Interactive Chemistry Teaching Units Developed with the Help of the Local Chemical Industry .
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Applying Classroom Principles to the Real Needs of Local Companies To Help Students Develop Skill in Teamwork, Communications, and Problem Solving J. A. Pontin, E. Aricd, J. Pltoscio Filho, P. W. liedemann, and R. lsuyama
University of S51o Paulo, P.O. Box 20780, 01498, SBo Paulo, SP, Brazil
G. C. Fettis University of York, Heslington, York YO1 5DD, UK A Brazilian Project A Social Approach to Chemistry As part of a process of effective curriculum innovation, we are developing a project to produce teaching materials for chemistry undergraduate courses, with a n emphasis on ~roiect the concerns of the local chemical industrv. This . " was started in response to a growing awareness that our chemistrv courses should incornorate more of the skills demanded 6 y the changing needslofboth industry and society (14). Many universities are encouraging the development of the more socially enlightened chemist. A social approach to a given subject allows chemistry to be taught in a thorough and relevant manner (7-9). It also helps the students to develop a variety of professional skills and abilities, for example, learning to work well in a group make soundjudgements based on limited information analyze and evaluate apparently unrelated data make effective decisions based on insufficient information make successful oral presentations Teamwork and Communications Because chemists rarely work entirely on their own, they must develop the abilities to work with others in an effective way. The skills needed to work as part of a team should be practiced during the university career, and the ability to convey ideas should also be developed ( 1 0 , l l ) . Chemists must develop skill in both written and oral communication. A good chemistry curriculum should provide plenty of practice m writing clear and n~ncisereports and in giving-verhal presentations. For example, course work should include experience in stating a n opinion briefly or in clearly presenting the results of a study to a group, especially when restricted to a set amount of time.
Organizing Courses around Problem Solving Traditionally students have been expected to develop these abilities by themselves, but we believe they must be taught. If higher education institutions are to respond effectively to the demands for better professionals, they must change their assumptions about the design of courses and the facilitation of learning. Despite many decades of development of new approaches to teaching, cuurses in univers~tifsere usually G/ll organized arnund the academic structures of the discipline and the interests of the toachinestalf IJnfortunatrlv. ", learninecentered and problem-based courses, which can be especially appropriate in professional subjects, are rare.
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The Interactive Units Challenges Centered on Industrial Realities Our teaching material is produced as units that deal with a given subject. Aunit centers on a narrative that depicts a situation in industry and poses a variety of pmblems concerning plant operations. Examples include the challenges presented by the need to substitute one raw material for another debate surrounding the choice of a manufacturing process or a quality control method environmental prohlems generated by a plant The narrative is developed through a series of questions, one logically followingthe other. We call this the story line. These units can be used by teachers in their regular courses. with each unit reauirine four to eieht hours of classroom time. Ex~osureto industrial thinkine shows students how the chemical principles learned in their courses are actually applied in industry (6, 7). This is at the heart of our purpose in developing the units described. In each unit a subject is developed in both depth and breadth, and a particular production process used by a company is highlighted.
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Thus, in planning a n industrial process, students encounter many parameters that are related to more than just the chemistry, such as the practical viability of the process and the economic and environmental aspects. Students see how and why these parameters may be decisive. Role-playing activities, in which the students assume the role of the industrialists, are often used to acquaint the students with the interrelationships among cost, production, environmental factors, and political concerns. Development of a Unit
Production of a unit involves the following steps. Chaasing a subject that is relevant to the field of chemistry, easv to eonflate with the rest of the chemistrv curriculum, and consistent with cultural values and national goals. Finding industrial plants whose precesses and concerns are relevant to the chosen subject. Then visiting the plant and discussing the subject with technical staff, brainstorming with the project participants to develop the narrative, olannine the sections of the unit so that each will reoresent a logical step in the narrative, developing story lines in which students are challenged to creatively apply chemistry topics in unconventional but interesting bays, editing a trial unit, holding trial workshops using the unit, and revising the unit, taking into account the workshop experiences and suggestions made by the participants
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The unit has eight sections, each of which is described below. Parts of each of the eight sections are reproduced as they appear in the unit. Section 1 What is the effect of a n increase of certain gas concentrations in the atmosphere? The greenhouse effect is introduced and discussed. This first activity breaks the ice and gets the group involved in discusssion. Although this topic is simple, it is provocative, interesting, and somewhat controversial. Also, most students already know something about it and are thus able to quickly provide partial answers. The students will readily exchange the information that they already hold on the subject. This prepares them to share their knowledge and then use it as a base to develop a more thorough understanding through participation in the other activities in the unit. The first activity is described below.
