Exploration - Understanding Data: Let’s Make Coffee! Lesson 1: What is Chemical Engineering?
What is Chemical Engineering? q What are some things that you think chemical engineers do? q Where do you think chemical engineers work?
Meet Melanie, Chemical Engineer https://www.youtub e.com/watch?v=k- 7B_YfHWXQ https://www .youtube.co m/watch?v= RJeWKvQD9 0Y
There are different types of chemical engineers. Product Engineers Process Engineers
Assignment: chemical engineering Research and describe a specific process technology or product that chemical engineers work on. Describe how chemical engineers add value to the process or product. Be specific and provide details in describing what they do. (At least 150 words) q Air and Water Quality q Industrial Safety and Operations q Agriculture q Materials Engineering q Cell and Tissue Engineering q Nanotechnology q Computing q Nuclear Engineering q Energy q Pharmaceuticals q Foods q Sustainability, Reuse, and q Forest Bioproducts Recycling q Fuels and Petrochemicals
Can brewing coffee be a chemical engineering challenge? q What happens when you brew coffee? q How can you brew strong coffee? n Think (2 minutes): Given whole coffee beans and water, what could you do to make strong coffee? List these in your engineering notebook. n Pair (2 minutes): Compare answers with your team mates. Add to the list in your engineering notebook. n Share : We will generate a class list of ideas. Add to the list in your engineering notebook.
How can we measure coffee “strength”? q Given a cup of coffee, how can you tell how “strong” it is? n What does it look, taste, smell, or feel like as compared to a “weak” cup of coffee? n Are there any quantities you can measure to quantify a cup of coffee as “strong” or weak”? q In your groups, think of at least two quantitative and two qualitative ways to analyze coffee strength. Note these in your engineering notebooks.
What are potential qualitative and quantitative test methods? q Quantitative Test Methods involve measuring specific quantities and ensuring measurements match desired set points Examples: pH, concentration, viscosity, density q Qualitative Test Methods compare qualitative observations to expected characteristics Examples: color, taste, smell, visual appearance
The chemistry of brewing coffee q What happens chemically when coffee grounds are placed in water? q Thousands of different compounds are extracted from the coffee grounds into the water. n These compounds are responsible for qualities such as aroma, acidity, taste, color, and concentration of caffeine. n The rate and amount of extraction of these compounds is dependent on factors such as the size of the coffee grain, the temperature of the water that the coffee is placed in, and the amount of coffee grain present.
Concocting the Perfect Cup of Coffee (Courtesy of Science Friday ) https://www.youtube.com/watch?v=_NCPQMC2L1U http://sciencefriday.com/videos/concocting-the-perfect-cup-of-coffee-2/
The chemistry of brewing coffee q Here are a few of the compounds that get extracted from coffee grounds. How measure concentration? bitter taste, brown color, and acid reflux
Measuring Concentration q Molecules that are formed in the coffee brewing process produce ions . n From chemistry we know that migration of ions produces an electrical current (conductivity). n The higher the amount of ions in a solution, the higher the conductivity of the solution. q Conductivity can therefore be used as a measure of concentration . n Higher conductivity à stronger coffee
The Conductivity Sensor q Measures concentration indirectly by measuring electrical conductivity (EC) across one centimeter of the solution. q High EC = Lots of ions in solution = High concentration of extracted coffee molecules. q The unit of conductivity is inverse of ohm (ohm -1 ), also known as the “mho” in μS.
Due End of Class Oct 17/18 q In your Engineering Notebook: n Chemical Engineering Professions Research Assignment n Notes from Think-Pair-Share n Qualitative and Quantitative Measurement Methods q particularly proud of or would like me to see.
Homework and What’s Next q Be working on your research project into chemical engineering fields and professions. q Next time, we will explore how a chemical engineer might approach brewing “the perfect cup of coffee”.
