[Music] so we're going to move into topic one thermaker now um just before we start there's always a question and it's always in there somewhere um they always say oh like how should I use today how should I study today should I take lots of notes what should I do I think the best utilization for today is if you haven't seen this stuff before so some of the fuel stuff I'm sure you will have because you will have done a bit of Head Start everyone does um but if you have only been through a few things you're going to start to see some stuff that you you haven't been over before I think the best utilization for today is to sort of sit back maybe have a notepad there and just jot down big broad points I don't want you to go through like example for this slide and write down all these dot points why one because you're going to get these slides there's no point writing this all down two because you're not going to go back to these notes you're going to go back to notes that are big broad sort of Concepts saying I need to revise this I need to look into this I need to go through um different types of fuels that's going to get you to come back to it because you want to come back here all right I need to go and do that so then you're going to go ahead and do that so but today what I say is sort of sit back just sort of take it in and just jot down some points that you think are important or some points that you want to come back to sort of like little little tick boxes to say hey I want to come back and look at that that's sort of the best way to go about the content you'll see today so we're going to start off with fuels essentially fuels can be broken into two things fuel choices and obtaining energy procure so what is a fuel a fuel is a substance that can be reacted with other substances EG oxygen leading to the release of energy that can be hardest for a specific purpose what's really important about this is that this is an explicit definition that you need to know what's going to be really annoying about this first part of fuels it's a lot of rote learning what I mean by rote learning for those who don't know what that's what it means it means you just need to memorize things it starts to feel like I always pick on the other side subjects um and I would say that it starts to feel a lot like psychology because it's just memorizing there's the first part of fuels there's not a lot of there's a lot of math and there's not a lot of sort of explicit thinking or trying to problem solve it's really just what can I remember put it back down on the page so the wording for the definition here is important because fuels you do you don't want to say fuels can be combusted you need to say the fuels can be reacted with other substances um so just a really important wording there uh as I said supposedly said in the study design and then what is renewal versus non-renewable another set of definitions which isn't explicitly asked for but has been asked before an exam um so what is renewable renewable is a resource that could be replenished by natural processes in a relatively short period of time another way of wearing this in a wording that I tended to use was um it's a natural process which can renew the fuel quicker than we utilize the fuel well it's quicker in producing than what we use it so think about if you're doing something and you're utilizing something but it's being produced quicker than you can utilize it thus you're always going to get more whereas non-renewable is the opposite as you use it it cannot be replenished in that period of time so fossil fuels for example they take thousands of years to form we can use lots of fossil fuels in a day but we can't produce lots of fossil fuels in a day it takes thousands thousands of years to to form so that's the sort of idea behind renewable and non-renewable and then we have puzzle viewers versus biases so essentially this is how you sort of break down your non-renewable so it fossil fuels derived from living matter underground for millions of years biofuels derived from plant matter it can be produced at the same rate we consuming so what are the ones you need to know these are the ones that you need to know so you need to know coal cosine gas crude oil LPG crude oil is the main one you need to know you'll know that as sort of crude oil petroleum uh Petro diesel petrolezel falls under crude oil uh biogas buyeth no biodiesel they're the three mains you want to you need to know for biofuels really important this is the one you need to know the most about so this is the one you need for the most about this one you don't need to know the most about they always will ask you to compare biodiesel with petrogenzel that's where they always ask you to compare that's just what happens and these are the things I like to ask you to compare energy content renewability environmental impacts we'll go through them so we're just going to go through each of these quickly now what's really important about these slides is I've sort of been creating these slides over the last four years so there's way too much information in them Etc and all that sort of stuff so essentially what I'm trying to say to you is that I will highlight what is most important so key Point introduced by anaerobic bacteria that decomposes organic waste so essentially what happens is you put organic waste whatever that is into this sort of big dome as you can see there it's just like a big sort of composter in a sense um and essentially there's lots of bacteria in there bacteria deal with it and they produce biogas they produce a methane type gas now what's really important about this is that it's mostly methane but it's not pure methane this is the fuel component this is the non-hill component don't worry about these values I'm just trying to explain that essentially there's a lot of methane but there's not 100 methane and then there's also Trace Amounts of other products this was asked for once about seven eight years ago and it has been asked