Using Human and/or animal waste to power a car?

I read about an experimental vehicle that runs on methane captured from poop. I think this is a terrific idea and could meet all our energy demands, being that 70 homes, in a day, produces enough energy to fuel a car for up to 10,000 kilometers! The methane is sequestered through a fermentation process. Is there a way that the average person could do this? I know human feces is some really hazardous stuff, but could you do this as an amateur with some safer scat, like goat or bovine feces, without having to spend hundreds of thousands of dollars?

Biogas Car

it takes a lot of animals or a lot of humans to power a car. Start by making enough to power a stove.

I just listened to a show which dispelled the hipe behind solar panels and reviewed all forms of alternative energy.

Here is the list, at least what I can remember -

Rated from easiest/cheapest set up and pays for its self.

#1 water turbine - set in a year round creek with 6-8 foot drop. Most people will not have the water set up for this one, to bad.

#2 Gasifer - fema burning materials without oxygen in a furnace.

#3 Bio-gas - this is the one you mention - lots of youtube videos on these.


.... some others go in here, but I cannot remember just now. So we come to the end -


# Wind - very depended on area if you want to generate electricity (or more than just pump your well). Expensive if you are going for the wind turbines.

# Solar Panels - most expensive for up-front costs, labor and longest ROI

The guys point was that mostly all we hear about are the last two.... something to think about.

Hehehe - how about using humans to generate electricity like this?

Dead Heat - crematorium to sell power for National Grid

currently working on my gasifier system, and I can tell you it is NOT easier than solar panels. Cheaper? maybe, if you don't count time collecting fuel.

For cooking, solar is definitely cheaper than biogas, electricity, gasiefier, etc. Seriously, you can build a solar cooker for about $3: http://solarcooking.org/plans/windshield-cooker.htm

Biogas is easy, as long as you have very local access to tons of feedstock. If not, you're really looking at cooking, lanterns, possibly space heating (forget transportation).

Wind energy can be cheap if you build the units yourself. I've made about 200 wind turbines for under $50 each : http://www.velacreations.com/chispito.html

Gasifier is really the only practical thing for transportation energy (besides bikes). Still, you're looking at $500 min for a junk-yard unit for your car.

Abe Connally wrote:it takes a lot of animals or a lot of humans to power a car. Start by making enough to power a stove.

It is very low tech to move gas to stove and burn it. Compressing the gas and shoving it into modified cars is probably a good idea, but not for the home or small farm scale. Does anyone know of "blueprints" or even youtube videos for a digester (I have seen those in the Designers Manual but they don't seem detailed enough). I can't get anything other than huge operations or small barrels when I search on the internet.

I also would like in fo on biogas for car fuel. How to make it? Can it be compressed like propane to get about 100 miles on fill up? I live it the bigest milk producing county in Texas. And have unlimented amount of cow manure. Tkinks Jerry

jerry littlefield wrote:I also would like in fo on biogas for car fuel. How to make it? Can it be compressed like propane to get about 100 miles on fill up? I live it the bigest milk producing county in Texas. And have unlimented amount of cow manure. Tkinks Jerry

That's pretty cool. You could just fill up truck loads with it and dump it all in your digester. Like someone else said, there aren't very many detailed plans on this. I think it would be cool heating a house or running a stove with this first, or even a generator.

#2 Gasifer - fema burning materials without oxygen in a furnace.

Could you gassify comosted, human waste or dried manure like you would biomass?

I like the idea of using excrement to grow food and produce energy, because its a cyclical process. You eat your food first, and then use what's left afterwards to power your home or transportation and then to grow new food. The idea of growing crops specifically to produce power doesn't make a lot of sense to me. I'd rather meet food needs first.

I think gassifying dried or processed excrement with waste materials, like saw dust would be even better.

Human feces is not "really hazardous stuff". There are certain things to be careful of like anything in life. I've composted my family's "waste" and used on our garden multiple times following the method in Humanure, written by Joseph Jenkins. When properly composted there is no problem. I've even done it in the suburbs and it works great. It fits into permaculture's value/ethics system perfectly. I've also visited a dairy farm in VT that powered the farm and 3 other households using farm produced methane. They were not compressing it for car use though. I just wanted to contribute some more positive info about composting human feces as it is a valuable resource and should be treated as such, bearing in mind the correct methods of composting and handling.

