Using waste for propulsion ?

Le Nov/28/2016 à 9:53 PM, Fred J. McCall a écrit :
Alain Fournier wrote:

On Nov/27/2016 at 10:26 PM, Fred J. McCall wrote :
Alain Fournier wrote:

On Nov/27/2016 at 1:17 AM, Fred J. McCall wrote :
JF Mezei wrote:


100pax over 3-4 months will consume large amounts of food. That is a lot
of mass that you have to lift and accelerate out of earth's orbit
towards mars most of which will become waste. Not doing anything with it
means wasting that mass which you spent much fuel accelerating.


I know it's hard for you, but think about it. Most of the mass of
food (and feces) is water. You're going to get the water back for
recycling on the back side of the process. That means each person
will generate 1-2 ounces of solid waste per day once the water has
been recovered (and you'll get 3-6 ounces of water out of the same
waste stream). Let's use the larger number as more 'favorable' to
your case; 100 people (not sure what 'pax' are when they're up and
dressed) will generate around 12.5 pounds of solid waste per day. That
waste is a mix of dead bacteria, indigestible food elements like
cellulose, minerals, and indigestible fats. You're not going to turn
it into methane without giving up a lot of the recovered water and
even then most of it isn't going to 'convert'. Recovering the water
is more valuable, since you can make things like breathing air out of
that stuff. So you're going to accumulate a little over half a ton of
such cruft during the course of the trip.

It's not one or the other. You can very well recover the methane and the
water and grow food. Plants don't need the methane from human waste to
grow. So after extracting methane, the waste isn't any less fertile than
it was before extraction.


What 'methane' is there to recover? To get methane from ****e, you
have to process the ****e, removing carbohydrates. That makes it less
fertile because you've removed all the carbon and hydrogen.


Plants don't need carbon in soil, removing carbohydrates is not a
problem. Plants get their carbon from CO2 in the air.


Try growing plants in soil with no carbon in it and see how that works
for you (it mostly will work very poorly, if at all).

Do you have a site to support that claim.
https://en.wikipedia.org/wiki/Plant_nutrition#Carbon
Doesn't seem to agree with you.

You can't
'recover' the water because you need it as part of processing the
****e.

To recover the water see what I wrote just after:


So why make the methane in the first place if you can only burn it in
a condensing chamber? I did read what you wrote, but it made no
sense.

As I said, I don't favour doing so. I was just stating that it can be
done. Also, I wasn't suggesting to only burn it in a condensing chamber.
I said you could make electricity with it.

If you want to recuperate the water that was lost in the fermentation,
you can burn the methane and make electricity, water and CO2. The CO2
will be taken by the plants you want to grow. Of course, if you do so,
that means you can't use Mr Mezei's idea of burning the methane as
rocket propellant. Which probably isn't worth the trouble anyway.


Indeed. How much power, equipment, space, and effort are you going to
expend to try to make half a tonne of ****e 'useful'.


Even growing food on the spaceship probably isn't worth the trouble. The
trip is not long enough to do serious farming. I think that the best use
of human waste on a spaceship bringing colonists to Mars is to store it.
Land it on Mars. And then, once on Mars compost it and use it to grow
food. You will want to have lots of fertilizer handy for your colony on
Mars.


I don't think so, either. Probably makes more sense to just start
dumping it in a crater someplace.


That is not what farmers do with their manure here on Earth. Earth soil
is typically more fertile than Martian soil and will not need less
fertilizer.


I thought it was obvious what happened next, but apparently not. Once
you collect enough **** to be useful (it will take a lot more than one
trip) you can process it with in situ resources. Doing it half a
tonne at a time would just be stupid.

I'm glad to see we mostly agree on that point. I think that the first
half tonne can be useful. You want to start the process of growing
plants as fast as you can. Of course you would later move up to a larger
scale.


Alain Fournier

Alain Fournier wrote:

Le Nov/28/2016 à 9:53 PM, Fred J. McCall a écrit :
Alain Fournier wrote:

On Nov/27/2016 at 10:26 PM, Fred J. McCall wrote :
Alain Fournier wrote:

On Nov/27/2016 at 1:17 AM, Fred J. McCall wrote :
JF Mezei wrote:


100pax over 3-4 months will consume large amounts of food. That is a lot
of mass that you have to lift and accelerate out of earth's orbit
towards mars most of which will become waste. Not doing anything with it
means wasting that mass which you spent much fuel accelerating.


