/ News & Press / Video / √ Petroleum Refining - Crude Oil - Production of Materials - Petrochemical - Chemistry-
√ Petroleum Refining - Crude Oil - Production of Materials - Petrochemical - Chemistry-
WEBVTT Kind: captions Language: en
00:00:11.670 hi everyone today we start a new topic 00:00:14.73000:00:14.740 which is called the production of 00:00:16.04900:00:16.059 materials and this is one of three core 00:00:18.32900:00:18.339 topics for HSC chemistry now we as 00:00:22.05000:00:22.060 humans in the past have sought our 00:00:23.84900:00:23.859 natural environment for all of our needs 00:00:25.40900:00:25.419 such as food shelter and clothing but as 00:00:29.46000:00:29.470 we've evolved and wanted bigger and 00:00:31.20000:00:31.210 better things we've needed new materials 00:00:33.12000:00:33.130 to keep up with our evolution and this 00:00:35.58000:00:35.590 topic is describing how we find these 00:00:38.10000:00:38.110 new materials and how we utilize them 00:00:40.53000:00:40.540 and refine them for our day-to-day needs 00:00:43.82000:00:43.830 so let's start by looking at petroleum 00:00:46.29000:00:46.300 refining here we have a petroleum 00:00:48.51000:00:48.520 refinery and these are found all over 00:00:50.43000:00:50.440 the world I'm sure you've seen one as 00:00:52.46000:00:52.470 you can see it is a very large scale 00:00:55.44000:00:55.450 process and the reason for this is that 00:00:57.87000:00:57.880 we need the products that are coming out 00:00:59.81900:00:59.829 of this refinery because humans are big 00:01:02.46000:01:02.470 consumers of many things and therefore 00:01:05.18900:01:05.199 it has to be a large-scale process now 00:01:08.39900:01:08.409 what goes into a petroleum refinery we 00:01:11.60900:01:11.619 start by looking at fossil fuels 00:01:13.16900:01:13.179 now all fossil fuels are hydrocarbon 00:01:15.98900:01:15.999 based compounds and this means that they 00:01:18.33000:01:18.340 have to contain carbon and hydrogen 00:01:22.24900:01:22.259 they combust in air and oxygen which 00:01:24.84000:01:24.850 means they can be burnt and by doing so 00:01:26.94000:01:26.950 they release energy and this energy we 00:01:30.30000:01:30.310 utilize for our needs such as 00:01:32.52000:01:32.530 electricity so there are three main 00:01:36.02900:01:36.039 fossil fuels the first of which is coal 00:01:38.92900:01:38.939 now coal generates electricity in power 00:01:42.20900:01:42.219 plants such as this one here now the 00:01:44.94000:01:44.950 majority of our domestic and industrial 00:01:47.06900:01:47.079 electricity actually comes from coal 00:01:49.46900:01:49.479 power plants but the problem with these 00:01:51.59900:01:51.609 as you can see is that it produces a lot 00:01:54.62900:01:54.639 of pollution the second type of fossil 00:01:58.26000:01:58.270 fuel is natural gas it has many many 00:02:01.52900:02:01.539 applications 00:02:03.01000:02:03.020 and most homes in Australia not all but 00:02:06.13000:02:06.140 most have natural gas for their cooking 00:02:08.10900:02:08.119 and for their heating the third one is 00:02:12.00900:02:12.019 petroleum which we'll be talking about 00:02:13.86900:02:13.879 today 00:02:14.64000:02:14.650 now petroleum is the fuel for Transport 00:02:17.77000:02:17.780 for our cars trucks boats planes all 00:02:20.38000:02:20.390 sorts of things it's also the raw 00:02:22.69000:02:22.700 material for the petrochemical industry 00:02:24.19000:02:24.200 and there are many things produced by 00:02:26.47000:02:26.480 the petrochemical industry such as 00:02:28.57000:02:28.580 plastics so let's look at how to refine 