Loads of good info here on compressing methane: http://cr4.globalspec.com/thread/14709

here's a starting point for you guys: http://www.builditsolar.com/Projects/BioFuel/biofuels.htm#Methane

Methane has about 600-700btu per cubic ft (ft3). It takes about 4 pounds of manure to produce a ft3. A gallon of gasoline has about 100,000 btu. So, you need about 167 ft3 of methane at atmosphere pressure to make one gallon of gasoline. That would require 668 lbs of manure - for one gallon of gas.

Say you compress that 167 ft3 to 200psi, then you have 12.5 ft3, or about 94 gallons of 200psi methane, and that still equals just one gallon of gasoline.

If you bring that pressure up to 3,000 psi, then the 167 ft3 of methane becomes 0.83 ft3 of methane (3Kpsi). That's about 6.25 gallons or so, for one gallon of gasoline equivalent. So, to match a 20 gallon gas tank on your truck, you'll need a pressure tank of about 125 gallons at 3000psi. Not a lot of those in the junk pile.

My math may not be 100% accurate here, but it gives you an idea.

Abe Connally wrote:here's a starting point for you guys: http://www.builditsolar.com/Projects/BioFuel/biofuels.htm#Methane

Methane has about 600-700btu per cubic ft (ft3). It takes about 4 pounds of manure to produce a ft3. A gallon of gasoline has about 100,000 btu. So, you need about 167 ft3 of methane at atmosphere pressure to make one gallon of gasoline. That would require 668 lbs of manure - for one gallon of gas.

Say you compress that 167 ft3 to 200psi, then you have 12.5 ft3, or about 94 gallons of 200psi methane, and that still equals just one gallon of gasoline.

If you bring that pressure up to 3,000 psi, then the 167 ft3 of methane becomes 0.83 ft3 of methane (3Kpsi). That's about 6.25 gallons or so, for one gallon of gasoline equivalent. So, to match a 20 gallon gas tank on your truck, you'll need a pressure tank of about 125 gallons at 3000psi. Not a lot of those in the junk pile.

My math may not be 100% accurate here, but it gives you an idea.

So, its not all that efficient in terms of range and space, and you wouldn't get very far unless you have a lot of goats, pigs, or cows. There's a reason we do use gasoline, and that's because it is so damn efficient in terms of space.

I wonder how far the road warrior could run his rig with the entire trailer tank filled with methane at 3000 psi. I'm gonna have to do the math on that sometime.

yeah, if you don't have to transport it (3Kpsi tanks are heavy), it is great.

I go through a 5 gallon propane tank in about 3-4 months for cooking. That is about 1.5 gallons of propane a month. Propane is about 92,000 btu for a gallon, so that 1.5 gallons is about 138Kbtu per month. That's about 4600 btu per day.

So, to switch over from propane, I'll need 4600 btu a day of methane (600 btu/ft3), so about 7.66 ft3, or 8ft3 per day. That's only 32 lbs of manure a day. I've measured pigs at around 8-12lbs a day, so 3 pigs, plus a bit of humanure and whatever else, and you should be well covered.

With that 8 ft3 a day, I don't need pressure tanks or anything. Just need an air-tight bag that can hold about 60 gallons, and run a hose to the house.

Abe Connally wrote:yeah, if you don't have to transport it (3Kpsi tanks are heavy), it is great.

I go through a 5 gallon propane tank in about 3-4 months for cooking. That is about 1.5 gallons of propane a month. Propane is about 92,000 btu for a gallon, so that 1.5 gallons is about 138Kbtu per month. That's about 4600 btu per day.

So, to switch over from propane, I'll need 4600 btu a day of methane (600 btu/ft3), so about 7.66 ft3, or 8ft3 per day. That's only 32 lbs of manure a day. I've measured pigs at around 8-12lbs a day, so 3 pigs, plus a bit of humanure and whatever else, and you should be well covered.

With that 8 ft3 a day, I don't need pressure tanks or anything. Just need an air-tight bag that can hold about 60 gallons, and run a hose to the house.

That doesn't sound too difficult at all, and thanks for the info. I just have to get some animals. I'd probably develop a scheme or a container that makes it easier to transfer any remaining sewage sludge into the thermophylic compost bin.

there are some good methane articles out there, but you have to look for them. Try this place: http://www.cd3wd.com/cd3wd_40/cd3wd/index.htm

One of these days, I will get a methane system going for our cooking needs, but for now, it is a low priority project because alternatives are fairly cheap. I've been collecting info on biogas for over a decade, though.

Abe Connally wrote:currently working on my gasifier system, and I can tell you it is NOT easier than solar panels. Cheaper? maybe, if you don't count time collecting fuel.

