Search found 302 matches

by Bob
Fri Nov 29, 2002 3:22 pm
Forum: Anaerobic Digester
Topic: mini digester...?
Replies: 32
Views: 94204

startup

Shadow, the amount of time it will take to get gas production going will depend on how many live bugs you have to start with. There is some discussion of 'seeding' or 'inoculation' in this conference Worst case would be that it never produces any gas at all. This could happen if you load up your dig...
by Bob
Tue Nov 26, 2002 5:53 pm
Forum: Anaerobic Digester
Topic: mini digester...?
Replies: 32
Views: 94204

ok, here are some pictures of a simple gas collector. The pieces are: 1- 4" PVC coupling 1- 2-liter soda bottle (7-Up not necessary) 1- 6" length of 3" ABS sewer pipe 1- 3-1/2" diameter disk cut from 1/4" PVC sheet material 1/8" ID (1/4" OD) polyethylene tube & fittings and/or vinyl tube and fitting...
by Bob
Fri Nov 22, 2002 11:39 am
Forum: Anaerobic Digester
Topic: mini digester...?
Replies: 32
Views: 94204

"I'm going to see which pre-treatment of two helps to produce more biogas." That sounds like a worthy goal. How are you going to pretreat it? "I think we will be feeding the digester approx. 1/2 lb. of chicken "waste" a day." The designs described above are suited for a batch feed process rather th...
by Bob
Fri Nov 15, 2002 1:47 pm
Forum: Composting Toilet
Topic: A new and "better"? batch composting toilet design
Replies: 14
Views: 33161

Hi Shawn, Sounds like the 6'x 6'x 5' work space you have available should work fine. Do you also have free access to at least one side of the enclosure, to allow removing and replacing drums? Ideally, you should have room to maneuver a hand truck able to handle a drum that weighs >150 lbs (volume of...
by Bob
Wed Oct 30, 2002 9:44 am
Forum: Anaerobic Digester
Topic: science project
Replies: 8
Views: 12147

Hi Laurel, Thanks for the info. Think I'll go out & stomp around in a swamp with a funnel & some matches this weekend. Fun. Another thought regarding seeding: Diversity. The term "methanogen" doesn't apply to a particular organism or species, but to bazillions of different organisms--about as many a...
by Bob
Sat Oct 26, 2002 7:33 am
Forum: Composting Toilet
Topic: A new and "better"? batch composting toilet design
Replies: 14
Views: 33161

Hi Shawn, Nice to see you here. To bring others up to date, here is a description of the current system, and here is what I said in my email: <blockquote> "In fact I'm in the process of designing a new, improved version for my own house. Having experimented with the low-flush (Sealand) toilet model ...
by Bob
Thu Oct 24, 2002 3:09 pm
Forum: Anaerobic Digester
Topic: science project
Replies: 8
Views: 12147

"I wonder if cooked makes any difference to the digestion efficiency?

I would guess that, to the extent that heating breaks down cell walls, it would be more 'bio-available'. But there probably isn't a completely straightforward answer. It probably depends a lot on the material.
by Bob
Thu Oct 24, 2002 2:58 pm
Forum: Anaerobic Digester
Topic: science project
Replies: 8
Views: 12147

"I will have to weigh the chicken manure the same in all three containers as well as the three different materials that I add, grass clipings,decaying leaves and I have not come up with the third yet. Any ideas?" kitchen scraps -- as Nathan suggests? Assuming that you're doing this for more than ju...
by Bob
Thu Oct 24, 2002 9:51 am
Forum: Anaerobic Digester
Topic: mini digester...?
Replies: 32
Views: 94204

Good points, Nathan. "The new design will experience some error due to evaporation in the second jug" True if you measure the height of the floating cover above the top of the stationary container rather than to the standing water level. But if you measure it to the water level, it shouldn't matter....
by Bob
Tue Oct 22, 2002 10:08 am
Forum: Anaerobic Digester
Topic: mini digester...?
Replies: 32
Views: 94204

sketch

http://biorealis.com/images/digestersketch3.jpg Here's another idea: Jug #1 is the same as in the previous sketch , but jugs 2&3 are replaced with a 'gasholder' -- a water-filled container with a floating cover. Measure and mark (calibrate) the floating cover as described in the ItsAGas site, so yo...
by Bob
Tue Oct 22, 2002 8:21 am
Forum: Anaerobic Digester
Topic: science project
Replies: 8
Views: 12147

