ChemECar National 08

1
CALIBRATION RESULTS We use 2 M HCl, different
lengths of Mg, and varying loads to calibrate our
car reaction. To obtain our equation, we assume
that the length of Mg varies linearly with the
load and distance. Temperature was also
varied, but made little change in our
equation. Our car performance is also affected by
fuel cell consistency and efficiency.
POWER MECHANISM A hydrogen fuel cell is used to
generate an electric current to power the car. A
reaction of 2 M hydrochloric acid and magnesium
produces the hydrogen for the fuel cell Mg 2
HCl ? H2 MgCl2  The hydrogen produced is then
bubbled through water in a 240 mL filter chamber
containing 175 mL water in order to remove acidic
vapor from and add moisture to the hydrogen gas.
Finally, the filtered hydrogen gas enters the
fuel cell to generate power for the motor H2
½ O2 ? H2O energy The car stops when the
reaction no longer produces enough hydrogen to
power the motor. We control the reaction using
magnesium as the limiting reagent.
BRUIN CAR
CAR SCHEMATIC AND DIAGRAM
SWITCH Changes the flow of the circuit Description
12V lighted toggle switch. Safety Feature(s)
No exposed electrical components.
FUEL CELL Generates electric current to power the
car Description Hydrogen gas passes a TekStak 5
cell stack into its anode while oxygen gas from
the atmosphere passes through the cathode. In the
anode, the hydrogen fuel splits into positive
hydrogen ions and electrons. The semi-permeable
Polymer Electrolyte Membrane allows only positive
ions to flow through toward cathode containing
oxygen gas to create water. Meanwhile, the
electrons flow into an external circuit to create
electricity. Environmental Feature(s) Water is
the only byproduct of fuel cells. Fuel cells do
not create deadly emissions like combustion
engines. Thus, fuel cells do not contribute to
the alarm of rising carbon dioxide emissions and
increasing global temperature.
MOTOR GEARS Converts electrical energy into
mechanical energy to move the car Safety
Feature(s) No exposed gears.  
LOAD CONTAINER Carries 0-500 mL water
MAGNETIC STIR BARS Hold up Mg ribbon Description
Two standard magnetic stir bars allow us to
control when the Mg is dropped into the HCl to
start the reaction Safety Feature(s) Allows
entire reaction to be completely contained so no
hydrogen gas is released to the surroundings.
Length Mg (11.66081/- 1.771067)
Load(0.022271/- 0.003212) Distance(0.082829
/- 0.022105)
ELECTRICAL WIRES Allows electricity from fuel
cell to power the car Safety Features All wires
are covered and insulated none exposed.
PRESSURE TEST Pressure testing was performed to
confirm the integrity of our assembly. Normal
operating condition and obstructed condition were
tested using the maximal amount of
reactants. Normal Operating Condition The system
pressure remained at 0 psig throughout the
three-minute test. Pressure did not build up
because the exhaust of the fuel cell was open to
the atmosphere. Thus, no pressure gauge or
pressure-relief valve is required. Obstructed
Condition This experiment modeled the worst-case
scenario of pressure build-up. The system
pressure quickly reached 4.0 psig after 5 seconds
and then slowly decreased for the remainder of
the 3 minutes. No visible damage to the vessels
resulted. Video documentation of the testing is
available upon request.
FILTER VESSEL Ensures that none of the
hydrochloric acid used in the power reaction
leaks into our fuel cell Description 8 oz.
(240mL) wide-mouth glass jar with green urea cap
and PTFE seal from McMaster-Carr (Product ID
4239T34). Dimensions are 70 mm mouth OD, 2 7/8
base diameter, and height is 3 ½. Lid has two
¼ OD tube-to-tube PVDF coupling (McMaster-Carr,
5533K522). One connects tubes to generate a flow
from the reaction vessel and down into the filter
vessel. Another connects a hose to the fuel
cell. As the gas bubbles through the water, the
hydrochloric acid can dissolve in the water and
this guarantees that the gas moving into the fuel
cell is purely hydrogen gas. We used an
indicator called phenol red during testing to
make sure no hydrochloric acid is entering the
filter vessel through from the reaction
vessel. Safety Feature(s) Secondary containment
is used to prevent acid spillage in the occasion
that it should leak. Material Compatibility
POWER SYSTEM REACTION VESSEL Contains the
chemical reaction between 2 M HCl and
magnesium Description 4 oz. (120mL) wide-mouth
glass jar with black urea cap and PTFE seal from
McMaster-Carr (Product ID 4239T32). Dimensions
are 58 mm mouth OD, 2 3/8 base diameter, and
height is 2 11/16. Lid has a ¼ OD tube-to-tube
PVDF coupling (McMaster-Carr, 5533K522). Safety
Feature(s) PTFE and PVDF are both highly
resistant to HCl Material Compatibility
ENVIRONMENTAL BENEFITS Vehicles powered by fossil
fuels release greenhouse gases that contribute to
global warming and climate change.  Our
Chem-E-Car provides a small-scale application of
hydrogen fuel cells, which emit only water
vapor.  This design also eliminates the need to
use fossil fuels.
Acknowledgements The team would like to extend
our appreciation to Dr. James Drake, Dr. Yi
Tang, and Dr. Harold Monbouquette for their
advice and support.
SAFETY FEATURES Some safety features of our
Chem-E-Car include secondary containment for our
reaction vessel, no exposed wiring, a filter
vessel, and complete containment of chemicals
while the car is in motion.