for again so I wouldn't worry too much about it um and because it contains less methane than fossil fuel gases so calcium gas has 96 percent um methane it releases less energy because that's where the energy comes from so being less percentage is going to be less energy released and then this is the combustion equation by ethanol so this is produced from the fermentation of glucose by yeast um so essentially glucose gets fermented and it produces ethanol at CO2 um and you'll see it a lot in those sort of E10 peels so you know if you drive past I think it's United you know I don't always tend to have it um they always have E10 at the top and you always think ah their petrol is really cheap but it's not because it it's their E10 that they're advertising as their main petrol um and E10 is always cheaper because uh buy ethanol is pretty easy to produce it just doesn't have a lot of energy so E10 fuel is not as strong or as sort of fuel efficient as normal fuel that's why it's a little bit cheaper because you need more you need to fill up more often at least you don't get as much out of it um and then biodiesel this is the most important one it's produced by using plant oils or animal fats in a transestification reaction so you would get triglyceride plus methanol close to ghost diglycerol plus biodiesel and essentially this is a really ugly and big reaction right here don't worry about this right now you will learn this when you get more into food chemist the one important part of food can that you'll learn so don't worry too much about this right now but it's nice to sort of just visualize what's going on but this is most important when we get to prepare so what's really what's really important to note that the bite is or is the name so we call it a fatty acid methyl Ester or a Fame but you're always going to call it a fatty acid methyl Ester um and it's one of the most confusing parts of the course because it mixes knowledges from multiple area studies as you can see there so don't stress too much we're going to go through this in organic chem and then mainly through through cancer it's mainly going to be uniform so some disadvantages and advantages now why I've got these slides in here is because I think it's a really good way to revise this content so this content is really difficult to revise that is the reality of it um because it's rote learning it's memorization it's things like flash cards writing things down it's the only way to learn and like flashcards are pretty useless these days like to be honest the way vcar exams are being written and the way that they're being produced um flash cards are not really that useful was why do I say that it's because beta is writing exams in the way that if you memorize something you're going to get one of the four marks they want you to be able to sort of problem solve and work your way through an example cam exams are really really like that however this topic fear less so so this topic here is one of those ones where you just kind of have to memorize and so doing these tables like this so doing a table where you say all right what is the advantage and disadvantage of fossil fuel this is a biofuel and you make a totally say all right my managers are high energy content easy to release energy relatively easy to obtain extensive existing infrastructure so one of the other things about that is common sense things think of this as a common sense example this isn't something that's going to be explicitly taught to you but it's common sense we've been using fossil fuels for the last hundred years so there's lots of or like remaining infrastructure we have coal mines everywhere like those things have been built for many many years we've sort of refined that science there to a point where we're very good at obtaining fossil fuels yes it's not good for the environment it's something we've been doing forever so we already have it there whereas if you think about biofuel probably the last 20 years or the last 15 years as we've really started to push the environmentally friendly fuels and we've really tried to start dephasing or phasing out our sort of coal mines and our crude oil and all of that stuff and there's pushback everywhere but eventually it will happen but one of the things that slows that down is that we don't have the infrastructure in place we don't have the things built to produce biofuels so as you can see there it's a massive Advantage for positives disadvantages non-renewable amidst large amounts of CO2 so it's a really bad greenhouse gas lots of other things there so again more common sense things it's fairly damaging to the environment um so as you can see that doesn't really look all that great uh biofuels advantages renewable relatively carbon neutral now we'll talk about this in a second so don't worry about that terminology burns more cleanly easy to Source materials Etc disadvantages lower energy content so thus you're going to need more biofuel to get the same amount of energy out can be complicated and costly to produce can require large amounts of water to grow crops fertile land Etc so what does it mean by carbon neutral so what we say about carbon neutral is that when a plant is growing it absorbs carbon or cut via carbon dioxide so it reduces it absorbs that and then essentially what happens is when we take that plant and we produce the biofuel we produce a little bit of CO2 so we sort of say that it's offset the CO2 that was absorbed by that plant some of it is being re-released but that's okay because that plant already absorbed it so we think of that as a sort of offsetting we then transported biofuel again releases a little bit of CO2 again we like to think of that as offsetting so if this was a hundred percent we like to say this might have been like 30 this might have been like another 30 and then we say the biofuel is used and then we say the rest of the CO2 is reproduced so we say maybe like 40 might be a little bit more might be a little bit less as long as it's