Exploration - Understanding Data: Let’s Make Coffee! Lesson 2: Designing Coffee or Brewing the Perfect Coffee through Chemical Engineering
Your Coffee Brewing Task EYW Coffee Co. provides high-quality ready-to-drink coffee brews. They have just sent you a memo regarding a new project proposal: Having experienced much success from our regular strong brews, we have decided to expand into an untapped market: lighter brews for people who enjoy just a hint of coffee without bitterness. Instead of the standard coffee conductivity of 1800 µS , our light brew will have a conductivity of 300 µS when brewed in deionized water. We start with whole coffee beans and water. Our processing plant only has a grinder, heater, and brew tank, so we can only adjust particle size, temperature, residence time, and the coffee/water ratio. Examine different conditions and help us determine which combination will give us the desired cup of coffee in a consistent and efficient manner while considering trade-offs.
What variables are involved in our experiment? q Dependent - What are we measuring? n Coffee conductivity q Independent - What are we changing? n Coffee/water ratio n Temperature n Particle size n Residence time q Controlled - What must stay constant? n Coffee bean brand and type n Water quality
Kontor, Zachary Eng 8 Coffee Concentration Temperature Bean or Ground What are the ranges of our independent Gregory, Cole Eng 1 Low High Whole Bean Tatum, Maddie Eng 1 High High Whole Bean Johnson, Holly Eng 1 High Low Whole Bean variables ? Gaige, Casey Eng 1 High Low Ground Mueck, Ben Eng 1 Low High Ground Osman, Deen Eng 1 Low Low Whole Bean Hulett, Blake Eng 1 Low Low Ground Both Teams Eng 1 High High Ground Low High Coffee/Water Ratio 0.01 g/mL 0.05 g/mL Ambient Temperature (approximately 20-25°C) 65-75°C Particle Size whole bean fine ground For Residence Time , we will take conductivity measurements (about 5 seconds in duration) every minute for 15 minutes.
Kontor, Zachary Eng 8 Coffee Concentration Temperature Bean or Ground Gregory, Cole Eng 1 Low High Whole Bean Tatum, Maddie Eng 1 High High Whole Bean Johnson, Holly Eng 1 High Low Whole Bean Gaige, Casey Eng 1 High Low Ground Mueck, Ben Eng 1 Low High Ground Osman, Deen Eng 1 Low Low Whole Bean Hulett, Blake Eng 1 Low Low Ground Both Teams Eng 1 High High Ground
Let’s try it – brew some coffee! ❑ Set up your notebook for your experiment ■ Document your assigned condition ■ Create a data table for conductivity over time ■ Leave a space to record initial temperature and initial conductivity ❑ Follow the experimental procedures and record your data in your engineering notebook ❑ Add your data to the class data set
Analyze Class Data Set ❑ What do you notice about the class data set? ❑ What do you think a graph of conductivity (µS) versus time will look like? ❑ How can we make sure we get consistent data moving forward?
How many experiments do we need to run? ❑ Recall our variables: ■ Coffee/water ratio: 0.01 to 0.05 g coffee per 1 mL water ■ Temperature: 40° C to 50° C (low) to 65° C to 75° C (high) ■ Particle Size: fine ground to whole bean ❑ Let’s agree to test only the extremes of each variable. ❑ How many different experiments (different combinations of factors) are possible? ❑ Predict the results of each experiment ❑ How many trials should we run for each combination of factors?
Design of Experiments (DoE/DoX) ❑ Design of Experiments refers to the design and planning of an experiment to test the effect of factors on a controlled variable. ■ We must check eight combinations in our three-factor DoE. ❑ For efficiency, teams will share data to create a class data set. ❑ Each group will test four combinations. ❑ If your group finishes early, test more combinations to increase the data in our data set. (Why?) ❑ Record and sketch graphs of your data in your engineering notebooks.
Notebook Check q Place post-it notes on the appropriate pages in your notebook to denote the following items: n Coffee Brewing Challenge n Fixed and Variable Factors (with ranges) n Experimental Data (trial) n Experimental Data (assigned combinations) q Write down the name of the appropriate item on each post-it. q Place a post-it in your notebook for anything else you are particularly proud of or would like me to see.
Homework and What’s Next q Be working on your research project into chemical engineering fields and professions. q Next time, we will discuss how to analyze the data that we have collected.
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