CDB 3082
Chemical Engineering Lab 4
September 2017
[Experiment 4]
[FLASH POINT BY ERAFLASH]
Group No:
4
Name:
1. ELFERRA FARREL TIMPAS
22028
2. AIMAN BIN NOORUDIN
22221
3. AMIRUL ASHRAF BIN ABDUL RAZAK
23157
4. NESHA PRIYA A/P ARASU
22106
5. NURULSYAZANA BINTI ONN
21293
HARIZ BIN ROSLAN
16000703
GA Name:
Examiner
1
Mark
CDB 3082
Chemical Engineering Lab 4
September 2017
Table of Content 1.0
Introduction ...............................................................................................................3
2.0
Methodology. ..............................................................................................................4
3.0
Results and Discussion ..............................................................................................5
4.0
Conclusion ................................................................................................................13
5.0 Reference ..........................................................................................................................13 6.0 Appendix ...........................................................................................................................14
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1.0
Chemical Engineering Lab 4
September 2017
Introduction
By definition, flash point is stated as lowest temperature at which a liquid generates flammable vapours which can be ignited in air by a flame above its surface. A flame is presented at regular intervals to the liquid surface. If a flash occurs in the vessel, it indicates that the temperature of the tested liquid has reached (or exceeded) the flash point. The test vessel can be opened or closed. (Agnes & Jacques, 2013). Meanwhile, the fire point is the temperature at which combustion will be sustained. The flash and fire points are useful in determining the substance’s volatility and fire resistance. The flash point can be used to determine the transportation and storage temperature requirements for the substance. The flash point can also be used to detect potential product contamination (Torbacke, Kassman & Kassfeldt, 2014). The fire point for engine oils is usually 20- 30 ℃ higher than flash point. A fire point happens when an ignition source is applied and the heat produced is self-sustaining, as it supplies enough vapours to combine with air and burn even after the removal of the ignition source. (Diar,2016).
In this experiment, the flash is experimented in the close system called “close-up”, even though the flash point can determine by two ways which are in “open -cup” and “closeup”.
The objectives of the experiment are:
1. To determine the flash point of pure liquid components. 2. To determine the flash point of mixture liquid components
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CDB 3082
Chemical Engineering Lab 4
September 2017
2.0 Methodology. 2.1
Experiment 1: To determine the flash point of pure liquid components (CRM, Diesel and Kerosene).
i)
Procedure load sample
1. The eraflash flash point tester and chiller is switched on. 2. The cup with the stirrer bar is cleaned up before the sample is filled in. 3. The chamber door is opened and placed with the cup. 4. The chamber door is closed for the process is started.
ii)
Setting parameters and run test
1. After the flash point is switched on after 1 min, the setting for tester is ready. 2. The measurement standard, profile, sample id and expected flash point is selected for first sample which is Certified Reference Material (CRM). 3. Run button is pressed for next step.
iii)
Test finished
1. The measurement procedure of the sample on the screen is visualised by the instrument followed by the temperature also the pressure gauge is displayed the pressure increase after ignition. 2. The flash point temperature is corrected for atmospheric pressure and will be rounded to the next 0.5 0C. 3. The result is displayed on the screen and automatically saved in the corresponding result file. 4. The cup is removed from the measurement chamber. 5. The sample fuel is removed and poured into waste drum from the cup. 6. The cup is cleaned and stirred with the tissue. 7. The cleaned cup is ready for next sample. 8. The experiment is repeated with other samples which are kerosene and diesel.
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September 2017
2.2 Experiment 2 : To determine the flash point of mixture liquid components (Diesel and Kerosene).
All of the steps stated in Experiment 1 are repeated with varying percentage of mixture of diesel and kerosene as shown below Kerosene (%)
Diesel (%)
0
100
25
75
50
50
75
25
100
0
3.0
Results and Discussion
3.1
Experiment 1: To determine the flash point of pure liquid components (CRM, Diesel and Kerosene).
Flash point measured (◦c)
Flash point expected (◦c)
Margin Error (%)
CRM
77.4
75.1
2.9
Kerosene
53.3
53.0
0.6
Diesel
86.3
85.0
1.5
Sample
Table 3.1: Flash points measured for CRM, kerosene and diesel.
