sulphuric acid

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Uncle Jesse
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sulphuric acid

Post by Uncle Jesse »

If you read Hirsch (http://homedistiller.org/wiki/index.php/Manufactu ... d_Cordials) you will see that sulphuric acid was (is) used quite commonly with aluminum hydroxide to create, via chemical reaction, aluminum-sulphate. This process combined with the extra acidity of the wash will raise your specific gravity. In his Rum example it is raised from 1.060 to 1.062 by this process. It is also thought to help remove certain salts which cause scaling in your still column.

Lea and Piggot (http://homedistiller.org/wiki/index.php/Fermented ... Production) say "...The molasses used is treated with sulfuric acid to reduce the pH to between 4.5-4.8 which suppresses bacterial growth; while ammonium sulphate, a nitrogen source at 0.03-0.06% w/v is added to stimulate yeast growth."

Jaques, Lyons and Kelsall, (http://homedistiller.org/wiki/index.php/Alcohol_Textbook%2C_The)
however, recommend a multi-stage approach to avoid scaling. As it states, "The scale formed in the distillation columns when running molasses beer is mainly calcium sulfate, otherwise known as gypsum. If sulfuric acid is used to acidify the dilute molasses in the fermenter to control bacterial contamination, some of the calcium salts will be converted to calcium sulfate, which is fairly insoluble. Some distillers acidify partially diluted molasses with sulfuric acid in a pretreatment in an attempt to remove the calcium salts and thereby reduce the scaling. Unfortunately, this does not work very well. Calcium sulfate is not as insoluble as many people believe; and it is peculiar in that its solubility decreases at higher temperatures instead of decreasing (as occurs with table salt, sugar, etc.). This means that when the molasses beer enters the pre-heaters or the steam-heated stripping column, the calcium sulfate precipitates as scale. The solubility also decreases with increased alcohol concentrations; so if too much alcohol is refluxed onto the stripping column beer feed plate, scaling will increase."

They recommend a multi-stage approach instead, as follows:

1. Dilute molasses to 45 brix with hot water held over 70C for a few hours to settle out suspended solids.
2. Use fermenters with steep-bottomed slopes.
3. Decant the beer twice to remove solids.
4. Have a good proof control system in your rectifying system because "this ensures high proof ethanol does not periodically (or continuously) go down to the beer feed plate of the stripper and cause scaling precipitation"
5. Choose your stripper column wisely with the avoidance of scaling in mind.
6. Use hydrochloric acid instead of sulphuric acid
7. Decant any stillage before pumping it to remove solids.
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pintoshine
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Post by pintoshine »

If the molasses is nearly neutral, it generally was made so with calcium hydroxide(lime). The calcium hydroxide reacted with sulfuric acid, will give lots of calcium sulfate. When using aluminum sulfate, which is a mild buffer, you get a reaction that creates calcium sulfate and aluminum hydroxide by simple replacement.

You missed on part of this reaction that is quite significant. The resulting aluminum hydroxide(nearly completely insoluble) combined with the calcium sulfate(generally insoluble) removes the negative charges from most suspended solids. The negative charges repel each other and causes them to distribute evenly through the liquid.
Removing that charge causes them to fall due to gravity. This causes almost all suspended solids to first coagulate due to the sticky aluminum hydroxide, and then flocculate due to the calcium sulfate. All the stuff falls to the bottom and can be racked off. This reaction is quite fast even in cold liquids and the coagulation/flocculation assisted by gentle stirring happens in minutes. The settling in a still solution takes only 10s of minutes.

Here is a couple pictures of my using aluminum sulfate, that I make at home to clarify pond water that has a lot of mud and algae in it. This algae is such fine particulate that I am not able to successfully filter it with a sand filter but I can remove it from the water with the Aluminum sulfate.
First picture is the before:
algea1.jpg
The second image is after adding 10 grams of the stuff to this 75 gallon tank. that is about 10ppm.
I stirred it for about a minute to get the flocks to join up and then it settles. Notice all the sediment in the bottom. The tank stayed fogged up and the glass has a slight bluegreen tint. The water is crystal clear looking in from the top.
algea2.jpg
I am sure the wash would have to be made pH neutral before the addition of the aluminum sulfate because aluminum hydroxide only exists as a solid at or near 7 pH. Lower and it reverts back to reverts back to aluminum sulfate and higher and it changes to aluminum ions and the base such as sodium hydroxide.