The section continues with a auantitative discussion of the effect of greenhouse gases onAclimate.Various data are nrovided for several ereenhouse eases: annual concentration increase life time relative absorbance relative contribution to the greenhouse effect
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I n this section students are asked to l ~ s sources t o f these gases mterpret the data in the table r n v out e n l ~ l n c l n n zumng rhc dnLa
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Introducing the Units in the Classroom
The Benefit of Using Small Student Groups The units are introduced in workshop sessions. Student work is carried out in small p u p s of about four people, so students can interact effectively and contribute to the learning of one another. The Expanded Role of the Instructor The written material is handed out in sections to help t h e teacher monitor the uroeress amone the various groups. The instructor's sglls as a facilitatk are import'~ The instructors nlav ant to a w o r k s h o ~ success. " manv roles; they are exiected to
Students end the section with the conclusion that COz is the greenhouse gas that causes the most concern. Section 2
How can COz be removed from the atmosphere? In this section students have the opportunity to propose actions to reduce atmospheric COz concentrations, based on their background knowledge and social awareness.
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stimulate discussion among the members of each group, give hints, check progress, and actively participate in the students'learningprocess. After a section has been finished, or whenever the teacher senses the need for it, a discussion that involves the entire class is started. All the characteristics of a good teacher--enthusiasm, leadership, willingness to guide and h e l p a r e always important.
Example Unit The chemistry taught in the unit described here-"Ammonia, Fertilizers and Carbon Dioxide Fixationn-concerns ammonia production. The objective of this unit is to stndv the issues that surround the monitorine of ammonia prodktion, with an emphasis on improving ;he efficiency of nlant onerations. The Brazilian fertilizer industw currently spends millions of U.S. dollars per year on energy, uart of which could be saved bv a more intellieent and efficient use of energy. 224
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In this section students realize that solving an environmental problem requires concerted action. Section 3
What is the best way of removing the largest amount of COz from the atmosphere? A quantitative comparison of COz absorption by forests and by crops is made. Students realize that trees are a better sink for carbon. However, crops must be grown to feed the country's population. The question arises of how much land is needed for this. To simplify matters, students assume that Brazil's population consumes only rice.
Students are given the composition of naphtha. Then they are asked to
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determine the formula of naphtha, wntp the storchiometrie quation for ammonia prdurriun startingwith naphtha, and calculate the amount of carbon dioxide released from the ammonia production plant.
Section 6
How can carbon dioxide emission be reduced? To examine the possibility of reducing the amount of COz derived from burning naphtha, the energetics of each step of ammonia production must be examined. Using fertilizers frees a considerable area of land for growing timber and thus absorbing more COz.However, COz is a by-product of fertilizer production. Students discover that they must learn more about this before they can determine whether less COzis trapped or released to the atmosphere when using fertilizers and cultivating a small area or 'not using fertilizers and cultivating a large area In this section, students practice the ability to form an opinion based on scarce data. Section 4
What do fertilizers contain? I n this part students discover why ammonia is the most important product in the fertilizer industry and the most important regarding COzemissions. The role of fertilizers in providing essential macro- and micronutrients for plants is discussed. A list of the main compounds that make up commercial fertilizers is given. In this section students are expected to carry out stoichiometric calculations involving these compounds, write reactions for the industrial pmduction of each, and 'determine whether COzis released in the process and whether heat is required. If heat is required, then an additional source of COz is involved: the huming of fossil fuel. I n this section, reading tables and setting them u p a n ability students often lack-is also practiced.