Sample Kerosene Diesel (%) (%)
100 75 50 25 0
0 25 50 75 100
Flash point measured (◦c)
Flash point expected (◦c)
Margin Error (%)
53.3 57.3 61.3 69.1 86.3
50.0 58.9 65.9 74.7 85.0
6.2 2.8 7.5 8.1 1.5
Table 3.2: Flash points measured for different composition mixture of kerosene and diesel .
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Chemical Engineering Lab 4
September 2017
Flashpoint for Kerosene and Diesel 100 86.3
90 80 70 ) c ◦ ( t n i
o p h s a l F
60
53.3
50 40 30 20 10 0
Sample Kerosene
Diesel
Graph 3.1: Bar chart of kerosene and diesel flash points.
Kerosene Composition vs Flash Point Measured 100 90 80 ) c ◦ ( t n i
o p h s a l F
70 60 50 40 30 20 10 0 0
20
40
60
80
Kerosene composition (%)
Graph 3.2: Kerosene composition against flash points measured.
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September 2017
Diesel Composition vs Flashpoints Measured 100 90 80 ) c ◦ ( t n i o p h s a l F
70 60 50 40 30 20 10 0 0
20
40
60
80
100
120
Diesel Composition (%)
Graph 3.3: Diesel composition against flash points measured.
DISCUSSIONS 3.1
Experiment 1: To determine the flash point of pure liquid components (CRM, Diesel and Kerosene).
Flash point measured
Flash point expected
Margin error
(◦c)
(◦c)
(%)
CRM
77.4
75.1
2.9
Kerosene
53.3
53.0
0.6
Diesel
86.3
85.0
1.5
Sample
Table 3.1: Flash points measured for CRM, kerosene and diesel. The flash point tester instrument was calibrated by using the CRM sample. According to our result, the margin error of the flash point measured and expected for CRM is low which is only 2.9%, hence, it can be said that the instrument is working properly and its measurement system performance is validated to give us accurate result.
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Chemical Engineering Lab 4
September 2017
Before we measure the flash point of our sample using the flash point tester instrument, we set the expected flash point by referring to its theoretical flash point. For fuel oil sample, its theoretical flash point varies between 60 ℃ to 174℃ (U.S. Oil & Refining Co., 2008). Kerosene has flash point with range of 38 ℃ to 54℃ while diesel has range of 82℃ to 93℃ (NIIR Board of Consultants & Engineers, 2015). We picked any value that is within each of the fuels’ flash point range. Based on our findings as shown in Table 3.1, the flash points measured for all the samples are within the range. It can be said our experiment results are accurate. The margin errors for our results are lower than 5% which are very small.
Flash Point for Kerosene and Diesel 100 86.3
90 80 70 ) c ◦ ( t n i o p h s a l F
60
53.3
50 40 30 20 10 0
Sample Kerosene
Diesel
Graph 3.1: Bar chart of kerosene and diesel flash points.
Figure 4.1: Petroleum distillation tower and petroleum fractions (Kennepohl, 2015).
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September 2017
According to Graph 3.1 , the flash point of diesel is higher than kerosene. This can be explained from the production of these oils during petroleum refining as illustrated in Figure 4.1, diesel has higher number of carbons and boiling point compared to kerosene. Diesel has 16-60 number of carbons with boiling point of 260-350 ℃ whereas kerosene has 10-16 number of carbons with boiling point of 180-260 ℃. The most volatile and lowest boiling point components condensate at the top of the column whereas the least volatile and highest boiling points condensate at the bottom of the column. Therefore, the higher the boiling point, the higher the flash point will be. 3.2
Experiment 2: To determine the flash point of mixture liquid components (Diesel and Kerosene).
Kerosene Composition vs Flashpoint Measured 100 90 80 ) c ◦ ( t n i
o p h s a l F
70 60 50 40 30 20 10 0 0
20
40
60
80
Kerosene composition (%)
Graph 3.3: Kerosene composition against flashpoints measured.
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Diesel Composition vs Flashpoints Measured 100 90 80 ) c ◦ ( t n i
o p h s a l F
70 60 50 40 30 20 10 0 0
20
40
60
80
100
120
Diesel Composition (%)
Graph 3.4: Diesel composition against flashpoints measured. Based on Graph 3.2, as the composition of kerosene in the mixture increases, the flash point of the mixture decreases whereas in Graph 3.3, when the composition of diesel in the mixture increase, the flash point of the mixture increases. This is due to the fact that, as shown in Table 3.1, pure kerosene has lower flash point than diesel which is 53.3℃ while pure diesel has flash point of 86.3 ℃. Hence, when the composition of kerosene is higher than diesel in the mixture, the mixture is dominant of kerosene therefore reducing the flash point of the mixture and vice versa for increasing composition of diesel in the mixture. The importance of flash point and fire point in the transportation and storage of dangerous materials.
