Previous in Forum: Ballistics of Flying Rock   Next in Forum: What's the Grade ST44 Equal to in API 5L Standard
Close

Comments Format:






Change Mode
Close

Subscribe to Discussion:

CR4 allows you to "subscribe" to a discussion
so that you can be notified of new comments to
the discussion via email.

Close

Rating Vote:







Add Vote
30 comments
Rate Comments: Nested
Govind Rao
Power-User
India - Member - New Member

Join Date: Jan 2009
Posts: 114

Combustion Reactions

11/10/2014 2:46 AM

Dear All,

I am a mechanical engineer who has strayed into chemical engineering. I am attaching an Xl sheet showing different combustion reactions. I am unable to understand the quantity of SO2 depicted in the sheet in various reactions, where the SO2 does not appear in the equations. Would anybody help me and explain the same the same please.

NAMEREACTIONMOLES OF O₂MOLES OF CO₂MOLES OF SO₂MOLES OF H₂O
REQUIREDFORMEDFORMEDFORMED
HYDROGENH₂ + 0.5O₂ → H₂O0.5010
CARBON MONOXIDECO + 0.5O₂ → CO₂0.5100
METHANECH₄ + 2O₂ → CO₂ + 2H₂O2120
ETHANEC₂H₆ + 3.5O₂ → 2CO₂ +3H₂O3.5230
ETHELYNEC₂H₄ + 3O₂ → 2CO₂ + 2H₂O3220
PROPANEC₃H₈ + 5O₂ → 3CO₂ + 4H₂O5340
PROPYLENEC₃H₆ +4. 5O₂ → 3CO₂ + 3H₂O4.5330
BUTANEC₄H₁ₒ +6. 5O₂ → 4CO₂ + 5H₂O6.5450
BUTYLENEC₄H₈ + 6O₂ → 4CO₂ + 4H₂O6440
PENTANEC₅H₁₂ + 8O₂ → 5CO₂ + 6H₂O8560
HYDROGEN SULFIDEH₂S + 1.5O₂ → SO₂ + H₂O1.5011
Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Good Answers:

These comments received enough positive votes to make them "good answers".

"Almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, vote them!
3
Tornado
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 21017
Good Answers: 795
#1

Re: Combustion Reactions

11/10/2014 3:01 AM

For one thing, it looks as though the SO2 and H2O columns have been reversed. I'm not too keen on fractional mols, either, but maybe that's how they do chemistry these days.

__________________
 In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply Good Answer (Score 3)
Go to Next Good Answer
Govind Rao
Power-User
India - Member - New Member

Join Date: Jan 2009
Posts: 114
#2
In reply to #1

Re: Combustion Reactions

11/10/2014 3:49 AM

I thought so ! However, let me wait till others comment
Register to Reply Score 1 for Good Answer
Go to Next "Almost" Good Answer
dhayanandhan
Guru
Engineering Fields - Mechanical Engineering - New Member

Join Date: May 2008
Location: CHENNAI, TAMIL NADU, INDIA.
Posts: 1851
Good Answers: 65
#20
In reply to #1

Re: Combustion Reactions

11/10/2014 12:05 PM

Dear Mr.Tornado,

You are right and I concur with your point. Interchanging of the column heading and data is inter-changed.

But in the last item, in the XL sheet, the last item hydrogen Sulfide, which reads as follows and I observe an error, since molecule can exist in full number. I am not sure, whether I am correct.

The Equation should read as 2H₂S + 3O₂ = 2SO₂ + 2H₂O

DHAYANANDHAN.S

The XL sheet shows as below, as found in the original posting.

HYDROGEN SULFIDEH₂S + 1.5O₂ → SO₂ + H₂O1.5011
Register to Reply
2
James Stewart
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 14331
Good Answers: 162
#27
In reply to #20

Re: Combustion Reactions

11/11/2014 10:23 AM

Dear friend: It has long been common practice in chemical equations to represent the combustion of one mole of the target reactant, and use fractional moles of oxygen (not molecules). Thus the original posting of the table is correct with the exeption of the swapped column headers for SO2 and H2O. Once the headers are swapped back (without moving the data), then it makes sense.

