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biogas: inputs and outputs

 
Posts: 1502
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From my studies on biogas, it would take a lot of material to produce enough gas for daily cooking needs for a family of 4.

The other issue, is that you have to collect the material, meaning penning animals, or growing specifically for the digester.

We compost humanure, chicken manure (20 chickens), and rabbit manure (15 rabbits).  We hope to get some pigs and/or goats in the future.

Are there any resources to know the biogas output according to the animals you have?  Like 3 humans, 20 chickens, 15 rabbits, and 2 dogs, how many cubic feet daily could be produced from that (assuming I am collecting at least 90% of their manure and including enough carbon for a proper C/N ratio).

I think from what I calculated, I would need at least a pig on top of what I currently have.
 
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Dear velacreations,

Unfortunately I don't think it's a simple question, since so many factors pertain.

For example, at least as I see it, I would not both put the human wastes into a digester and use the effluent for edible crops. The reason is that it takes a good while before the nasties in humanure are rendered harmless by anaerobic digestion (6 months or more), and meanwhile one is not going to get a great whopping output from the digestion thereof (1 cu ft per day per adult). Having a digester that would be able to keep everything it is fed for 6 months before it was pushed out the outlet would mean that it would have to be far larger than it would be if the only desired outcome were simply biogas. Not only would a far larger digester cost more in materials to build, but one would have to heat the digester, and the water in the slurry would take a lot of calories to heat.

Mind you, in some other situation, AD with humanure as the input would make sense, but as I say, perhaps not in this one.

As regards the amount of biogas expected from the animals, there is abundant information about "commercial" animals such as chickens, but far less information about animals that are rarely commercial, such as rabbits. It you can't find it (the meat) in the supermarket, it will be hard to find it (info on biogas production from the manure) on the Internet.

Do not forget, however, that from anything you can compost you can also make biogas. This would include your kitchen wastes, which may in fact just at the moment offer you far more biogas than all the manure you have. Because information about biogas in the early days came mostly from studies on municipal sewage (that's where the need was and that's where the money for research was), then most of the information available about biogas until recently was focused on manures. But there is really much more biogas available from a given weight of organic stuff available before it has been digested by an animal than there is after. After all, the little bitty biogas buddies are well adapted to mammalian guts, and so they eat what we eat.

In some cases, such as for lignocellulosic stuff (woody material), you might get more biogas after an animal has digested it than before, but for almost anything that will produce compost quickly, it will also produce biogas quickly, and in amounts that comfortably exceed anything a comparable amount of manure will produce.

One of the most interesting resources with regard to this (aside, of course, from the Complete Biogas Handbook, ahem), is found here (use the fourth link): http://www.cropgen.soton.ac.uk/deliverables.htm. The database is very hard to use, but if you know what you are doing, you can link to it from within Excel, and see the raw data for every table.


d.
 
Abe Connally
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thanks for your reply.

I don't mean to degrade biogas, but I am having a hard time seeing how it is more efficient overall than other biofuels.

1) The stuff on ethanol vs biogas doesn't include hi output crops like Jerusalem Artichokes (900 gallons ethanol per acre) or cattails (3,000 gallons ethanol per acre), both of which are far more efficient than corn (200-300 gallons ethanol per acre).  What sort of biogas output are we looking at for the same feedstocks?  By my calculations, you need about 1 lb biomass per cubit foot of biogas (this can vary, but at an average).  So, with that average, if we take the Jerusalem Artichoke example above, we could potentially produce about 100K cubic feet of biogas per acre of JA. That would mean we would get out about the same amount of BTUs going through biogas, however, we still have a lot of food value in the waste of the ethanol system, whereas the biogas system leaves us with good fertilizer, but no food.  Are these figures way off?

2) For transportation fuel (which is the hardest to produce at home or on a farm), compressed gasses are harder to manage that solid feedstocks.  Wood gas has a solid feedstock, at about 15-20 lbs of biomass per gallon of gasoline equivalent.  Biogas seems like you would need about 120-200 lbs of biomass for the same energy, though you have to carry it as a compressed (3500 psi?) gas.  Ethanol is liquid, so much easier to handle there.

I think the BEST solution on any energy strategy has to be a combination of efforts.  Say, if you used cattails to make ethanol, then used the waste from fermentation to make biogas, you could greatly increase the overall efficiency.

