Final Project – Holly Coutu, Audra White, Allison Schuler & Adanma Ude

This we week we finished our final presentation and experiment to our class and a few groups from other sections of this course. My group came to be known as the “Hydrogen Group” including myself, Audra, Adanma and Allison. The lab we picked was from a website called Instructables, which Audra found for us. Instructables is a web-based documentation site where people post successful science projects to share with others, that can be tested at home. The Instructables website began at the MIT Media Lab.

For our final project, we are investigating hydrogen as an alternative fuel source for vehicles that use combustion engines. Hydrogen has several qualities that make for a great alternative fuel source as opposed to gasoline. It is clean-burning, has potential for domestic production and has high efficiency for fuel cell vehicles. We are attempting to solve an energy efficient method to producing hydrogen as well are providing a portable source for  hydrogen.

Hydrogen is an energy carrier, not an energy source, so energy is required to separate it from other compounds. Once produced, hydrogen stores energy until it is delivered in a usable form, for example, hydrogen gas delivered into a fuel cell. Natural gas reforming, renewable electrolysis and gasification are just a few ways of producing hydrogen, although they are still early in their development.

Why are we looking at hydrogen as a fuel source? The energy in 2.2 lb (1 kg of hydrogen gas) is about the same as the energy in 1 gallon of gasoline. A light-duty fuel cell vehicle stores 11-29 lb of hydrogen to enable an adequate driving range of 300 miles or more. Since hydrogen has a low volumetric energy density, storing this much hydrogen would require  a large storing tank, roughly the size of the trunk of a typical car. Unfortunately, only advanced technologies could reduce the required storage space and weight.

Our experiment calls for a soda can, liquid metal, water and a test tube or graduated cylinder. First, the can must be cut into small strips, about a half inch by 1 inch. Be sure to sand off any plastic from the label of the can, inside and out. The finished strip should be clean and shiny.

Next, add a drop of the liquid metal onto the piece of the can. Smear the liquid metal onto the strip with a q-tip or other utensil, do not use your finger! Once the liquid metal “wets” the aluminum strip it is ready. Before adding the water to the test tube, be sure to get the volume of water that was originally poured into the tube. Drop the activated strip into the test tube or graduated cylinder of water. Watch the aluminum as it converts into alumina and the hydrogen bubbles off. Also, try listening to the test tube once the strip has been submerged into the water. In some cases, the graduated cylinders began smoking and increased in temperature.

This reaction solves the problem of hydrogen storage. The activated aluminum strip acts as the storage medium, extracting the hydrogen on demand once it hits the water. After the exhaustion of the reaction, the aluminum oxide is shipped to a power generator plant that reduces it back to aluminum. Since alumina is a suspension in water it can be delivered via pipelines to the station.

Originally, we were looking to measure the amount of hydrogen being produced by attaching a balloon to opening of the cylinder. Unfortunately it takes an extensive amount of time for our experiment to show significant results, as well as there being a precaution for an explosion. As there is an increase in time, water levels in the graduated cylinder began to decrease and we even noticed a change in the meniscus. We decided that rather than measuring the amount of hydrogen produced into the balloon, we would take the volume of water at the start of the experiment and subtract the volume of liquid in the tube at the conclusion of the experiment.

We did a trial procedure before committing to this experiment that actually ran very well. We noticed that having a visible reaction would take a greater amount of time than we anticipated, however there was evidence of the reaction taking place, such as the sound and increase temperature in the tube, that we could have students look for.

Our second run was for the class, which went even better than the first one. Audra had prepared the aluminum strips a week prior to when we would be performing the experiment with our class. We found this was beneficial for the reaction, which showed results much quicker than when the strips were made as we were doing the experiment. We found that there was a better reaction with the liquid metal and the water. The reaction was not only happening quicker, but there was also some smoke, condensation and the graduated cylinders got really warm. We had planned for more time than we thought, so we were going to go through our slides to give time for the reaction to take place, then measure the remaining volume of liquid. Although we weren’t able to complete the experiment for the class, there was a lot of positive feedback from our classmates who seemed really interested in our experiment.

Our final experiment was with a group from another section of this course who did a windmill experiment with the Lego Mindstorm. We used aluminum strips prepared two weeks before. Unfortunately the experiment didn’t go as planned. There was little to no reaction in the first cylinder of water. Luckily, the strip we added to water in the second cylinder made a reaction that the other students could hear as well as changing to a murky substance.

As a result the reaction solves the problem of hydrogen for a hydrogen economy. The activated aluminum from the liquid metal acts as the storage medium, freeing hydrogen on-demand once mixed with the water. After the exhaustion, the remaining alumina can be shipped to a power generator plant that reduces back to aluminum, making this also a recycle process.