I know it's hard for you, but think about it. Most of the mass of
food (and feces) is water. You're going to get the water back for
recycling on the back side of the process. That means each person
will generate 1-2 ounces of solid waste per day once the water has
been recovered (and you'll get 3-6 ounces of water out of the same
waste stream). Let's use the larger number as more 'favorable' to
your case; 100 people (not sure what 'pax' are when they're up and
dressed) will generate around 12.5 pounds of solid waste per day. That
waste is a mix of dead bacteria, indigestible food elements like
cellulose, minerals, and indigestible fats. You're not going to turn
it into methane without giving up a lot of the recovered water and
even then most of it isn't going to 'convert'. Recovering the water
is more valuable, since you can make things like breathing air out of
that stuff. So you're going to accumulate a little over half a ton of
such cruft during the course of the trip.

It's not one or the other. You can very well recover the methane and the
water and grow food. Plants don't need the methane from human waste to
grow. So after extracting methane, the waste isn't any less fertile than
it was before extraction.


What 'methane' is there to recover? To get methane from ****e, you
have to process the ****e, removing carbohydrates. That makes it less
fertile because you've removed all the carbon and hydrogen.


Plants don't need carbon in soil, removing carbohydrates is not a
problem. Plants get their carbon from CO2 in the air.


Try growing plants in soil with no carbon in it and see how that works
for you (it mostly will work very poorly, if at all).

Do you have a site to support that claim.
https://en.wikipedia.org/wiki/Plant_nutrition#Carbon
Doesn't seem to agree with you.


While carbon isn't used directly by plants, it seems to be very
important in enabling soil chemistry that is essential to plant
growth.

http://www.unep.org/yearbook/2012/pd..._2012_CH_2.pdf

You can't
'recover' the water because you need it as part of processing the
****e.

To recover the water see what I wrote just after:


So why make the methane in the first place if you can only burn it in
a condensing chamber? I did read what you wrote, but it made no
sense.

As I said, I don't favour doing so. I was just stating that it can be
done. Also, I wasn't suggesting to only burn it in a condensing chamber.
I said you could make electricity with it.


That makes recovering the water much more difficult.

If you want to recuperate the water that was lost in the fermentation,
you can burn the methane and make electricity, water and CO2. The CO2
will be taken by the plants you want to grow. Of course, if you do so,
that means you can't use Mr Mezei's idea of burning the methane as
rocket propellant. Which probably isn't worth the trouble anyway.


Indeed. How much power, equipment, space, and effort are you going to
expend to try to make half a tonne of ****e 'useful'.


Even growing food on the spaceship probably isn't worth the trouble. The
trip is not long enough to do serious farming. I think that the best use
of human waste on a spaceship bringing colonists to Mars is to store it.
Land it on Mars. And then, once on Mars compost it and use it to grow
food. You will want to have lots of fertilizer handy for your colony on
Mars.


I don't think so, either. Probably makes more sense to just start
dumping it in a crater someplace.


That is not what farmers do with their manure here on Earth. Earth soil
is typically more fertile than Martian soil and will not need less
fertilizer.


I thought it was obvious what happened next, but apparently not. Once
you collect enough **** to be useful (it will take a lot more than one
trip) you can process it with in situ resources. Doing it half a
tonne at a time would just be stupid.


I'm glad to see we mostly agree on that point. I think that the first
half tonne can be useful. You want to start the process of growing
plants as fast as you can. Of course you would later move up to a larger
scale.


Nothing is probably 'waste'. Even if you dump it somewhere for a
while, you'll eventually probably wind up mining it back out. This is
one of my favorite approaches for asteroid 'mining', by the way. Toss
them into craters and then mine them out just like you would an open
pit mine on Earth.


--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw

The weight and trouble associated with anaerobic digestion on board a 100 person ship is not worth the effort for methane propellant.

http://www.dept.aoe.vt.edu/~mason/Ma...toryGalley.ppt

With four toilets for 100 persons at 450 kg per toilet that's 18 kg per passenger. Watering down each passengers manure for efficient bacterial growth and holding it for 28 days masses 26 kg for the water alone per passenger.

