Temperatures, Oil Consumption of French Fry Plants

When I look over your questions I think, "Gee, maybe we could save a lot of energy/other resources if we just got off French Fries." Then, would they truly become "Freedom Fries"?

All kidding aside, I've thought about processes like this in passing before, but never dwelt on it for very long.

Your question does raise the point generally. How much energy is expended in unnecessary products. Are we WAY over-producing, using up resources that in the end are precious because they are finite? By over-producing, I mean producing items of luxury and whimsy. One example would be pet rocks. While people around the world struggle for food every day, millions of consumers are buying silly products that DO use energy and resources to produce them. This could be a larger discussion of the issue you raise.

In the case of French Fries, energy and "oil" (albeit, usually vegetable -- but ultimately energy, also) is wasted on a final product that only contributes to degenerative diseases, like atherosclerosis and diabetes -- which have the off-shoot complications of strokes, heart disease, dementia, etc. Most of us "like" the taste of French Fries, but I think they truly are an "indulgence" that we could live without. Of course, many would cry that this kind of reasoning leads to that dreaded "slippery slope" whereby we reason ourselves out of existence. Gasp! No. I'm just wondering, "Should we produce anything possible just for the sake of production, irregardless of how it affects the planet and future life on it?"

[I thought about marking my comments as off-topic. But your specific questions are really a subset of this larger question. (If these comments seem off-topic -- in other words not contributing to answering your questions specifically, and even diverting discussion of your specific questions, then maybe a moderator will demote them to that status.)]

I think by coming up with estimates for answers to your questions, it will serve the larger view of asking the larger question this raises.

Thank you for bringing it up.

Not interested in living in a cave though that would be more efficient - for a few. I'll stick to french fries though I eat them maybe once in two weeks.

The quantity of surplus/waste heat available from the french operation would be:

1) minimal

2) very low grade - meaning expensive to recapture

3) dirty - believe you would spend more energy cleaning the system than was recovered

Never spent 1 cent on a pet rock - never had one and have no interest in that type of thing. My toys tend to be more expensive I am afraid.

Well, I didn't mention living in a reasonable house as being extravagant or whimsical. I wish everyone could have decent housing. I'm all for some sort of plumbing in a house for waste disposal -- which a cave is unlikely to have. (Although, as you point out, it might be very efficient for some. There are plenty of people around the world living life at a very basic level -- and surviving quite well.)

Also, I was trying to match your answers up with the questions raised. Here's the one's I think you responded to:

How much water is removed from the fries? 1) minimal

What oil is used? How much is used per tonne of fries? 2) very low grade - meaning expensive to recapture

Is oil consumption due only to absorption by the fries, or does oil have to be renewed due to rancidity? 3) dirty - believe you would spend more energy cleaning the system than was recovered

Your response is rather glib.

I never had a pet rock, either. And, actually, your response implies that you think of it as pretty silly, too. That was my point. Unfortunately, since the "market" decides what is produced, it paints a somewhat shallow picture of human beings, as a species, doesn't it?

Taking comments personally - no - not my style. If I did I would simply unsubscribe from the thread.

The concept of heat recovery seems to give many people a bit of trouble to understand.

1) I meant the heat available for recovery is not much - minimal

2) Low grade heat means low temperatures to work with

3) You are working with a slimy, oily mess - very difficult on a small scale

Can it be done - yes. Can it be done with a positive result - I seriously doubt it.

Probably solar thermal panels would provide a much better return on investment. You have to have a use for the hot water but then you were planning on using the waste heat somehow. Look for the best return on investment and not just in a monetary sense.

My reply was not glib at all - you are talking the same kind of game as the perpetual motion guys essentially. No way to make the concept worthwhile. This is a common approach on many green sites on the web - to suggest doing something that is impractical but sounds neat.

I don't think the old USSR had pet rocks for sale - care to try that system - who knows, it might work next time though I doubt it.

There always have been luxuries - there always will be luxuries - for some and not much at all for others - unfortunate, yes - wrong, I don't think so.

The countries with the poorest populations generally don't care about their own citizens - proven fact - just look around the world and see. I've been many places and seen for myself.

I am not planning on losing any sleep over the world's situation myself.

I didn't have time to respond to your last post until the end of the day -- not that it means much to do so. Apparently, most people couldn't care less about this thread, judging by all the posts.

Don't assume I'm the original poster. I'm not trying to reclaim energy from French Fry production plants. I was tying the OP questions to a larger issue.

I'm also pretty sure both of us are "older", shall we say. We've both had "discussions" like this many times before with other people. So we probably would both agree that there isn't much point in prolonging a "back and forth" point by point commentary or rebuttal of statements.

