrogen from hydride; but no concrete theory for this relationship.
To reach a 4% absorption rate To open the possibilities for other chemical containment methods.
Very thoroughly well-thought out. Many different ideas and proposals were considered. Reservations: They should’ve used 70MPa, since that’s the most used for hydrogen gas fuel cells. Using a more efficient cooling system probably could have speeded the hydrogen charge capacity even more.
D. Mori & K. Hirose. “Recent Challenges of Hydrogen Storage Technologies for Fuel Cell Vehicles" International Journal of Hydrogen Energy. 34 (2009): Pages “Why CFRP?” Composites World. 30 Nov Composites Technology. 2 Dec cfrp “GFRP – Glass Fiber Reinforced Polymer.” Stromberg. 2 Dec