This week we created and presented our project to our adviser, Dr. Dan Nily, and other participants.
View the presentation below!
View the presentation below!
Week 9: Final Experimental Procedures Executed
This week, we have successfully carried out the main part of the experiment, determining the energy density of samples of biodiesel using our constructed calorimeter design. We executed 3 trials for biodiesel made from two types of biodiesel, soybean based and peanut oil based, for a total of 6 runs. Our results are displayed in the chart below.
Additionally, we tested a sample of regular diesel and compared our experimental values to the theoretical values of energy density for the sample of diesel based on its octane rating. The experimental results are displayed below.
As is shown in the table, the average energy density of the diesel was measured to be 13.3 MJ/kg. The theoretical energy density of diesel is 43.2 MJ/kg [2]. The calorimeter was extremely innacurate, accounting for only 1/4 of the total energy of the diesel.
We are currently investigating this issue to see how this inaccuracy could have resulted. Current theories include that the diesel was not burned properly. During the testing, extremely large amounts of soot, which is incompletely burned diesel, arose from the spirit burner. A large amount of mass was most likely lost through the soot. Thus, the calculations would have included unburned diesel as part of the burned diesel, greatly reducing the calculated energy density. It seems as if this calorimeter simply was not built to handle diesel's property of burning so uncleanly. Another theory is that the calorimeter was simply not very accurate to begin with. Though the original design did not include a ventilation hole, one needed to be added in order to supply oxygen required for the combustion reaction. This hole greatly reduced accuracy. Most likely, the answer involves a combination of these two among other factors. Further research and investigation may clear this up.
A solution to this problem would be to measure the energy density of another fuel, such as one that burns more cleanly than diesel. However, due to time constraints, we will not be able to test additional fuels.
[1]http://webarchive.nationalarchives.gov.uk/+/http://www.berr.gov.uk/files/file14925.pdf
[2]http://beimex.com/page.php?id=40
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| Table of biodiesel energy density calculations and values |
As can be examined from the chart, our average energy densities for the Soybean and Peanut oil biodiesel are 22.977 MJ/kg and 20.898 MJ/kg respectively. These values were achieved using the methods described in the Calculations sections of the "Experimental Procedure" page. These values are roughly 1/2 to 2/3 of the average professionally manufactured biodiesel energy density of 37.27 MJ/kg [1]. While this may value may indicate that our calorimeter is inaccurate, it is possible that these biodiesel samples greatly differed in energy densities when compared to professionally manufactured biodiesel. The samples we tested were created by students in a lab, thus, their exact energy densities may be higher or lower than the average of 37.27 MJ/kg.
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| Table of diesel energy density calculations and values |
We are currently investigating this issue to see how this inaccuracy could have resulted. Current theories include that the diesel was not burned properly. During the testing, extremely large amounts of soot, which is incompletely burned diesel, arose from the spirit burner. A large amount of mass was most likely lost through the soot. Thus, the calculations would have included unburned diesel as part of the burned diesel, greatly reducing the calculated energy density. It seems as if this calorimeter simply was not built to handle diesel's property of burning so uncleanly. Another theory is that the calorimeter was simply not very accurate to begin with. Though the original design did not include a ventilation hole, one needed to be added in order to supply oxygen required for the combustion reaction. This hole greatly reduced accuracy. Most likely, the answer involves a combination of these two among other factors. Further research and investigation may clear this up.
A solution to this problem would be to measure the energy density of another fuel, such as one that burns more cleanly than diesel. However, due to time constraints, we will not be able to test additional fuels.
[1]http://webarchive.nationalarchives.gov.uk/+/http://www.berr.gov.uk/files/file14925.pdf
[2]http://beimex.com/page.php?id=40
Week 8: Preliminary Tests Completed
This week, we successfully implemented the first
preliminary tests using our final calorimeter design. This design, as pictured,
incorporates a self-made spirit burner, surrounded by a cutout tin can. On top of that tin
can is another tin can that holds water. This model includes a styrofoam
housing for insulation. The bottom tin can’s role is to protect the styrofoam
from possibly melting in the case that the fire somehow comes into contact with the styrafoam.
The styrofoam has a cutout on the side. The purpose of this cutout
is to allow oxygen to flow to the wick and allow for the combustion reaction to
occur. Originally, the we had thought it may be possible to burn the biodiesel
in a sealed container, based on the theory that there may be enough oxygen in the
container to allow for a temporary burn. However, our testing has found that
combustion ceases within seconds of sealing the lid.
While we originally wanted to have the container completely sealed
to allow for maximum insulation, our experiments have concluded that it is not
possible with the current design. Thus, we experimented with various sized
openings in the lower portion of the styrofoam container to find the smallest
hole possible that would allow for the biodiesel to burn with a strong flame.
Next week, we expect to be able to carry out the main part of the experiment, determining energy content of biodiesel, completely.
