• Submitted By: Christine Thompson
• Administration: Edit Resource
• Resource Type: Lesson Plan
• Subject:
  • Science
  • Environmental Studies
• Topic:
  • Climate Change
  • Corporate Social Responsibility
  • Sustainable Development
• Level:
  • Secondary
• Added: May 26, 2011

Web Pages Used

• EPA

Attachments

• Handouts
• Desulfurization Process
• Ontario Curriculum Connections

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Description

In this lesson students will apply their knowledge of balancing chemical reactions and stoichiometry to understand the process of desulfurization, an air pollution control method. First they will be taught why it is harmful to our environment and human health to have extra SO2 from industrial processes in our atmosphere. Next they’ll be asked to solve a problem using stoichiometry and the desulfurization process.

This can be used as an extension to Tread Lightly lesson 3.1 - Climate Change Policy and Solutions

Time Required: 1 class

 

Learning Objectives

By the end of this lesson students will:

- understand the basics of the desulfurizaton process
- understand how to to stoichiometric calculations (mass to mole, mole ratios)

Teaching Process

Part A - Sulfur Dioxide information, balancing equations and stoichiometric calculations.

Part B - Desulfurization Process

Part C - Final Problem (assessment)

Teaching Notes

Background: SO2 is naturally occurring in our environment, but some industrial processes emit SO2

- 73% of SO2 emissions are from fossil fuel processing

- The process described below is desulfurization used in coal burning plants

- 20% from industrial processes (EPA)

- In 1971 standards were set for SO2 concentrations (30ppb)

- From 1990-2009 emissions went down 65%

- It most affects the respiratory system as SO2 is a precursor for particulates which can irritate the lungs

- SO2 is also a precursor for acid rain

Part A – SO2, Balance equations and practice stoichiometry (20-30 min)

- Explain to students what sulfur dioxide is and why its emissions were decided to be targeted to be reduced (from background info)

a) Show the following reactions that produce sulfur dioxide and solve the questions with students (Sulfur - It's Everwhere! Handout)

Part B – Desulfurization Process

- Show students the process for desulfurization on the overhead/board/smart board. Have the students balance the reactions as you put them up. (Desulfurization process attached document)

Notes: Even though SO3 is being removed, the process still produces CO2. Mention to students that even though processes are being developed to reduce pollution and greenhouse gas emissions, no process is perfect and there still needs to be further development of clean technology. Yes, this is an improvement in coal production, but it is still not “clean” as it's claimed by many companies and media. You could go further into a discussion about this with students.

Part C – Final Problem

- Give students the final problem on the desulfurization process to be handed in and marked (attached document)

Assessment/Evaluation

Desulfurization Problem Marking Scheme
(8 marks total)

(2) SO2 mass → moles, correct stoichiometric ratio

(2) NaHSO3 moles → moles SO2, correct stoichiometric ratio

(2) SO2 moles → mole CaSO_3∙1/2 H_2 O, mass CaSO_3∙1/2 H_2 O

(2) SO2 moels → moles CO2, mass CO2

 

Other Tools

- Sulfur - It's Everywhere! Handout - Desulfurization Process Handout