Complete combustion Vs Incomplete combustion - Episode 3
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- เผยแพร่เมื่อ 28 เม.ย. 2024
- Have you ever wondered why some fires create smoke and others don't? It's all explained here.
EDIT: I probably should have used a premixed flame as the example of complete combustion rather than burning wood. But you'll get the idea :) - วิทยาศาสตร์และเทคโนโลยี
Wow! Great explanation of fire/smoke chemistry. First time I finally understand why fire lecturers are always saying smoke containers a lot of water. Thank you from an amateur fire student. Going to watch all your videos in order.
Best from Cleveland, Ohio, USA
You’re welcome! I’m glad the video helped! All the best with the study 🔥
These videos are really helpful! Thanks! Laura FF in UK
it explains why carbon rich dust in the presence of heat or flame is so dangerous. Carbon forms because not enough 02 is present... Once the concentration balance out, or enough oxygen suddenly becomes present with heat... we go to the next clip....
Good explanation.
Thanx that helps for GCSEs
Thanks for this! I'm gonna show this to my students.
Great job
Best video on this topic
Thankyou!
Best video on the subject ... great job ... thank you ...
Thanks! Glad you liked it 👍🏼
I will say you know its good moonshine when u can burn it and you can barely see the flame and theres almost no visible smoke
Ello Matt , your videos are wonderful.
Thanks! Glad you like them 🙂👍
If you want to really demonstrate the difference, the flame on your blow torch is close to complete combustion, gas stoves, jet lighters, etc, if it is a hydrocarbon, alcohol, ketone, carbohydrate or anything that contains only hydrogen, carbon and oxygen, the flame should appear clear or faint blue this is because excited hydrogen and carbon radicals have emission spectrums that mostly fall in the blue range of visible light, in complete combustion all of the material is saturated with oxygen and you get CO2 and H2O as the by-product. When incomplete combustion occurs, particles of soot in the flame fluoresce and emit light over a wider range of frequencies and the flame can look orange to yellow, if the flame is an orange/ yellow colour assuming there are no metals present, it is incomplete, whether there is a substantial amount of smoke or not and soot and carbon monoxide will be present. Complete just means that the fuel has consumed as much oxygen as it can, incomplete means that it can still technically be oxidized further, eg wood gas (carbon monoxide, soot and maybe unburned hydrocarbons or carbohydrates, alcohols, etc) will burn. The candle is producing both soot and CO, it's in small enough amounts to where lighting a few candles in the bath or for a romantic meal etc or when the power goes out, you should be fine, still I wouldn't want to be in a small room with 50 candles going!
Pyrolysis is when it is heated with very little oxygen, the material splits into smaller molecules, the "gas" you see from a candle is actually just paraffin condensing into it's liquid and solid phase in the cool air, paraffin won't burn in it's solid phase, that is why the wax doesn't ignite, just the wick where it is being boiled off, a porous material can smoulder in the solid phase if there is adequate oxygen.
Hi there,
Thankyou for you comments. You have clearly put some thought into them. Firstly I agree, the flame examples I used for the video were not the best. However, these videos a made for firefighters. A premixed flame with genuine complete combustion of the fuel is highly unusual in terms of firefighting (infact it's almost irrelevant). So I made the decision to use examples that were relevant to the people who the video was made for. I get it, This is the internet, there will always be someone out there to correct you. And you are not the first to mention that I should have used a premixed flame as an example. But that's a decision I made to help keep things in context.
Additionally, pyrolysis can occur in the total absence of oxygen or even in an atmosphere with an abundance of oxygen. It is not reliant on the presence of oxygen at all.
Hi, Matt...great job on your videos. I'm a firefighter in Canada, I specialize in Hazmat. I'm thinking of creating my own video series. Any advice you could give on getting started would be appreciated.
Hi Stuart, Thanks. I'm glad you like them. Honestly I'm still learning and making it up as I go. But one tip would be sound quality is really important. It's hard to watch videos with bad audio. A youtuber by the name of Boothjunkie has lots of videos on creating makeshift recording areas at home. I found a few of them to be useful. Other than that I just worked out a list of subjects to follow and I'm trying to make sure they make sense as I go haha
Good
Hey Matt, great video but just a quick question... why wouldn’t the the byproduct be oxidised on the incomplete combustion maybe i missed the point haha
What is meant by only receiving one oxygen sorry
Hey there, flames aren't always all that efficent and so some products are only partially oxidized e.g. carbon monoxide. Complete combustion would see it become carbon dioxide. It happens when there wasn't enough oxygen available at that point in the reaction to fully oxidize. I hope that answers your question 🙂
Hey Matt,
This is Manish from India.
I work in a most reputed fire service teaching institute in India. How to get in contact with you if I need your help sometime. Will be very grateful to learn from you.
Hi Manish, This channel is the best way to contact me. I'm always happy to try and answer questions and help out where I can 👍🏼🙂
Great but subscript the numbers in chemical formulas please.
Thanks and excellent point! 🙂👍🏼 I've started showing it correctly in the more recent videos (it was due to a lack of knowledge in the editing software and some oversight).
@@MattDavis5 Thanks, I'm using the video with my class, it's great!
Thanks! And thats nice to know! Glad you like it 👍🏼