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| This image displays our final calorimeter design during preliminary tests. The original cutout was larger, but we made it as small as possible to decrease the escape of energy. We also found that a smaller opening noticeably hinders the burn rate. |
Week 7: Successful Burning Mechanism Achieved
This week, we were able to successfully develop a wick mechanism that will allow the biodiesel to burn at a sufficient rate. Previously, all the wick designs resulted in flames that died out quickly or burned too slowly. After experimenting with varying placement, number of wicks. and amount of biodiesel in the container, we have come up with a simple and effective design. This design involves braiding three pieces of string together to create one wick. The instructions for braiding are located here. We place three of these braided wicks into the container. We then completely soak them in biodiesel. Additionally, we make sure the container is at least half filled with biodiesel. To achieve the most accurate results, we pre-burned the wicks to the point that they no longer burn. At this point, the wicks themselves cease to burn and the flame continues because the wick is pulling up the biodiesel.
What we have concluded was our main problem originally with respect to burning the biodiesel at a sufficient rate was that the conditions did not allow the biodiesel to climb up the wick quickly enough. To fix this, we increased the amount of wick and raised the level of the biodiesel within the container.
What we have concluded was our main problem originally with respect to burning the biodiesel at a sufficient rate was that the conditions did not allow the biodiesel to climb up the wick quickly enough. To fix this, we increased the amount of wick and raised the level of the biodiesel within the container.
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| This burner design, incorporating 3 triple braided wicks, is extremely effective. |
Week 6: Burning Biodiesel
Burning the biodiesel has become a very problematic issue. The
rate of the combustion reaction appears too slow and a very small amount of the
biodiesel is burned. While observing the flame, we have seen that smoke builds
up within the container. We believed it was possible that the smoke was hindering the flame. To combat this issue, we created a metallic covering to fit on top of the container. This purpose of this piece is to hold up the
wick and block any smoke from going into the container.
As illustrated by the above picture, the flame is still small. Thus, we concluded that the smoke entering the container is not an issue.
Another test conducted today involved attempting to burn biodiesel directly. Though all our research indicated this was not possible, we attempted it anyway. We found that the research held true, eliminating our design for a cheap version of a "bomb calorimeter" discussed in earlier posts.
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| This spirit burner design is ineffective due to the small burn rate. |
Another test conducted today involved attempting to burn biodiesel directly. Though all our research indicated this was not possible, we attempted it anyway. We found that the research held true, eliminating our design for a cheap version of a "bomb calorimeter" discussed in earlier posts.
Week 5: Final Design Changes
After further research, we have concluded that we will most likely not
need the metallic tubing. Originally, this was needed so that we would be able
to provide oxygen for the combustion reaction. However, due to the small amount
of fuel we will be using, it may be possible for the combustion reaction to
proceed with the amount of oxygen that can fit inside our “combustion chamber,”
which will be an aluminum can. In the case that this doesn't work, we will revert back to our original metallic tubing design.
The final hurdle of this design is to figure out a way to ignite
the fuel and have it burn completely. This is a challenge for biodiesel
because of its high auto-ignition temperature, which means it burns at extremely
high temperatures. This is why special engines are required in order to use
diesel or biodiesel in automobiles. Our current solution is to experiment with
wicks to see if they will allow the biodiesel to continuously burn until the
end
We have also decided that we will create either Sketch Up or Creo models in order to display our designs during presentations.
Week 4:Designing our Calorimeter Pt. 2
Rather than deciding between which type of calorimeter to use, we have decided to construct both and run the experiments. This will allow us to find which device is more accurate in determining the energy density. In addition to determining which method is more accurate, the addition of a second device will help us isolate areas of inefficiency, including, but not limited to, loss of heat and oxygen deprivation.
Our first calorimeter will express a similarity to Figure 1 shown below. Rather than incorporating a drought shield, we will use a Styrofoam container, similar to the type that contains dry ice. This method will contain a majority of the heat that would normally be lost in atmosphere as Styrofoam is an excellent insulator. A thin can containing water will be suspended above a flash filled with our biodiesel. The flask will have a wick that we will ignite. This design is rather simple, but should increase our efficiency over the design in Figure 1.
The second calorimeter is a slighly more complex design as it introduces the combustion chamber. This chamber will be submerged underwater in a container that will house the biodiesel burning. The heat released by the burning will increase the temperature of the surrounding water. The complexity introduced here is that we now have to consider providing oxygen to the reaction process since it takes place under water. Our solution is to inject oxygen through the use of metallic tubing, and to allow exhaust gasses to escape. Again, our goal is to create these devices using low cost materials that are easily accessible for third world countries. So each component we introduce is carefully thought of before it is implemented.
Our next challenge is to determine exactly how we are going to ignite the biodiesel for our second design. Since the fuel will be isolated in a chamber below water, we will not be able to ignite it with a lighter. We are considering the idea of a rapid burning fuse. The fuse will allow us to ignite the fuel from the exterior of the chamber.