00:02:32.71000:02:32.720 petroleum first of all crude oil we get 00:02:36.61000:02:36.620 crude oil what's in crude oil now 00:02:39.13000:02:39.140 petroleum or crude oil is a mixture of 00:02:42.10000:02:42.110 different hydrocarbon compounds now 00:02:44.41000:02:44.420 they're all hydrocarbon compounds so as 00:02:46.99000:02:47.000 you can see from the diagram the 00:02:48.78900:02:48.799 majority is gasoline which we call 00:02:51.16000:02:51.170 petrol in the United States they call it 00:02:53.53000:02:53.540 gasoline there's quite a bit of diesel 00:02:55.96000:02:55.970 which we use for diesel cars and trucks 00:02:57.94000:02:57.950 some jet fuel heavy fuel oil and other 00:03:01.47900:03:01.489 products now we have to separate these 00:03:04.21000:03:04.220 for their uses so we get the petroleum 00:03:06.30900:03:06.319 but we can't just use petroleum and put 00:03:08.34900:03:08.359 it in a car it doesn't work like that we 00:03:10.44900:03:10.459 need to separate them for specific uses 00:03:12.96000:03:12.970 so how do we do that what we know is 00:03:16.93000:03:16.940 that each fraction has different boiling 00:03:19.47900:03:19.489 points and it's this physical property 00:03:22.50900:03:22.519 of different boiling points that we 00:03:24.43000:03:24.440 utilize to separate the different 00:03:26.44000:03:26.450 fractions to do that we use something 00:03:29.41000:03:29.420 called fractional distillation and this 00:03:31.83900:03:31.849 is quite an important part of this topic 00:03:33.87900:03:33.889 for you to learn so looking at 00:03:36.84900:03:36.859 fractional distillation as I touched on 00:03:39.37000:03:39.380 it's based on different boiling points 00:03:41.28900:03:41.299 of the fractions we're shorter chains 00:03:45.25000:03:45.260 will have a lower boiling point such as 00:03:47.58900:03:47.599 this chain here this is propane so it 00:03:50.77000:03:50.780 has three carbons so the prefix is pro 00:03:54.19000:03:54.200 and it's now cane which means it only 00:03:58.30000:03:58.310 has single bonds so this is propane and 00:04:00.99000:04:01.000 it has a lower boiling point longer 00:04:04.83900:04:04.849 chains such as this one which is octane 00:04:07.37900:04:07.389 1 2 3 4 5 6 7 8 carbons 00:04:12.34000:04:12.350 therefore the prefix is ox 00:04:14.92000:04:14.930 it's an alkane so it's octane longer 00:04:17.92000:04:17.930 chains have a higher boiling point and 00:04:20.11000:04:20.120 you'll need to remember this for this 00:04:21.99900:04:22.009 section of the topic so looking at a 00:04:25.27000:04:25.280 fractional distillation column this is a 00:04:28.15000:04:28.160 quite a crude diagram but if you imagine 00:04:30.70000:04:30.710 a fractional distillation column excuse 00:04:33.64000:04:33.650 me in industry these things are 00:04:36.21900:04:36.229 absolutely massive you could imagine 00:04:37.84000:04:37.850 maybe the size of a silo they're very 00:04:40.60000:04:40.610 very large what happens is crude oil is 00:04:43.54000:04:43.550 brought into the fractional distillation 00:04:45.87900:04:45.889 column and it's then heated up shorter 00:04:50.68000:04:50.690 chain fractions because we just touched 00:04:52.62900:04:52.639 on they have a lower boiling point the 00:04:55.39000:04:55.400 shorter chain fractions will then rise 00:04:57.21000:04:57.220 so fractions up here like refinery gas 00:05:00.31000:05:00.320 and petrol with lower boiling points 00:05:04.02900:05:04.039 will rise and therefore on the flip side 00:05:07.00000:05:07.010 the longer chains will condense lower 00:05:11.08000:05:11.090 down on the column with a higher boiling 