A toilet processing the waste back into oxygen and fresh water in a closed cycle system operating alongside the air reprocessing system is far less massive then holding watered down waste in a huge airtight tank for 28 days while it rots and produces a few grams of methane that then must be purified and mixed without mishap in a zero boil off tank.

Far less odour and disease risk too processing it back to water and oxygen and carbon Black and phosphate.

On Nov/29/2016 at 9:47 AM, Fred J. McCall wrote :
Alain Fournier wrote:

Le Nov/28/2016 à 9:53 PM, Fred J. McCall a écrit :
Alain Fournier wrote:

On Nov/27/2016 at 10:26 PM, Fred J. McCall wrote :
Alain Fournier wrote:

On Nov/27/2016 at 1:17 AM, Fred J. McCall wrote :
JF Mezei wrote:


100pax over 3-4 months will consume large amounts of food. That is a lot
of mass that you have to lift and accelerate out of earth's orbit
towards mars most of which will become waste. Not doing anything with it
means wasting that mass which you spent much fuel accelerating.


I know it's hard for you, but think about it. Most of the mass of
food (and feces) is water. You're going to get the water back for
recycling on the back side of the process. That means each person
will generate 1-2 ounces of solid waste per day once the water has
been recovered (and you'll get 3-6 ounces of water out of the same
waste stream). Let's use the larger number as more 'favorable' to
your case; 100 people (not sure what 'pax' are when they're up and
dressed) will generate around 12.5 pounds of solid waste per day. That
waste is a mix of dead bacteria, indigestible food elements like
cellulose, minerals, and indigestible fats. You're not going to turn
it into methane without giving up a lot of the recovered water and
even then most of it isn't going to 'convert'. Recovering the water
is more valuable, since you can make things like breathing air out of
that stuff. So you're going to accumulate a little over half a ton of
such cruft during the course of the trip.

It's not one or the other. You can very well recover the methane and the
water and grow food. Plants don't need the methane from human waste to
grow. So after extracting methane, the waste isn't any less fertile than
it was before extraction.


What 'methane' is there to recover? To get methane from ****e, you
have to process the ****e, removing carbohydrates. That makes it less
fertile because you've removed all the carbon and hydrogen.


Plants don't need carbon in soil, removing carbohydrates is not a
problem. Plants get their carbon from CO2 in the air.


Try growing plants in soil with no carbon in it and see how that works
for you (it mostly will work very poorly, if at all).

Do you have a site to support that claim.
https://en.wikipedia.org/wiki/Plant_nutrition#Carbon
Doesn't seem to agree with you.


While carbon isn't used directly by plants, it seems to be very
important in enabling soil chemistry that is essential to plant
growth.

http://www.unep.org/yearbook/2012/pd..._2012_CH_2.pdf

Maybe I missed something in there. But here is what I saw.
1) Soil organic matter is important because it slows down water run off
which is important not only because plants need the water but also
because this reduces erosion and loss of soil and nutrients.
2) The large amounts of carbon in soil world wide is important because
if all that carbon was released in the atmosphere that would exacerbate
global warming.
3) The biota, mainly bacteria, in the soil decomposes soil organic
matter, releasing the carbon into the atmosphere, which leaves behind
important nutrients.

Point 1) There shouldn't be any large sudden rain fall in the spaceship
carrying colonist to Mars. So this is irrelevant here.
Point 2) I think we will both agree that spacecraft greenhouse warming
is a non-issue.
Point 3) Basically says that to provide nutrients to plants, the carbon
must be removed.


Alain Fournier

Alain Fournier wrote:

On Nov/29/2016 at 9:47 AM, Fred J. McCall wrote :
Alain Fournier wrote:

Le Nov/28/2016 à 9:53 PM, Fred J. McCall a écrit :
Alain Fournier wrote:

On Nov/27/2016 at 10:26 PM, Fred J. McCall wrote :
Alain Fournier wrote:

On Nov/27/2016 at 1:17 AM, Fred J. McCall wrote :
JF Mezei wrote:


100pax over 3-4 months will consume large amounts of food. That is a lot
of mass that you have to lift and accelerate out of earth's orbit
towards mars most of which will become waste. Not doing anything with it
means wasting that mass which you spent much fuel accelerating.