__________________
 If it ain't broke, don't fix it. Just build a better one.
Register to Reply Good Answer (Score 2)
No more Good Answers. Go to first "Almost" Good Answer
dhayanandhan
Guru
Engineering Fields - Mechanical Engineering - New Member

Join Date: May 2008
Location: CHENNAI, TAMIL NADU, INDIA.
Posts: 1851
Good Answers: 65
#21
In reply to #1

Re: Combustion Reactions

11/10/2014 12:17 PM

Dear r. Tornado,

In continuation to your Posting No.1 and my reply posting No.20, I for got to mention about the error that in addition to Hydrogen Sulfide, CO i.e., Carbon Monoxide Equation also chemically balanced. It should be 2C + O₂ =2CO.

Like that few equations are not correct.

DHAYANANDHAN.S
Register to Reply
Tornado
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 21017
Good Answers: 795
#26
In reply to #21

Re: Combustion Reactions

11/11/2014 7:38 AM

That could well be right. I didn't scan all the reactions for correct balance.

__________________
 In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
Noudge79
Guru

Join Date: Feb 2011
Posts: 1119
Good Answers: 11
#3

Re: Combustion Reactions

11/10/2014 3:52 AM

Simply, a mole of Sulfur (S) plus a mole of diatomic Oxygen(O2) mixed and ignited to form 1 mole of SO2

1 mole S + 1 mole O2 = 1 mole of SO2 and Wallahh! there it is, how did you pass internal combustion and Reaction of gases to become a mechanical engineer?

__________________
 " To infinity and beyond" - Buzz Lightyear
Register to Reply
Govind Rao
Power-User
India - Member - New Member

Join Date: Jan 2009
Posts: 114
#4
In reply to #3

Re: Combustion Reactions

11/10/2014 3:57 AM

Please go through the question and come back !!!!!!!
Register to Reply
Noudge79
Guru

Join Date: Feb 2011
Posts: 1119
Good Answers: 11
#5
In reply to #4

Re: Combustion Reactions

11/10/2014 3:59 AM

Who made that sheet? You copied this?

__________________
 " To infinity and beyond" - Buzz Lightyear
Register to Reply
Noudge79
Guru

Join Date: Feb 2011
Posts: 1119
Good Answers: 11
#10
In reply to #4

Re: Combustion Reactions

11/10/2014 4:41 AM

why should I, you are a funny man. I believe if these are real gases, there might be sulfur constituents not shown in the ideal reaction equation and your table corresponds to a reading of a gas analyzer.

It is your burden now. If you are a mechanical engineer, this is chicken topic.

__________________
 " To infinity and beyond" - Buzz Lightyear
Register to Reply Score 1 for Off Topic
Govind Rao
Power-User
India - Member - New Member

Join Date: Jan 2009
Posts: 114
#13
In reply to #10

Re: Combustion Reactions

11/10/2014 5:22 AM

I have already found out. Don't chicken out. You are a "guru" Tell me what's wrong in that and recast it.
Register to Reply
Govind Rao
Power-User
India - Member - New Member

Join Date: Jan 2009
Posts: 114
#6
In reply to #3

Re: Combustion Reactions

11/10/2014 4:00 AM

Learn to read the question and then comment "GURU"
Register to Reply
Noudge79
Guru

Join Date: Feb 2011
Posts: 1119
Good Answers: 11
#8
In reply to #6

Re: Combustion Reactions

11/10/2014 4:08 AM

I guess you copied and is willing to submit this assignment with that excel sheet.

At ideal gas reaction equation why is that some by products includes SO2 where in the first place, it does not exist in the reactants.

You are making your own problem here, pls. see the person you copied this from, he is just fooling you.