Our first calorimeter will express a similarity to Figure 1 shown below. Rather than incorporating a drought shield, we will use a Styrofoam container, similar to the type that contains dry ice. This method will contain a majority of the heat that would normally be lost in atmosphere as Styrofoam is an excellent insulator. A thin can containing water will be suspended above a flash filled with our biodiesel. The flask will have a wick that we will ignite. This design is rather simple, but should increase our efficiency over the design in Figure 1.
The second calorimeter is a slighly more complex design as it introduces the combustion chamber. This chamber will be submerged underwater in a container that will house the biodiesel burning. The heat released by the burning will increase the temperature of the surrounding water. The complexity introduced here is that we now have to consider providing oxygen to the reaction process since it takes place under water. Our solution is to inject oxygen through the use of metallic tubing, and to allow exhaust gasses to escape. Again, our goal is to create these devices using low cost materials that are easily accessible for third world countries. So each component we introduce is carefully thought of before it is implemented.
Our next challenge is to determine exactly how we are going to ignite the biodiesel for our second design. Since the fuel will be isolated in a chamber below water, we will not be able to ignite it with a lighter. We are considering the idea of a rapid burning fuse. The fuse will allow us to ignite the fuel from the exterior of the chamber.
Week 3: Designing our Calorimeter
The most critical component of our experiment is the calorimeter. This device will be used to determine the energy density of the biodiesel as it combusts. Before implementing our own design, we will first analyse an industrial grade machine to determine its mechanics and efficiency. We will design our machine based on this information with a relatively low budget in mind. Our greatest concern for the design is to eliminate wasted energy from the burning fuel. Our goal is to transfer 100% of the heat from the burning fuel to the water.
The design shown in Figure 1 is a relatively simple setup that shows a given mass of water containing a thermometer, elevated above a spirit burner containing a fuel source. There is a shield surrounding the reaction base that prevents loss of heat, and a insulator at the top of the device to maximize the amount of heat contained. We realize, however, that this process is highly inefficient and is susceptible to a large amount of energy loss. A more accurate solution is a bomb calorimeter, which encapsulates the reaction under the water. This sealed container will retain the heat and transfer it to the surrounding water. In order to maintain the reaction, we must introduce an oxygen source.
The bomb calorimeter shown in Figure 2 is considerably more efficient. With consideration to Figure 1, the bomb calorimeter requires an oxygen supply, ignition source, and an internal encapsulation device that is able to resist the heat of combustion, and water sealed to prevent the inlet of water during the reaction process. The heat of the reaction is not let into the atmosphere, but to the surrounding water instead. Thus, increasing efficiency. For our purposes, we may utilize a Styrofoam enclosure as the insulating jacket; an aluminum soup can that will enclose the reaction; and a model rocket fuse to initiate the burning process.
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| Figure 1 |
The design shown in Figure 1 is a relatively simple setup that shows a given mass of water containing a thermometer, elevated above a spirit burner containing a fuel source. There is a shield surrounding the reaction base that prevents loss of heat, and a insulator at the top of the device to maximize the amount of heat contained. We realize, however, that this process is highly inefficient and is susceptible to a large amount of energy loss. A more accurate solution is a bomb calorimeter, which encapsulates the reaction under the water. This sealed container will retain the heat and transfer it to the surrounding water. In order to maintain the reaction, we must introduce an oxygen source.
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| Figure 2 |
Week 2: Determining Calculation Methods
We have found multiple methods that are available in quantifying the efficiency of the conversion process. A simple measurement of the volume of the products after the reaction will inform us of the amount of biodiesel that was created after the reaction took place, keeping in mind that there may be impurities that will interfere with our calculations. These impurities change depending on our type of feedstock as well as the alcohol group we are using. We've decided that the most detailed analysis of the product biodiesel would be to measure the energy density. Today's fuel sources utilize a standard that indicates the power output in mega joules per given kilogram of fuel. This ranges from 4.6 MJ/kg for trinitrotoluene (TNT explosive), to 330,000,000 MJ/kg for Deuterium-Tritium nuclear fusion reactions. This rating is an energy density. In order to measure energy density, the method of calorimetry is used. This relatively simple method of measuring energy density requires us to find the change in heat of water when the biodiesel is burned. A mathematical calculation is performed, incorporating the change in mass and temperature, yielding the energy density. In an engineering standpoint, we are conflicted with the design of the low cost calorimeter. Considering this method requires burning our biodiesel, we must determine the most efficient method of transferring this heat to the the water, to measure the change in heat
Week 1: Formulating our plan
Our team conjectured that we will focus on determining a method of quantifying biodiesel production after the process of conversion. Upon researching various techniques of conversion, we have successfully determined a low-cost method to create biodiesel, a method in which we will utilize to test our quantification techniques. The compounds to be used are abundant resources and are easily available for testing on campus. After hypothesizing on theoretical techniques that we can apply, we found some trouble in the idea of measuring the efficiency of the product converted. That is, whether to calculate the volume of product versus reactant, or even complex enough to compare viscosity and ignition temperature of synthetic diesel as opposed to fossil fuel based oil.
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