1. Is it enough to h o w the enthalpy of the overall reaction in determining whether or not the process re-
quires heat? 2. Write a stoichiometrie equation for each step of the
ammonia production proeess described below and calculate the carresponding enthalpy of reaction. The discussion leads students to realize that fuel consumption depends on the heat required in each step of the process. Though the overall reaction is exothermic, the first step of the steam-reforming process is highly endothermic. The main steps of ammonia production are described, and students are asked to write eauations and calculate AH for each. Through these simple ~alculationsit is shown that the efficiency of steam reformer-based plants depends critically on the carbon monoxide shift reaction. The hightemperature section demands a substantial stoichiometric excess of steam, making it one of the factors that limit the energy efficiency. The recoverable energy from the ammonia synthesis is not equivalent to that required to raise the temperature in the steam reformer to the level needed. Section 7
What is the limit for carbon dioxide emission? I n this section students compare the energy used in a Brazilian ammonia plant with that used in some of the most efficient plants in the world.
Section 5
How much COa is released in ammonia production? I n this section the amount of carbon dioxide released from the plant is calculated. First the total amount of naphtha used i n the process is calculated from energy data.
A comparison is made between overall energy consumption by the Brazilian ammonia plant and by modem, very efficient plants (data are provided). Thus, students can make a rough estimate of the cost of producing ammonia in an outdated plant relative to a modern one. Section 8
To use or not to use fertilizers? Students compare the amount of COzreleased in ammonia production with the amount of COzabsorbed by trees that can be grown on the additional land freed by the use of fertilizers for growing crops. AU of this is done on the basis of the amount of food needed for the Brazilian population. Students can then decide what is more advantageous for reducing the greenhouse effect: using fertilizers while cultivating a small area of land or not using fertilizers while cultivating a large area of land Volume 70 Number 3 March 1993
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Students complete the unitdiscussing various uses of timber as related to reemission of COz to the atmosphere. Each group of students makes a five-minute presentation showing a comprehensive diagram of the land needed for crops and for timber in both cases: with and without adding fertilizers. General Comments The units are written mainly by junior faculty members at the beginning of their academic career because improving the skills of university lecturers is one of the project's goals. When a unit such as the one described here is developed, many chemical concepts must be reexamined, furthering the authors' knowledge of chemistry. Through this project, the teachers as well as the students are challenged to practice an important skill: using logical and clear reasoning to successfully reach an objective. Success in developing these teaching materials requires the active cooperation and effective participation of the chemical industry However, cooperation is not restricted to visits. Other data were needed, and the following were made available.
Students have responded very positively to these teaching materials. They welcomed the opportunity to work together in small groups, to discuss realistic problems, to make decisions and predictions. They felt it gave themuseful practice in collaborative work. This project has been running for over two years with direct cooperation between the University of SBo Paulo and the University of York, UK. During this period, about 20 Brazilian chemical com~anieshave also collaborated very closely with this This positive interaction between industrv and universitv will contribute a meat deal to improving ihemical education. Acknowledgment The authors thank D. J. Waddington and C. J.Garratt of the University of York, UK, for many helpful discussions during the development of this project. Financial support from the British Council, the SBo Paulo State Foundation for the Support of Research, the Coordination for the Improvement of Higher Education, and the Vitae Foundation is gratefully acknowledged. Literature Cited ~~
processes flaw sheets data an sources
east composition and physical properties of raw materials energy consumption waste treatment and disposal problems Summary Workshops that used the project units showed that replacing abstract and logical concepts with a lively narrative makes chemistry more attractive to students. The classes that have used these units have helped students to better appreciate the practical applicability of the subject discussed.
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1. Revs", J. "Edu~atio"and the competeneie. % " i d in Modem s0deh.D; Hiphe, Educelion Reuiaw 1982, 15,4757. 2. B I ~ ~ s ~ ~~Y .I " ~ , ~ d~ d i ~~ ~ hthe curneulum ~ ~ ~ ~~ ~ ~useam l ~~ m. s:~, 4 , z of. 3. Cohen,B. "Skills, Professional Education and the Disabling University": Stud& in HigherEducofion 1985.10.175-186. 4. Birch. W. Towards s Model for Roblem.Baaed laarnin
