The ChemE Car Competition is an event sponsored by AIChE where we power a small car by a chemical reaction. We build this car and choose a reaction that will carry a certain amount of water a specific distance (the exact distance and amount of water aren't given until the day of the competition). Our job is to have a car travel as close to the correct distance as possible.
Last year the team traveled to the University of Illinois at Urbana-Champaign for the AIChE North-Central Student Regional Conference. This was Notre Dame's first ever time sending a team to the competition. We had the chance to meet other chemical engineers from around the region, go to a poster presentation of all the car teams, attend several chemical engineering guest lectures.
For the 2016 competition we're thinking about pneumatic motors, biological reactions and batteries to power the car this year. We are still brainstorming and all ideas are welcome.
This is a fantastic way to get to know older CHEGs. You can learn a little bit more about your major, and gain experience working in a lab.
If this club sounds interesting to you, please email either Matt Owens (firstname.lastname@example.org) or James Sigman (email@example.com). We would like to gauge interest in the club for next year. We'll have our opening meeting in the first few weeks to get a head start on the competition.
ChemE Car 2015
The reaction we chose to use to create hydrogen was the oxidation of zinc with hydrochloric acid. The reaction entails the loss of the electrons on the zinc metal to the chlorine in the hydrochloric acid. This is a single replacement reaction, in which the zinc displaces and forces the hydrogen to vaporize, thus bubbling out of the solution. This reaction results in an ionic bond formed in the solution between zinc and chlorine and the formation of hydrogen gas.
The iodine clock reaction follows a classical two-stepped kinetics dominated reaction sequence. In this particular car design, we have employed the use of the hydrogen peroxide variation of this reaction. It begins by creating a stock starch solution, which is used as the iodine indicator once the proper form of iodine is produced in the reaction. To this is added sodium thiosulfate and potassium iodide. Then a separate solution of hydrogen peroxide with sulfuric acid is created and added to the previous solution.
The key to the kinetics control lies in controlling the speed of the first reaction step, which is directly proportional to the amount of hydrogen peroxide present. The second step occurs almost instantaneously, and the iodide ions proceed to bind to the starch molecules in the indicator, causing a distinct and sudden color change.
We use the precise kinetics and timing of the color change in conjunction with a photoresistor. When the solution becomes dark, the photoresistor spikes in resistance, reducing the power supplied to the motor to below its operating threshold. With a lack of power, the motor cuts out, bringing the car to a stop.
The fuel cell uses the hydrogen produced from the powering reaction and oxygen from the air to produce heat, water vapor, and electricity. First, upon entering the cell, both the gases are converted to ions via a platinum catalysts, producing the electricity to power the motor. Then, the protons travel through the proton exchange membrane (PEM), until they reach the ionized oxygen atoms. The two ions combine to form water and create heat.