But, right now, I have a hard time seeing how biogas on its own would be easier to use as some of the other biofuels.  Definitely solid and liquid fuels are easier to handle, and nothing is easier to produce that wood gas.

Could you help me with some of this, as I am sure it would help others as well.  And please, I don't want to slam biogas, I am just trying to understand how homesteaders like myself can use it to our advantage.
 
David House
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Dear velacreations,

velacreations wrote:
...I am having a hard time seeing how it is more efficient overall than other biofuels.

1) The stuff on ethanol vs biogas doesn't include hi output crops like Jerusalem Artichokes (900 gallons ethanol per acre) or cattails (3,000 gallons ethanol per acre), both of which are far more efficient than corn (200-300 gallons ethanol per acre). [...]

What sort of biogas output are we looking at for the same feedstocks?  By my calculations, you need about 1 lb biomass per cubit foot of biogas (this can vary, but at an average).  So, with that average, if we take the Jerusalem Artichoke example above, we could potentially produce about 100K cubic feet of biogas per acre of JA.




Certainly JA is more productive, but while an argument could be made for it, I would not say it's more efficient, than corn; and the difference is important in such a discussion.

I say that because the reason that ethanol suffers in studies such as Sampson's is, precisely, efficiency. Making ethanol requires cooking the mash, (sometimes cooling it and adding enzymes), keeping the wort warm while it ferments, and then distilling it-- and, David Blume notwithstanding, all that taken together is very energy intensive. Now, by so saying I'm not saying that none of us should be making ethanol. If you want, have at it.

But both the biological process of anaerobic digestion and the fermentation process of ethanol production can make use of whatever energy there is in the given crop: and there is clearly more in switchgrass than corn, more in J. Artichoke than switchgrass, and still more in cattails, again for either process to harvest. For this reason among others, it is not valid to assume that for 1 unit weight of any otherwise unspecified organic material we will get some given output volume of biogas, any more than such a logical process can be applied to the production of ethanol. For example, for either, the yield from the JA tubers vs. JA halums would be quite different, pound for pound, primarily because there is more inulin in the tubers.

In the case of JA, based on at least one reference (there's surely a limit to what's useful/required simply for an answer such as this) and assuming 25% tubers and 75% haulms et al are harvested from a given unit of land, the figure I come up with in cu ft/a for JA is 245,000. Assuming that's close to the mark, and taking your figures for ethanol at face value, then in terms of raw calories, at 80,000 BTU per gal for the ethanol and 912 BTU per cu ft for methane (and assuming 65% methane in the biogas), what I get is 72 mil BTU for the ethanol from JA per acre, vs. 145 mil BTU for the biogas. Figures for cattails, I would assume, would track similarly.

Now, importantly and to get back to the initial point made above, this is not net energy, but gross energy. There are a number of studies which show, as I implied above, that the net/net for ethanol is rather lower than net/net for biogas. Furthermore, there are studies that show that converting biogas into electricity and running an efficient electric car vs. using the same land and inputs to produce ethanol which is burned directly in an ICE in a small car, one gets about twice the distance with biogas.

Even given all this, however, the conclusion is not "always go for biogas". I agree with you that a mix will be best, if we are considering society as a whole, even if we narrow the focus to thee or me, either of us may have a situation that leads us to favor ethanol or biogas (or something else) for our personal energy production, should we choose to become a producer.





But, right now, I have a hard time seeing how biogas on its own would be easier to use as some of the other biofuels.  Definitely solid and liquid fuels are easier to handle, and nothing is easier to produce [than] wood gas.




Each to his own. I would not reach exactly the same conclusions-- for example, I couldn't say from personal experience, but based on discussions I have seen on the gasification forum to which I belong, wood gas is not simple, by any means-- but that's fine. I'm interested in information about energy, and the idea of being "loyal" to a given form of ASE is... well a bit bizzare, as I see it (and apparently as you do as well), so for me it's just about the facts and the numbers, as nearly as I know and can understand them.




d.
 
Abe Connally
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Thanks for your great information.  It looks my first numbers were off on the biogas from JA.  I am glad you cleared that up.  One thing, where do you get 900+- BTU per cubic foot of biogas?  I had always seen 600 BTU per cubic ft, if it was only 65-75% methane.  That is a good thing if it contains more BTU per cubic foot.

To me, it is not a matter of being loyal to one form or another.  It is more of an issue to determine what form is easiest to produce locally, which is cheapest, and of course, efficiency has a lot to do with all of this.

