Percent Excess Air (Combustion)

[sulaiman]

Thank you. I hope I dont fail material and energy balance tomorrow

[BaldurKhr]

I think the answer for the 100% excess air has to be 3334 moles of air, because 100%= (n-1667)/1667 => n= 1667 + 1667 =3334. Isn't it so? Nice explanation by the way, thanks!

[adrianpalencia]

A furnace is fire with coal with 72.65% C, 13% ash, 1.6% N, and 3.2% S.
The Residue in the furnace contains negligible combustible matter. The air enter the furnace at 38 degress celsius and 5 psig and 75% RH.
The stack gas leaves at 300 degress celsius with 8.4% CO2; 2.5% CO; 0.8% H2 and 10% O2. Calculate:

a. % Excess Air
b. Ultimate analysis of the coal
c. m3 of stack gas/kg of coal

[siirinsahibi]

Hi, I am planning to heat ethanol under vacuum. Will try to produce carbon nanotubes.

Is there an explosion risk? Air will be all vacuumed. In case of a small air leakage to vacuum chamber will it immediately explode?

Second question After separating carbon molecules, water will also appear in the chamber. Does water vapor and Ethanol vapor create any explosion on hot surfaces above 700C degrees?

What is the maximum air pressure I must have to prevent an explosion?
I can go down to 0.01 Bar. If there are some little amount of air remaining, can this reaction still create a big explosion?

Amount of ethanol 1 ml
Size of the tank 0, 05m3
Tank material steel 2mm thick.

There is already such a method actually but I will do it alone for the first time and have some worries that I have overseen something.

Thanks!

[AsimAli-dmgy]

how did you get 3333 for air fed I don't understand how you arrived at that number

[akashrajpoot]

Thank you very much u clear my doubt ver well

[adrianpalencia]

1. A bituminous coal has 27.15% VCM; 62.55% FC; 7.06% Ash; 0.95% S and .28% N. It has a calorific value of 32.3 MJ/kg.
The coal is fired with excess air supplied at 30 degrees celsius and 1 atm. Partial Orsat analysis reports 9.78% CO2, and 2.45% CO. Calculate:

a. % Excess Air
b. Ultimate Analysis of the coal
c. Complete analysis of the stack gas.

[dir]

is it possible if theres 0 percent of air?

[Ariniarum]

A separator is designed to remove 75% of the CO2 in flue gas (assume N2) that is fed to adsorption unit, not the fresh feed. The CO2 is removed from the bottom of the separator. The exit composition of the stream leaving the separator contains 10% CO2 and the balance is N2. a recycle stream is used, where part of the exit of the separator is recycled and unites with the fresh feed. Draw and label a process flow chart. Calculate the flow rate and compositions of all unknown streams??

[Bilal]

For percent excess, it's easier to simply multiply 2024 by 1.25 and you will get the answer.