Chem E Car Competition: Incorporating Safety With The Help Of Industry Partners.

The Chem-E-Car competition has been utilized for the last five years as part of multiple courses in the chemical engineering curriculum at Oklahoma State University. Typically, a number of teams comprised of two to three juniors were formed in the Fall semester for the competition to be held in the subsequent Spring semester. Three to four sophomores were included to enhance cross-class participation and to provide application-oriented examples. A folder containing compartments for log sheets, pictures/sketch, reaction/safety, analysis, and calibration was given to each team. During the Fall and Spring semesters, the teams had to complete certain tasks and place them in the folder. Initial tasks included identifying the chemical reaction(s) used in powering the car, providing the accompanying material safety data sheets, and sketching the car with associated pictures of the prototype. At the end of the Fall semester, reports were shipped to ChevronPhillips (the sponsoring organization) for review and feedback from Dr. Dave Register. Feedback from ChevronPhillips was given to the students in the Spring semester. The first task for the students was to respond to the concerns raised in the report. On the day of the competition, the students presented a poster to the ChevronPhillips judges, and the competition was conducted according to the national guidelines. The outcome of these interactions from the perspective of the students, as well as from Dr. Dave Register is discussed. Also, lessons learned from the viewpoint of instructors are included. INTRODUCTION. The Chem-E-Car competition is a powerful tool to enhance technical writing skills, provide engineering analysis opportunities [1], and apply team management skills. Since its beginning in 1999, the Chem-E-Car Competition has evolved as the major attraction at the regional, national, and international American Institute of Chemical Engineers (AIChE) student conferences [2]. The basic principle of the competition is that each team has to design a car that will carry up to 500 mL of water and travel a specified distance (up to 100 feet). Teams are notified of the water weight and travel distance one hour prior to the competition. A chemical reaction must be used to propel the car, and no mechanical mechanisms may be used to stop the car. The components of the car must fit within a shoebox that is 40 cm ×30cm×18 cm. Detailed rules are posted on the AIChE website [3]. While the creation of these cars is fun, the competition is often entertaining and is a valuable recruiting and retention tool [4, 5]. However, the contest clearly reveals issues of process safety, reliability, economics, reproducibility, teamwork and environmental care that face chemical engineers in industry everyday. Interestingly, thorough safety analysis via thermodynamics and/or reaction engineering is often overlooked. For example, estimation of the gas pressure via reaction kinetics and thermodynamics for the acetic acid/baking soda reaction, a popular reaction used to propel a car, is rarely calculated. Further, many pressure vessels have been constructed not knowing the strength of materials and lack of incorporating pressure relief valves which has resulted in unwarranted accidents. In 2006, national AIChE made a significant effort to address the safety and environmental aspects of the Chem-E-Car competition through P ge 12354.2 2 the incorporation of a required safety training seminar. Detailed information on the safety must be adequately described in a required poster presentation prior to the competition. Over the past five years, we have utilized reaction-powered cars to provide a hands-on experience for students through designing and building cars propelled by chemical reactions in multiple chemical engineering courses at Oklahoma State University. Within the school, an annual Chem-E-Car competition is held, based on national AIChE rules. Preparation for the competition begins in the Fall semester in the junior thermodynamics course and ends in the Spring semester chemical reaction engineering course. The sophomores join the teams in the spring semester and are included to enhance cross-class participation and to provide applicationoriented examples. This annual event is supported by ChevronPhillips both financially and in reviewing the reports submitted by the students. In this report, we summarize the interaction of industrial partners in incorporating the safety of the Chem-E-Car competition. TEAM FORMATION. During the Fall semester, teams of 3-4 students were chosen in the Thermodynamics course. Students were allowed to select their own teams, although the faculty member makes the final decision regarding the team members. After the formation, each team was given a folder containing various compartments for log sheets, pictures/sketch, reaction/safety, analysis, and calibration. In addition, information on the Chem-E-Car rules, scheduled tasks (Table 1), and brief instructions on what is expected was provided. For each scheduled task, students were told to submit the entire folder, placing the required document in the corresponding compartment. Further, log-sheets were also given to individual students and at the bottom of the log-sheet there was a location for the signature of other team members. Students were required to write the number of hours in the log-sheet and submit the signed log-sheet. Comparison of the number of hours within the team was used to evaluate the team participation. A reimbursement of $150 per vehicle was allowed. Table 1. Time Table of Events in 2005-2006 Competition Day Date Task to be completed ChE 3473: Thermodynamics Course Wednesday Oct 13 Teams identified: 3 per team, 1 team with 4 Friday Oct 22 Chemical reactions identified: Safety and environmental report Wednesday Nov 3 Detailed sketch of car Wednesday Nov 17 Thermodynamic equilibrium of CO2 systemgroup homework Friday Dec 3 First prototype built with a picture and initial test Dec 10 Shipped to ChevronPhillips Jan 10 Received from ChevronPhillips ChE 3123: Chemical Reaction Engineering Course Jan 31 Memorandum on the progress of the car and response to Dr. Dave Register’s comments Friday Feb 11 Preliminary calibration chart Friday Feb 25 Reaction engineering analysis with measured parameters Friday Mar 11 Final calibration chart; demonstration to faculty Thursday Mar 24 3:00 4:00 p.m. Poster set up Thursday Mar 24 4:00 – 5:00 p.m. Poster presentations w/snacks Thursday Mar 24 5:00 – 7:00 p.m. Car competition Thursday Mar 24 7:00 – 8:30 p.m. Dinner and Awards Ceremony P ge 12354.3 3 REACTION IDENTIFICATION AND SAFETY. Prior to any construction, the first assignment was to identify the reaction(s) that would be used to propel the car. Teams were told to write a two-page report that included the reaction information as well as the safety and environmental issues. Attachment of appropriate MSDS sheets for reactants and products was also required. Further, teams had to write the report in their own words rather than the direct copying of parts from the MSDS sheets. Safety precautions, clean up issues, procedures for emergencies, etc were also required in the report. For example, if a team selected decomposition of the hydrogen peroxide reaction using catalase, the team wrote that the car would be propelled by the gas formed from the reaction 2 2 2 2 2 2 Catalase H O H O O → + . As the reaction proceeded, the conversion rate of the hydrogen peroxide decreased and the oxygen gas pressure increased within the reactor. If the initial report contained some vague safety considerations, the faculty member notified the team to make sure that the students were aware of the safety precautions and were not considering unsafe chemicals. BUILDING THE CAR. The next task was submission of a hand-drawn sketch of the car, suitable for guiding car prototype assembly. In the instructions, teams were told that the sketch must include car dimensions, reaction vessel dimensions and other appropriate details. Also, a detailed list of materials required to build the prototype and a price estimate should be submitted. An example of the sketch submitted by one of the groups is shown in Figure 1a. The parts list submitted by the same group is shown in Table 2. Following the prototype submission, teams were instructed on the thermodynamic analysis for a baking soda-vinegar reaction (used as an example) using an equation of state and assuming complete reaction. All teams were then required to utilize thermodymic principles to provide an estimate of the maximum pressure and temperature for their given car and reaction system. Table 2. Parts list with cost After approval from the instructors, each teams was allowed to build their car and provide a corresponding picture. The teams also needed to state in writing how the car functioned on the initial test (i.e. Did it work?, How far did it go?, etc.). They were told that points would be Parts Cost Wheels $24.60 Aluminum Stock $15.50