Calculating specific heat

[bensingbrewery]

So i'm working on some calculations for my system in an attempt to optimize it. I am attempting to find a way to calculate the specific heat of my washes. What i'm looking for is a way to estimate the specific heat of my washes after fermentation. Does anyone have a way of going about it outside of the traditional way of heating the substance, taking the change in temp and calculating the specific heat?

Here is what I have so far

My example batch

OG 1.082
FG 1.005
60.750 L Water (4.186 J/g C) (Ethyl Alcohol is 2.400 J/g C)
15.000 kg sucrose (table sugar) (1.260 J/g C)
70.000 L Total Volume of Wash

Calculations for mass of alcohol (http://www.beeradvocates.org/articles/h ... -0021.html)
1.050 * (1.082- 1.005) = 0.081 kg/l
.081 kg/L * 70 L = 5.670 Kg of Ethyl Alcohol produced (making a simple assumption)

So in fermentation, sugar and CO2 are directly correlated at a 1:1.05. So if 5.670 Kg of alcohol was created the 5.954 Kg of CO2 was released.

Given that the density of water is 1 kg/l and at FG of 1.01, I now have a total volume of 60.750 kg (H2O) + 15.000 kg (Sucrose) - 5.954 kg (CO2) = 69.796 kg

If you are still following me, i have broken it up into % by mass:

H2O = 87.040% (60.75 kg)
Sucrose = 4.84% (3.376 kg)
Ethyl = 8.12% (5.670 kg)

No i'm using the the %/kg as a ratio to the J/g C of each substance:

H2O = 4.186 * .8704 = 3.6435
Sucrose = 1.260 * .0484 = .061
Ethyl = 2.4 * .0812 = .1949

So after weighting my components, I have come up with a new specific heat of 3.899 J/g C

Wheewwwww....that was alot...so what do you think?

[Godstilla]

To be honest.... You are wasting your time.

[eternalfrost]

'heat is NOT a Noun " heat" is a VERB i.e. you HEAT a brick of substance


you do NOT Transmit a piece ofheat to them"

[bensingbrewery]

*stilla

I'm using this info to create an alogrithm

*eternal

What are you talking about? Are you refering to the scientific measure of specific heat?

[Hawke]

Is this for calculating the amount of energy as fuel?
Only reason I could think of to waste that much time. Once you have the j/g C, you would need to figure the energy needed to make your wash usable as fuel. I believe the outcome would be a negative.

[Ayay]

The traditional way you describe of measuring the heat input and temperature rise would give you the most accurate answer for all the variables in your setup. You can then reverse engineer it if you want.

I'm lost with your calculations. Doesn't it come down to more heat or more time to get the same answer which is to get the wash in the boiler to the right temperature? What is the use of knowing the specific heat of the wash?

[bensingbrewery]

The reason i'm attempting to figure out a way to calculate the specific heat is for an ultimate equation that when you input your OG, FG, and total wash vol. you will get out how many watts/hr it would take to raise it temp from a speficied begginning temperature to a specified ending temperature.

I'm going to experiment with my little theory through the use of basic techniques (heating the substance and timing its raise in temp and so forth). Since, in a standard wash, you have left over starches, ehtyl acetates, mythenol, and other minerials and such that would affect the specific heat of the wash. So using these calculations as a base, i'm go to see 1) how close they are 2) if they are close, attempt to figure our a correction factor i can use to adjust the equation to get a more probable answer.

[Godstilla]

I read someone's signature that said "You could squeeze shit hard enough to get a few drops of shit juice, but who wants it?"

That is what I think of your algorithm. I'm not being mean I just don't understand what good it would do.

[bensingbrewery]

I read someone's signature that said "You could squeeze shit hard enough to get a few drops of shit juice, but who wants it?"

That is what I think of your algorithm. I'm not being mean I just don't understand what good it would do.

It's for a QA/QC (Quality Assurance/Quality Control) procedure i'm writing. I'm currently planning a miro-distillery and right now i'm working on my processes and procedures. I using ISO and Six Sigma outlines for staistical controls and analysis.

I'm not aware of any homedistiller using any of these calculations too much, but they provide that ability to create and maintain control over manufacturing processes. I'll be able to calculate probabilites that will control how much grain is used, how much heat is used, etc. so I may maintain my level of quailty.

Basically,it gives me a better method of creating spirits than the usual "add a pinch of this and a fist of that....ehh give it a few more minuites."