I prepare it by reacting aluminum foil with sodium hydroxide(violent). Neutralizing the sodium hydroxide with hydrochloric acid makes a white, gelatinous substance in salt water. The gelatinous substance is aluminum hydroxide. This is what is commercially know as DiGel the antacid. The gelatin can be washed to remove the salt water solution by using filter paper. The gel combined with a very small amount of sulfuric acid dissolves it completely to aluminum sulfate and water. It can be dried to make a powder. This is the stuff that clarifies water so well and is used around the world as a water clarifier. The homemade stuff is nearly flavorless.

In a pinch you can use ordinary Alum form the canning or spice section of the grocery store. It is usually ammonium aluminum sulfate but it works the same.
manu de hanoi
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Re: sulphuric acid

Post by manu de hanoi »

could alun or aluminium hydroxyde be used for clarifying wash before distiillin beverages ?
pintoshine
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Re: sulphuric acid

Post by pintoshine »

pintoshine wrote:I am sure the wash would have to be made pH neutral before the addition of the aluminum sulfate because aluminum hydroxide only exists as a solid at or near 7 pH. Lower and it reverts back to reverts back to aluminum sulfate and higher and it changes to aluminum ions and the base such as sodium hydroxide.
For the ideal substance for neutralizing the wash I would use Calcium Hydroxide. The resulting reaction after adding the Aluminum Sulfate would be calcium sulfate(Gypsum) and Aluminum hydroxide to glue it all together. This combination settles out very fast. I have never tried it with a wash though. I personally never wait for a wash to clear before distilling. I wait for it to be nearly sugar free. I am a deviant in the respect that I believe clearing the wash removes the necessary flavor profile I like.
punkin
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Re: sulphuric acid

Post by punkin »

I personally never wait for a wash to clear before distilling. I wait for it to be nearly sugar free. I am a deviant in the respect that I believe clearing the wash removes the necessary flavor profile I like.
Here i was thinking i was Robinson Crusoe. :roll:

I wait for my wash to finnish.

I've tried carefully siphoning my washes into the still without disturbiing the yeast layer ect, and i think it's just as good turning the tap on and just running it through the grainbed. I don't give a rats if there is yeast, or if it's cloudy, or if there is a kilo of small pieces of grain.
If the yeast or grain burns under the power of full on gas, i can't taste it, and if i can well i like it.
So there :lol:







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Dnderhead
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Re: sulphuric acid

Post by Dnderhead »

I'm with you there punkin ---but easy on Robinson Crusoe I look like him ( no hair cut-or shave in 5-6 years) thank like mackgyver ( make everything out of nothing) Live alone and go to town once a month. most of My "friends" are aaaa --"shoppers"
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Re: sulphuric acid

Post by blanikdog »

And I'm with you too, dunder. I stopped shaving and haircutting in 1972 when the government pulled the troops from Vietnam and I left the army. I've had the occasional haircut these days and only go to town when we really have to.

And I never wait for the wash to settle either.

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Re: sulphuric acid

Post by theholymackerel »

Too much hair makes the cops in these parts pay too close attention.

I buzz all my hair off when ever it gets too fuzzy (about 3-4 times a year). I do it my self 'cause I'm cheap.

I like a well settled wash/mash to charge my boiler.
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Re: sulphuric acid

Post by Husker »

hehe,

I guess ppl that buzz their own heads (Im cheap also), like to settle the wash out. Well, sometimes I get the wife to buzz the head, but same end result, no outlay of cash for a quite simple thing like a haircut.

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punkin
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Re: sulphuric acid

Post by punkin »

Husker wrote:hehe,

I guess ppl that buzz their own heads (Im cheap also), like to settle the wash out. Well, sometimes I get the wife to buzz the head, but same end result, no outlay of cash for a quite simple thing like a haircut.

H.

Sorry mate, been shearing myself for near twenty years (at $10 a snip five times a year, that's a gorrilla in my pocket) and i like a wild swirling wash.