00:05:13.54000:05:13.550 point so if you can keep in mind that 00:05:17.29000:05:17.300 the shorter the chain the higher up the 00:05:19.93000:05:19.940 column and the lower the boiling point 00:05:21.96900:05:21.979 and the opposite for longer chains so 00:05:26.46900:05:26.479 what happens is we then collect these 00:05:28.06000:05:28.070 fractions as you can see these are a few 00:05:31.18000:05:31.190 examples now there's more than just in 00:05:33.39900:05:33.409 this diagram there are many things that 00:05:35.11000:05:35.120 come off from petroleum these are just a 00:05:38.08000:05:38.090 few examples petrol naphtha which is 00:05:40.39000:05:40.400 used for making chemicals diesel oil the 00:05:44.08000:05:44.090 separate fractions will come off and we 00:05:46.00000:05:46.010 collect them at different boiling points 00:05:47.46900:05:47.479 so they'll be pure not just one big heap 00:05:50.26000:05:50.270 of everything together now around the 00:05:54.39900:05:54.409 world the composition of the fractions 00:05:55.96000:05:55.970 will vary depending on where the crude 00:05:57.79000:05:57.800 oil is mined so for example if the crude 00:06:01.02900:06:01.039 oil was mined in North Queensland in 00:06:02.77000:06:02.780 Australia it would have a very different 00:06:04.83900:06:04.849 composition to crude oil and overseas 00:06:07.45000:06:07.460 for example in the Gulf of Mexico in the 00:06:09.76000:06:09.770 United States 00:06:11.49000:06:11.500 so that now sums up our theory part of 00:06:14.46000:06:14.470 this section so just to remind you of 00:06:17.19000:06:17.200 what we've spoken about today's lesson 00:06:19.29000:06:19.300 was mostly about refining petroleum and 00:06:21.39000:06:21.400 the use of fractional distillation to 00:06:24.15000:06:24.160 separate different products from one 00:06:26.85000:06:26.860 crude oil product and the way we do this 00:06:30.39000:06:30.400 is by using the physical property of 00:06:32.55000:06:32.560 boiling point so try to remember that 00:06:35.19000:06:35.200 the smaller the higher up the column and 00:06:38.19000:06:38.200 the lower the boiling point the longer 00:06:40.44000:06:40.450 the hydrocarbon the lower down and the 00:06:43.14000:06:43.150 higher the boiling point so now let's 00:06:46.08000:06:46.090 look at some questions question one 00:06:49.23000:06:49.240 which physical property enables 00:06:51.63000:06:51.640 hydrocarbons to be separated during the 00:06:54.06000:06:54.070 process of fractional distillation well 00:06:56.88000:06:56.890 I just summed that up with boiling point 00:06:59.34000:06:59.350 that's right so back to our diagram once 00:07:03.18000:07:03.190 again as I said the smaller the 00:07:06.75000:07:06.760 hydrocarbon compound the higher up on 00:07:09.75000:07:09.760 the column and the lower the boiling 00:07:11.43000:07:11.440 point the larger the hydrocarbon the 00:07:16.35000:07:16.360 lower down the column it will condense 00:07:17.76000:07:17.770 and the higher the boiling point now 00:07:21.65000:07:21.660 just as another point to note when we 00:07:24.87000:07:24.880 take things off a fractional 00:07:26.25000:07:26.260 distillation column we call it Ellucian 00:07:31.43000:07:31.440 so Ellucian basically means when a 00:07:35.10000:07:35.110 physical when we use the physical 00:07:36.54000:07:36.550 property of boiling point when something 00:07:38.40000:07:38.410 comes off at a different level we say 00:07:41.07000:07:41.080 that it alludes or comes off a bit like 00:07:44.55000:07:44.560 water out of a tap 00:07:50.13000:07:50.140 so now remembering this question this 00:07:55.24000:07:55.250 