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Specialty Chemistry Forums => Chemical Engineering Forum => Topic started by: kaimynas on May 29, 2018, 05:22:20 PM

Title: Chemistry theory on biomass combustion
Post by: kaimynas on May 29, 2018, 05:22:20 PM

So hey, i'm making a computational fluid dynamics simulation where theres a biomass furnace in which there are 2 inlets, air and biomass(in my case Birch wood/hardwood chips/wheat straw pellets) and i need some theory about the chemical reactions happening in the combustion. I don't need very hard reactions, just really some basic or intermediate ones. So does anyone have a link or a paper where i can find chemical reactions happening in combustion. Thank you very much.

Title: Re: Chemistry theory on biomass combustion
Post by: kaimynas on May 29, 2018, 05:27:29 PM

By the way might be something in direction of CO2, H2O, NO and how ash is formed. But not necessary

Title: Re: Chemistry theory on biomass combustion
Post by: Enthalpy on May 30, 2018, 06:00:18 AM

In combustion in air, the amount of nitrogen oxides is tiny. Important for our health, but negligible for streaming, heat amount and so on.

N₂ from air stays essentially untouched. The products are CO₂ (no CO under adequate combustion conditions) and H₂0, plus ash that may stay in place or fly with the fumes.

The difficult part is that you generally ignore the detailed composition of the combustible. You don't need too many details neither: usually, only the proportions of C, H O, N are given - and P, S etc if you care about pollutants - plus a heating value. Double-check if the units are moles% or mass%.

The combustion takes O₂ from air and produces CO₂ and H₂O BUT

• It never suppresses all the O₂ because CO would begin to appear, so the fire is tuned to avoid it;
• The combustible brings oxygen, don't forget! For instance cellulose is a C_n(H₂O)_m, where only C takes oxygen to burn;
• The combustible contains humidity, and not little. Double check whether the composition includes it.

Title: Re: Chemistry theory on biomass combustion
Post by: kaimynas on May 31, 2018, 09:04:49 AM

I need chemical reactions

Title: Re: Chemistry theory on biomass combustion
Post by: billnotgatez on May 31, 2018, 03:21:37 PM

You might want to read our forum rules again.
Click on the link near the top center of the forum page.
Forum Rules: Read This Before Posting.
http://www.chemicalforums.com/index.php?topic=65859.0 (http://www.chemicalforums.com/index.php?topic=65859.0)

You might also want to do some outside reading like WIKI
https://en.wikipedia.org/wiki/Combustion
Or do a GOOGLE on
biomass combustion

Then you can post a question that on what you do not understand.

Title: Re: Chemistry theory on biomass combustion
Post by: Enthalpy on June 01, 2018, 08:33:48 AM

Quote from: kaimynas on May 31, 2018, 09:04:49 AM

I need chemical reactions.

Alas, that's impossible. Combustion of wood in air is not simple enough for that. You'll have to invest your time in the question.