__________________
 " To infinity and beyond" - Buzz Lightyear
Register to Reply Off Topic (Score 3)
Govind Rao
Power-User
India - Member - New Member

Join Date: Jan 2009
Posts: 114
#9
In reply to #8

Re: Combustion Reactions

11/10/2014 4:30 AM

Recast it and post it if you know chemistry!!!
Register to Reply
stitchintime
Participant

Join Date: Nov 2014
Posts: 1
#23
In reply to #3

Re: Combustion Reactions

11/11/2014 12:34 AM

I am going to make one statement, and I never again will waste my time. This thread like 99 percent of others on CR4 yields zero contribution. You speak petty nonsense to make yourself feel big, but you look mighty small. Like Twain said, "Keep away from people who try to belittle your ambitions, small people always do that…" The four things this site is supposed to offer is (1) A connection with engineering and technical professionals (These "comments" are the best foot forward of "professionals"?). (2) Find answers to scientific and technical questions (My sense is that you would rather play one up or gotcha). (3) Join professional discussions (not at this site!). (4) Collaborate with the people you've connected on CR4. (The remarks made here are not to convey or achieve anything meaningful, but for the express purpose of trying to show off. This site is not frequented by those who own a set of big boy pants, -i.e. Noudge79, who thinks of himself as a Guru yet so far flapped his gums 552 x with possibly 5 good answers, - or at least someone thought so. BTW, I am a girl, so don't get fresh with me!
Register to Reply
Tornado
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 21017
Good Answers: 795
#24
In reply to #23

Re: Combustion Reactions

11/11/2014 6:33 AM

Hi! Goodbye!

__________________
 In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
James Stewart
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 14331
Good Answers: 162
#28
In reply to #23

Re: Combustion Reactions

11/11/2014 10:27 AM

Come on, stitch! come back and make your presence felt more often. We need more professionals like you!

__________________
 If it ain't broke, don't fix it. Just build a better one.
Register to Reply
Noudge79
Guru

Join Date: Feb 2011
Posts: 1119
Good Answers: 11
#30
In reply to #23

Re: Combustion Reactions

11/12/2014 9:09 AM

Hi, I am sorry I offended you. I do not think I am guru enough. I admit our stress outlets (fun) sometimes get's stress increasing and offended others. Whoever you are, I apologize.

I does not bother getting good answers GA credits because fact is, we are rated by members who is not all the time superb at everything at the same time it depends if you've got lots of friends around. Sometimes, somebody got a GA with no sense at all.

If you got GA or post a lot, does not matter. Fact is, truth does not appreciate a substitute.

If you and I are telling the truth of the matter, well, that counts.

Science has no feelings, void of emotions and facts do not have also-with no intrinsic value. It does not need a company.

Why would I show off, what would I get? I do not take credits on everything here since, I do not used my real name.

Again, I ask an apology.

__________________
 " To infinity and beyond" - Buzz Lightyear
Register to Reply
IdeaSmith
Guru

Join Date: Mar 2012
Location: Out of your mind! Not in sight!
Posts: 4424
Good Answers: 108
#7

Re: Combustion Reactions

11/10/2014 4:03 AM

I would also question the Moles of H2O formed.

I would question the whole table and call in the Chemical Handbook for help.

Is this part of an assignment that you need to check?

__________________
 Common Sense Dictates
Register to Reply
Crabtree
Guru

Join Date: Jul 2007
Location: Commissariat de Police, Nouvions, occupied France, 1942.
Posts: 2599
Good Answers: 77
#11

Re: Combustion Reactions

11/10/2014 5:00 AM

It's wrong. Google "stoichiometry" and start from there, Mildred.

__________________
 Good moaning!
Register to Reply
Govind Rao
Power-User
India - Member - New Member

Join Date: Jan 2009
Posts: 114
#14
In reply to #11

Re: Combustion Reactions

11/10/2014 5:29 AM

You are right sir!!!
Register to Reply
3
energyconversion
Guru

Join Date: Aug 2008
Location: England & Ireland
Posts: 1063
Good Answers: 61
#12

Re: Combustion Reactions

11/10/2014 5:19 AM

Yes, very simple explanation: they have the SO2 and H2O columns reversed. Very obvious - surprised you even asked the question.
Register to Reply Good Answer (Score 3)
Go to Next Good Answer
Govind Rao
Power-User
India - Member - New Member

Join Date: Jan 2009
Posts: 114
#16
In reply to #12

Re: Combustion Reactions

11/10/2014 6:28 AM

When a person in authority casts such information and posts it as part of an article in a well known journal, a novice like me tends to believe it. I would not disclose the author as decency on my part.
Register to Reply Score 1 for Good Answer
No more "Almost" Good Answers.
rkgupta
Member

Join Date: Aug 2008
Posts: 8
#17
In reply to #16

Re: Combustion Reactions

11/10/2014 7:18 AM

So nice of you Mr. Govind, we learnt some thing from this statement Thank you.
Register to Reply
Noudge79
Guru

Join Date: Feb 2011
Posts: 1119
Good Answers: 11
#19
In reply to #16

Re: Combustion Reactions

11/10/2014 8:21 AM

I apologized Mr. Govind for the prejudice and mistreatment, knowing your humble heart and attitude defeats all the knowledge and brilliance, I could concur.