will help us for the next question 00:07:56.80000:07:56.810 so remember boiling point and the 00:07:59.05000:07:59.060 different fractions will condense at 00:08:01.42000:08:01.430 different stages so to recap longer 00:08:05.14000:08:05.150 chains higher boiling point lower down 00:08:07.60000:08:07.610 the column and of course shorter chains 00:08:12.18000:08:12.190 lower boiling points they will condense 00:08:14.92000:08:14.930 higher up the column 00:08:17.10000:08:17.110 so just to recap if we had Ethan for 00:08:21.76000:08:21.770 example I'll just draw that over here 00:08:24.31000:08:24.320 just so you can see the answers if I had 00:08:27.43000:08:27.440 Ethan for example which is c2h6 00:08:31.12000:08:31.130 on a very small scale column in a 00:08:34.57000:08:34.580 laboratory for example and I also had 00:08:37.57000:08:37.580 let's say hexane with six carbons one 00:08:41.23000:08:41.240 two three four five six hexane just 00:08:47.65000:08:47.660 imagine for me that these are all 00:08:48.94000:08:48.950 hydrogen's then you could imagine that 00:08:52.08000:08:52.090 Ethan would elute higher up the column 00:08:55.27000:08:55.280 and hexane would alert lower down the 00:08:57.88000:08:57.890 column longer chain lower down the 00:09:00.19000:09:00.200 column so that's question one now we'll 00:09:03.25000:09:03.260 move on to question two what types of 00:09:07.63000:09:07.640 intermolecular forces exist between 00:09:09.52000:09:09.530 hydrocarbon molecules and explain the 00:09:12.16000:09:12.170 origin of these forces the answer to 00:09:15.46000:09:15.470 that is weak dispersion forces and weak 00:09:18.70000:09:18.710 being the optimal word because 00:09:20.94000:09:20.950 hydrocarbons are actually nonpolar which 00:09:23.56000:09:23.570 means they don't have an inherent charge 00:09:25.18000:09:25.190 charge excuse me by themselves but what 00:09:28.78000:09:28.790 happens is they will have a temporary 00:09:31.30000:09:31.310 dipole what's called a temporary dipole 00:09:33.69000:09:33.700 now these are vacillating or changing 00:09:36.76000:09:36.770 and moving instantaneous charges at 00:09:39.34000:09:39.350 either ends and this creates temporary 00:09:42.10000:09:42.110 dipoles so looking at our diagram if we 00:09:45.37000:09:45.380 imagine that this is one hydrocarbon 00:09:47.32000:09:47.330 molecule on the Left let's imagine it's 00:09:49.75000:09:49.760 by itself for now pretend that one's not 00:09:52.00000:09:52.010 there these symbols here are symbols for 00:09:55.51000:09:55.520 Delta which means slight 00:09:58.18000:09:58.190 so we have a slight Delta negative 00:10:00.75900:10:00.769 slight negative charge on the left and a 00:10:03.51900:10:03.529 slight positive charge on the right and 00:10:05.25900:10:05.269 that's an original temporary dipole so 00:10:08.31900:10:08.329 remember these dipoles can change and 00:10:10.03000:10:10.040 they are always changing now let's 00:10:12.28000:10:12.290 imagine we bring in a second molecule 00:10:14.12900:10:14.139 what happens is it will have an induced 00:10:17.91000:10:17.920 temporary charge now because this side 00:10:20.67900:10:20.689 of the molecule is positive it will 00:10:23.23000:10:23.240 therefore have an induced negative or 00:10:25.80900:10:25.819 opposite charge induced in it so that 00:10:31.15000:10:31.160 therefore now what we have in between 00:10:32.65000:10:32.660 these two molecules are weak dispersion 00:10:36.22000:10:36.230 forces and there's a weak attraction 00:10:37.92900:10:37.939 there so these two will actually come 00:10:40.15000:10:40.160 into contact with each other