For cooking, solar is definitely cheaper than biogas, electricity, gasiefier, etc. Seriously, you can build a solar cooker for about $3: http://solarcooking.org/plans/windshield-cooker.htm

Biogas is easy, as long as you have very local access to tons of feedstock. If not, you're really looking at cooking, lanterns, possibly space heating (forget transportation).

Wind energy can be cheap if you build the units yourself. I've made about 200 wind turbines for under $50 each : http://www.velacreations.com/chispito.html

Gasifier is really the only practical thing for transportation energy (besides bikes). Still, you're looking at $500 min for a junk-yard unit for your car.

Such a very amazing link!
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Nathan King wrote:I read about an experimental vehicle that runs on methane captured from poop. I think this is a terrific idea and could meet all our energy demands, being that 70 homes, in a day, produces enough energy to fuel a car for up to 10,000 kilometers! The methane is sequestered through a fermentation process. Is there a way that the average person could do this? I know human feces is some really hazardous stuff, but could you do this as an amateur with some safer scat, like goat or bovine feces, without having to spend hundreds of thousands of dollars?

Biogas Car

Nathan, where did you get that figure about "70 homes, ..."? On its face it doesn't seem credible (unless it considers all the chemical energy derived from photosynthesis on residential lots... if so, then that may be).

The fermentation process you're referring to does not require manure. The process involves mixing a slurry of water and all manner of organic material such as grass clippings, food waste, manure, dead animals, etc. After a few days the oxygen will be consumed to form primarily CO2 which is vented from the system. After the oxygen is depleted the anaerobic bacteria will take over and start producing primarily methane. The rate of methane production is proportional to temperature with the rate generally increasing with temperature. After methane is generated the remaining material can be used as a fertilizer.

Assuming your motivation is to avoid using fossil fuels, another alternative is wood gasification. One of the best examples is Wayne Keith's operation at www.driveonwood.com. Make sure to check out the post I made recently on this forum for the Steven Harris interviews as he has some great information. In my opinion, a sustainable operation should make use of all organic "waste" to generate methane, then use the byproduct for fertilizer in the garden. However, wood should be set aside for use in a gasifier. The ash from the gasifier is a source of minerals that can also be put to use in a garden.

A practical approach to making use of biogas for transport fuel is to dual-fuel a Diesel engine with biogas. The advantage here is higher thermal efficiency and greater convenience. Plus, you can always continue to drive with pure Diesel fuel if the biogas runs out. In this configuration biogas is admitted into the air filter housing. Since Diesel engines operate with excess air at all times, a combustible gas is introduced into the cylinders will burn to increase cylinder pressure and torque (i.e. it will run the engine). Biogas can handle the high compression of a Diesel engine without causing pre-ignition (i.e. "knock"). So, just compress biogas into a cylinder, then put a regulator and throttle valve on a line leading to the air filter housing, then put an auxiliary pedal on the main pedal to throttle the biogas to the engine. The result is a dramatic reduction of Diesel fuel (which could be biodiesel or pure vegetable oil). Still, you would have to produce a lot of biogas to make an impact here and/or reduce your driving.

Another reasonable approach to fueling a 100% sustainable automobile would be to dual-fuel it with biogas plus a very small wood gasifier. The wood should probably provide the bulk of the energy because a tank of biogas cannot be compressed to more than about 200 psi without very expensive equipment. This could make using a very small gasifier feasible since the wood gas would power the vehicle for idling and maintaining constant speed on level ground (so it need not provide more wood gas than required to maintain 20 hp or so). The biogas could be used as a boost for acceleration and hill climbing. This configuration could greatly reduce the size of the wood gasifier required and make a compact bio power plant possible. Personally, I like this idea because I am from a region that is heavily wooded. I like the idea of getting out and gathering my own fuel on the side of the road, .

Marcos Buenijo wrote: One reasonable approach to fueling a 100% sustainable automobile would be to dual-fuel it with biogas plus a very small wood gasifier. The wood should probably provide the bulk of the energy because a tank of biogas cannot be compressed to more than about 200 psi without very expensive equipment. This could make using a very small gasifier feasible since the wood gas would power the vehicle for idling and maintaining constant speed on level ground (so it need not provide more wood gas than required to maintain 20 hp or so). The biogas could be used as a boost for acceleration and hill climbing. This configuration could greatly reduce the size of the wood gasifier required and make a compact bio power plant possible.

That is an EXCELLENT hybrid idea!!! Getting the air ratio right would be a little tricky, but a woodgas and "something else" hybrid would be more practical for a lot of people and situations. It could be methane, biodiesel, ethanol, or whatever you can get.