In those studies comparing the ethanol, did they take into account the energy required to keep the digester up to proper temps (90 degrees or so), because those temps are very similar to ethanol fermentation temps.  The difference being, of course, that ethanol fermentation is maybe a week long, whereas biogas is continuous.  I definitely see where net/net of biogas could be higher, though I do think for both systems solar heat is the only reasonable way to go.

The next thing I am thinking is how much energy is required to compress methane into a transportable form?  I think that is where ethanol gets a lot of attention, because it is liquid. But maybe it doesn't take much to get to 3500 psi.  Do you know?

All of these systems could be improved considerably by including solar heat (heat the digester or fermentation tank, distill ethanol with solar heat, compress biogas with solar or wind, etc)

In my area, transportation fuel is the big issue.  Electric vehicles are not feasible here for 2 main reasons. 1. distances -  the large city, which is the source of the majority of goods and manufacturing is just over 100 miles away, making it a 200 mile roundtrip 2. roads -  many of our ranch and rural roads are dirt and require trucks or high clearance vehicles (I am not saying a truck can't be electric).  Cars are not viable here.

The point here being that our situation requires unique solutions that would not be suitable for other areas.  The most reasonable solution here is to produce our transportation fuels on our small farms, with whatever feedstocks give the most energy for the work involved.

I am in Northern Mexico, in a fairly poor, rural area. ( by poor, I mean the average income is less than $4,000 USD per year)

What would you suggest our route to be?  We have a lot of ag wastes, from spoiled apples to tree trimmings, spoiled hay, etc.  Much of this waste is currently just burned or left to rot. Growing our fuel would definitely be possible, as we have land, as long as we can do it in an environmentally (permaculture) compatible way.

Wood gas seems like a viable solution for the woody stuff, and I can say from experience, it is actually pretty easy to make (you actually make it every time you burn wood).  Once you build the production unit (tons of free plans online), it is a matter of filling it up and starting a small fire.  It is not as convenient as some of the other fuels because of the startup time, but it is very efficient in terms of biomass, especially compared to ethanol (15-20 lbs biomass = 100K+ BTU).

But biogas could probably process the vast majority of our wastes, including some animal wastes.  The main obstacle there would be the need to compress the gas (I don't know the energy required), and locating proper transportation tanks.

Biogas also would have a huge impact in the households as far as cooking gas is concerned.  Propane is the current choice, and although it is not expensive here, it is still a recurring cost.  The advantage with a stationary application would be that there is no need to compress the gas, hence saving on equipment and energy.

Anyway, what would be your suggestions for a reliable energy solution to our needs? Would biogas be an appropriate solution here? I don't expect you to completely design a solution for us, just some advice.  You do seem to really know your material, and I hope you continue to share your information with us on this forum.

Thanks!
 
David House
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velacreations wrote:
Thanks for your great information.  It looks my first numbers were off on the biogas from JA.  I am glad you cleared that up.  One thing, where do you get 900+- BTU per cubic foot of biogas?  I had always seen 600 BTU per cubic ft, if it was only 65-75% methane.  That is a good thing if it contains more BTU per cubic foot.




Sorry for the confusing way in which I put it, but what I said was

David House wrote:
...912 BTU per cu ft for methane (and assuming 65% methane in the biogas)...



That is, yes, methane has 912 net BTU, and where there is 65% methane in the biogas, then the BTU per cu ft would be calculated as less than. Because 912 is so close to 1000, many folks simply add a zero to the percentage of methane. By that calculation, the BTU of 65% methane-containing biogas would be 650, rather than the 593 we get when we do the math.

I would say, with regard to math, that it makes no sense in most cases to carry things out to more than one or two significant digits because the measurements we generally make are not that accurate. If we measure a football field with a foot long ruler and express the result to a sixteenth of an inch, we may have done the addition accurately, but we have failed to understand the limits of our tools and procedures.



In those studies comparing the ethanol, did they take into account the energy required to keep the digester up to proper temps (90 degrees or so), because those temps are very similar to ethanol fermentation temps.  The difference being, of course, that ethanol fermentation is maybe a week long, whereas biogas is continuous.  I definitely see where net/net of biogas could be higher, though I do think for both systems solar heat is the only reasonable way to go.



