We found out that oils ,which are more expensive and regarded as better quality, are more efficient. This is because the biodiesel obtained from olive oil burnt for the longest as shown in Table 1 and Table 2. From Experiment 1, biodiesel from olive oil could burn for a long time, while the wasted oil could burn for a shorter time and the vegetable oil could burn for the shortest time, 4.35 mins(average timing from both experiment).
However, the biodiesel obtained from used cooking oil (wasted oil) in Experiment 1, heat up to a higher temperature than biodiesel obtained olive oil.
Comparing the results obtained for the consistency of the biodiesels, biodiesel obtained from olive oil burnt the longest, as compared biodiesel obtained from vegetable oil and wasted oil. Wasted oil clocked the second highest timing and vegetable oil clocked the shortest time for the flame to extinguish.
4.3 Evaluation of Hypothesis
Our hypothesis was proven wrong. We only did research on the most efficient oil to make biodiesel. Restaurants use oil in a large quantity to fry food etc. Using the used cooking oil (leftover from oil) from there, the cash needed to purchase new oil such as olive oil would be lessen or saved. The research we did suggested used cooking oil (wasted) as it is not as expensive as new oil. Other than that, wasted oil is more environmental friendly as we are able to recycle and reduce the amount of resources used. After we collected our results, we started to research on the quality of oil that makes the best biodiesel and our results shown that it should be olive oil. According to Oilgae (n.d.)., olive oil can be used to produce biodiesel. However, it is unlikely that this crop will be a sustainable candidate for biodiesel, as olive oil is more pricy.
4.4 Area of improvement
There are few things which can be improved. First of all, we must be aware of the chemical reactions. The methanol is highly reactive with plastic. So when we put our biodiesel inside the clean plastic containers, the methoxide inside the biodiesel reacted and melted the plastic. This reaction might affect the results greatly as the biodiesel was not pure anymore.Thus, we must keep biodiesel inside glass containers.
Secondly,the wasted oil was not filtered properly.The wasted oil contained lots of impurities so it was essential to filter it. However, due to time constraint, we could not filter it properly. These impurities might affect the results.Thus,it could have been better if we used other types of oil such as soybean oil. Thirdly, we could have used the cotton or wool to wrap around the beaker to preserve the heat of the oil. The temperature of the oil is one of the most essential part in the biodiesel production. However, we did not have a proper apparatus to preserve the heat.
The temperature of the oil might affect the results especially the production of biodiesel.