and come 00:10:41.82900:10:41.839 very close but remember that they're 00:10:44.11000:10:44.120 very very weak now the instantaneous 00:10:47.98000:10:47.990 dipoles as I said they're weak and the 00:10:51.75900:10:51.769 original dipole will induce a dipole in 00:10:55.42000:10:55.430 a neighboring molecule so just think if 00:10:57.85000:10:57.860 I had a molecule over here and let's 00:11:01.99000:11:02.000 swap up the charges let's say that it 00:11:03.79000:11:03.800 had a delta positive on the left and a 00:11:06.63900:11:06.649 delta negative on the right so the 00:11:08.53000:11:08.540 opposite of that and then this molecule 00:11:10.96000:11:10.970 comes running in this will induce a 00:11:14.59000:11:14.600 temporary charge here of Delta positive 00:11:17.07900:11:17.089 because these two dispersion forces or 00:11:20.80000:11:20.810 charges will always be opposite and 00:11:23.19900:11:23.209 therefore there's a weak attraction 00:11:25.47000:11:25.480 excuse me a weak attraction occurring 00:11:27.97000:11:27.980 between these two molecules so the weak 00:11:31.78000:11:31.790 dipoles oppositely charged they'll 00:11:34.74900:11:34.759 attract each other and form dispersion 00:11:37.12000:11:37.130 forces 00:11:37.62900:11:37.639 so to recap what types of intermolecular 00:11:40.66000:11:40.670 forces occur between hydrocarbon 00:11:43.09000:11:43.100 molecules weak dispersion forces okay so 00:11:47.37900:11:47.389 temporary dipoles will occur and if 00:11:51.97000:11:51.980 another molecule comes in 00:11:58.39000:11:58.400 Delta negative side Delta negative Delta 00:12:01.15000:12:01.160 positive Delta negative Delta positive 00:12:03.76000:12:03.770 you'll have a weak attraction between 00:12:05.68000:12:05.690 the Soumya mall excuse me molecules okay 00:12:13.15000:12:13.160 now question one and question two 00:12:15.58000:12:15.590 talking about boiling point and 00:12:17.32000:12:17.330 dispersion forces are going to help us 00:12:20.50000:12:20.510 in answering question three so if we put 00:12:23.23000:12:23.240 all that information together and look 00:12:25.06000:12:25.070 at question three explain why the 00:12:27.88000:12:27.890 melting point and the boiling point of 00:12:29.77000:12:29.780 alkanes increase as the size of the 00:12:32.83000:12:32.840 molecule increases well if you increase 00:12:36.73000:12:36.740 the mill excuse me molecular mass in 00:12:38.98000:12:38.990 large molecules it causes greater 00:12:41.26000:12:41.270 dispersion forces because there is a 00:12:43.75000:12:43.760 greater number of electrons so this 00:12:46.78000:12:46.790 temporary dipole will be stronger or 00:12:49.42000:12:49.430 relatively stronger in molecules that 00:12:56.02000:12:56.030 are larger so if you think going back to 00:12:59.05000:12:59.060 our friend Ethan if we think about 00:13:01.48000:13:01.490 ethane c2h6 is two carbon atoms if we 00:13:10.57000:13:10.580 think about once again our friend hexane 00:13:12.94000:13:12.950 one two three four five six 00:13:18.75000:13:18.760 hydrogen hydrogen hydrogen more carbons 00:13:22.30000:13:22.310 means more electrons means that if we're 00:13:26.07900:13:26.089 thinking about our dipoles okay the 00:13:31.51000:13:31.520 dipoles are going to be greater because 00:13:32.92000:13:32.930 there's more electrons so this Delta 00:13:35.05000:13:35.060 negative here and Delta positive here 00:13:37.63000:13:37.640 will be relatively greater than the 00:13:40.99000:13:41.000 Delta positive here and the Delta 00:13:43.18000:13:43.190 negative there and therefore when the 00:13:46.66000:13:46.670 two molecules come into