Ethanol also makes use only of the sugars in the material (the "oses": sucrose, maltose, galactose, fructose). Now, many substances (such as the polysaccharides) are made of simpler sugars, such as cellulose, but the yeast that ferment the soup can't make direct use of complex sugars. Thus one has to break them down somehow. The group of anaerobic beasties in digesters, by contrast, tear down almost everything in to simpler constituents, many or most of which are made into biogas. Thus, in almost all situations, biogas turns more of the energy potential in the substrate into energy we can use.

So why can't the same beasties break down the complex stuff when making alcohol? Well, we cannot generally ask a non-yeast group of microbes to break down the complex sugar-containing substances into simpler compounds, because they will simply take things all the way, and digest the sugars as well, leaving nothing for the yeast. Thus we have to keep things sterile when making alcohol, which is a consideration that is irrelevant with biogas. The difference shows up in more complex procedures and more complex equipment.

Furthermore, besides keeping the wort warm for fermentation, producing alcohol requires distillation, which is very energy intensive. The latent heat of vaporization of water is enormous, a fact which has far-reaching consequences for life on earth, the climate, and any number of other things. What is that latent thing, you ask? (Or someone will, anyway.) Well, it has to do with the fact that if you take a unit volume of water from close to freezing to close to boiling, you will use a given amount of energy. To take the temperature a few degrees further, and actually boil it away (vaporize it) will require more than five times the energy it took to get it from near freezing to near boiling. That energy is captured in the steam produced, and is released when the steam is condensed back to liquid water-- even if both the steam and the water are nearly the same temperature.

It's the latent heat of vaporization which steals so much energy from combustion (where one of the by-products is water vapor, steam) or from distillation, and it's hard to re-capture that heat and use it well.

All these things push the efficiency of alcohol production towards the wrong side of the ledger.



The next thing I am thinking is how much energy is required to compress methane into a transportable form?  I think that is where ethanol gets a lot of attention, because it is liquid. But maybe it doesn't take much to get to 3500 psi.  Do you know?

In my area, transportation fuel is the big issue.  Electric vehicles are not feasible here for 2 main reasons. 1. distances -  the large city, which is the source of the majority of goods and manufacturing is just over 100 miles away, making it a 200 mile roundtrip 2. roads -  many of our ranch and rural roads are dirt and require trucks or high clearance vehicles (I am not saying a truck can't be electric).  Cars are not viable here.




It takes an enormous amount of energy to liquefy methane. Jean Pain notwithstanding, it would be hard to generate enough biogas to power our cars, trucks and tractors, but of course the same thing is true of ethanol and biodiesel.

Thus, as I have been saying, I don't think it makes a great deal of sense to try to produce enough alternative energy to fuel our automobiles and support an otherwise ordinary American lifestyle. If we are going to take the step towards independence, then we will have to rearrange our lives. Clearly that will require rethinking every aspect of what we do, how we earn our living, where our food comes from and so on. It's a process. It sounds like you are on the right road, however.



d.
 
Abe Connally
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About compressing biogas, I'm not talking about liquefying it, I'm talking about compressing it to a stage where it is feasible to travel.  I think that is like 2500-3500 psi, something like that.  CNG, basically.

As far as energy for ethanol, and biogas, solar heat is very effective for keeping something at 100 degrees.  For distillation of ethanol, solar is an extremely viable option that is not pursued in the developed world, but it has a huge following in Asia, South America, etc.

Another thing, I am not looking for the solution for the world.  I am looking for a solution for my home, and possibly, for my village at a later time.  We do not have a standard American petrol diet, which makes a conversion easier.  Most households average less than 300 gallons of petrol a year, and many are well below that average.

At these lower use levels, and with plenty of farmland and people willing to work it, I would say that it DOES make sense to replace petrol with an alternative fuel.  And what I am trying to determine is whether biogas, ethanol, biodiesel, or wood gas could be our solution.  But again, this is not a world-wide solution, this is a local solution.  Each locale would be different, and I can only try and do what I can here in our village.

With ethanol, we are looking at about 1/2 acre or less per household (less than 100 households) for transportation fuels.  If biogas can do better per acre at lower required energy, maybe we should consider it.

Do you have resources for converting fuel injected vehicles to CNG?  A lot of vehicles in our are use propane, so I imagine kits are available, but I think most of the trucks I have seen using propane are carburetor systems.

So, what I am talking about is a local solution for a relatively low use situation.  With ethanol, we could reasonably produce our fuel in less than 50 acres, and using solar, we could keep the energy input low.  Could biogas be a better option for us?