I know it's hard for you, but think about it. Most of the mass of
food (and feces) is water. You're going to get the water back for
recycling on the back side of the process. That means each person
will generate 1-2 ounces of solid waste per day once the water has
been recovered (and you'll get 3-6 ounces of water out of the same
waste stream). Let's use the larger number as more 'favorable' to
your case; 100 people (not sure what 'pax' are when they're up and
dressed) will generate around 12.5 pounds of solid waste per day. That
waste is a mix of dead bacteria, indigestible food elements like
cellulose, minerals, and indigestible fats. You're not going to turn
it into methane without giving up a lot of the recovered water and
even then most of it isn't going to 'convert'. Recovering the water
is more valuable, since you can make things like breathing air out of
that stuff. So you're going to accumulate a little over half a ton of
such cruft during the course of the trip.

It's not one or the other. You can very well recover the methane and the
water and grow food. Plants don't need the methane from human waste to
grow. So after extracting methane, the waste isn't any less fertile than
it was before extraction.


What 'methane' is there to recover? To get methane from ****e, you
have to process the ****e, removing carbohydrates. That makes it less
fertile because you've removed all the carbon and hydrogen.


Plants don't need carbon in soil, removing carbohydrates is not a
problem. Plants get their carbon from CO2 in the air.


Try growing plants in soil with no carbon in it and see how that works
for you (it mostly will work very poorly, if at all).

Do you have a site to support that claim.
https://en.wikipedia.org/wiki/Plant_nutrition#Carbon
Doesn't seem to agree with you.


While carbon isn't used directly by plants, it seems to be very
important in enabling soil chemistry that is essential to plant
growth.

http://www.unep.org/yearbook/2012/pd..._2012_CH_2.pdf

Maybe I missed something in there. But here is what I saw.
1) Soil organic matter is important because it slows down water run off
which is important not only because plants need the water but also
because this reduces erosion and loss of soil and nutrients.
2) The large amounts of carbon in soil world wide is important because
if all that carbon was released in the atmosphere that would exacerbate
global warming.
3) The biota, mainly bacteria, in the soil decomposes soil organic
matter, releasing the carbon into the atmosphere, which leaves behind
important nutrients.

Point 1) There shouldn't be any large sudden rain fall in the spaceship
carrying colonist to Mars. So this is irrelevant here.
Point 2) I think we will both agree that spacecraft greenhouse warming
is a non-issue.
Point 3) Basically says that to provide nutrients to plants, the carbon
must be removed.


The proof is in the pudding. Go grow some plants of various types in
sand with no carbon content. Fertilize at will, but nothing with
carbon as a component. Let us know how that goes.


--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw

On Nov/30/2016 at 6:31 AM, Fred J. McCall wrote :
Alain Fournier wrote:

On Nov/29/2016 at 9:47 AM, Fred J. McCall wrote :
Alain Fournier wrote:

Le Nov/28/2016 à 9:53 PM, Fred J. McCall a écrit :
Alain Fournier wrote:

On Nov/27/2016 at 10:26 PM, Fred J. McCall wrote :
Alain Fournier wrote:

On Nov/27/2016 at 1:17 AM, Fred J. McCall wrote :
JF Mezei wrote:


100pax over 3-4 months will consume large amounts of food. That is a lot
of mass that you have to lift and accelerate out of earth's orbit
towards mars most of which will become waste. Not doing anything with it
means wasting that mass which you spent much fuel accelerating.


I know it's hard for you, but think about it. Most of the mass of
food (and feces) is water. You're going to get the water back for
recycling on the back side of the process. That means each person
will generate 1-2 ounces of solid waste per day once the water has
been recovered (and you'll get 3-6 ounces of water out of the same
waste stream). Let's use the larger number as more 'favorable' to
your case; 100 people (not sure what 'pax' are when they're up and
dressed) will generate around 12.5 pounds of solid waste per day. That
waste is a mix of dead bacteria, indigestible food elements like
cellulose, minerals, and indigestible fats. You're not going to turn
it into methane without giving up a lot of the recovered water and
even then most of it isn't going to 'convert'. Recovering the water
is more valuable, since you can make things like breathing air out of
that stuff. So you're going to accumulate a little over half a ton of
such cruft during the course of the trip.

It's not one or the other. You can very well recover the methane and the
water and grow food. Plants don't need the methane from human waste to
grow. So after extracting methane, the waste isn't any less fertile than
it was before extraction.


