The world depends on a great deal of its energy in the form of fuels. It is primaly used as a source of energy in converting to different form of energy in able to fully operate engines and different fuel-running facilities. There is different type of fuels to be used in a specific activity. These fuels undergo processes such as chemical and mechanical process in able to produce another form of energy that will be essentially needed.
Many fuels are hydrocarbons such as methane (CH4) and propane (C3H8), i.e. compounds containing only hydrogen and carbon. Other fuels such as ethanol (C2H5OH) contain oxygen in addition to carbon and hydrogen. These “oxygenated” fuels are currently mandated in many urban areas because they are believed to lead to less pollution. Examples of fuels include Ethanol, diesel and gasoline. Gasoline is a transparent, petroleum-derived liquid that is used primarily as a fuel in q spark-ignited internal combustion engines. It is mostly of organic compounds obtained by the fractional distillation of peteoleum, enhanced with variety of additives. This fuels have different characteristics, different chemical composition and different properties in which differentiate it's potential use.
Because of the wide variety of fuels, it is a must to determine its properties for a proper use. It is also essential to identify a good fuel and its efficiency. A good fuel is any substance which gives out large amounts of energy when it is burnt. In most cases, fuels are burnt in oxygen (air) i.e. they are oxidized.
The potential energy released by the form of heat is measured by calorimetry and by the use of fuel efficiency measures. Fuel efficiency is a form of thermal efficiency, meaning the
ratio from effort to result of a process that converts chemical potential energy contained in a carrier (fuel) into kinetic energy or work. The specific energy content of a fuel is the heat energy obtained when a certain quantity is burned (such as a gallon, litre, kilogram). It is sometimes called the heat of combustion. There exists two different values of specific heat energy for the same batch of fuel. One is the high (or gross) heat of combustion and the other is the low (or net) heat of combustion. The high value is obtained when, after the combustion, the water in the exhaust is in liquid form. For the low value, the exhaust has all the water in vapor form (steam). Since water vapor gives up heat energy when it changes from vapor to liquid, the liquid water value is larger since it includes the latent heat of vaporization of water. Neither the gross heat of combustion nor the net heat of combustion gives the theoretical amount of mechanical energy (work) that can be obtained from the reaction. (This is given by the change in Gibbs free energy, and is around 45.7 MJ/kg for gasoline.) .
The main objective of this experiment is to differentiate and evaluate the potential energy produced by Ethanol, diesel and gasoline in the process of combustion and by measuring the heat content of each of the subject with the use of calorimeter with the consideration of time. Each of the subject will undergo similar process and comparison through the actual experimentation.
Results and Discussion
This section presents a discussion of the data analyzed from the experiment and interpreted to answer the problem of the present experiment of data and relate the experiment to the existing theory and knowledge. Tables, figures, and graphs were used to enable students to understand how the data collected were presented.
I. Temperature of H2O
This section of the experiment aimed to determine the temperature of H2O in the
Calorimeter.
In table 1.1, it was shown that using 10 ml of ethanol having a mass of 7.89 grams in the first trial to the initial temperature of the 100 ml of H2O in the calorimeter was 30 ̊C and reached the final temperature of 74 ̊C. In trial two, same mass and volume of ethanol, the H2O obtained a initial temperature of 30 ̊C same with the temperature in the first trial and increased to 78 ̊C which is the final temperature.
In table 1.2, it was shown that using 10 ml of ethanol having a mass of 7.9 grams in the first trial to the initial temperature of the 100 ml of H2O in the calorimeter was 30 ̊C and reached the final temperature of 84 ̊C. In trial two, same mass and volume of ethanol, the H2O obtained an initial temperature of 30 ̊C same with the temperature in the first trial and increased to 89 ̊C which is the final temperature.
In Table 2, it was shown that there was no difference in mass of the calorimeter with and without H2O. Both of trials weighed same 20 g of calorimeter without H2O on it and when the H2O was added on the calorimeter, both weighed 122 g.
IV. Temperature Change in Water
In the course of the experiment, 10 ml of Ethanol last up to 9 minutes while 10 ml of Gasoline last until 10 minutes. In figure 1, it was shown that the heat capacity of ethanol is less than the heat capacity of gasoline. In the first 60 second interval, all of the fuels increased by 5 degree Celsius. The next interval, Ethanol increased 4.5 degrees Celsius while gasoline increased by 5 degree Celsius. The temperature increased to 41 ̊C after 60s then another 60s resulting for the temperature to rose up to 43 ̊C. The next 60s made the temperature to 43 ̊C and went up to 49 ̊C as 60s passed by. The data implied that the temperature increases in every 60s intervals. A 56 ̊C increased in temperature after another 60s. The next 60s made it to 68 ̊C in temperature. In 9 minutes, it reached it maximum temperature at 74 ̊C.
As for the second trial of ethanol, it was shown that the heat capacity of ethanol increased to 78 ̊C from the first trial. In the first 60 second interval, all of the fuels increased by 5 degree Celsius. The next interval, Ethanol increased 4.5 degrees Celsius while gasoline increased by 5 degree Celsius. The temperature increased to 43 ̊C after 60s then another 60s resulting for the temperature to rose up to 43.5 ̊C. The next 60s made the temperature to 48 ̊C and went up to 57 ̊C as 60s passed by. The data implied that the temperature increases in every 60s intervals. A 69 ̊C increased in temperature after another 60s. The next 60s made it to 78 ̊C in temperature. In 9 minutes, it reached it maximum temperature at 78 ̊C.
As for the first trial using gasoline, it was shown that the heat capacity of ethanol is less than the heat capacity of gasoline. In the first 60 second interval, all of the fuels increased by 5 degree Celsius. The next interval, gasoline increased 40 degrees Celsius while gasoline increased by 5 degree Celsius. The temperature increased to 42 ̊C after 60s then another 60s resulting for the temperature to rose up to 44 ̊C. The next 60s made the temperature to 50 ̊C and went up to 56 ̊C as 60s passed by. The data implied that the temperature increases in every 60s intervals. A 63 ̊C increased in temperature after another 60s. The next 60s made it to 70 ̊C in temperature and 77 ̊C for another 60s. In 10 minutes, it reached it maximum temperature at 84 ̊C
As for the second trial using gasoline, it was shown that the heat capacity of ethanol is less than the heat capacity of gasoline. In the first 60 second interval, all of the fuels increased by 5 degree Celsius. The next interval, gasoline increased 39 degrees Celsius while gasoline increased by 5 degree Celsius. The temperature increased to 44 ̊C after 60s then another 60s resulting for the temperature to rose up to 44.5 ̊C. The next 60s made the temperature to 49 ̊C and went up to 55 ̊C as 60s passed by. The data implied that the temperature increases in every 60s intervals. A 63 ̊C increased in temperature after another 60s. The next 60s made it to 71C in temperature and 79 ̊C for another 60s. In 10 minutes, it reached it maximum temperature at 89 ̊C.
