RossD
MegaDork
11/4/19 9:05 a.m.
Does anyone know the products of incomplete methanol combustion?
Also, whats the redline of a monster truck engine? Wiki says a 575 cubic inch engine. Does that sound typical for engine size?
Any help would be appreciated.
I am calculating ventilation rates for a event center running monster truck events.
Thanks
Curtis
UltimaDork
11/4/19 9:47 a.m.
Complete combustion just produces mainly water and CO2. Incomplete combustion generates plenty of CO. Not to mention the tons of methanol vapor.
Methanol carries some of its own oxygen that dissociates during the combustion, so it can be pushed way past stoich. That's why you often see liquid methanol spouting out of top fuel dragster headers.
I can't speak intelligently as to HOW FAR monster trucks push it past stoich, so it's hard to guess how much methanol bypasses combustion. I do know that top fuel dragsters will often have an A/F of 1:1. Might be able to calculate from that the cubic feet of one pound of methanol in gaseous state, times how many pounds they would burn during the event.
RossD
MegaDork
11/4/19 9:57 a.m.
Thanks Curtis. A random website called out stoich at 6.4 : 1 but 5.5:1 for WOT.
Duke
MegaDork
11/4/19 10:29 a.m.
My gut reactions say WBO on the ventilation system, whatever CFM that ends up being.
RevRico
PowerDork
11/4/19 10:41 a.m.
Wide Berking Open is my guess.
I can't be of much help, when I've seen Monster Trucks it was outside, or they were able to open the roof of the civic arena.
Can you look into stadiums that already carry those events and get an idea from an already proven formula?
NickD
PowerDork
11/4/19 10:52 a.m.
Don't forget to account for all the extra CO2 emissions from people screaming their heads off when a monster truck does a berkeleying sick front flip
Call Feld entertainment who run the Monster Jam and talk to them? (941) 722-1500
RossD
MegaDork
11/4/19 11:33 a.m.
In reply to NOT A TA :
We are already in contact with the arena people and have some operational info from the monster truck. They just dont seem to care about their exhaust emissions.
Another byproduct of methanol combustion is Formaldehyde. That is one of the things that reminds me of my time working with IRL and Champ cars.
Just want to hop in here to mention that "...but I asked the GRM board" is not a valid legal defense when half the audience come to and use what few brain cells they have left to hire an attorney.
But these things happen indoors frequently enough that there's got to be existing data, right? I'd look up their previous schedules and start calling facility managers at venues where they've appeared before.
codrus
UberDork
11/4/19 5:50 p.m.
Curtis said:
Methanol carries some of its own oxygen that dissociates during the combustion, so it can be pushed way past stoich. That's why you often see liquid methanol spouting out of top fuel dragster headers.
I think you're thinking of nitromethane (CH3NO2) rather than methanol (CH3OH). The oxygen in an alcohol molecule (ethanol, methanol, whatever) is already bonded to a carbon and a hydrogen, and it takes just as much energy to break those bonds as it releases when you reform that oxygen into H2O or CO2. As such, that oxygen atom is just along for the ride and doesn't directly increase the power available in the fuel (octane effects are different).
Nitromethane hangs the oxygens onto a nitrogen (a "nitro group") and, well... that's a different story. :)
RossD
MegaDork
11/4/19 5:53 p.m.
In reply to JG Pasterjak :
We have some info from other venues but they arent engineering folk, but rather maintence staff. There are already existing fans in place that, before they went into disrepair, served the purpose of monster truck ventilation. I am trying to validate what was there with, ya know, engineering. Big block, methanol burning engineering! Whooo!
Also, what is redline for a monster truck? 6k rpm?
In reply to RossD :
I know there were people involved with the Central-IL autocross club who know the local monster truck team. Maybe nocones would know who?
In person it sounds a LOT higher than 6k.
nocones
UltraDork
11/4/19 6:27 p.m.
Hall brothers Racing runs the Raminator. They have a phone number listed on Google.
Raminator
Tom Meents is in Paxton Il and runs maximum overdrive and Monster Jam University.
MonsterJam training
Can't find a phone but I bet they would respond.
I can ask around and see if I can find anyone who knows them personally. (Pete Gossett maybe?)
Given that most of them run rich- lots of CO, lots of various HCs, more oxygenated versions of HC, aldehydes, formaldehyde, and NOx (which is mostly NO).
For an enclosed area on a very short term basis, the CO is the most dangerous one. The rest will be incredibly irritating in very short order. And given what they are, the effects can be long lasting.
Some helpful links for CO- https://www.cpsc.gov/Safety-Education/Safety-Education-Centers/Carbon-Monoxide-Information-Center/Carbon-Monoxide-Questions-and-Answers
https://www.osha.gov/OshDoc/data_General_Facts/carbonmonoxide-factsheet.pdf
The safe peak level seems to be 70ppm. And those trucks are likely to be putting out in excess of 10,000ppm.
RossD
MegaDork
11/4/19 6:43 p.m.
In reply to alfadriver :
Do you have the chemistry ... equation of the incomplete combustion with all of the bad stuff in it? I found one that had CO in it but nothing else thats dangerous.
There is no "equation"- odd things happen in combustion. The nice thing for Methanol is that it's a pretty simple alcohol, so the amount of oddball HC's is less than for gasoline- which has a pretty broad variety of HC to start with. But while CH3OH should burn nicely, formaldehyde is CH2O- so that's an example of one of the many things that is incomplete combustion.
xCH3OH + yO2 + zN2 ----> CO2 + H2O + N2 + CO + HxCy + HxCyOz + NOx
x, y, and z are probably limited to the 1-5 range, but combustion does odd things AND Methanol isn't as pure as most think.
But on the very short term basis, by far, CO is the most dangerous- it can kill people pretty quickly. Everything else, on a short term, can be very irritating- which is really bad for business. Long term, they can cause health problems.
If there is a problem have the trucks switch to Ethanol fuel, much less hazardous byproducts.
This is what they do at the Chili Bowl Indoor Midget race, However that race generates a lot more exhaust than the Monsters.
One or two trucks running for a much shorter time.... Although the airspace in an arena is smaller than the Tulsa Expo Center.
Woody
MegaDork
11/4/19 8:46 p.m.
I've only been to one indoor monster truck event and it was a looong time ago, but even as a kid. I remember looking around and thinking, "Wow, this is a really bad idea."