BIODIESEL & SVO DISCUSSION FORUMS





Sponsors    Biodiesel and SVO Forums Home    Forums  Hop To Forum Categories  Biodiesel  Hop To Forums  Acid Esterification    trap grease problems

Moderators: Shaun, The Trouts
Go
New
Find
Notify
Tools
Reply
  
trap grease problems
 Login/Join
 
Member
posted
I have searched the topics about the trap grease. There are still something not very clear.

(1) When the grease trap company clean the traps, they only pump the grease or they need to empty everything in the trap? (The grease is on the top layer while water is in the botom)

(2) What is the average percentage of the oil(grease) in the total liquid pumped from the traps? 30% or less?

(3) After settling the trap grease, can you just get the grease and let the water flow into the sewer? (Since the function of the grease trap is to collect the grease while let the water flow into the sewer, I suppose after the settling, we can also do this. But just not sure.)

(4) I think Acid reaction is what we should start. The problem is how to pretreat the trap grease. There are a lot of contaminations in the grease. How to get rid of them? For example the bad smell?(Sure we can filtered the solids particles etc. But I belive there are also other contaminations that can not be get rid of by filtering) Maybe we can use water washing the trap grease?

I believe convert the FFA to biodiesel is not so complicate, but how to get rid of other contamination(4) is really challenge, any thoughts?

Thanks a lot!
 
Registered: February 17, 2009Reply With QuoteReport This Post
member
posted Hide Post
quote:
Originally posted by Green energy:
I have searched the topics about the trap grease. There are still something not very clear.

(1) When the grease trap company clean the traps, they only pump the grease or they need to empty everything in the trap? (The grease is on the top layer while water is in the botom)

As close to everything that's in the trap as possible, not close to everything.

(2) What is the average percentage of the oil(grease) in the total liquid pumped from the traps? 30% or less?

I would think that is close to accurate.

(3) After settling the trap grease, can you just get the grease and let the water flow into the sewer? (Since the function of the grease trap is to collect the grease while let the water flow into the sewer, I suppose after the settling, we can also do this. But just not sure.)

That's what grease trap collectors did in my past experience

(4) I think Acid reaction is what we should start. The problem is how to pretreat the trap grease. There are a lot of contaminations in the grease. How to get rid of them? For example the bad smell?(Sure we can filtered the solids particles etc. But I belive there are also other contaminations that can not be get rid of by filtering) Maybe we can use water washing the trap grease?

I believe convert the FFA to biodiesel is not so complicate, but how to get rid of other contamination(4) is really challenge, any thoughts?

Thanks a lot!


Filter and dewater would be my guess.
 
Location: central virginia | Registered: March 13, 2008Reply With QuoteReport This Post
member
posted Hide Post
I have only seen grease traps cleaned one time, this was behind a large restaurant, they had 5 traps. The folks cleaning these out sure had the right equipment, they had a brand new 40 ft stainless steel semi tanker trailer and pulled a vacuum on the entire tank using a big roots-type blower. They used semi-rigid 5 inch diameter hoses that appeared to simply be dropped to the bottom of the traps to suck everything, they did not make any attempt to control the depth of the hoses to only collect the grease floating on the water.

The trap grease that I have seen has been congealed into something like gray pudding, I would think you would have to heat it until it melts before you could do much of anything to clean it.

I have not treated actual trap grease but I have collected some pretty bad dog vomit vegoil, I water wash this with baking soda in the mix, it takes about a week for the bubbling/oil/water/BS/ soap reaction to stop, another week of settling and I have nice pretty clean oil floating above the crud/soap/water, the cleaned oil has only a little smell but the crap on the bottom is REALLY foul smelling.

Doing this type of BS or lye caustic stripping on trap grease will likely convert far too much of the grease into soap so, yes, acid processing to FFA has always been what I have read as the first step to processing trap grease.
 
Location: fisher,illinois,usa | Registered: June 03, 2003Reply With QuoteReport This Post
Member
posted Hide Post
Thanks Double D.

30% is maybe a reasonable number as possible biodiesel feedstock. If the grease is too little, for example 10%, I don't think it is worth to do that.

Filter or dewater should be necessary. But this can only get rid of water and solid contaminations. I believe there are other contaimination which can not be get rid of by these two method.

Since the trap is only use to collect the grease and solids, why need to pump everything in the trap? why not just pump the grease while leaving the water in the trap and flow to the sewer? This may increase the grease content and make the pretreatment more easier.