contact as I 00:13:48.97000:13:48.980 said we've got dispersion forces between 00:13:50.94900:13:50.959 the two molecules to take these 00:13:53.23000:13:53.240 molecules apart and change their state 00:13:55.24000:13:55.250 or to boil them or to melt them you need 00:13:58.60000:13:58.610 more energy to take these molecules away 00:14:01.54000:14:01.550 from each other because the forces are 00:14:03.13000:14:03.140 greater 00:14:03.51900:14:03.529 so just remember here why is the melting 00:14:06.97000:14:06.980 point and boiling point why does it 00:14:09.04000:14:09.050 increase as the molecule increases 00:14:10.62000:14:10.630 because there's more electrons therefore 00:14:13.18000:14:13.190 the dispersion forces are going to be 00:14:15.57900:14:15.589 relatively greater than in a smaller 00:14:17.71000:14:17.720 molecule and so to boil or melt these 00:14:21.82000:14:21.830 substances requires more energy 00:14:24.19000:14:24.200 therefore higher melting point and 00:14:26.68000:14:26.690 higher boiling point so now we'll move 00:14:31.51000:14:31.520 on to question four describe the 00:14:34.81000:14:34.820 composition of petroleum petroleum 00:14:37.60000:14:37.610 consists of crude oil and natural gas it 00:14:42.87000:14:42.880 is a mixture of up to 300 different 00:14:45.43000:14:45.440 hydrocarbons as well as sulfur and 00:14:48.01000:14:48.020 nitrogen compounds and in these 300 00:14:50.98000:14:50.990 hydrocarbons 00:14:51.97000:14:51.980 it also contains what we call cyclo 00:14:54.55000:14:54.560 alkanes which are alkanes instead of 00:14:58.84000:14:58.850 being in a line like this they're 00:15:01.56900:15:01.579 actually in rings like this one here 00:15:04.06000:15:04.070 which is a basic diagram for cyclohexane 00:15:06.96000:15:06.970 with its hydrogen's of course 00:15:10.30000:15:10.310 now crude oil to start with as I said 00:15:14.15000:15:14.160 there's two parts to this there's crude 00:15:15.98000:15:15.990 oil and natural gas thinking about crude 00:15:18.31900:15:18.329 oil the majority of crude oil is made up 00:15:21.82900:15:21.839 of alkanes and alkenes from C 1 to C 25 00:15:26.72000:15:26.730 and if you remember alkanes have only 00:15:29.44900:15:29.459 single bonds alkenes have at least one 00:15:32.42000:15:32.430 double bond and C 1 to C 25 denotes that 00:15:36.23000:15:36.240 there's either one carbon all the way up 00:15:38.32900:15:38.339 to 25 carbons now natural gas on the 00:15:44.21000:15:44.220 other hand the majority of natural gas 00:15:46.28000:15:46.290 is made up of methane gas which is 00:15:48.80000:15:48.810 between 75 and 90 percent and methane is 00:15:53.21000:15:53.220 ch4 also contains some ething five to 00:15:57.86000:15:57.870 ten percent which is c2h6 and a little 00:16:02.87000:16:02.880 bit of propane and butane three to six 00:16:05.18000:16:05.190 percent which is C 3 and C 4 00:16:08.71000:16:08.720 there's also smaller amounts of other 00:16:11.03000:16:11.040 alkanes and depending on where the 00:16:14.12000:16:14.130 natural gas is mined it may contain 00:16:16.10000:16:16.110 nitrogen water vapor carbon dioxide and 00:16:19.25000:16:19.260 traces of hydrogen sulfide now the 00:16:22.25000:16:22.260 chemical formula for hydrogen sulfide is 00:16:24.85000:16:24.860 h2s and h2s is that rotten egg gas smell 00:16:28.75900:16:28.769 that I'm sure you've all smells in class 00:16:30.62000:16:30.630 before and it's really really horrible 00:16:33.07900:16:33.089 so that's not nice stuff so that's your 00:16:37.31000:16:37.320 composition of petroleum 00:16:38.75000:16:38.760 it's just remember you've got crude oil 