Ethanol in Gasoline Analysis by Gas Chromatography and Infrared Spectroscopy
Introduction:
In the constantly developing economy, gasoline has become an important resource used worldwide and in everyday life. Gasoline serves as the main fuel source of both private and industrial vehicles that allow a majority of the world to move from place to place. However, as the demand for gasoline increases, the supply of oil decreases and pure gasoline is hard to come by. On average, the gasoline purchased at a gas station consists of approximately 90% gasoline, composed of hydrocarbons, and 10% ethanol. Gasoline is not necessarily a pure substance, but instead a combination hydrocarbons ranging from four to 12 carbons. Ethanol functions as an additive
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Once the liquid has become vapor, a carrier gas can be used to move it down a charged, polar, column. In this experiment, the carrier as serves as the mobile phase and the stationary phase is the column. A flame ionization detector is part of the machine and can detect ethanol by producing a signal that correlates to the ions produced after the fluid entering the column, also known as eluent, is burned by using H2 and air. The mixed compounds in gasoline exiting the column, also known as eluate, will reach the detector at different times. This process aids in the identification of the ethanol peak by providing retention time. Whenever a gas interacts with the stationary phase its progression through the column slows down and reaches the detector later. The gas continues moving forward due to the mobile phase, which urges it to move on. The detector will show many peaks due to the amount of hydrocarbons in gasoline. With the peaks, the detector will also include retention time and peak area which can be used in the process of distinguishing compounds and ethanol identification. The alcohol group on ethanol makes it stay in the column longer due to charge interactions, and thus ethanol takes longer to leave the column. By providing the different times molecules move through the charged column, gas chromatography can be used to identify and determine the amount of ethanol in gasoline. The signals …show more content…
The FTIR spectrometer is a sensitive machine that utilizes light to collect an IR range of emission/absorption values of gases, liquids, or solids. When molecules absorb photons they become excited and reach a higher energy state, and alternatively when a molecule emits a photon the energy given off represents the amount of energy the molecules fall by. This technique can also be to analyze the percent ethanol present in gasoline. The OH group present in the structure of ethanol can help distinguish it from the hydrocarbons in gasoline since it absorbs at around 3500-3000 cm-1 and would form a peak within that range. Another peak of interest would be the one formed by the C-O bond in ethanol, which can be seen at approximately 1200 cm-1. The other C-H groups present in the sample of gasoline would all absorb around the same range, and will form peaks at in the same area. Thus the presence of an OH group and CO bound are determining factors in identifying ethanol and analyzing its percentage in gasoline. The information gathered from the FTIR spectrometer such as peak area, can be used along with the standard addition values to plot a linear graph and derive the amount of starting ethanol in the gasoline sample by setting the equation of the line equal to zero and solving for
The boiling point of the product was conducted with the silicone oil. Lastly, for each chemical test, three test tubes were prepared with 2-methylcyclohexanol, the product, and 1-decene in each test tube, and a drop of the reagent were added to test tubes. The percent yield was calculated to be 74.8% with 12.6g of the product obtained. This result showed that most of 2-methylcyclohexanol was successfully dehydrated and produced the product. The loss of the product could be due to the incomplete reaction or distillation and through washing and extraction of the product. The boiling point range resulted as 112oC to 118oC. This boiling point range revealed that it is acceptable because the literature boiling point range included possible products, which are 1-methylcyclohexene, 3-methylcyclohexene, and methylenecyclohexane, are 110 to 111oC, 104oC, and 102 to 103 oC. For the results of IR spectroscopy, 2-methylcyclocahnol showed peaks at 3300 cm-1 and 2930 cm-1, which indicated the presence of alcohol and alkane functional group. Then, the peak from the product showed the same peak at 2930 cm-1 but the absence of the other peak, which indicated the absence of the alcohol
As the components of the sample were eluted from the column they were passed over a detector which determines the quantity present and plots a peak on a chromatogram at a specific retention time.
In this experiment my lab partner and I collected an unknown sample (sample A) and performed a series of tests and analyses to determine the chemical composition of the unknown. One of our learning goals was to practice performing the basics of analyzing an unknown; this entails measuring boiling point, melting point, and noting its physical properties (color, smell, etc.) In addition to this, we also practiced reading basic spectra, looking at and interpreting test results, synthesizing derivatives of our unknown, and testing the melting point of said derivatives to help us further identify our unknown.
The fuels are Ethanol, Propanol, Propan-2-ol. Butanol and Butan-2-ol. Setting up the practicals. Because there are some restrictions on the time we are going to have to perform the experiment, we are first going to find out a set up. that would allow us to produce definite results quickly.
The molar absorption coefficient can be found in an absorption spectrum. The absorption spectra is generate...