What 'methane' is there to recover? To get methane from ****e, you
have to process the ****e, removing carbohydrates. That makes it less
fertile because you've removed all the carbon and hydrogen.


Plants don't need carbon in soil, removing carbohydrates is not a
problem. Plants get their carbon from CO2 in the air.


Try growing plants in soil with no carbon in it and see how that works
for you (it mostly will work very poorly, if at all).

Do you have a site to support that claim.
https://en.wikipedia.org/wiki/Plant_nutrition#Carbon
Doesn't seem to agree with you.


While carbon isn't used directly by plants, it seems to be very
important in enabling soil chemistry that is essential to plant
growth.

http://www.unep.org/yearbook/2012/pd..._2012_CH_2.pdf

Maybe I missed something in there. But here is what I saw.
1) Soil organic matter is important because it slows down water run off
which is important not only because plants need the water but also
because this reduces erosion and loss of soil and nutrients.
2) The large amounts of carbon in soil world wide is important because
if all that carbon was released in the atmosphere that would exacerbate
global warming.
3) The biota, mainly bacteria, in the soil decomposes soil organic
matter, releasing the carbon into the atmosphere, which leaves behind
important nutrients.

Point 1) There shouldn't be any large sudden rain fall in the spaceship
carrying colonist to Mars. So this is irrelevant here.
Point 2) I think we will both agree that spacecraft greenhouse warming
is a non-issue.
Point 3) Basically says that to provide nutrients to plants, the carbon
must be removed.


The proof is in the pudding. Go grow some plants of various types in
sand with no carbon content. Fertilize at will, but nothing with
carbon as a component. Let us know how that goes.

The hard part of that would not be growing the plants. It would be
extracting all carbon from manure. Of course that means that on a
spaceship they also wouldn't be able to extract all the carbon in a
bio-digester, only most of it. Therefore your pudding isn't germane to
the current discussion. But if you do succeed in extracting all the
carbon from manure without extracting other nutrients and add it to
sand, there shouldn't be much of a problem to grow plants in there.

Also, how can you possibly imagine that Martian colonists would bring
sand as the base for their soil?


Alain Fournier

Carbon dioxide is plentiful on Mars.

On Thursday, December 1, 2016 at 12:32:00 AM UTC+13, Fred J. McCall wrote:
Alain Fournier wrote:

On Nov/29/2016 at 9:47 AM, Fred J. McCall wrote :
Alain Fournier wrote:

Le Nov/28/2016 Ã* 9:53 PM, Fred J. McCall a écrit :
Alain Fournier wrote:

On Nov/27/2016 at 10:26 PM, Fred J. McCall wrote :
Alain Fournier wrote:

On Nov/27/2016 at 1:17 AM, Fred J. McCall wrote :
JF Mezei wrote:


100pax over 3-4 months will consume large amounts of food. That is a lot
of mass that you have to lift and accelerate out of earth's orbit
towards mars most of which will become waste. Not doing anything with it
means wasting that mass which you spent much fuel accelerating.


I know it's hard for you, but think about it. Most of the mass of
food (and feces) is water. You're going to get the water back for
recycling on the back side of the process. That means each person
will generate 1-2 ounces of solid waste per day once the water has
been recovered (and you'll get 3-6 ounces of water out of the same
waste stream). Let's use the larger number as more 'favorable' to
your case; 100 people (not sure what 'pax' are when they're up and
dressed) will generate around 12.5 pounds of solid waste per day.. That
waste is a mix of dead bacteria, indigestible food elements like
cellulose, minerals, and indigestible fats. You're not going to turn
it into methane without giving up a lot of the recovered water and
even then most of it isn't going to 'convert'. Recovering the water
is more valuable, since you can make things like breathing air out of
that stuff. So you're going to accumulate a little over half a ton of
such cruft during the course of the trip.

It's not one or the other. You can very well recover the methane and the
water and grow food. Plants don't need the methane from human waste to
grow. So after extracting methane, the waste isn't any less fertile than
it was before extraction.


What 'methane' is there to recover? To get methane from ****e, you
have to process the ****e, removing carbohydrates. That makes it less
fertile because you've removed all the carbon and hydrogen.


Plants don't need carbon in soil, removing carbohydrates is not a
problem. Plants get their carbon from CO2 in the air.


