This module focuses on the sources and sinks of energy and CO2 during the production of biomass fuels. Particular attention is paid to ethanol fules though some reference to biodisel will be provided. The path of biomass production will be followed by a series of laboratories dealing with photosynthesic efficiency, fermentation of a carbohydrate, distillation of the ethanol and combustion value of different fuels. Ancillary labs relating to global warming include potentiometric study of carbonate/bicarbonate, measuring a source of CO2 by acid-base titrimetry and preparation and buffer capacity of a carbonate buffer. Two additional laboratories relating to the carbon cycle include hydrolysis knetics of carbonate minerals and hydrolysis kinetics or carbon dioxide.

Student exercises and problem sets are being developed for searching the literature to obtain data relevant to determining the true energy, material and environmental costs of ethanol produced from biomass. Laboratory experiments will be developed around combustion, light, photosynthesis, fermentation and distillation to allow students to understand how such data is obtained and to appreciate the uncertainties in the data. Demonstrations will be developed to be used as discussions, debates, quizzes or exams.

Structure of the Module

In the first round of testing the following these were some of the questions answered by students at Colorado College:

• What are current prices of liquid fuels?
• How much energy can be obtained from the combustion of different liquid fuels?
• Is price determined by energy content? Why or why not?
• How much energy can be obtained from plant biomass?
• How much does it cost to produce liquid fuel from biomass?
• How has the CO2 budget changed as a result of automotive technology?
• Is there a fair price to charge companies and consumers for CO2 "pollution"?

Interdisciplinary Connections:

Biology (photosynthesis and fermentation), economics (pollution taxes and cost of energy), physics (thermodynamics and properties of light), and technology (distillation, agricultural costs).

Pedagogical Strategy:

The module is designed to enable students to answer the following three questions:

1. What would the (CO2) tax on gasoline have to be to make ethanol the same price? Is it fair that ethanol would not be taxed? Why?
2. Is there a net energy gain in the production of ethanol from biomass? (i.e. can one have a self-sustaining cycle of ethanol production with no input of additional ethanol or other fuel)
3. How much energy from the incoming solar flux on an acre of land is accounted for in the combustion of ethanol produced from biomass on an equivalent acre of land? (i.e. can a series of solar collectors on an equivalent acre of land produce more energy than the energy resulting from the combustion of ethanol produced on the same acre when all energy factors for production are accounted for)

To answer these questions, the following pedagogical strategies were tested:

Cooperative laboratory assignments:

1. heats of combustion for different fuels
2. photosynthetic efficiency
3. an estimation of auto emission by acid-base titrimetry
4. the determination of ethanol yield in fermentation and
5. the energy cost of distillation.
6. chromatography of plant pigments

Demonstrations:

sunlight actinometry (planned)
hydration of CO2
sunlight calorimetry (planned)

Scientific Literature:

student supplements
biomass report which required the use of literature and the WWW

Group Problem Sets:

as parts of lab
independent from lab

In Lecture Analysis: as an adjunct to all topics

• Fuel cell module

• Problem sets (unedited)
• Laboratory procedures (5 labs, unedited)
• Handouts
• Bibliographic material
• Pedagogical recommendations.