Stochiometry might not be your favorite subject way back then. Anyhow, you see all the comments now, you can re-affirm on your post of what went wrong.

__________________
 " To infinity and beyond" - Buzz Lightyear
Register to Reply Score 1 for Off Topic
James Stewart
Guru
Safety - Hazmat - New Member United States - US - Statue of Liberty - New Member Engineering Fields - Chemical Engineering - Old Hand

Join Date: Mar 2011
Location: Lubbock, Texas
Posts: 14331
Good Answers: 162
#29
In reply to #16

Re: Combustion Reactions

11/11/2014 10:29 AM

Good man! You did the right thing, as compared to this one particular butt nugget who insists on how right he is, and how wrong everyone else is all the time. The problem with being the only one who is right, you might be crazy.

__________________
 If it ain't broke, don't fix it. Just build a better one.
Register to Reply
rkgupta
Member

Join Date: Aug 2008
Posts: 8
#15

Re: Combustion Reactions

11/10/2014 5:39 AM

Mr Tarnado has given you right ans. you have reversed the column of H2O and S
O2. if you want to learn something in a very simple way, please purchase this book "Stoichiometry" by Mr. S. N. Bhatt. a very good example to learn you.

Given
GCV45071KJ/KG.
Excess Air25%
Inadequate Air0%
Air Temperature298°K
Composition of Fuel
Carbon88.40%
Hydrogen9.40%
Sulphur2.20%
Oxygen0.00%
Nitrogen0.00%
Other0.00
Moisture0.00%
Weight100Kg Residual fo
Temperature of flue gas523K
Pressure of flue gases100.7kpa a

SOLUTION:-

GCV45071KJ/KG.10783Kcal/kgTHEO O2 REQ.

CONSTITUENT

KG

MOL.WT

KMOL

REACTION

KMOL.

CARBON

88.4127.367C+O2-->CO27.367

HYDROGEN

9.424.7002H2+O2-->2H2O2.350

SULPHUR

2.2320.06875S+O2-->SO20.06875

OXYGEN

0320(-) O2

NITROGEN

0280NO O2 REQ.0.000

OTHER

0.00

TOTAL

100.0010612.1359.785
THEORETICAL O2 REQUIREMENT FOR COMPLETE COMBUSTION9.7854KMOL
THEORETICAL O2 REQUIREMENT TO FUEL RATIO3.1313Kg O2/Kg Of Fuel
N2 ENTERING WITH O2 THROUGH AIR(79/21)*O2 KMOL36.81KMOL
TOTAL N2 IN THE FLUE GAS(N2 IN FO+WITH O2 IN AIR)36.81KMOL
Total Dry Air Requirement46.60KMOL
WEIGHT OF DRY AIR(WT.OF THEO. O2 REQU+ ENTERING N2)1344KG
( KMOL OF O2*MOL.WT O2+KMOL N2*MOL. WT)
DRY AIR REQUIRED( STOICHIOMETRY)/FO RATIO13.44KG/KG of fuel
Actual Air Supply(excess air + Theoretical requirement)16.80KG/KG of fuel
Weight of Actual Air Supply1679.83Kg
Actual O2 Supply12.23Kmol
N2 accompanying O246.015Kmol
N2 in coal0Kmol
Total N2 in Coal46.01Kmol
TOTAL WATER VAPOUR FORMED(=KMOL H2 )4.700mol
Total moisture in flue gas4.700mol
TOTAL WATER VAPOUR FORMEDKMOL H2/2 * MOL WT.42.30kg
LETENT HEAT OF WATER AT 298 K( STEAM TABLE)2443KJ/KG @298 K
Latent Heat LOSS IN WATER VAPOUR(WT OF WATER VAPOUR.*LH)103330kj/ kg fo
LETENT HEAT LOSS IN WATER VAPOUR/KG FO1033kj/kg
NCV(GCV- LETENT HEAT LOSS IN WATER VAPOUR)44038KJ/KG of FUEL@298 K