Seems very challenge.

quote:
Originally posted by Double D:
quote:
Originally posted by Green energy:
I have searched the topics about the trap grease. There are still something not very clear.

(1) When the grease trap company clean the traps, they only pump the grease or they need to empty everything in the trap? (The grease is on the top layer while water is in the botom)

As close to everything that's in the trap as possible, not close to everything.

(2) What is the average percentage of the oil(grease) in the total liquid pumped from the traps? 30% or less?

I would think that is close to accurate.

(3) After settling the trap grease, can you just get the grease and let the water flow into the sewer? (Since the function of the grease trap is to collect the grease while let the water flow into the sewer, I suppose after the settling, we can also do this. But just not sure.)

That's what grease trap collectors did in my past experience

(4) I think Acid reaction is what we should start. The problem is how to pretreat the trap grease. There are a lot of contaminations in the grease. How to get rid of them? For example the bad smell?(Sure we can filtered the solids particles etc. But I belive there are also other contaminations that can not be get rid of by filtering) Maybe we can use water washing the trap grease?

I believe convert the FFA to biodiesel is not so complicate, but how to get rid of other contamination(4) is really challenge, any thoughts?

Thanks a lot!


Filter and dewater would be my guess.
 
Registered: February 17, 2009Reply With QuoteReport This Post
Member
posted Hide Post
Good information Tim c cook.

what is exactly the baking soda you used? Kind of NaOH solution? Why you use that?

Also, what is the bubbling/oil/water/BS/ soap reaction?

How about only use water wash? Will the dirty things disolve in the water while the clean oil float above the water? (I don't want use NaOH, because it will conver the FFA to soap)

Thanks!



.............................
I have not treated actual trap grease but I have collected some pretty bad dog vomit vegoil, I water wash this with baking soda in the mix, it takes about a week for the bubbling/oil/water/BS/ soap reaction to stop, another week of settling and I have nice pretty clean oil floating above the crud/soap/water, the cleaned oil has only a little smell but the crap on the bottom is REALLY foul smelling.

..........................................



quote:
Originally posted by Tim c cook:
I have only seen grease traps cleaned one time, this was behind a large restaurant, they had 5 traps. The folks cleaning these out sure had the right equipment, they had a brand new 40 ft stainless steel semi tanker trailer and pulled a vacuum on the entire tank using a big roots-type blower. They used semi-rigid 5 inch diameter hoses that appeared to simply be dropped to the bottom of the traps to suck everything, they did not make any attempt to control the depth of the hoses to only collect the grease floating on the water.

The trap grease that I have seen has been congealed into something like gray pudding, I would think you would have to heat it until it melts before you could do much of anything to clean it.

I have not treated actual trap grease but I have collected some pretty bad dog vomit vegoil, I water wash this with baking soda in the mix, it takes about a week for the bubbling/oil/water/BS/ soap reaction to stop, another week of settling and I have nice pretty clean oil floating above the crud/soap/water, the cleaned oil has only a little smell but the crap on the bottom is REALLY foul smelling.

Doing this type of BS or lye caustic stripping on trap grease will likely convert far too much of the grease into soap so, yes, acid processing to FFA has always been what I have read as the first step to processing trap grease.
 
Registered: February 17, 2009Reply With QuoteReport This Post
Member
posted Hide Post
Grease trap waste is very difficult to process, I know, Ive been doing it. Grease content varies wildly from less than 2% all the way to 25% by volume.

The smell is very strong and is difficult to clean out of the oil. Also everything this oil gets in contact with will hold that smell for weeks.

Very few companies will let you collect grease trap oil aka 'brown grease' without proper licensing, bonding, equipment, and at least a $1,000,000 liabilty insurance policy.

Once you pass these fun milestones you have to deal with some of the highest FFA oil you have ever seen. The best I have ever gotten titrated at about 40T with the worst at 94.5T and an average if about 60T (I expect to break the record tomarrow when I visit the town of Buckeye WWTPSmile)

Once you build a reactor to handle a proper acid esterification to deal with such high FFA oil you move onto base transesterification as usual (but with less methonal since you already converted over a large portion of the oil [FFA's] into biodiesel during esterification)

After that there is still one big obstacle, gelling. Grease trap oil is primarily animal fats and will gel at very high temps. This is a problem I am still working on.

It has taken a very large financial investment for me to collect and process brown grease, Im not saying dont try it, because I think its a good step to take, just be prepared to put in a lot of time, energy, and $$$ to making it happen.
 
