How Do Our Cars Run?
2015 University of Maryland Regional Competition Car: "Walt" (named after Walter White of "Breaking Bad" fame)
Reaction: "Walt" utilizes a reaction of solid magnesium and 3M sulfuric acid.
Mg(s) + H2SO4(aq) → MgSO4(aq) + H2(g)
- Reaction products, as seen above, are magnesium sulfate and hydrogen gas (used in a hydrogen fuel cell to run the car)
- Hydrogen gas produced in the original reaction vessel is transferred to a connected vessel filled with water to remove unwanted vapor produced by the reaction
- The gas then travels through a desiccant which removes any excess water vapor, resulting in purer H2 that flows to the fuel cell
- The fuel cell is used to power two electric motors attached to the rear wheels that move the car forward
Picture of "Walt" Prototype, reaction vessels in back, stopping mechanism in front
- In accordance with AIChE regulations, we have taken necessary steps to ensure "Walt" is safe to use in competition.
- All hydrogen gas produced by the reaction is consumed by the hydrogen fuel cell
- The other reaction product, Magnesium Sulfate or Epsom Salt is non-toxic
- All vessels with chemicals are double contained by being placed in a sealed plexiglass chamber
- Chemicals are properly disposed of following each of the cars runs
2016 Regional Competition Prototype Car: "Jesse" (named after Jesse Pinkman also of "Breaking Bad" fame)
Reaction: "Jesse" is being designed to run by producing a temperature gradient across a system of thermoelectric generators
- The cold side of the gradient will reach a temperature of -78oC using the combination of acetone and dry ice
- Safe and effective exothermic reactions are currently being researched to be used on the hot side of the gradient
- Two systems of electric generators will be sandwiched between metal conductors and surrounded by reaction vessels where the gradient will be produced
Jesse is still in the developmental stages but stay tuned for more information and design parameters as they are refined!
How Do Our Cars Stop?
2015 University of Maryland Regional Competition Car: "Walt"
Stopping Mechanism: Ion Exchange Resin Bead Reaction
- Aqueous NaOH is put in solution with salt, water, and an acid-base indicator as a visual aid
- Addition of ion exchange resin beads will decrease the pH of the solution which is monitored by the probe
- Once it reaches the desired pH stoppage of the motors is triggered by the probe
- Depending on the amount of NaOH, Resin Beads, and the pH the probe is set to check for, the car will run for different amounts of time/distances
- All parts of the stopping mechanism are housed within the same double containment as the reaction vessels
- Mechanism is found in a separate compartment from the vessels to avoid contamination of other chemicals used
- Chemicals are properly disposed of in a base waste container after completion of each run
2016 Regional Competition Prototype Car: "Jesse"
Proposed Stopping Mechanism: Iodine Clock Reaction
H2O2 (aq) + 2H+ (aq) + 2 I- (aq) → 2 H2O (l) + I2(aq)
2 S2O32-(aq) + I2(aq) → S4O6 2-(aq) + 2 I- (aq)
2 I3- (aq) +starch → black starch-I5-complex + I- (aq)