TOTAL HEAT LIBERATED BY COMPLETE COMBUSTION(ASSUMING THAT

FORMED MOISTURE IS IN VAPOUR FORMED), Q = WT FO * NCV

4403770kj
COMPOSITION OF FLUE GASES WITH EXCESS AIRGiven
COMPONENTORSAT ANALYSIS
Mol Wt.WeightWET BASISDRY BASIS considering SO2 as CO2
KMOLKgMOLE%MOLE%
CO27.36744324.1312.1613.30
H2O4.7001884.607.76-
SO20.069644.400.11-
N246.015281288.4175.9482.32
O22.4463278.284.044.38
CO0.00
OTHER0.00
0.00
TOTAL60.597186.0001779.830100.00100.00
C/H ratio9.40
NOTE MAX CO2 CONTENT MAY BE 17% FOR FO CONFIRMING TO IS : 1593
The mole fraction of represents Kmol of SO2 per mol of wet gases
volumetric relationship follows the same pattern
ppm by Volume1135ppm
Concentration by wt of SO2 ppm by w/w2472mg/kg
Volume of flue gases @ given temp. K and pressure kpa a2617m3
Concentration SO2 ppm by w/w1682mg/m3
Register to Reply Score 1 for Good Answer
Go to Next "Almost" Good Answer
Govind Rao
Power-User
India - Member - New Member

Join Date: Jan 2009
Posts: 114
#18
In reply to #15

Re: Combustion Reactions

11/10/2014 7:46 AM

Thank You Mr. Gupta. I do have number of books and going through it as already mentioned, I am not well versed with chemical engineering. I was really stumped to see the sheet. I don't blame the author as he is well known and could have been an oversight.
Register to Reply
rkgupta
Member

Join Date: Aug 2008
Posts: 8
#22
In reply to #18

Re: Combustion Reactions

11/10/2014 11:12 PM

Mr. Govind, keeping book will not help, neither reading it without aim, If you really want to get some knowledge, you should get assignment. Assignment may be from your job related from your boss or you appear for a diploma, degree or something like this. Fortunately I am lucky, i was having both and being a mechanical engineer, i completed part time chemical engineering degree. Same happened when I have to deal in projects and financial analyses of projects was hitting me and then completed part time MBA. It is not author mistake it happens in excel sheets.

Best of luck
Register to Reply
ZakariaSalim10
Associate

Join Date: Nov 2014
Posts: 43
Good Answers: 1
#25

Re: Combustion Reactions

11/11/2014 6:35 AM

I think that is naturally SO2 produced equation of the combustion especially for hydrogen sulfide.

Source: http://quizlet.com/39163439/hl-chemistry-environmental-flash-cards/
Register to Reply Score 1 for Off Topic
Register to Reply
Have a Different Question?
30 comments

Good Answers:

These comments received enough positive votes to make them "good answers".

"Almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, vote them!
Copy to Clipboard

Users who posted comments:

Crabtree (1); dhayanandhan (2); energyconversion (1); Govind Rao (8); IdeaSmith (1); James Stewart (3); Noudge79 (6); rkgupta (3); stitchintime (1); Tornado (3); ZakariaSalim10 (1)

Previous in Forum: Ballistics of Flying Rock   Next in Forum: What's the Grade ST44 Equal to in API 5L Standard

Advertisement

Got Something to Say?
Ask a Question
Start a Discussion

Search this Forum
Chemical & Material Science:
Go

CR4 Sections
Aerospace
BioMech & BioMed
Chemical & Material Science
Civil Engineering
Communications & Electronics
Education and Engineering Careers
Electrical Engineering
General Discussion
Instrumentation
Manufacturing
Mechanical Engineering
New Technologies & Research
Software & Programming
Sustainable Engineering
Transportation

Site Directories
Forum Directory
Blog Directory
User Group Directory
RSS Feeds

CR4 Rules of Conduct
CR4 FAQ
Site Glossary

Who's Online (149 right now)
Show Members
Advertisement