Try growing plants in soil with no carbon in it and see how that works
for you (it mostly will work very poorly, if at all).

Do you have a site to support that claim.
https://en.wikipedia.org/wiki/Plant_nutrition#Carbon
Doesn't seem to agree with you.


While carbon isn't used directly by plants, it seems to be very
important in enabling soil chemistry that is essential to plant
growth.

http://www.unep.org/yearbook/2012/pd..._2012_CH_2.pdf

Maybe I missed something in there. But here is what I saw.
1) Soil organic matter is important because it slows down water run off
which is important not only because plants need the water but also
because this reduces erosion and loss of soil and nutrients.
2) The large amounts of carbon in soil world wide is important because
if all that carbon was released in the atmosphere that would exacerbate
global warming.
3) The biota, mainly bacteria, in the soil decomposes soil organic
matter, releasing the carbon into the atmosphere, which leaves behind
important nutrients.

Point 1) There shouldn't be any large sudden rain fall in the spaceship
carrying colonist to Mars. So this is irrelevant here.
Point 2) I think we will both agree that spacecraft greenhouse warming
is a non-issue.
Point 3) Basically says that to provide nutrients to plants, the carbon
must be removed.


The proof is in the pudding. Go grow some plants of various types in
sand with no carbon content. Fertilize at will, but nothing with
carbon as a component. Let us know how that goes.


--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw

On Thursday, December 1, 2016 at 1:58:27 PM UTC+13, William Mook wrote:
Carbon dioxide is plentiful on Mars.

On Thursday, December 1, 2016 at 12:32:00 AM UTC+13, Fred J. McCall wrote:
Alain Fournier wrote:

On Nov/29/2016 at 9:47 AM, Fred J. McCall wrote :
Alain Fournier wrote:

Le Nov/28/2016 Ã* 9:53 PM, Fred J. McCall a écrit :
Alain Fournier wrote:

On Nov/27/2016 at 10:26 PM, Fred J. McCall wrote :
Alain Fournier wrote:

On Nov/27/2016 at 1:17 AM, Fred J. McCall wrote :
JF Mezei wrote:


100pax over 3-4 months will consume large amounts of food. That is a lot
of mass that you have to lift and accelerate out of earth's orbit
towards mars most of which will become waste. Not doing anything with it
means wasting that mass which you spent much fuel accelerating.


I know it's hard for you, but think about it. Most of the mass of
food (and feces) is water. You're going to get the water back for
recycling on the back side of the process. That means each person
will generate 1-2 ounces of solid waste per day once the water has
been recovered (and you'll get 3-6 ounces of water out of the same
waste stream). Let's use the larger number as more 'favorable' to
your case; 100 people (not sure what 'pax' are when they're up and
dressed) will generate around 12.5 pounds of solid waste per day. That
waste is a mix of dead bacteria, indigestible food elements like
cellulose, minerals, and indigestible fats. You're not going to turn
it into methane without giving up a lot of the recovered water and
even then most of it isn't going to 'convert'. Recovering the water
is more valuable, since you can make things like breathing air out of
that stuff. So you're going to accumulate a little over half a ton of
such cruft during the course of the trip.

It's not one or the other. You can very well recover the methane and the
water and grow food. Plants don't need the methane from human waste to
grow. So after extracting methane, the waste isn't any less fertile than
it was before extraction.


What 'methane' is there to recover? To get methane from ****e, you
have to process the ****e, removing carbohydrates. That makes it less
fertile because you've removed all the carbon and hydrogen.


Plants don't need carbon in soil, removing carbohydrates is not a
problem. Plants get their carbon from CO2 in the air.


Try growing plants in soil with no carbon in it and see how that works
for you (it mostly will work very poorly, if at all).

Do you have a site to support that claim.
https://en.wikipedia.org/wiki/Plant_nutrition#Carbon
Doesn't seem to agree with you.


While carbon isn't used directly by plants, it seems to be very
important in enabling soil chemistry that is essential to plant
growth.

http://www.unep.org/yearbook/2012/pd..._2012_CH_2.pdf

Maybe I missed something in there. But here is what I saw.
1) Soil organic matter is important because it slows down water run off
which is important not only because plants need the water but also
because this reduces erosion and loss of soil and nutrients.
2) The large amounts of carbon in soil world wide is important because
if all that carbon was released in the atmosphere that would exacerbate
global warming.
3) The biota, mainly bacteria, in the soil decomposes soil organic
matter, releasing the carbon into the atmosphere, which leaves behind
important nutrients.