Biogas would be the preferred method for home cooking, for sure, but it would take a better integration of our waste streams.

For transport, we would have to grow our feedstock, no matter what we do, so it is in our interest to research what solution would be serve our situation.
 
David House
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Velacreations,

velacreations wrote:
About compressing biogas, I'm not talking about liquefying it, I'm talking about compressing it to a stage where it is feasible to travel.  I think that is like 2500-3500 psi, something like that.  CNG, basically.




3500 psi will liquefy methane. Other than that, a good deal depends on how you and your neighbors intend to use the biogas for fuel. Shorter trips could be supported by tanks and compressors that are cheaper and less energy intensive, but which will not support liquefaction. There's no reason that one cannot use a propane tank (at, say, 200 psi max) to store scrubbed biogas for mobile uses, but it will take more such tanks vs. something which is more robust. On the other hand, it may be all you need for some uses.



...I am not looking for the solution for the world.  I am looking for a solution for my home, and possibly, for my village at a later time.  We do not have a standard American petrol diet, which makes a conversion easier.  Most households average less than 300 gallons of petrol a year, and many are well below that average....

With ethanol, we are looking at about 1/2 acre or less per household (less than 100 households) for transportation fuels.  If biogas can do better per acre at lower required energy, maybe we should consider it.



The best I can offer is to get better information and pursue the knowledge. These days, almost anything you would want to know you can find out on the Web... or at least theoretically, because the Web is a bit like an explosion in a library, where the library (pre-explosion) was mostly devoted to student essays.

So my suggestion is to start collecting-- and carefully reading-- some good books. For alcohol, it would be hard to beat David Blume's book "Alcohol Can Be a Gas" (which, as it happens is found at http://www.permaculture.com/ ). Likewise, for biogas, as likely would be no surprise, I recommend TCBH, at http://completebiogas.com/ . For biodiesel... Well, I would recommend starting at http://www.journeytoforever.org/biodiesel.html . Keith can set you right, although I suggest having the facts in hand before posting to his biofuel list: he does not suffer fools gladly. As far as wood gas or producer gas, the best book I have seen is by Vesa Mikkonen. Go to http://www.ekomobiili.fi/Tekstit/english_etusivu.htm for more information. And if you think that wood gas is simpler, then I'll bet you won't after reading about what she (Vesa) did to convert several vehicles thereto.




Do you have resources for converting fuel injected vehicles to CNG?  A lot of vehicles in our are use propane, so I imagine kits are available, but I think most of the trucks I have seen using propane are carburetor systems.



I suggest Googling it, since as a practical matter whatever you want is something that should be local to you. As regards the general subject, yes, CNG conversion would allow well-scrubbed biogas (which is then often called biomethane) to be used in a vehicle.





d.
 
Abe Connally
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David, thanks for the info.  I am familiar with the alcohol, biodiesel, and lots of wood gas information, but my biogas research doesn't go much beyond home use (cooking, lighting, etc).

I guess I need to grab your book!   I'll be sure to do that, as I am sure it answers a lot of questions I have.

I didn't realize that 3500 psi would liquify methane.  What pressures are the normal CNG working at?

The low-pressure vessels for local travel is definitely an option, as it would be pretty much plug and play with an LP system.

I'll need to research what is needed to convert a fuel injected engine over to methane or propane.  Ethanol also requires conversions, and so does wood gas, so it will come down to what is overall cheaper to produce AND use.

Thanks again for helping me with this.  You have cleared up a lot of info for me.  I appreciate your time.
 
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I would like to comment here.

this is something that kinda bugs me about ethanol vs everything. most of the stuff ethanol is derived from in great quantities is seasonal in many places and what is not is either a grass or grows in a swamp.  IMO stay out of my swamp for your fuel,  i would like clean water and healthy fish thanks all the same. Stop thinking monocrop and petroleum fertilizers on the grasses that will further stress the marsh and swamp causing further degradation to water quality.


biogas is not dependent on a yearly cycle crop.  none of us are going to stop eating or defecating for 6 months at a time.

my big problem with about all the arguments for ethanol are dependent on cropping and those that look best depend on cropping in wetlands. i dont know how others feel but i like my marsh left to do its job. to my mind clean water is way WAY more important than some drivers wishes for a burger or even some guy/gal on deaths door. millions dead if we dont stop screwing up the water supply VS ethanol,  frankly ethanol looses hands down. 
 
