For Questions That Don't Merit Their Own Thread

[shynung]

@Spaced Out Is this for large scale (marine, industrial, spaceships) or small scale (cars, motorcycles, trucks, buses)? If the former, nuclear. If the latter, battery-electric.

[p1t1o]

6 hours ago, Spaced Out said:

Okay guys, next question. What are your ideas for bio-friendly fuels? By this I mean fuels that don't contribute to global warming etc.

If you grow wood specifically for fuel, then it is perfectly carbon-neutral.

You grow trees, which sequester carbon form the CO2 in the air.

You burn the wood which releases this CO2.

Zero net increase in atmospheric CO2. 

Wood-fired cars FTW.

 

[shynung]

@p1t1o Depends on how much CO2 is emitted by the machines processing that wood, and where does their fuel came from. Sawmills and chemical factories can indeed be powered by wood-fired boilers, but doing the same for the trucks and tractors shuffling all that wood around isn't an easy task.

[p1t1o]

1 minute ago, shynung said:

@p1t1o Depends on how much CO2 is emitted by the machines processing that wood, and where does their fuel came from. Sawmills and chemical factories can indeed be powered by wood-fired boilers, but doing the same for the trucks and tractors shuffling all that wood around isn't an easy task.

Yeah, thats the caveat for all of these things. Even down to staff driving to work in their petrol-fired cars.

[shynung]

Just now, p1t1o said:

Even down to staff driving to work in their petrol-fired cars.

This is actually the simplest caveat to work around - have them commute to work in company-owned electric/wood-fired buses.

[monophonic]

@shynung & @p1t1o,

Where do you want me to drop this link?

https://en.m.wikipedia.org/wiki/Wood_gas

 

[shynung]

@monophonic I'm aware of that, thanks. But I question the feasibility of using wood gasifier setups for mass-market automobiles. It's not very convenient to operate in comparison to standard gasoline/diesel engines or battery-electric setups, what with the long warm-up (and post-shutdown cool-down) times, and the bulky gas generator system.

[kerbiloid]

1 hour ago, shynung said:

If the former, nuclear. If the latter, battery-electric.

Though the nuclear requires tens of procedures and huge amounts of fluorine, chlorine, nitric and sulfur acids before the uraninite turns into fuel.
_{(Not a nuke hater, vice versa, a nuke fanboy with educational background. )}

1 hour ago, p1t1o said:

If you grow wood specifically for fuel, then it is perfectly carbon-neutral.

You grow trees, which sequester carbon form the CO2 in the air.

You burn the wood which releases this CO2.

Zero net increase in atmospheric CO2. 

 

33 minutes ago, monophonic said:

Where do you want me to drop this link?

https://en.m.wikipedia.org/wiki/Wood_gas

Keyword is grow. This means captured nitrogen.
If grow plants without fertilizer - the soil becomes wasteland in several years.
If use manure, you should be getting it somewhere, so grow cows or chickens, then wait until the manure (with straw) gets rotten into compost, exhausting huge amounts of methane into the atmosphere.
If synthesize fertilizer from air, you need a chemical plant, and intermediate products are ammonia, nitrogen oxides, nitric acid and other things, and you still have to deal with hydrocarbons before the air becomes fertilizer.
Without this, no trees - only wasteland.

Any source of energy brings the Earth closer to the end.

Edited September 11, 2017 by kerbiloid

[shynung]

Just now, kerbiloid said:

Though the nuclear requires tens of procedures and huge amounts of fluorine and chlorine before the uraninite turns into fuel.

I know. But their substantial energy density compared to fossil fuels more than makes up for it.

[p1t1o]

1 minute ago, kerbiloid said:

Keyword is grow. This means captured nitrogen.
If grow plants without fertilizer - the soil becomes wasteland in several years.
If use manure, you should be getting it somewhere, so grow cows or chickens, then wait until the manure (with straw) gets rotten into compost, exhausting huge amounts of methane into the atmosphere.
If synthesize fertilizer from air, you need a chemical plant, and intermediate products are ammonia, nitrogen oxides, nitric acid and other things, and you still have to deal with hydrocarbons before the air becomes fertilizer.
Without this, no trees - only wasteland.