Point 1) There shouldn't be any large sudden rain fall in the spaceship
carrying colonist to Mars. So this is irrelevant here.
Point 2) I think we will both agree that spacecraft greenhouse warming
is a non-issue.
Point 3) Basically says that to provide nutrients to plants, the carbon
must be removed.


The proof is in the pudding. Go grow some plants of various types in
sand with no carbon content. Fertilize at will, but nothing with
carbon as a component. Let us know how that goes.


--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw

Supercritical Water Oxidation is a well established treatment process for closed cycle systems and is 99.99% efficient.

Supercritical water oxidation defined as oxidation pro- cess which occurs in water above its critical point (Tc=374°C and Pc=22.1 MPa). It uses supercritical water as a reaction medium and exploits the unique solvat- ing properties to provide enhanced solubility of organic reactants and permanent gases (like oxygen and carbon dioxide), a single-phase environment free of inter-phase mass transfer limitations, faster reaction kinetics, and an increased selectivity to complete oxidation products (Tester et al., 1993; Savage et al., 1995; Schimeider and Abeln, 1999).

So, all the carbon in the waste becomes carbon dioxide whilst the ashes and other products (primarily phosphates) are easily removed by low pressure water distillation. Hydrogen is then used to reduce carbon dioxide to methane, and the methane is pyrolysed to form elemental carbon with recovery of the hydrogen which is recycled in the process. The carbon black is used to absorb odours from the air.

128 grams per day per person translates to 12.8 kg per day for 100 persons. Watering this down for processing, from as excreted, translates to 80 litres per day for a crew of 100. 800 millilitres per day per person of urine translates to 80 litres per day for 100 persons. A total of 240 litres of dark water per day from four aircraft style toilets. Each unit processes 3 litres per hour - and any three can support the crew in the event of one unit failing. Each unit expends 870 kJ/hour - or a 242 Watt heater - with a typical heat exchanger. The reduction of solids is 99.99% and occurs very quickly - done continuously. All four toilets operating at full capacity consume 1 kW which is easily supplied by the solar power system.

The carbon dioxide produced by the SCWO process is processed by the atmospheric processor, which is part of the toilets as well. Gallies and showers are attached to the units that make use of the recycled water. Packaging and toiletries are also reducible through SCWO to elemental carbon and oxygen as well.

Beta-glucan molecules assembled into a polysaccharide using a micro-scale chemical processor is a handy renewable resource to produce fibres on demand for reconstituting tissues, toilet papers, packaging, disposable plastic dishes, utensils, bandages, clothing, blankets, pillows, and the like using 3D print technology in combination with the compact micro-scale chemical proccessor.

http://inhabitat.com/joshua-harris-3...e-new-apparel/

On Monday, November 28, 2016 at 4:53:30 PM UTC+13, Fred J. McCall wrote:
JF Mezei wrote:

On 2016-11-27 01:17, Fred J. McCall wrote:

cellulose, minerals, and indigestible fats. You're not going to turn
it into methane without giving up a lot of the recovered water and

Ok, that is a fair point. I had not considered that aspect.


So now, the question becomes whether the ISS program would start to
develop and test systems that can process solid human waste (they
already have one for urine) to recover as much as possible from it.


That's a long, long way down the road, if ever. First they need to do
a lot of work here on Earth.


"turning it into food/veggies" is basically composting the waste. And
guess what, composting requires O2 and generates methane.


Guess what? I don't think that's what they're talking about.



Not much it can be used for, which is why they throw it away on ISS.


They throw it away on ISS because they don't have any system to process
it ...


Because there's nothing useful it can be 'processed' into.


... and with only 3 to 6 occupants who get monthly deliveries by
Progress/Dragon/Cygnus (and formerly Shuttle, HTC and ATV).


Irrelevant. Do you seriously think processing ****e will
substantially reduce resupply requirements? It won't, which is why
they just toss it.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn

This is a good reference;

https://books.google.co.nz/books?id=...dition&f=false

All wastes, including plastic, cotton and paper wastes, are easily recycled using super-critical water oxidation. This produces CO2 from every carbon source which is reduced to methane and water using hydrogen. Methane is easily reduced to elemental carbon recovering the hydrogen. Carbon may be used for odour absorption. Carbon may also be used in a micro-reactor system to produce beta glucans which are then assembled 3D printer fashion into any fabric or plastic desired.