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manu de hanoi
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Re: sulphuric acid

Post by manu de hanoi »

my hair is random and i like experimenting, ill try the ALSO4 vely vely soon
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Re: sulphuric acid

Post by Old_Blue »

Settle the wash..a little

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Re: sulphuric acid

Post by rad14701 »

I buzz my head every two weeks... Saves a lot of money and now if it gets over a half inch long it drives me nuts...

I let my wash settle and siphon off - twice, so my vote goes to letting it settle...
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Re: sulphuric acid

Post by HookLine »

Clear my washes twice, over a week or so.

Had long hair and no haircut at all for many years (and only shave once a week, and only cause I'm in the tropics, heat and humidity don't go well with beards). But then the thinning on top got too obvious, so now it's a No. 4 every 3-4 months, a lot easier to deal with than long hair I have to say.
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Re: sulphuric acid

Post by Uncle Jesse »

haven't had a haircut since 1992 but I'm about to. just sick and tired of having long hair. finally more tired of long hair than I was of haircuts when I stopped cutting it.

plus, working in the central valley heat with a boiler and still going, long hair just adds to the oppressive heat factor. it's become a hassle.
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Re: sulphuric acid

Post by Uncle Jesse »

by the way, to post on topic...I've been meaning to ask what's the difference between muriatic (hydrochloric) acid and sulfuric acid? what are the implications for distillers? I have always tended to use citric acid because I was once told it doesn't have the same risks as other types of acids for off-flavors. that could be folklore of course.
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punkin
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Re: sulphuric acid

Post by punkin »

Uncle Jesse wrote:haven't had a haircut since 1992 but I'm about to. just sick and tired of having long hair. finally more tired of long hair than I was of haircuts when I stopped cutting it.

plus, working in the central valley heat with a boiler and still going, long hair just adds to the oppressive heat factor. it's become a hassle.

And your washes?
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Re: sulphuric acid

Post by Uncle Jesse »

punkin wrote:
Uncle Jesse wrote:haven't had a haircut since 1992 but I'm about to. just sick and tired of having long hair. finally more tired of long hair than I was of haircuts when I stopped cutting it.

plus, working in the central valley heat with a boiler and still going, long hair just adds to the oppressive heat factor. it's become a hassle.

And your washes?
I've never cleared a wash other than letting it settle, or if I get creative, racking it and letting it settle a couple of times to clear it.

When I experiment with molasses I've done some of the pH lowering combined with heat and it's worked very well to settle out detritus. I just wonder if it's more trouble than it's worth to avoid scaling in the column.
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manu de hanoi
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Re: sulphuric acid

Post by manu de hanoi »

Uncle Jesse wrote:by the way, to post on topic...I've been meaning to ask what's the difference between muriatic (hydrochloric) acid and sulfuric acid? what are the implications for distillers? I have always tended to use citric acid because I was once told it doesn't have the same risks as other types of acids for off-flavors. that could be folklore of course.
I use sulphuric acid to lower my wash ph, it's the cheapest source of H+, doesnt affect the flavor and is very dangerous to handle. never tried the chlorhydric acid but I thouht chlorine inhibited growth
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Re: sulphuric acid

Post by The Chemist »

Uncle Jesse wrote:by the way, to post on topic...I've been meaning to ask what's the difference between muriatic (hydrochloric) acid and sulfuric acid? what are the implications for distillers? I have always tended to use citric acid because I was once told it doesn't have the same risks as other types of acids for off-flavors. that could be folklore of course.
Both sulfuric acid and hydrochloric acid are "strong" acids, i.e. they completely dissociate in water. Citric acid is "weak" acid, and doesn't. So, per molecule, you get "more bang for the buck" with the strong acids when adjusting pH. All can cause problems is used improperly, but I would be more suspect of sulfuric...sulferous stuff can be really, really smelly...

So basically, I'd stick to what you've found works. What works for a rum distiller running 100KL through a continuous still every day may not work for everybody.
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Re: sulphuric acid

Post by timmyjane »

Can someone combine these first two post for me. Im not fully understanding the clarification process. The aluminum sulfate process looks like it would be useful. Please correct me if Im wrong but as I understand it clarified molasses will make for a cleaner still and a better tasting rum. Thanks.
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