Any source of energy brings the Earth closer to the end.

Good point.

However there are solutions, nitrogen-fixing plants are an ancient one. There are even some tree that are capable of this.

[kerbiloid]

4 minutes ago, p1t1o said:

However there are solutions, nitrogen-fixing plants are an ancient one

Yes, any bean culture captures the nitrogen.
The problem is that they leave not so much of it inside the soil, but usually are a raw material for the mentioned manure.
So, using only plants without cows, they have to have large fields with low-concentrated nitrogen.
And the larger is the field - the more efforts and energy they have to spend to deal with it.

Edited September 11, 2017 by kerbiloid

[p1t1o]

1 minute ago, kerbiloid said:

Yes, any bean culture captures the nitrogen.
The problem is that they leave not so much of it inside the soil, but usually are a raw material for the mentioned manure.
So, using only plants without cows, they have to have large fields with low-concentrated nitrogen.
And the larger is the field - the more efforts and energy they have to spend to deal with it.

This is about where my farming knowledge ends. But as I understood it, the old way was 3 years growing whatever, then a year growing beans, which are plowed directly back into the soil, rinse and repeat.

There are pathways available for carbon-neutral fuels, it might not be able to meet industrial outputs, but it can be done.

[Grand Ship Builder]

@kerbiloid

Are you sure you know what you're talking about?

[kerbiloid]

Not exactly about nitrogen, but similar.

Spoiler

Crops yield in Russia, XX cent, centner/hectare (100 kg / 10000 m²).
(In 1795-1950 - mostly natural fertilizers: bean cultures, manure.
Since 1950s - industrial shift, mass production and usage of synthesized ones).

Spoiler

 

Terrans' god of fertility.

Spoiler

https://en.wikipedia.org/wiki/Fritz_Haber

[p1t1o]

4 hours ago, kerbiloid said:

Not exactly about nitrogen, but similar.

  Reveal hidden contents

 

Not for nothing but you know whats a great source of phosphate and lime? Wood ash!

[kerbiloid]

12 minutes ago, p1t1o said:

Not for nothing but you know whats a great source of phosphate and lime? Wood ash!

Yes, it's great. But the main are apatites.
https://en.wikipedia.org/wiki/Fertilizer#Production

http://feeco.com/processing-phosphates-for-use-in-the-fertilizer-industry/

Edited September 12, 2017 by kerbiloid

[Grand Ship Builder]

Which would be more advantageous? Methane or metallic hydrogen as a rocket fuel?

[shynung]

3 hours ago, Grand Ship Builder said:

Which would be more advantageous? Methane or metallic hydrogen as a rocket fuel?

Depends. Methane is comparatively easy to make in-situ, but delivers chemical-grade (300-400 s) ISP. MetalH theoretically has a nuclear-grade (800-1000 s) ISP, but we haven't an idea how to make it yet AFAIK.

[YNM]

On 9/11/2017 at 3:56 PM, p1t1o said:

If you grow wood specifically for fuel, then it is perfectly carbon-neutral.

You grow trees, which sequester carbon form the CO2 in the air.

You burn the wood which releases this CO2.

Zero net increase in atmospheric CO2. 

Wood-fired cars FTW.

 

Apart from the fact you need heavy equipment to plant and tend them, machineries to prepare them, transport to deliver them, and you'll eat up a lot of precious land area.

There's a good reason why biofuels are IMO a bit stupid - they're harvested materials not spent for food. In an already crammed world, it's not a good idea.

Unless you're having it from the sea or something.

[p1t1o]

6 hours ago, YNM said:

Apart from the fact you need heavy equipment to plant and tend them, machineries to prepare them, transport to deliver them, and you'll eat up a lot of precious land area.

There's a good reason why biofuels are IMO a bit stupid - they're harvested materials not spent for food. In an already crammed world, it's not a good idea.

Unless you're having it from the sea or something.

Im not saying its necessarily an industrially viable solution, or that it can save the world, Im just saying that carefully managed, wood can be a renewable, carbon-neutral fuel. If I went out now and cut down a (young-ish, for the sake of argument) tree and burned it for fuel, the only carbon that would need offsetting would be that produced making the food that provided the calories I need to cut and dress the tree myself. But I kinda lump that carbon into another category because its roughly a constant no matter what fuel I use.