I've been to other countries, too. I don't disagree with your statement that many governments of poorer countries don't seem to care about their own citizens. Change does occur when enough people in bad circumstances become active politically or militarily -- or they die trying.

Here's my overall take on your comments: You reacted to my post, where I posed a question about whether or not developed countries produce things which are trivial and unnecessary, with comments that assume I'm some sort of "bleeding heart liberal", a Communist ... or a "Socialist". Your comment about no pet rocks in the USSR are the giveaway for that interpretation. You've assumed I think that a Communist system would be better. Or that the only consistent course of action based on Ronseto's comments is to live in poverty. (Why such a reactionary response if you aren't taking it somewhat personally?) Not in the least. I'm thinking we can have a more enlightened Capitalism. Efficiency (i.e., little waste) is generally a core principle of engineering design. I never used the word wrong. I'm saying we can do better. But as I also said, the "market" supports what is happening and it does speak poorly of our species at the moment.

I also don't lose sleep over the state of the world. But during my waking hours I can care about the suffering of others. And when the opportunity to reason in favor of improving the way the world works presents itself, I take it. Minds are changed one at a time by other minds. You may change people to your way of thinking with your comments. That's the point of discussions.

Quote: "By over-producing, I mean producing items of luxury and whimsy. One example would be pet rocks."

This one statement brings up a very good point. How can we justify spending thousands of dollars on designer gowns, perfumes, jewelry, Rolex watches, luxury yachts, quarter million dollar cars, etc. I don't have any idea how much money is generated by luxury items in terms of the GNP of a nation. Sure a nice smelling and dressed woman is nice, but does it have to be such an expensive thing? I don't have a Rolex watch or a Ferrari and I don't miss not having them. If the world's money were redirected away from frivolous spending, I'm sure many of the worlds problems would be eliminated.

Ok no problem - you can donate yours down to just above poverty level any time you choose.

I didn't work for so many years to retire in anything except comfort.

To each his own!

I'll certainly agree to that! To each his own. And I think if you work hard you deserve your "comfort". Most of us feel that way. But Ronseto is responding to a legitimate question. And I don't think he was saying we should be living at a "poverty level".

Your response to my earlier post and to Ronseto's implies that anyone who raises these kind of questions can be shown to be hypocritical and therefore should not ask the question. Yes, most of us have toys and luxuries, too. My comments were intended to be about the limited resources on the planet. A basic part of engineering is planning. Since this is an engineering forum I wouldn't expect that sort of discussion to be considered oddball. I'm only suggesting that we, as a species try to do a little planning when it comes to using our resources. I'm sorry if you took the comments personally.

Converting potato's to french fries, is a way to extend their shelf life & ease storage/transportation.

there is a spectrum of oils used from lard to canola. The overall efficiency of the process also varies greatly. I wouldn't imagine OreIda is going to leave money on the table & will implement any improvement that has a decent return on investment...

Here's a link to the "how it's made" version of the process

My original post seems to have produced an outpouring of social commentary rather than the technical information I had hoped for. I will comment briefly on my motive for pursuing this.

All waste heat is low-grade by definition. If it weren't low-grade, it would not normally go to waste. It can be profitable to recover waste heat, however, particularly if it is upgraded and returned to the process from which it leaked.

Mess. Yes, the vapor coming off a frying vat contains a fog of free fatty acids, which will need to be separated. But those acids are the cause of rancidity in edible oil; their removal may extend the oil's useful life. Also, free fatty acids have a market. Hence my question regarding oil renewal.

Magnasol is commonly used to prolong the life of fryer oil.

vacuum extraction of the water in some facilites... I saw a thing earlier this year about a crisp plant in the UK that was filtering the recovered water, selling the starch. The water is used for washing the potatoes. The plants water usage was reduced to about 10% of the year before

A frito lay cornchip plant [outside stockton ca], uses solar preheating of the oil to reduce the energy [natural gas] use

many of these production facilities sell their spent oil to biodiesel producers.

Garthh is well versed in this - and on topic - so as to temperature questions - obviously the blanching is water at ~100 C and generally the oil is in the range 160 to 180 C. But mass flow of product can change heating inputs, producing higher zone temperatures in poorly circulated vats.

The work I did in the oil life area in the 80's will be dated, but back then, the life determinate was dioxin formation in oil held at frying temperatures. It would not surprise me if the life of oil is now regulated or legislated.

As for how much oil is used per fry or crisp - they were, and I believe still are quite secretive/sensitive about that, judging by an Innocentive challenge a few months ago.

Hope this helps.