Whoa! Interesting as a science project, but don't expect to get too much electricity from 8 chickens... Did you check out the amount of biogas you can get from 8 chickens, using my digester calculator ? It looks like maybe about 3 cu ft/day biogas (2 cu ft methane), say about 1,800 Btu/day (at 900 b...
by Bob
Mon Oct 21, 2002 4:29 pm
Forum: Anaerobic Digester
Topic: mini digester...?
Replies: 32
Views: 94204

It's a gas

http://biorealis.com/images/digestersketch1.jpg Here is a sketch of the setup (if I understand it correctly) described in the ItsAGas website. Here's how it works: Gas pressure generated in the digester (jug #1) displaces water in jug #2 to flow into jug #3. The rising water level in jug #3 is equa...
by Bob
Mon Oct 21, 2002 8:05 am
Forum: Anaerobic Digester
Topic: mini digester...?
Replies: 32
Views: 94204

Yeah, I see what you mean. That's a good site as far as it goes, but there's not enough detailed info there. (Intended as a "lesson plan", it seems to be designed to generate as many questions as answers, questions to be answered by doing, in the classroom.) As described, I don't think it will make ...
by Bob
Sat Oct 19, 2002 10:17 am
Forum: Anaerobic Digester
Topic: mini digester...?
Replies: 32
Views: 94204

Hi Shadow, That's great, that you are building a digester for your science fair project. Can you say a little bit more about your proposed design? The answer(s) to your questions about stirring, temperature control, gas collection, etc. have a lot to do with exactly what it is that you are building....
by Bob
Fri Oct 18, 2002 4:04 pm
Forum: About Biorealis Systems, Inc.
Topic: Hi Robert
Replies: 1
Views: 12882

Hi John,

I was just doing some housekeeping here & came across this message that I realize I had never replied to. Sorry for the long delay. Can you refresh my memory (via email) wrt particulars of Garsett's site?
by Bob
Tue Oct 15, 2002 9:29 am
Forum: Anaerobic Digester
Topic: saving the world and other fun stuff...
Replies: 30
Views: 69733

Well, anaerobic digestion itself, as a metabolic process, is exothermic. But I'm not sure that's what you're asking. There are different groups of bacteria, which only live within very specific range of temperatures. If the heat loss from the reactor vessel is greater than the heat generated by meta...
by Bob
Mon Oct 14, 2002 7:47 am
Forum: Anaerobic Digester
Topic: Biogas Digester for Dog Kennel wastes on Cyprus?
Replies: 19
Views: 27568

Peter, It's been a while, so I don't know if you ever resolved your problems with the dog waste. I recently came across a design that looks like right up your alley. A low-tech, low-cost site built digester.
by Bob
Tue Oct 08, 2002 7:02 am
Forum: Anaerobic Digester
Topic: saving the world and other fun stuff...
Replies: 30
Views: 69733

Hmmm... I don't know why the image wouldn't display, Nathan. It works ok on mine. Maybe try reloading the page. (I did have to edit the image, so maybe you loaded the page before it was fixed and the broken version is in your cache). Anyway, in case you can't see it, it is Figure 4. Schematic of Sol...
by Bob
Mon Oct 07, 2002 9:24 am
Forum: Anaerobic Digester
Topic: saving the world and other fun stuff...
Replies: 30
Views: 69733

... water and glassware is no problem, but gas analysis and COD reactor... I'm not even sure what I'd be looking for. Well, I guess quantity of biogas and methane for starters. Probably the easiest way to do that would be to bubble it up under an inverted bottle with markings on it (or graduated cy...
by Bob
Sun Oct 06, 2002 8:27 am
Forum: Anaerobic Digester
Topic: saving the world and other fun stuff...
Replies: 30
Views: 69733

Further thoughts... 1. WRT limewater, I think that should have been Ca(OH)2 above, right? 2. I wouldn't be surprised if the digestibility of wheat straw & chaff has been already well researched. I know that bagasse (sugar cane residue), rice straw and other agricultural "waste" fibers are favored fe...