Abe Connally
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Ernie,

Why can't we have clean water and harvest from wetlands sustainably? Plants like cattails are used to filter waste out of water, so that is why we grow them, but periodic harvesting at a reasonable rate should not interfere with that, and in some cases, should improve the growth of the plants.  This is being done at several locations across the US, and it is completely sustainable.

Biogas has its issues as well as ethanol.  And although none of us are going to stop defecating, we don't defecate enough to supply ourselves with a fuel, even for household cooking.  So, for any fuel, we'll have to grow something.

The best strategy I can imagine is to develop methods like permaculture where we can harvest without destroying environments.  No biofuel requires that we crop and use chemicals.  It is up to us to find ways to grow our fuels without damaging our environment.
 
David House
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velacreations wrote:
I didn't realize that 3500 psi would liquify methane.  What pressures are the normal CNG working at?



I was incorrect in not qualifying that statement. Gases have what is called a critical temperature, which is the temperature above which they will not liquefy and (this is important) they will not want to stay liquid above that temperature either. For methane, the critical temperature is -82C, and methane will not-- not at any pressure-- liquefy when it is warmer than that. Likewise, gases have a critical pressure, which is the pressure above which they will not liquefy nor want to stay liquid. For methane that pressure is about 680 psi.

So, yes, methane can be liquefied at 3500 psi, but only if it is really, really cold, and it must be kept cold if it is to remain liquid. Carbon dioxide is easier to liquefy, and gaseous methane will, to some degree, dissolve in liquid carbon dioxide. I have not done the math so I am not sure, but it may be, based on this fact, that increased storage of methane can be gotten where one is compressing and cooling biogas with the proper ratio of carbon dioxide and methane such that the carbon dioxide goes liquid, vs. what would happen at the same pressure/temperature for methane alone.

The take home, however, is that it is very hard to liquefy methane.



d.
 
Ernie Wisner
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Vela have you ever seen anyone harvest a wetland sustainably? further more; have you ever seen a mono crop system that was sustainable?  In 30 years of looking first hand and historically there is not one indication of any industrial entity with this ability.  this is not going to change cause no matter what its going to be more profitable to rip it all up twice a year then it is to take care and do a good job of it.

I dont care to take a chance at killing several million people for the ability to drive to mcdonalds. the amount of ethanol needed to supply this countries fuel needs makes it a sure bet that the chemicals to force the plants to grow faster will be used.

to be totally honest i dont like either tech cause i think folks are gadding about at to high of speeds, period! 

but of the two making our sewage into fuel is the best option i can see cause we all eat and we all pee and we have to grow food and we already waste a billion tons of plant matter every year in the harvest and disposal cycle. you want permaculture then look at using the out puts we already have instead of screwing with the filtration  system for clean water and the nursery for food that are the wetlands.

sorry for the soap box but its one of those things that we look at in a small window and miss the bigger view.

Wetlands and marshes produce far more protein than anything else and serve an essential function in our water supply air quality and carbon cycle which affect billions of people, are global concerns, and none which we have taken care of to date. we have already screwed up the swamps and wetlands to the point they are not able to keep up. we have systematically drained them and filled them for housing and golf-courses, And now folks are proposing to use them as a fuel source for the entire countries needs.  where do you see a benefit? cause i sure cant.
 
Abe Connally
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Ernie,

Yes, I have seen wetlands harvested sustainably, and have seen this in a lot of the non developed countries that depend on wetlands.

I don't think mono crops are sustainable, and I don't recommend them at all.

I think you are looking at it in a different way than me.  I don't see it as a source of feedstock for an industrial process or entity.  I see it as one part of a multi-part solution for small communities and farms.  They can afford to do it right.

I disagree on the amount of ethanol needed would require chemical inputs.  Most folks on this forum know that outputs are greater when a holistic, polyculture approach is taken, so why would we need chemicals?  The solution, as you said, is not farming as we have done, it will require new, sustainable approaches.

Cattails are a great crop for both filtering waste systems and fuel.  You are right, we all pee and poop, but we don't pee and poop enough to even support a household (even a small, very conservative household can't even cover cooking needs from their waste).  So, we can't make fuel straight from the pee and poop, we need to use those nutrients to grow fuels.  We can create more wetlands to help filter our waters and at the same time get fuel out of the situation.  It is a good solution for 2 problems.