Flash point and fire point are very important in the handling, transportation and storage of dangerous materials. Initial boiling point and flash point are the basis for classification of flammable liquids as it is related with the liquid’s volatility (Geyer & Wisuri, 2017). However, in this experiment we focus more on flash point. The vapor formation of the liquid is the main factor in determining fire and explosion hazard as the vapor of the liquid over the liquid (when it is at its flash point) that can form a flammable mixture when exposed to air not the liquid itself that burns. The lower the flash point of a substance, the more flammable the substance is. It can be a fire hazard, prone to flashing and possible continuous ignition as well as explosion (ASTM International, 2010).
Generally, liquids with flash point below ambient storage 10
CDB 3082
Chemical Engineering Lab 4
September 2017
temperature show a rapid rate of spreading of flame over the surface of the liquid. Hence, more vapor will be generated causing the substance more vulnerable to fire if not stored properly. According to Rekus (1994), fire point is defined as the temperature where liquid produces vapors at a rate enough to sustain steady combustion. Fire point is slightly higher than flash point. Fire point is different than flash point because at flash point, when the vapor is ignited, it will produce momentarily flame and will cease away once the source of the ignition is off. However, at fire point, the vapor will continue to burn even after the source of ignition is off. So, by knowing the flash point and fire point, we can store and transport any flammable and combustible materials accordingly to prevent fire and explosion accident from happening. For example, flammable liquids should be stored separately from other s ubstances and located in a contained area where when there is a fire happen, it will not likely rapidly involved in the accident. Apart from that, flammable liquids should be stored in its specific containers and any vehicles transporting the flammable liquid should be engineered to prevent the surrounding temperature affecting the temperature of the liquid. The importance of flash point experiment when there is no data available in the literature for mixture having different compositions.
The fundamental reason for flash point measurement is to assess the safety hazard of a liquid mixture or semi-solid regarding to their flammability. Although this is an empirical measurement that will vary with method and its parameters (Liaw & Chiu, 2006), it is an important property which is a critical factor for determining agent stability during dissemination, safe storage and handling. Since most substances are produced, packaged and delivered in their pure form, flashpoint measurement is necessary with the aim of classifying the liquid mixtures into their respective groups. The adulteration of a pure substance can increase the risk of danger. For example, the mixing of kerosene with highly volatile gasoline can cause numerous fires and explosions.
The flash point of mixture obviously differs from the flash points of their individual components. Estimating or computing the flash points of mixtures alone are not enough because chemical compounds are very likely to exhibit different characteristics once they are mixed with other compounds. Viscous liquids can only be heated slowly and liquid mixtures 11
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September 2017
always change their compositions are they evaporate. Hence, experiments must be conducted under various conditions to deduce the flash point of flammable chemical compounds. This is very crucial as flammable liquids (usually mixtures) have different safety precautions according to their hazard levels. It can be concluded that this experiment is vital for oil and gas industries as there are many hazards that have be looked into. Precautions can be taken to prevent fire hazards as well as to sustain the quality and grade of the goods. Chemical compounds and mixtures that have flash point of 37.78 oC (100F) and below, special precautions are necessary for safe handling while for compounds with flash points that exceed 65.56oC (150F), they may pose safety hazards under non-standard conditions. It is important to take note that mixtures containing an inert inhibitor can exhibit no flash point when a standard test are carried out, but they are still potentially flammable. Hence it is crucial to carry out more stringent tests when testing hydrocarbon-air mixture with inhibitors. (Raju, 2014) 3.3
Errors and Recommendations
There are few factors that affects the difference in measured and expected flash point of a flammable liquid which are oxidation, impurities, and composition. When oxidation happens, insufficiency of oxygen is bound to happen, when oxygen is lacking, as stated by Rajput (n.d.), the air is insufficient for complete combustion causing the fuel to burn partially hence, flash point temperature will have an increase in value. Impurities can also increase the flash point of a flammable liquid. When an impurity exist, such as water vapour which is when water is present in the sample, the flammable material dominates and the lower limit concentration will be reached at just a little over the temperature of the flash point of the pure flammable liquid (Astbury, 2004). As for composition, when two or more component liquids are being tested, the more volatile component will be richer in the vapour. Based on Astbury (2004), the loss of more volatile component due to the mixture with lesser volatile components will result in the flash point being far higher than the true flash point. •
Systematic error : As a result of the presence of impurities in the pure component (kerosene or diesel), the flash point will differ or increase in value slightly or dramatically above the flash point of the pure c omponent.