Detection of ammonia can be done using gas sensors. Examples of different application areas of ammonia gas sensing are; environmental monitoring, medical diagnostics, chemical laboratories and detection of ammonia in portable water and wastewater (Timmer et al., 2005). High concentrations of ammonia are easy to detect while for very low concentrations we require different gas sensors operating at different sensing principles. Ammonia gas sensors operate at different temperatures each having a specific detection limit range and response time to measure the ppm and sub-ppm concentrations rapidly. Commercial ammonia sensors make use of different techniques for ammonia detection and can be classified as metal oxide sensors, conducting polymer detectors, catalytic ammonia sensors and optical sensors. The ammonia gas sensors should be considered on basis of cost, maintenance, installation and most importantly specific sensors for the suitable application.
This is so I can calculate the mass which is lost in each alcohol. The spirit burner and alcohol I am using is on a brick under a tripod. On the tripod I placed a clay pipe triangle which holds a beaker containing 100ml of water. Light the spirit burner and stir the water with the thermometer constantly. When the temperature has risen to 30oC, I quickly place the top back on the spirit burner.
This software enables you to simulate experiments. This means that I am able to quickly carry out experiments to help in planning for my investigation. ---------------------------------------------------------------------- Alcohol Temperature Increase (oC) Mass of burner before exp. (g) Mass of burner after exp.
Based on the observed melting point range, the sample of Benzoic Acid was pure. The melting point range of the product read 122.5°C -123.2°C. The melting point fell within the melting point range of pure Benzoic Acid (121°C – 125°C), indicating both products are similar to one another. The melting point range of the sample was also very narrow (<1°C), indicating the sample was not comprised of any major impurities. Based on the observed melting point range, the sample of 2-naphthol was relatively pure. The sample’s melting point range (121.3°C – 122.6°C) was slightly below the range of pure 2-naphthol (123°C – 124°C), indicating the possibility of impurities. Yet, the melting point range of the sample was very narrow (≅1°C), indicating the sample was not comprised of any major impurities. Based on the observed melting point range, the sample of 1,4 – dimethoxybenzene was very impure. The sample’s melting point range (116.5°C – 120.9°C) was much higher than pure 1-4 dimethoxybenzene (58°C – 60°C), indicating major impurities within the sample. The wide observed melting point range also indicates a depressed melting point, leading to the conclusion that the compound is
Once reaching a constant mass after driving of the excess diethyl ether, the crude product had a mass of 0.327grams and a high percent yield of 97.8%. During the first TLC examination of the crude product it was found to have 3 spots on the plate, biphenyl, benzaldehyde, and benzhydrol with Rf values of 0.68, 0.36, and 0.10 respectively. It was expected to see benzhydrol, the product, and biphenyl, the impurity, on the plate, but the presence of benzaldehyde was telling that not all of the starting material had been consumed during
The working begins with an auto-sampler which picks up a definite amount of sample as programmed from the defined tube and passes in to the pump wherein it is mixed with the mobile phase in definite proportion. This is followed by entry of the mixture into the column under high pressure which aids in separation. The individual analytes in the mixture will interact with the stationary phase and finally be eluted out at a definite retention time. The retention time of each eluting component is recorded and based on this data the output is displayed in the graphical format. Peaks are seen on the graph and each peak corresponds to a particular component in the mixture, while the area under the curve of the peak denotes the concentration of the analyte. The higher the number of peaks, more is the number of analytes present in the
Ethanol production, either by dry or the wet method, creates by-products, which then are used exte...
The peak of on the electromagnetic spectrum shows the type of the atmospheric composition present in the atmosphere. However, infrared absorption spectroscopy does not show precisely the percentage of the compound present in the atmosphere. Another limitation of using this instrument is scientists are unable to trace the climate in the past as infrared absorption method was discovered in the 1800s. Therefore, this measurement limit scientist to analyse the climate change from 1800 to recent. For example, there will be a higher peak for methane in the data shown recently compared to the measurement done in the past. This suggests that there is a change in the amount of methane gas present in the atmosphere which has led to a discussion of climate
A refractometer is an optical device that is used to measure the optical density or refractive index of a substance. Refractive index is a dimensionless number that describes how light, or any other radiation is bent as it moves through a medium. It is the ratio of light’s velocity in a vacuum (n=1) to its velocity in the sample. The greater the increase in optical density or refractive index, the greater the speed of light is reduced in a solid, gas or solution. A refractometer measures the refractive index of liquids, gases and translucent solids like gemstones. There are four main types of refractometers: traditional handheld refractometers, digital handheld refractometers, laboratory or Abbe refractometers, and inline process refractometers, (Wikipedia - Refractometers). Scientists often use refractometers to measure the refractive index when studying the physical properties of different solids and liquids. Bench and handheld refractometers are usually used for more practical purposes, for example to measure the concentration of a dissolved substance.
The purpose of this experiment is to compare the processes of distillation and fractional distillation to discover which procedure enables a more pure sample of ethanol to be collected from an ethanol/water mixture.