R wannabe wrote: That is an EXCELLENT hybrid idea!!! Getting the air ratio right would be a little tricky, but a woodgas and "something else" hybrid would be more practical for a lot of people and situations. It could be methane, biodiesel, ethanol, or whatever you can get.

There are technical problems that I've considered, but I don't consider them too daunting. From what I've gathered, a Diesel engine will make the best candidate. Wood gas has a high octane rating and can handle a compression ratio up to 17:1. Also, my research shows that wood gas ignition is more reliable in Diesel engines, the power loss is inherently less than in a gas engine conversion, and the thermal efficiency can actually increase under certain conditions when wood gas is admitted (due to more complete combustion of the simple fuel gases in wood gas and the slower burn rate of wood gas that may achieve higher peak cylinder pressures at a favorable crank angle for higher engine torque at low engine speeds). Most important is that Diesel engines always operate with excess air in the cylinder because the intake air is not throttled as in gas engines. Therefore, any fuel admitted into the cylinders during operation will be combusted. So, a wood gas conversion would simply pipe wood gas directly into the air filter housing. There should be a means to throttle the wood gas delivered to the engine, and this can be easily accomplished by placing a valve in the line that supplies wood gas. I propose placing this valve somewhere in the engine compartment that allows a small foot pedal to operate it. I propose placing this pedal over the existing stock accelerator pedal. Furthermore, there should be a stop in the valve that prevents it from being fully closed, and the valve should be spring loaded against this stop (the pedal opens the valve against spring tension). The position of this stop is determined by testing. The goal is to allow just enough wood gas into the engine during idle to ensure (1) proper idling, (2) sufficient air drawn through the gasifier at idle, and (3) sufficient Diesel fuel admitted on each stoke for reliable ignition. I don't know how most Diesel engines are configured to control how much fuel is admitted during idle, but it may be necessary to reduce this somewhat. Perhaps the engine could be idled at a higher speed to compensate.

It may be necessary to increase the amount of Diesel fuel admitted on each stroke as wood gas is admitted, but my limited research shows that this is not likely. However, if this proves to be the case, then the wood gas pedal can be spring loaded onto the stock pedal forcing both to move in tandem. I hope this is not required, but details such as this are always determined in practice. The goal in my mind is to be able to maintain up to low highway speeds on level ground while admitting the same amount of Diesel fuel as consumed while idling the engine. Of course, while accelerating and climbing hills both pedals are being depressed (the wood gas pedal is fully depressed) to admit more Diesel fuel for more torque.

There are a few small companies making gasifiers. The best is probably All Power Labs (well, actually, Victory Gasworks makes a great one, but it's way too pricey in my opinion). However, a small company just started up called Vulcan Gasifier. They make two small units based on the proven "Imbert" design that should work well for this conversion. The dimensions of their units permit up to 25 hp on the smaller unit, and up to 50 hp on the larger unit.

Other modifications I've considered include placing a heat exchanger on the engine exhaust to preheat the air before it is admitted into the gasifier. This will further raise temperature in the gasifier for a more rapid fuel conversion rate, and this could also allow for using wood with a higher moisture content. Also, some of the engine exhaust could be used to dry fuel batches before the fuel is admitted into the gasifier. Finally, a simple wood "chunker" is a great idea that would allow one to chop branches with the pieces falling directly into the fuel dryer. NOTE: Adding heat to the system in the form of air preheating can not only allow for using wood with a higher moisture content, it can also improve the thermal efficiency of the system by encouraging the water gas reaction. That is, the additional moisture in the fuel can be converted to the fuel gases H2 and CO.

NOTE: Some problems I see with converting a gas engine in this manner is ensuring the proper air/fuel ratio. Diesels don't care. It seems possible for the stock oxygen sensor to do this automatically, but I have a funny feeling that it won't be so simple. Personally, I would approach a gas engine conversion in exactly the same manner as I describe for the Diesel, then just see what happens and go from there. Perhaps a hand operated air throttle valve would be necessary to back up the stock air throttle unit in case the oxygen sensor gets confused.

Just in case y'all haven't seen this..........

http://www.woodgas.net/files/FEMA_emergency_gassifer.pdf

At least 1 thing the gooberment did that's OK.......

Joe Braxton wrote:Just in case y'all haven't seen this..........

http://www.woodgas.net/files/FEMA_emergency_gassifer.pdf

At least 1 thing the gooberment did that's OK.......

and only OK, as nearly every person working in this area has come up with something BETTER.