[Godstilla]

If you'd turn Q.A. loose with that sort of shit. You'll bring production to their knees. You need to have room for a pinch of this and a fist full of that.
The government puts enough shit on business. Why on earth would you want to pile moron?

[theholymackerel]

You have made yer point, Godstilla, clearly and aggressively.

Ya told him he was wastin' his time. Then ya compaired his project to squeezin' a turd, then to a pile of shit.

Ya made yer point, now play nice, please.

If it works for him, his outfit will be more efficient and productive... and that just might be the difference between success and failure. If it doesn't work for him all he wasted was a bit of time, and even that may not be a waste. Often our failures make us learn more than our triumphs. Also, some folks seem to have to have mental puzzles to work in their head to be happy... maybe he's one of those.

Bensingbrewery, thanks for not risin' to the bait. I wish ya the best of luck in yer endeavours.

[Ugly]

I don't know the answer to the question, but you are on the right track. Just keep in mind while algorithms like these work when you you are producing millions of litres, their margin of error for smaller samples isn't all that great. It's simply the reality of handling raw goods where the input factors can differ because of how much sun a crop received. Their are separate sets of ISO practices for small businesses that are better tailored to smaller samples.

The job of a good QA team at a brewery/distillery is simply one of testing/measurement with said values being passed back to the brewmaster/master distiller for actionable items. A brewmaster/master distiller making too many adjustments rapidly finds his/herself turning to engineering for long term solutions. Where successful brewers/distillers tend to succeed is their ability to put out a consistent quality product that begs to be purchased one year to the next because the consumer is guaranteed a virtually identical product experience. This is something wineries struggle with and attempt to offset by retaining portions of their juice yields one year to the next to cover themselves for when the harvest is blechy (technical wine making term that).

Not sure why you're making the effort this far in advance of having a statistically significant sample, in normal ISO practice you would lay the framework, decide on the sample size needed to be significant and then build the process after you have time to reiteratively gate the process to make sure you weren't overlooking anything that was significant to the QA valuation metrics. In other words, you build the process using ISO input but you don't actually document the method until your business practice is established.

It's not a question of which came first, the chicken or the egg, you have to have a critter of some kind to get a damn egg

Regards,
Ugly

[PaulN]

Actually, this is exactly the sort of thing that a high school chemistry student should be working on. What I mean is, it's a relatively simple exercise in terms of doing the math. Converting this idea into practice is also fairly simple, but tedious as well. Power consumption can also be easily measured, and you can use that to do efficiency studies, etc. I think I get it.

I also think that what you will find is that distilling, or heating any liquid to boiling, is terribly inefficient in practice. Even with ideal conditions, i.e. tons of insulation and the like, I would have to guess that distilling any liquid is, at best, about 10-15% efficient. I've seen similar calculations done with aluminum casting (another interest of mine), and the efficiency of a standard home-build gas fired casting furnace was right around 10% efficient. The phase change is what eats up all the power. The good news was that in the end it was determined that heating with electricity is much more efficient that heating with a flame.

I'd like to see where this goes, and no, I don't think it's turd juice.

[bensingbrewery]

Your right, i'm ahead of myself in this aspect. I agree that a brewer/distiller has more control with the raw inputs than adjusting the process on a small scale. I'm always working on different ideas and ways of developing products.

[evilpsych]

I like this sort of 'turd-squeezin' exercise.. Why? because it produces other lines of thought for someone else. Perhaps that person will pull together a 'unified Distilling theory' formula that can be written into a software program that can control every aspect of the distilling/brewing process. i guarantee the beer companies have something like this already for beer, (and some distillers too!) but it's all tied up under NDA and 'trade secrets'

We regular folk are left to figure this out on our own.

[snuffy]

So i'm working on some calculations for my system in an attempt to optimize it. I am attempting to find a way to calculate the specific heat of my washes. What i'm looking for is a way to estimate the specific heat of my washes after fermentation. Does anyone have a way of going about it outside of the traditional way of heating the substance, taking the change in temp and calculating the specific heat?....

So after weighting my components, I have come up with a new specific heat of 3.899 J/g C

Wheewwwww....that was alot...so what do you think?

this approach will work IF you can somehow derive an efficiency factor for the fermentation. Theoretically, it is correct == conservation of mass = conservation of average specific heat of a mixture. But you have to accurately quantify the the % of each of the components. Yer little yeasty beasties can mutate on ya and then you don't get what you got yesterday.