Yes, a large plantation to be managed long-term would require significant infrastructure, but at smaller scale there is little problem. Besides, there are solutions to the machinery/infrastructure issues too.

Like I said - and it may not be the cheapest, or practical yet on any very significant scale, but - there are pathways to carbon neutral fuels.

Edited September 13, 2017 by p1t1o

[Green Baron]

In principle true and growing trees as economic resources was practised since the 18th century with fast growing trees. But it is abandoned because the forests, often monocultures became very susceptible to vermin, fungus and rolling lumber from wind and even suppressed domestic species. Today's foresters are trying to get back to mixed forests again (central and western Europe), but it takes several decades.

Edited September 13, 2017 by Green Baron

[YNM]

@p1t1o @Green Baron It's true that they're "carbon neutral". But think again.

How much land do they take ?

People often forget that land is the least renewable, most fixed resource in the world. It doesn't matter what you're doing, you need land space.

Say, we're about to get some plantation. Where you'd think we'd put it ? Most of the time it's going to be in forests previously "unused" (despite being massively useful).

So, tell me, which one is better ? Hectares upon hectares of plantation, eating up pristine lands, or just a few square metres for borehole and another acre(s) for refinery ?

[p1t1o]

15 minutes ago, YNM said:

@p1t1o @Green Baron It's true that they're "carbon neutral". But think again.

How much land do they take ?

People often forget that land is the least renewable, most fixed resource in the world. It doesn't matter what you're doing, you need land space.

Say, we're about to get some plantation. Where you'd think we'd put it ? Most of the time it's going to be in forests previously "unused" (despite being massively useful).

So, tell me, which one is better ? Hectares upon hectares of plantation, eating up pristine lands, or just a few square metres for borehole and another acre(s) for refinery ?

Well it depends on where in your list of priorities the carbon balance goes, but dude! It was a hypothetical question lol! I said more than once it wasnt necessarily a practical solution 

"What are your ideas for bio-friendly fuels?"

not

"Construct a viable plan for the carbon-neutral replacement of all mankinds energy uses with exhaustive socio-economic analyses."

 

I always liked wood as an example of this as most people start to think of exotic things like an all-electric economy, hydrogen fuel cells or esoteric tidal power stations, that sort of thing. People dont always think about the fact that burning something can be carbon neutral, or that good old fashioned wood can possibly be on the same list as advanced technological solutions.

 

You are of course correct in all of your points, as far as solutions and counterpoints are not addressed, but...

15 minutes ago, YNM said:

@p1t1o @Green Baron It's true that they're "carbon neutral".

...I heartily agree sir!  

Edited September 13, 2017 by p1t1o

[Green Baron]

1 hour ago, YNM said:

@p1t1o @Green Baron It's true that they're "carbon neutral". But think again.

How much land do they take ?

*snip*

So, tell me, which one is better ? Hectares upon hectares of plantation, eating up pristine lands, or just a few square metres for borehole and another acre(s) for refinery ?

Actually much more than the mere area they are planted upon since monoculture leads sooner than later to erosion by water or wind. Areas must be given up or fertilized.

I cannot tell you which one is better, but there are people who evaluate exactly that. I think (but i am not sure) such evaluations lead to the decision to grow crop for fuel additionally to using fossil fuel, knowingly accepting the disadvantages.

 

Not exactly my idea: Solar panels on the roof, charging station in the garage and an electric car. Nice solution here on 28N in the Atlantic, less for, let's say northern Europe. It is still expensive and the batteries not exactly friendly to environment, but they'll be thoroughly recycled i hope because stuff in them is just too valuable.

Edited September 13, 2017 by Green Baron

[peadar1987]

An interesting concept is for biofuels produced from algae, either in salt water ponds, or clear plastic tubes placed in the desert. They don't use up valuable agricultural land, increase the total amount of biomass, and don't require scarce fresh water.

At the moment the conversion isn't economical, but we're getting closer all the time. It could be a valuable addition to the energy mix at some point down the road.