Location: Buckeye | Registered: July 07, 2009Reply With QuoteReport This Post



Member
posted Hide Post
Very good information!

could you talk about more in details about "and at least a $1,000,000 liabilty insurance policy", How can I get this insurance?

I am not too worry about the FFA, gelling point. The bad smell and contaimination make me feel uncomfortable. The low grease content also is a concern.

Thank you very much!


quote:
Originally posted by buckeyebiodiesel:
Grease trap waste is very difficult to process, I know, Ive been doing it. Grease content varies wildly from less than 2% all the way to 25% by volume.

The smell is very strong and is difficult to clean out of the oil. Also everything this oil gets in contact with will hold that smell for weeks.

Very few companies will let you collect grease trap oil aka 'brown grease' without proper licensing, bonding, equipment, and at least a $1,000,000 liabilty insurance policy.

Once you pass these fun milestones you have to deal with some of the highest FFA oil you have ever seen. The best I have ever gotten titrated at about 40T with the worst at 94.5T and an average if about 60T (I expect to break the record tomarrow when I visit the town of Buckeye WWTPSmile)

Once you build a reactor to handle a proper acid esterification to deal with such high FFA oil you move onto base transesterification as usual (but with less methonal since you already converted over a large portion of the oil [FFA's] into biodiesel during esterification)

After that there is still one big obstacle, gelling. Grease trap oil is primarily animal fats and will gel at very high temps. This is a problem I am still working on.

It has taken a very large financial investment for me to collect and process brown grease, Im not saying dont try it, because I think its a good step to take, just be prepared to put in a lot of time, energy, and $$$ to making it happen.
 
Registered: February 17, 2009Reply With QuoteReport This Post
Member
posted Hide Post
Hello,

My name is Ralph Howe, I have been in the business of processing raw grease trap waste into fuels since 2004/05..

Things I can tell you is that raw grease trap waste is not Brown Grease per say. Normally "brown grease" is what is more of a food processing waste from industry that is mostly free fatty acids. Were raw trap waste is all the contents of an under ground grease trap. Then there is another grade even worse called "Black grease waste" from people I have talked to which is the grease waste from the clarification units on the head works of septic treatment or municipal treatment plants.

So your question about processing Raw Grease Trap Waste. The steps needed to process are not as simple as one would think. Nor are they as self evident as yellow grease, simply heat and filter.
I would be happy to help you with the technology needed in order to get high and cost effective energy returns from your RGTW.
IF you would like you can call me at 207-930-5247 or email me at BRFuels @ yahoo.com
 
Location: United States | Registered: February 23, 2012Reply With QuoteReport This Post
Member
posted Hide Post
Since there is probably a lot of solids could you do a hexane extraction of the fats? It would have to dry though. Then distill to recover your solvent. I've been experimenting with municipal sludge and I've been using that technique.
 
Location: Dunnville, ON | Registered: May 01, 2012Reply With QuoteReport This Post
Member
posted Hide Post
quote:
en distill to recover your solvent. I've been experimenting with municipal sludge and I've been using that technique.


This is a high cost method for extracting the oils. like I said in the post above, we have been doing this for years. We are more than happy to help people with this technology sector.
If you are really interested in refining grease from grease trap waste please give me a call.

Thank you.
Ralph Howe
Bio Renewable Fuels Corp.
4 Industrial Rd.
Fairfield ME 04937
www.biorenewablefuels.com
207-323-0679
 
Location: United States | Registered: February 23, 2012Reply With QuoteReport This Post
Member
posted Hide Post
We use a very fine bubble aerator in restaurant grease traps. The patented Vacuum Bubble Technology Aerator ("VBT TM") has proven over and over again to eliminate odors from H2S gas in a matter of hours and has proven successful in extending the grease trap pump out frequency. Typically we recommend that pump outs occur when the grease cap (surface grease) and sludge layer (bottom of the tank) reach 50% of the total tank volume.

In certain applications we install a Bio Amp along with the VBT which produces over 30 Trillion bacteria every day, day after day after day.

In addition to odor control, the VBT has also proven very effective in significantly reducing municipal surcharges that are applied to high strength wastes by pre-treating the waste stream before leaving the tank.
 
Location: Fort Myers, Florida | Registered: July 30, 2012Reply With QuoteReport This Post
  Powered by Social Strata  
 

Sponsors    Biodiesel and SVO Forums Home    Forums  Hop To Forum Categories  Biodiesel  Hop To Forums  Acid Esterification    trap grease problems

© Maui Green Energy 2000 - 2014