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Recommendation : When taking the sample (flammable liquids), make sure the apparatus such as beaker and dropper is cleaned from any impurities such as fine particles or water. •
Parallax error : The eyes when taking the measurement of the flammable material is at an angle which results in a reading which is consistently high or consistently low. Recommendation : When taking the measurement of the flammable material, the eye must be perpendicular to the meniscus.
4.0
Conclusion
Based on the results that we get, it was understood that kerosene has the lowest flash point and diesel has the highest. When mixing these two fuels, it was shown that as the percentage of the kerosene decreases, the flash point temperature of the sample had an increase in value. This proves the fact that diesel has a higher flash point temperature than that of kerosene. Fire point and flash point are important in classification of flammable liquids to prevent fire or explosion accident. Thus, testing of flash point experiment is important when there is no data available in the literature for mixture having different compositions.
5.0 Reference
ASTM International (2010). Significance of Tests for Petroleum Products (ASTM Manuals & Monograms - Manual 1) (8th ed.). Rand., S. J., (Ed.). Bridgeport, NJ: ASTM
International. Geyer, W. & Wisuri, J. (2017). Handbook of Storage Tank Systems: Codes: Regulations, and Designs. New York: Marcel Dekker, Inc, pp.275-276.
G.R.
Astbury.
(2004).
FLAMMABLE
FLASH
POINTS
SOLVENTS,
pp.
OF 2.
AQUEOUS
Retrieved
10
SOLUTIONS 19,
2017,
OF from
https://www.icheme.org/communities/subject_groups/safety%20and%20loss%20prev
ention/resources/hazards%20archive/~/media/Documents/Subject%20Groups/Safety_ Loss_Prevention/Hazards%20Archive/XVIII/XVIII-Paper- 32.pdf
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Kennepohl D. (2015). Conversion of Petroleum: Pyrolysis. Chemistry Libretexts. Retrieved from https://chem.libretexts.org/Textbook_Maps/Organic_Chemistry_Textbook_Maps/Ma
p%3A_Organic_Chemistry_(Vollhardt_and_Schore)/03._Reactions_of_Alkanes%3A
_BondDissociation_Energies%2C_Radical_Halogenation%2C_and_Relative_Reactiv
ity/3-03_Conversion_of_Petroleum%3A_Pyrolysis
Liaw, H. J., & Chiu, Y. Y. (2006). A general model for predicting the flash point of miscible
mixtures. Journal of hazardous materials, 137 (1), 38-46.
NIIR Board of Consultants & Engineers (2015). Modern Technology Of Petroleum, Greases, Lubricants & Petro Chemicals. 2nd ed. Delhi, India: Publication Division, National
Institute of Industrial Research, p.470. Occupational Safety and Health Administration (OSHA) (n.d.). Occupational Safety and Health Standards - Hazardous Materials - Flammable Liquids . USA: OSHA.
Rajput, R. (2010). Thermal Engineering. 8th ed. Boston, USA: Laxmi Publications (P) Ltd, pp.495-496. Raju, K. (2014). Chemical Process Industry Safety . New Delhi: McGraw Hill. Rekus, J. (1994). Complete confined spaces handbook . Boca Raton: Lewis Publishers, p.37. Torbacke, M., Kassman R., A. and Kassfeldt, E. (2014). Lubricants: Introduction to Properties and Performance . 1st ed. New Delhi: John Wiley & Sons, p.145.
U.S. Oil & Refining Co., (2008). Residual Fuel Oil. [Material Safety Data Sheet]. Retrieved from
http://www.usor.com/files/pdf/4/940.pdf
6.0 Appendix Sample calculations:
Expected flashpoints are calculated by the formula:
1 100% ℎ 100% ℎ Example: 50% kerosene and 50% diesel mixture =
= 65.9
.5 .5 + 53.3 86.3
o
14
