Research Project (Online version): Testing Biodiesels
As the economic (and environmental) cost of fossil fuels becomes increasingly problematic, the need to shift toward alternative forms of energy is gaining popularity. One promising new form of energy can be found in biodiesel, which can use various natural products and even waste to generate fuels to heat our homes, power our vehicles and charge our phablets. The process of generating biodiesel involves a reaction called transesterification, whereby fats and oils which contain a high percentage of triglycerides, are broken down into glycerol and fatty acid methyl esters (FAMEs). The process is shown below:
Biodiesel production: Transesterification of triglycerides (fats) to fatty acid methyl esters (FAMES)
A triglyceride is composed of 3 ester, functional groups. The process of transesterification involves treatment of triglycerides with methanol (an alcohol) in the presence of an acid or base catalyst, the original ester bonds are broken and new ester bonds are formed. Thus the original ester (triglyceride) is broken and the resulting methyl esters are derived from reaction of methanol with the 3 fatty acid chains. While the original triglyceride is too viscous to work in a conventional car engine, the resulting methyl esters are more volatile and can be combusted in slightly modified, conventional engines. Fatty acid methyl esters (FAMES) are very flammable with a rather low flash point while their free fatty acid (FFA) counterparts have much higher melting points and higher flash points, making them less desirable as fuels. Thus, biodiesel synthesis must be carried out in a way that minimizes formation of free fatty acids while maximizing the breaking of ester bonds in the triglyceride. This is best done in anhydrous environment using dry solvents under inert atmosphere such as Ar. However, such an environment can be expensive to produce and outweigh the benefits of the gain in reaction efficiency.
PART I. Background on biofuel terminology, uses and materials.
Purpose
Become familiar with scientific language relevant to this field.
Develop practical analysis skills using data and figures related to biofuel synthesis.
Use background literature to identify the knowledge gaps and areas for future work in a given scientific field.
Create your own ideas and research goals related to optimizing biodiesel use.
Task: Use this publication in PNAS to answer the following questions
Notice this article refers to 2 major biofuels, ethanol and biodiesel. What are the main crops used to produce these biofuels?
Define the term “Net Energy Balance”? Is it more desirable to have a positive or negative NEB? Why?
Evaluate figure 1. Compare the NEB of corn based and soybean based biofuels. Which has a more desirable NEB?
What is DDGS and soybean mean and how do these contribute to the net energy balance?
Life cycle environmental effects. This section of the paper compares the pesticide consumption and emissions of different biofuels.
Which biofuel consumes more pesticide? What is the impact of this pesticide usage on the Gulf of Mexico?
Compare the emissions of biodiesel blends with the emissions from ethanol blends. Which produces more SOx and NOx? Which produces more CO?
Potential US Supply. This section of the paper discusses the problems with off-setting fossil fuel productions with corn or soybean based biofuels.
How do soybean based biodiesel and corn based ethanol usage compare to fossil fuel usage in the US?
By what percentage could fossil fuel consumption be reduced if all soybean and corn were converted to biofuels?
Your opinion: What are the major obstacles to reducing fossil fuel consumption through use of biofuels? What are some possible strategies to increase the use of biofuels relative to fossil fuels?
Rubric for part I
5 pts
Scientist
Fulfills criteria for score level 4. Answers draw out more than the obvious meaning. Thorough analysis provided in explaining the major obstacles to wide-scale biodiesel use.
4 pts
Research Fellow
Answers illustrate clear grasp of academic language used in relevant literature. Analysis includes original thought related to potential problems with biodiesel productions and use.
3 pts
Lab technician
Accurately answers all questions but provides few insights and personal reflections.
2 pts
Lab aide
Assignment is generally incomplete, and answers reflect very little thought or effort.
1 pts
Developing
Large omissions/many unanswered questions.
Part II. Hypothesis and method formulation.
Purpose: In Part I you explored the relevant literature, introducing you to the academic language, data types and knowledge gaps in the field of biofuel development. In part II, you will build on this by formulating your own hypothesis and method related to biodiesel production, consumption or waste products. As part of this method, be sure to include build appropriate controls, as we have discussed in the past.
Task: Formulate a hypothesis and research question. For background on the difference between a research question and hypothesis, read “Research Questions, Hypotheses and Objectives written by Patricia Farrugia et al. the reading by Farrugia, 2010 (source linked below). The hypothesis should include a statement of rationale to justify why you have chosen to study your chosen independent and dependent variables. Notice that below Task 2, in this document, is a “Basic protocol” that suggests potential independent and dependent variables for you to choose. You can use any of these variables or choose your own.
Task: Formulate a method to test this hypothesis. To format your method, use the article by Wenying Shi and coworkers titled “Biodiesel production from waste chicken fat with low free fatty acids by an integrated catalytic process of composite membrane and sodium methoxide.” A .pdf of this article is also attached to the Canvas assignment. Use this as a guide for depth and style in writing your method. In particular, pay attention the level of detail in the method. There is a skill to writing scientific methods, it is possible to have both too much and too little detail. The abstract and introduction to the paper by Shi will also discuss more about the molecular structure of biodiesel, the methods for preparing biodiesel and some of the challenges facing researchers who are looking to use biodiesel as a clean-burning, renewable replacement for fossil fuels. In this process, you will also need to seek out additional resources such as your textbook, instructor or classmates for help understanding background information. A BC librarian has also provided you with a module to introduce you to browsing literature sources for use in formulating a research question and hypothesis.