Alain Fournier wrote:

On Nov/30/2016 at 6:31 AM, Fred J. McCall wrote :
Alain Fournier wrote:

On Nov/29/2016 at 9:47 AM, Fred J. McCall wrote :
Alain Fournier wrote:

Le Nov/28/2016 à 9:53 PM, Fred J. McCall a écrit :
Alain Fournier wrote:

On Nov/27/2016 at 10:26 PM, Fred J. McCall wrote :
Alain Fournier wrote:

On Nov/27/2016 at 1:17 AM, Fred J. McCall wrote :
JF Mezei wrote:


100pax over 3-4 months will consume large amounts of food. That is a lot
of mass that you have to lift and accelerate out of earth's orbit
towards mars most of which will become waste. Not doing anything with it
means wasting that mass which you spent much fuel accelerating.


I know it's hard for you, but think about it. Most of the mass of
food (and feces) is water. You're going to get the water back for
recycling on the back side of the process. That means each person
will generate 1-2 ounces of solid waste per day once the water has
been recovered (and you'll get 3-6 ounces of water out of the same
waste stream). Let's use the larger number as more 'favorable' to
your case; 100 people (not sure what 'pax' are when they're up and
dressed) will generate around 12.5 pounds of solid waste per day. That
waste is a mix of dead bacteria, indigestible food elements like
cellulose, minerals, and indigestible fats. You're not going to turn
it into methane without giving up a lot of the recovered water and
even then most of it isn't going to 'convert'. Recovering the water
is more valuable, since you can make things like breathing air out of
that stuff. So you're going to accumulate a little over half a ton of
such cruft during the course of the trip.

It's not one or the other. You can very well recover the methane and the
water and grow food. Plants don't need the methane from human waste to
grow. So after extracting methane, the waste isn't any less fertile than
it was before extraction.


What 'methane' is there to recover? To get methane from ****e, you
have to process the ****e, removing carbohydrates. That makes it less
fertile because you've removed all the carbon and hydrogen.


Plants don't need carbon in soil, removing carbohydrates is not a
problem. Plants get their carbon from CO2 in the air.


Try growing plants in soil with no carbon in it and see how that works
for you (it mostly will work very poorly, if at all).

Do you have a site to support that claim.
https://en.wikipedia.org/wiki/Plant_nutrition#Carbon
Doesn't seem to agree with you.


While carbon isn't used directly by plants, it seems to be very
important in enabling soil chemistry that is essential to plant
growth.

http://www.unep.org/yearbook/2012/pd..._2012_CH_2.pdf

Maybe I missed something in there. But here is what I saw.
1) Soil organic matter is important because it slows down water run off
which is important not only because plants need the water but also
because this reduces erosion and loss of soil and nutrients.
2) The large amounts of carbon in soil world wide is important because
if all that carbon was released in the atmosphere that would exacerbate
global warming.
3) The biota, mainly bacteria, in the soil decomposes soil organic
matter, releasing the carbon into the atmosphere, which leaves behind
important nutrients.

Point 1) There shouldn't be any large sudden rain fall in the spaceship
carrying colonist to Mars. So this is irrelevant here.
Point 2) I think we will both agree that spacecraft greenhouse warming
is a non-issue.
Point 3) Basically says that to provide nutrients to plants, the carbon
must be removed.


The proof is in the pudding. Go grow some plants of various types in
sand with no carbon content. Fertilize at will, but nothing with
carbon as a component. Let us know how that goes.


The hard part of that would not be growing the plants. It would be
extracting all carbon from manure. Of course that means that on a
spaceship they also wouldn't be able to extract all the carbon in a
bio-digester, only most of it. Therefore your pudding isn't germane to
the current discussion. But if you do succeed in extracting all the
carbon from manure without extracting other nutrients and add it to
sand, there shouldn't be much of a problem to grow plants in there.

Also, how can you possibly imagine that Martian colonists would bring
sand as the base for their soil?


I'm sorry. I was deafened by the screeching from you dragging the
goalposts like that.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn