finishing hog barn with AD System

[jdunn5]

Hello Bob,
Would like to add but another GREAT SITE!!!!

I am in the process of gathering as much info as I can for a design of two finishing hog buildings capable of holding 1200 head for a total of 2400. I want to incorporate the AD system in with the buildings to minimize cost as well as area needed to provide the most efficient process possible. I have reviewed allot of information from State sites that have done case studies, which about half are unsuccessful due to lack of planning and knowledge of the operations once the system was in place. (I try to learn from other people?s mistakes )
I have allot more to learn and was hoping to gain a little input or suggestions as to ideas for incorporating barns and AD System.

To start the hog barns are finishing so the hogs are all in on slated floors, where the manure will be forced down through the slats into a pit. There is no bedding for this reason, so the Solid ratio should be extremely low. (Im not sure how much the solids help or hinder the production of biogas and methane.

The hogs will produce an estimated 3,360 gal/day of manure.

I am hoping for this system to provide three things, Electricity from the burned methane through a generator, recover heat for heating the digester and the hog barn through engine heat, and provide odor reduction to comply with GAAMPS set up by the State of Michigan for the right to farm act.

Would it be possible to have the pit below the barn in two layers: the first layer would catch the manure and an auger system pull the waste into the first stage of the digester, which would allow the manure to enter the digester at the warmest possible temperature depending on how often it was augured.

Have the Digester setup in a Large Stainless Steal tank outside the buildings, where both buildings will pump into the same digester. The decision I guess would be to either have the digester in a stainless steel tank or concrete a tank.

Then after the digestive process have the manure augured back down the 2nd layer below the first where it will sit until pumped out to be knifed in for fertilizer. (which will happen about twice a year.)

This might a bit hard to visualize so I while throw together a quick drawing and post it or email it to you to give you a general idea of the schematics.

Any info or suggestions would be greatly appreciated, I?m trying to gather as much info good and bad about other systems and trying to come up with my own that could be more efficient than what I have read about in other case studies.

Thanks in advance.

[Bob]

To start the hog barns are finishing so the hogs are all in on slated floors, where the manure will be forced down through the slats into a pit. There is no bedding for this reason, so the Solid ratio should be extremely low. (Im not sure how much the solids help or hinder the production of biogas and methane.

I don't think there is a straightforward answer to that question. It's not just a matter of solids content, but the analysis of those solids. I'd guess that the lack of bedding, (cellulosic bedding in particular) would make it easier to handle, and easier for the bacteria to break down. The quantity and ratio of Carbon to Nitrogen per day is the main criteria for estimating gas production. (besides temperature & HRT, that is).

The hogs will produce an estimated 3,360 gal/day of manure.

The data I have on pigs indicates manure production of 6 gal/day/unit. Which works out to 14,400 gal/day for 2,400 pigs. So I assume that my data is for a different type of operation and/or that you will be adding about 2,000 gal/day of water? On that assumption, it looks like, if you do a 2-stage operation, using the HRT's I have used with my experimental system, you will want the first (acetogen) reactor to be about 10,000 gal capacity, and the second (methanogens) about 30,000 gallons.

I am hoping for this system to provide three things, Electricity from the burned methane through a generator, recover heat for heating the digester and the hog barn through engine heat, and provide odor reduction to comply with GAAMPS set up by the State of Michigan for the right to farm act.

Plugging that in to my handy dandy calculator, it looks like you can produce about 12,000 CF/day of biogas, or about 7,800 CF of methane (assuming 65% methane).

Would it be possible to have the pit below the barn in two layers: the first layer would catch the manure and an auger system pull the waste into the first stage of the digester, which would allow the manure to enter the digester at the warmest possible temperature depending on how often it was augured.

Sure. It sounds possible. Of course the devil is in the details.

Have the Digester setup in a Large Stainless Steal tank outside the buildings, where both buildings will pump into the same digester. The decision I guess would be to either have the digester in a stainless steel tank or concrete a tank.

I'm sure both have their advantages and disadvantages. I'd guess that concrete would be least expensive.

Then after the digestive process have the manure augured back down the 2nd layer below the first where it will sit until pumped out to be knifed in for fertilizer. (which will happen about twice a year.)

By "layer" do you mean in the same tank?

This might a bit hard to visualize so I while throw together a quick drawing and post it or email it to you to give you a general idea of the schematics.

Yeah. I'd be curious to see it. If you want to post your drawings here, you can upload them to 'ftp.biorealis.com' (or to your site), then link to them here.

To upload files, point your ftp client (e.g. FileZilla) to 'ftp.biorealis.com', username = forum, password = uploads.

Then, to add a link to the uploaded file, see "Adding an image to a post" in the BBCode tutorial. The location to be entered between the '[img]' tags will be "http://biorealis.com/forumuploads/filename", where filename is the name of the uploaded image file.

[Bob]

Also, have you checked out Agstar's Farmware program? It goes into the economics of the operation.