Joe Braxton wrote:Just in case y'all haven't seen this..........

http://www.woodgas.net/files/FEMA_emergency_gassifer.pdf

At least 1 thing the gooberment did that's OK.......

That's actually a great reference for an introduction to the technology. Although, the "FEMA" gasifier is known to produce a lot of tar in the gas. Still, I can't help to wonder if air preheating and insulation on the firetube could make one work well. I've seen a couple of FEMAs make pretty clean gas under some conditions, but those were stationary systems at a low constant rate.

The following "Handbook of Biomass Downdraft Gasifier Engine Systems" is the single best resource there is:

http://alternativefuels1.tpub.com/0276/index.htm

My favorite biodigester link

http://www.youtube.com/watch?v=3AZv6MjZylo&feature=player_embedded

Fascinating article I came across:

http://www.journeytoforever.org/biofuel_library/methane_pain.html

It seems the thermal energy generated by the system combined with making use of solar air heating could provide all space heating and water heating required for a home (that is, a properly designed modest off grid home). The relatively small amount of biogas generated can be used primarily for cooking gas, but also to produce electricity for backing up a solar PV system during inclimate weather. Anything left over could be used in a vehicle. It could also be used to power an ammonia absorption deep freezer. However, as I wrote in a previous comment, it seems to me that biomass sources ideal for use in a wood gasifier (i.e. wood chunks) should be set aside for primary automotive fuel.

I'm speculating here, but it seems the fermentation process should be self-regulating. As the temperature in the compost pile rises the reaction rate increases, but only to a point. It seems the rate should slow down and stabilize at a low rate as the excess temperature literally kills many microorganisms. What this suggests is that the rate at which the feed stock is consumed would depend on how quickly the energy is harvested. Imagine winter is approaching and you start to use more heat from the compost pile for air heating. Well, removing heat from the system will cause the temperature to fall back into the range that causes the reaction rate to increase. Therefore, the compost pile would start making more heat right when you need it most. If my thinking is correct, then insulating a compost pile very well should enhance the results.

Also, one simple idea for saving energy in a system like this (or any system) is to regenerate thermal energy wherever possible. For example, let's say you're taking a shower with heated water pumped through your compost pile. Well, why not place a heat exchanger on the drain of the shower to preheat the cool water before it's heated in the compost pile? This would save a lot of energy. Also, here is one way to store methane: http://www.youtube.com/watch?v=lrhlRIvNjTc

I once found an article dealing with an experiment of building a paine pile in Siberia in winter conditions. Sadly I lost the link when my computer drive got trashed by malware.
The point being a large enough pile will insulate the fermentation process enough to allow the bacterial process to continue. Unfortunately scaling up the process takes it out of the realm of small backyard experiments.

arild jensen wrote:I once found an article dealing with an experiment of building a paine pile in Siberia in winter conditions.

Now THAT sounds interesting! I'll search for it. I've been looking into the biogas methane production a bit. My limited research suggests the energy conversion rate is 60-70%, and this is gross. A well insulated digester like the Paine pile should pull it off, but many systems consume some methane just to heat the digester. It seems preferable with respect to energy recovery to simply dry biomass and burn it in a small updraft gasifier furnace. That would also be a lot simpler. Of course, the Paine pile seems to provide a lot of compost... but compost could be provided in other ways. Seriously, I'm thinking just force dry fluffy biomass with an auger into a simple gasifier furnace for direct heating applications. Sure, some biomass is probably ideal for compost, but some would work better in a simple furnace. I suppose the ash from the furnace could be recovered for the compost.

Look how good grass pellets burn! http://www.youtube.com/watch?v=-ukKHTgiNsE

Videos about Jean Pain (English subtitles):

Part 1: http://www.youtube.com/watch?v=JHRvwNJRNag

Part 2: http://www.youtube.com/watch?v=zGCj7NA0OIs&feature=relmfu

This reminds me of a great article I read in Home Power magazine awhile back. I found a link to it: http://homepower.com/article/?file=HP116_pg92_Adler It was a relatively low tech method, a large flexible membrane with gas line fitting on it, in a long tube shape, with an inlet and outlet on opposite ends. There was a constant water level, with the inlet and outlet below water level to maintain an air trap and keep the gas inside. Basically, wherever air is excluded from the decomposition process, methane is produced.

Al Rutan, aka "The Methane Man" also has done a lot of work around this and has developed a tank similar to the Costa Rican model. Here is a good article of his: http://www.green-trust.org/freebooks/methane1-3.pdf