around that 100 percent coming in and Huntington going out as long as it's around that could be 95 going out could be 105 going out doesn't really matter if it's a little bit more a little bit less and as long as it's very close to each other we call that carbon neutral so what we say is that it's the carbon absorbed or the carbon dioxide absorbed versus the carbon dioxide released so it's complicated but you just need to know sort of how to define it in that sense there now biodiesel versus petrazole so this is the one that vikar specifically wants you to be able to discuss so we're going to talk about a couple of aspects here so the most important thing that I I think we should discuss here is sort of the shape and yes this is a little bit of organic chem but organic chem is everywhere as you can see here they look identical other than this here they have an ester Bond that is the only thing that changes them between the two my ideas will have an ester Petro diesel does not this means that this molecule here is therefore polar it also means that this molecule here has a much sort of higher boiling point um and it therefore has a higher liquid point or a higher solid point you've got to remember that this polar aspect changes everything and this is where I said those introverses intermolecular bonds that's where this is really important what is this going to have it's going to have hydrogen bonds dipole dipole bonds it's going to have all those things whereas petrolezel so they're really going to have dispersion forces it's a non-polar molecule the other thing about Pedro diesel is it produces lots of particulates and other toxins this is sort of beyond the scope of V car but essentially like petrolezel sometimes has little extra bits here and there that are quite toxic um it's just a part of what it is so therefore we say that it's quite dangerous now we discussed some other things here it says strong dipole dipoleans making it more viscous so what is viscous viscosity viscosity is a word that means thickness so I always think of viscosity as water versus honey so you think about water versus honey for the both of the cup if I pour water out of the cup it's just going to pull so it's going to get everything wet I pour honey out of a cup it's going to happen it's probably going to take a good 20 seconds to actually leave the cup it's going to be really cloggy and thick and it's going to take a while to get out there that's the difference I like to think of that as a difference of viscosity this is less viscous the water it doesn't have a lot of viscosity because it's very fluid it's very it's a liquid it moves very freely the honey is extremely viscous why because it's thick it's cloggy it clogs things up um and that's what we like to think with biodiesel versus petrolysis biodiesel is more like the honey it's thicker it is more of like a big pluggy thing and it takes it can sometimes when cooled down block things up because it becomes so much like a galley whereas Petro diesel because of its non-polar and it's weaker dispersion forces it's more like a fluid it's like a water it just flows so if you think about using these in life let's just say be Antarctic you take a cardio Antarctic a biodiesel he's going to clog up those the fuel lines because you're going to try and use it and just going to clog things up whereas petrol diesel on the other hand he's not going to clog anything up because it's extremely like a liquid so it's just going to fly so that's one of the big things we like to talk about in terms of buying these pictures yeah the other thing here as well that I think is a really really important slide here is how we compare so vcar loves to ask let's compare and it's actually one of the things that they're starting to phase out so they're going to phase this out with next study design however they say they're phasing it out every year and it's always every year in the exam you can go back to last year's I'm pretty sure there's a question asking this so how do we compare so as you can see here this is an example vehicle question it's reference to chemical structure we've just somewhat we've just sort of made it a little more summarized this but this was based off of Eco question with reference to chemical structure compare the suitability of biodies on petrolezel as fuels to power vehicles in cold environments as you can see here there's no comparison when we say Petra diesel only experiences wheat Special Forces thus it has a lower Cloud Point making it more suitable to use at low temperatures there don't worry about that point we'll discuss that in a little bit essentially what we're saying here is there's no comparison there as you can see there it just says Petra diesel is weak or Pedro diesel is weaker but it doesn't compare to what what are we comparing it to b car examiners when they read a question don't read or when they read now so they don't read the question they read your answer they kind of want you to sort of explain what you're explaining they want you to sort of say what the question was within your answer without saying all right the question was this and my answer is this you don't want to say that you want to give a bit of summary so as you can see here it says wild biodiesel experiences or dipole attractions Petra diesel only experiences a weekly dispersion force thus petroleza has a lower Cloud Point than buy it is will make it more suitable for fuels at low temperatures this is telling me what the question was the question was what is is which is more suitable at low temperatures that is what this last sentence is telling me it's summarizing things and what's really important is we mentioned both we mentioned the biodiesel we mentioned the petriles we mentioned the biodiesel again we continue to mention these things like you need to mention both explicitly and talk about product explicitly when you do a comparison question so this is a really important slide maybe take anything else today thank you