Practically speaking, you would probably do as well for each mash recipe to empirically derive a SG to SP curve by doing the calorimeter dance and then crossing your fingers and hoping the relationship stays the same until then next time QA does the calibration test. Fudge tables are used all the time to turn fast linear or low-order polynomial algorithms into more elegant control surfaces, particularly in digital signal processing where time and clock cycles are scarce. I've been there and done that. I also used fudge tables to take two zip codes and get the truck miles between one fruit warehouse and another

(hint: they cluster geographically so the location is much more localized than the geographic center of gravity published for zip codes)

How's about you track the KW input (if you're doing electrical heating), rack that up with the volume and specific gravity, and punch those up with slope of your heating curve, eh? That slope will be linear until you hit the latent heat of vaporization, so you'll have your heating time estimate as soon as you get a meaningful set of points to plot.

If you're heating with combustion, it's another can of pickle smoke, unless you got steamheat and then you just go to the steam tables in the ol' engineers handbook.

*clobbers eternal frost with a sack full of phonons*

*pins War of the Northern Invasion 2nd Place Winner medal on godstilla*

[HookLine]

snuffy, anytime you decide to become a professional stand up comedian (speciality: geek humour), let me know, and I'll be first in the queue outside the theatre.

[snuffy]

This is more like slapstick than standup, but I get your drift.

Bp is going to be around 72-78C (depending on heads concentration), so if you know the slope and you know the Bp, you know how long until boiling time

liquidvapor.gif

this is one thermo probe in the liquid and one in the space just above it. the room was colder than the water, so they don't start out in equilibrium.

It's a pretty darn straight line.

The Gospel of the Rocket
In the days when the white engineers were disputing the attributes of the feeder system that was to be, one of them came to Enzian of Bleicheröde and said, "We cannot agree on the chamber pressure. Our calculations show that a working pressure of 40 atü would be the most desirable. But all the data we know of are grouped around a value of only 10 atü.

"Then clearly," replied the Nguarorerue, "you must listen to the data."

"But that would not be the most perfect or efficient value," protested the German.

"Proud man," said the Nguarorerue. "What are these data, if not direct revelation? Where have they come from, if not from the Rocket which is to be? How do you presume to compare a number you have only derived on paper with a number that is the Rocket's own? Avoid pride, and design to some compromise value."
--Gravity's Rainbow

[HookLine]

Reading Gravity's Rainbow again is one of the things I have promised myself I would do before I die.

[Ugly]

I like this sort of 'turd-squeezin' exercise.. Why? because it produces other lines of thought for someone else. Perhaps that person will pull together a 'unified Distilling theory' formula that can be written into a software program that can control every aspect of the distilling/brewing process. i guarantee the beer companies have something like this already for beer, (and some distillers too!) but it's all tied up under NDA and 'trade secrets'

We regular folk are left to figure this out on our own.

Let's just say... of course there is - know what drives it? Forecasting. Financial planning and market forecasting. Without the process number you can't even have an effective treasury department. Without those numbers, you can't predict (accurately) how much money a new product launch will make or lose. It all starts with comprehension of the details.

But this thread is about conforming to ISO business practices, not the same thing usually. (though you'd think they would be)

[rad14701]

Reading Gravity's Rainbow again is one of the things I have promised myself I would do before I die.

Tick... Tick... Tick... Tick...

One of these days, when I can sit and read something other than technical manuals, this is on my list also...

Tick... Tick... Tick... Tick...

[clbphllps]

I'd say you're def. in the right track with the math calculations. But it seems like measuring the specific heat experimentally would be an arduous task due to general heat loss. If I were you, I'd start by calculating the specific heat of a X proof water/alcohol solution and compare it to experimental data. This would be much more trivial than the former.

[eternalfrost]

ethanol is 1.925 J /cm3 /K
water is 4.186 J /cm3 /K

id say it would be plenty accurate enough to just take the %ABV of the wash, say 5% and apply it to the total volume, say 100L to get 5L ethanol and 95L water. then just plug-and-chug the numbers through dimensional analysis to get the amount of energy needed to heat it etc.

theres no reason calculating anything to better then 1-5% accuracy, real-world uncontrollable variables like heat losses and wiring inefficiencies will throw you mush further off than that anyways.