00:16:40.25000:16:40.260 which is the majority of alkanes and 00:16:43.18900:16:43.199 alkenes from C 1 to C C 25 excuse me and 00:16:46.55000:16:46.560 on the other hand we have natural gas 00:16:48.86000:16:48.870 which the majority is methane and ethane 00:16:53.19900:16:53.209 now question 5 to finish with is 00:16:56.24000:16:56.250 petroleum renewable and what are the 00:16:58.67000:16:58.680 environmental implications well as I'm 00:17:01.91000:17:01.920 sure you all know petroleum is not 00:17:03.98000:17:03.990 renewable I think as I mentioned when we 00:17:05.99000:17:06.000 had the the coal the coal power plan up 00:17:08.78000:17:08.790 there it's not renewable and it's it's 00:17:11.32900:17:11.339 very polluting unfortunately and also 00:17:14.92900:17:14.939 unfortunately all fossil fuels are due 00:17:17.60000:17:17.610 to run out at some point they will not 00:17:19.57900:17:19.589 go forever this is why we're trying to 00:17:22.93900:17:22.949 chemists and scientists are trying to 00:17:25.01000:17:25.020 look into more renewable resources such 00:17:27.50000:17:27.510 as wind and water and those sort of 00:17:30.35000:17:30.360 things so it's not greenhouse neutral 00:17:32.89900:17:32.909 either it pollutes our environment so 00:17:36.16900:17:36.179 when the fossil fuels are taken out of 00:17:37.78900:17:37.799 the ground and burnt the carbon that was 00:17:40.46000:17:40.470 locked away under the ground is burnt 00:17:42.62000:17:42.630 and it's transferred and transformed 00:17:44.99000:17:45.000 into carbon dioxide which I'm afraid is 00:17:47.69000:17:47.700 a greenhouse gas which is not good for 00:17:49.90900:17:49.919 our environment because it may be 00:17:51.83000:17:51.840 leading to global warming so that's the 00:17:55.88000:17:55.890 end of today's topic I'll just sum up 00:17:57.95000:17:57.960 for you what we went through the main 00:18:00.20000:18:00.210 points I'd like you to take is that we 00:18:01.90900:18:01.919 talked about petroleum refining and 00:18:04.27000:18:04.280 specifically about fractional 00:18:06.40900:18:06.419 distillation and if you remember here's 00:18:09.11000:18:09.120 a very simple diagram of our fractional 00:18:11.72000:18:11.730 distillation column with our different 00:18:14.12000:18:14.130 fractions coming off and if you remember 00:18:16.54900:18:16.559 that down the bottom is higher 00:18:22.27900:18:22.289 temperatures 00:18:25.57000:18:25.580 temperatures and at the top was lower 00:18:30.44000:18:30.450 temperatures lower temperatures so the 00:18:37.01000:18:37.020 smaller the hydrocarbon the higher up 00:18:40.79000:18:40.800 the fractional distillation column it 00:18:42.32000:18:42.330 will elute or come off and the longer 00:18:45.26000:18:45.270 the hydrocarbon chain the lower down the 00:18:48.68000:18:48.690 fractional distillation column it will 00:18:50.54000:18:50.550 come off and this is due to dispersion 00:18:53.66000:18:53.670 forces so the longer the chain the more 00:18:56.93000:18:56.940 electrons negative negative negative and 00:18:59.00000:18:59.010 the more electrons the stronger those 00:19:01.22000:19:01.230 weak dispersion forces 00:19:02.60000:19:02.610 so therefore this temperature for 00:19:04.76000:19:04.770 example four hundred degrees is of 00:19:09.11000:19:09.120 course hotter at the bottom then at the 00:19:10.91000:19:10.920 top and they're the main points that I'd 00:19:13.19000:19:13.200 like you to take from today's lesson so 00:19:16.04000:19:16.050 that's all for now and thank you
Office location
Engineering company LOTUS®
Russia, Ekaterinburg, Lunacharskogo street, 240/12