Search found 302 matches

by Bob
Thu Jun 05, 2008 9:04 am
Forum: About Biorealis Systems, Inc.
Topic: Am I in the right place?
Replies: 1
Views: 11795

Re: Am I in the right place?

Nothing here on methanol, yet, Chad. Mostly just about biogas.
by Bob
Sun Jun 01, 2008 6:26 pm
Forum: Anaerobic Digester
Topic: Can I use straw as a raw material input?
Replies: 5
Views: 16240

Re: Can I use straw as a raw material input?

Whoa! A Nathan sighting. :D
by Bob
Sun May 25, 2008 11:22 am
Forum: Composting Toilet
Topic: A new and "better"? batch composting toilet design
Replies: 14
Views: 32720

Re: A new and

Hi Eliza, Nice to see you here. I would need to know more about your specific site conditions to be able to say if, or how well my rotating drum, urine-separating design would work for you. Probably the single most important criterion is to have accessible space for it directly below the toilet. How...
by Bob
Tue May 13, 2008 6:33 pm
Forum: Biofilter
Topic: Drum Biofilter
Replies: 6
Views: 21211

Re: Drum Biofilter

I am trying to figure out how to do it without using electrical pumps. I also tried to figure out some way to eliminate pumps, but could find no way to achieve the present functions without them. Even moving water from tank 1 to tank 2 by gravity would create a difficult maintenance problem, and it...
by Bob
Mon May 12, 2008 10:44 am
Forum: Anaerobic Digester
Topic: Can I use straw as a raw material input?
Replies: 5
Views: 16240

Re: Can I use straw as a raw material input?

Here is a link to an FAO Document about the feasibility of treating straw for animal feeding. I would guess that the methods required to make it digestible by microbes would be similar.
by Bob
Mon May 12, 2008 10:25 am
Forum: Anaerobic Digester
Topic: Can I use straw as a raw material input?
Replies: 5
Views: 16240

Can I use straw as a raw material input?

Here is a message copied from Private Messages to new public topic: A couple of in principle questions about methane digestion. Can I use straw as a raw material input? Can straw be chopped up and added to the input to systems where the predominant input is say cow manure? My idea is to take straw t...
by Bob
Fri Apr 25, 2008 10:48 am
Forum: General Catchall
Topic: Aerobic Digestor Design
Replies: 1
Views: 10628

Re: Aerobic Digestor Design

Hi andrew. I have two different aerobic systems developed: a composter for human feces (but waterless, with urine separation), and an aerobic treatment unit for graywater. I'm not sure if either fit your description. (My own approach is to just not put feces in water in the first place. That simplif...
by Bob
Sat Mar 01, 2008 7:22 pm
Forum: Anaerobic Digester
Topic: Digesting crude biodiesel glycerol
Replies: 14
Views: 40405

Wow! I just spent some time at Graham Laming's website. What a great bunch of information.

There is far more -- and better -- information available now than there was when I last was into this a few years ago.

Thanks for the pointer, farmer.
by Bob
Fri Feb 29, 2008 5:20 pm
Forum: Anaerobic Digester
Topic: Digesting crude biodiesel glycerol
Replies: 14
Views: 40405

Speaking of biodiesel, here is a design I developed a few years ago as one component of a fully sustainable, renewable energy four-season food production facility for a rural Alaska village. The project wasn't fully funded, so this part didn't get built. What's unique about it is that it uses waste ...
by Bob
Fri Feb 29, 2008 4:20 pm
Forum: Anaerobic Digester
Topic: Digesting crude biodiesel glycerol
Replies: 14
Views: 40405

The glycerol is contaminated with methanol (about 25% by volume)
That seems awful high. Are you recovering (or attempting to recover) any of the methanol?

Thanks for the biodiesel links. Good stuff!
by Bob
Fri Feb 29, 2008 4:12 pm
Forum: Anaerobic Digester
Topic: Feedstock prep, what sort of pump?
Replies: 1
Views: 10495

What sort of prep are you doing on the front end? Would passing the feedstocks through a garbage disposal be effective mastication? I use a diaphragm pump -- commonly use for RV or boat holding tanks. But if the feedstock is fibrous, it will be a maintenance headache. And a nasty one. The extra ene...
by Bob
Fri Feb 29, 2008 4:01 pm
Forum: Anaerobic Digester
Topic: Methane Digester for village households
Replies: 8
Views: 21901

How do you think this would do in temperate climates? I am envisioning building an insulated house for the bag, then looping radiant heat tubing around the base of the bag to keep it around 90F... I guess that all depends on the ambient temperatures (which will determine how much of a building you ...
by Bob
Sun Feb 17, 2008 5:38 pm
Forum: Anaerobic Digester
Topic: Horizontal versus vertical
Replies: 1
Views: 10515

Space available? The horizontal layout requires more.

I think Aguilar's design is about as simple and inexpensive as can be done. It looks like it is particularly well-suited to places where (1) the climate is warm (i.e. tropics) and (2) where labor is cheap.
by Bob
Sun Feb 17, 2008 5:34 pm
Forum: Anaerobic Digester
Topic: Methane Digester for village households
Replies: 8
Views: 21901

I found it again at:

http://crat.africa-web.org/Biogas/technology.htm

(it's hard to keep up with link-rot...)
by Bob
Sat Feb 16, 2008 10:52 am
Forum: Anaerobic Digester
Topic: mini digester...?
Replies: 32
Views: 93171

Hey farmer,

Glad you found it. When you get it built, post some pictures! :D
by Bob
Sat Feb 09, 2008 7:24 pm
Forum: Anaerobic Digester
Topic: AD Thoughts
Replies: 1
Views: 10700

Hi kjankows, (I just discovered your message, posted here almost 2 weeks ago -- but overlooked.) Thanks for the insights -- and the pointer to the online pdf document. It looks excellent. (When I get a chance, I'll print it out and read it in detail.) re comments and/or corrections, I appreciate you...
by Bob
Tue Jan 29, 2008 10:25 am
Forum: Anaerobic Digester
Topic: Methane Production Vs. C.O.D
Replies: 3
Views: 14706

Thanks, kjankows. Good info.

(I think the time production curve question refers to reaction velocity -- a function of population, useful in batch studies.)
by Bob
Tue Jan 08, 2008 6:19 pm
Forum: Anaerobic Digester
Topic: fixed film in AD
Replies: 5
Views: 16174

Are you familiar with the USEPA's Agstar program? They have some design software and a comprehensive handbook free for downloading, that may fit your application better than my smaller scale stuff.

http://www.epa.gov/agstar/resources.html
by Bob
Tue Jan 08, 2008 4:52 pm
Forum: Anaerobic Digester
Topic: fixed film in AD
Replies: 5
Views: 16174

Hi Angus, The online calculator waste composition data is taken from Other Homes and Garbage by Leckie, Masters & Young. A screenshot of the lookup table is posted in this topic . (Scroll down to to near the bottom of the thread.) It shows 30 lb/day for horse manure. At an estimated 60-65 lb/cu ft, ...
by Bob
Sat Jan 05, 2008 7:08 pm
Forum: Anaerobic Digester
Topic: fixed film in AD
Replies: 5
Views: 16174

Hi Angus, Adding fixed film media wouldn't actually add hydraulic retention time, but it should achieve a similar effect by giving the microorganisms something to hang on to. That said, though, I've found fixed film media to add cost and complexity. But of course there are all kinds of media, some m...