In addition, all of the recommended resources and searching techniques may be found at: https://bellevuecollege.libguides.com/CHEM162.
Basic Protocol (Use this link to see a video demonstration of the basic protocol from MCC Alt Fuels)
Make sure all glassware is clean and dry
Dissolve approximately 2.25 g of NaOH in 50.0 mL of methanol in an Erlenmeyer flask.
Independent variable option: This may be a step you want to modify for your experiment. Do you want to try a different catalyst? Do you want to change the reaction conditions in some way?
Experimental note: You should be able to determine the appropriate equipment for these mass and volume measurements. Also, you should be able to explain why we are using an Erlenmeyer flask instead of a beaker for this step).
Experimental note: If you do not add exactly 2.25 g of NaOH or exactly 50.0 mL of methanol this will not cause error in this experiment. Why not? You should make sure to record exactly how much NaOH and methanol that you do add, why is this important?
Cover flask with a watch glass and stir until the NaOH dissolves (you have now produced sodium methoxide).
Independent variable option: You may want to compare how KOH compares to NaOH as catalysts for this reaction.
Experimental note: Determining how to stir this, safely, is the responsibility of the scientist. Note that using a glass stir rod is labor intensive but still considered stirring.
Add 225 g of vegetable oil to a separate Erlenmeyer flask.
Independent variable option: This may be a step you want to modify for your experiment. Do you want to try a different feedstock?
Experimental note: Does it matter if you use exactly 250.0 mL of vegetable oil? What is something you should do after making this measurement?
Experimental note: Be sure to fully think through your protocol before you perform it. Notice what you will be doing in the next step. Use this information to determine which Erlenmeyer flask to use here. Should you record which piece of glassware you actually used?
Slowly and carefully add the sodium methoxide solution to the vegetable oil. Heat this mixture to 55-60 oC with stirring for about 45 minutes (How will you stir this?).
Pour mixture into a separatory funnel and let sit for about 10-15 minutes. Make sure the stopcock is closed before adding your mixture to the funnel. The separatory funnel will allow for separation of the glycerol (d = 1.26 g/mL) from the biodiesel (d ≈ 0.85 g/mL). Make sure to record your observations here.
Slowly drain the glycerol layer into a small beaker by turning the stop cock.
Drain the crude biodiesel into a clean container to save for later use.
Experimental note: You will need to wash this biodiesel you will be able to use it in your vehicle.
Possible dependent variables
Dependent variable to measure: Fuel value.
You have already designed a protocol for testing the heat of combustion of your fuel. This is one protocol you might use to test your hypothesis.
Dependent variable: Products of combustion
Collect the exhaust from combustion of your fuel. Analyze this exhaust for different components including carbon dioxide, carbon monoxide and soot.
Dependent variable: Efficiency of transesterification reaction.
Use GCMS to measure the products of your reaction. This would be useful if you were testing different catalysts or reaction conditions for biodiesel preparation.
Dependent variable of your choice: Discuss with instructor.
What you will submit for Part II:
A research question and hypothesis, submitted electronically to Canvas. Make sure your question and hypothesis follow the guidelines outlined by Farrugia. Notice that the basic protocol contains suggestions for independent and dependent variables to consider in formulating your hypothesis. Please choose one of the independent and dependent variables suggested. If you would like to design your own independent and dependent variable please make sure that this experiment will be feasible given the equipment available.
A 2 paragraph statement of rationale, or introduction containing background information supporting your hypothesis. This introduction should cover the overall goal of synthesizing and testing biodiesel and eventually describe the focused, scientific question you hope to answer.
A method outlining the steps taken to prepare and to test biodiesel. Make sure this procedure contains statements of rationale for each step. The purpose of this procedure is so that in the future, you can exactly replicate the product of this procedure. This method should also clearly identify any negative and positive controls to ensure that your dependent variable is only responding to your independent variable and that you are able to adequately measure this response.
Rubric for part II
Hypothesis and rationale
5 pts
Scientist
Fulfills criteria for score level 4. Analysis of chosen variables will draw out novel conclusions.
4 pts
Research Fellow
Hypothesis addresses relevant problems identified by literature sources. Literature sources are primarily of high quality.
3 pts
Lab technician
Hypothesis attempts to address relevant problems identified by valid literature sources and/or literature sources are of moderate quality
2 pts
Lab aide
Hypothesis asks question that is poorly supported by literature sources and/or literature sources are of poor quality and/or proposed data collection is impossible or impractical.
1 pts
Developing
Hypothesis does not directly propose a question for study and/or hypothesis is not supported by valid literature sources and/or data collection would be impossible or dangerous.
Method development
5 pts
Scientist
Fulfills criteria for score level 4. Formulates method based on forming multiple connections between literature, preliminary observations and theory. Results of proposed project will likely result in advancement of the field.
4 pts
Research Fellow
Method controls for variables by considering background literature, preliminary observation and scientific principles. Makes all relevant connections between each of these components. Proposed study is feasible and likely to result in useful results.
3 pts
Lab technician
Proposed study has obvious limitation that make data collection difficult and interpretation problematic. Presentation is generally organized.
2 pts
Research Assistant
Few connections made between scientific principles and procedure/data/observations. Data will lead to biased conclusions that can’t quantitatively link the dependent variable to the independent variable..
1 pts
Developing
Method appears random and without rationale. Potential collected data do not relate to hypothesis.