I am not saying use the wetlands as a fuel source, I am saying increase the amount of wetlands to grow more efficient crops that we use as a fuel source.  It  can be done in a sustainable way.  We can increase the wetlands to a stage where they were before we started screwing them up and make it financially and environmentally beneficial to do so.  How is that not a benefit?

And what would be your solution?

If you know of anyone that can make their fuel from just their wastes, please share, as almost all evidence shows it is not mathematically possible, nor desireable.

 
                                
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velacreations wrote:
Ernie,

Yes, I have seen wetlands harvested sustainably, and have seen this in a lot of the non developed countries that depend on wetlands.

I don't think mono crops are sustainable, and I don't recommend them at all


yup - all those rice farmers across the world should be imprisoned - how dare they disturb mud-dwellers ?
 
Abe Connally
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joan
I think Ernie was talking more about natural wetlands being distrubed rather than a system of rice culture, though rice culture in many areas could be used as an example of sustainably harvested wetlans, as many are very old and have been cultivated over time.

Rice culture doesn't have to be mono-cropped, and inf act, many times it is a polyculture.  Fukuoka is a good example of that.
 
Ernie Wisner
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joan the only thing a rice paddy produces is what you put in. you run them right and i got no problem with it. run one like they do down in the gulf states and you betcha i will be haveing a big problem with it. you can make as many as you want in your blighted landscape to the east as long as you keep your trash in your own yard and use you own damn water. you start peeing in my puddle and we gonna be fighting.

fact is i dont actually care if you convert the paddies into cattails it would be better than what's there now and produce a better grade of food to boot. keep your sticky fingers off the wetlands and marshes that provide the bulk of the worlds food and water supplies.

to answer the question asked; this is my suggestion for fuel in the new millennium.

stop driving around so much. i know its a huge concept, complex and removes all free choice from your life but we all have to make sacrifices.

did you know in the bad ol days before coal and oil we used to send millions of tones of materials across the country in a machine powered by wood?

round that same time we used to move billions of tons with a couple sticks and a few bed sheets.

course now days we are truly modern and know that even bricks will fly if we put enough petroleum fuel behind it. just look at our cities; all those cars whizzing around at 70 MPH taking folks here and there as fast as a herd of wombats in a high hurdle competition.

most people spend the bulk of there lives within 50 miles of the house, no one will die cause the newest Iphone comes out a week later than it could. that million tones of sulfer is not going to rot if its transported by sail. you don't need apples produced in Argentina, oranges are not a staple food. Your home computer makes it unnecessary to commute to the rat cage you process a paper in every day.

we currently have the way to reduce the fuel river down to a trickle. We dont use it and the folks looking for ways to power the newest wizbang machine are looking for a way to keep folks in the car instead of on the shoe leather.

lets be real clear here there is no way to grow enough plant material to produce enough fuel to power the population at the current levels without starving out a large part of the planet. there is no way currently to produce enough fuel without petroleum fertilizers to force the plants to grow faster than normal. there is not enough clean water now and will be even less if we try to grow fuel crops to keep all the cars, trucks, ships, planes, power plants, factories, houses Etc. running.  it is a tiny fraction of the world population that thinks permaculture the rest only think of them selves and how they dont have what the americans have. the solution to the problem is not to produce ever more fuel/energy. IMO the solution is in the problem; we use to much energy and fuel. the solution is "use less energy and fuel". its not a manufacturing problem; it's a personal problem. 

you want the most efficient way to power a house?
give each house a generator of its own and make the folks living in the house hand carry the fuel to run the generator.
energy use would drop in a hurry folks would be burning brain cells to figure out more efficient systems in the house. permies are by and large the folks that carry the fuel for the house either in our minds or in our realities. look at how much brian time we spend thinking about efficiency.

i am done with my argument.

I would like to see the companies you spoke of that are working in wet lands without destroying them. so far i have found none large enough to be companies in the western sense of the word.

 
                                
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velacreations wrote:
joan
I think Ernie was talking more about natural wetlands being distrubed rather than a system of rice culture, though rice culture in many areas could be used as an example of sustainably harvested wetlans, as many are very old and have been cultivated over time

 
my point exactly - without proven and productive sustainably harvested wetlands there would be a lot of hungry folks -
unfortunately, there are those who feel this ball of dirt we inhabit takes precedence over humanity - they have all the tree-hugger rhetoric down pat and seem to enjoy their blinders -
 
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