New Energy Vehicles (NEVs) in China

FairAndUnbiased

FairAndUnbiased

Brigadier
Registered Member
Nutrient said:
Yes, you're right. The "40 acres of wheat per gallon of gasoline" was sensational enough that I stopped there. However, my conclusion stands: biomass is not a scalable option for renewable energy.




The article goes on to say, "we would need to harvest 22 percent of all land plants just to equal the fossil fuel energy used in 1997". This calculation is for using plant material directly, not as prehistoric biomass.

The 22% is roughly the fraction of arable land in the US -- and that assumes the US only uses energy at the average global rate, which we know isn't true. The US uses far more. So to produce the necessary biomass, the Americans would have to use up more than all the arable and farmable land they have, leaving nothing left for trivial things like growing food.

Only 7% of China's land is arable, so using valuable farmland to grow biomass is even less feasible. What's more, China's energy needs will probably grow four or five times in the next century. This makes biomass utterly insufficient.

Conclusion: biomass is not a scalable option for renewable energy.

Solar power is enough for Earth, many times over, if we use solar power satellites (SPSs). However, the satellites are probably several decades in the future. If we're stuck on terra firma, we need to store the solar energy for nighttime, which means either batteries or hydrogen. Batteries have a problem: there may not be enough resources to make enough batteries for terawatts of power storage. That leaves us with hydrogen, which should work.
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ok, it seems that you did not understand my argument, which is from a chemical thermodynamics perspective.

your statement about biodiesel is not relevant to the response to "where does the carbon for methanol come from" because in my proposal, the biomass is a renewable source of carbon, not of energy.

The energy comes from the enthalpy of formation of the methanol from the hydrogenation of the products of biomass gasification. It is a scheme for the utilization of hydrogen with renewable carbon.

It is not a biodiesel scheme. I never used the words biodiesel. biomass usage as carbon source in a gasification process is not biodiesel.

Again, from a chemical perspective, here is how the gasification + hydrogenation process looks:

plants (CxHyOz in general) + O2 + heat -> C + CO + CO2 + H2O + some energy of combustion

C + H2O -> CO + H2 (syngas formation, +181.33 kJ/mol)

CO + 2H2 -> CH3-OH (methanol formation, -127.9 kJ/mol)

CO2 + 4H2 -> CH3-OH + H2O (
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)

Net enthalpy change: -111.57 kJ/mol. You are free to check my work and calculate the enthalpy of reaction for each reaction yourself.

This is thermodynamic proof that for gasification and hydrogenation of generic carbon containing plant material, there is net energy gain as long as the H2 in the equations are "free".

The H2 from renewables is "free".

This is actually a hydrogen power scheme, not a biodiesel scheme.
 
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FairAndUnbiased

FairAndUnbiased

Brigadier
Registered Member
Let's try a path using only proven reactions that have already been industrially applied:

Gasification of plant matter with limited oxygen:

plants (CxHyOz in general) + O2 + heat -> C + CO + CO2 + H2O + some energy of combustion

Now, convert produces of gasification (C + CO + CO2 + H2O) into methanol:

CO2 + C → 2 CO
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So all plant material is now carbon monoxide. Then convert carbon monoxide to methanol with hydrogen: CO + 2H2 -> CH3-OH (methanol formation, -127.9 kJ/mol)

CO2 + C → 2 CO (+170 kJ)
2CO + 2H2 -> 2CH3-OH (-255.8 kJ)

Overall reaction: CO2 + C + 2H2 -> 2CH3-OH (-85.8 kJ/mol)

Still works as long as H2 is obtained from renewable energy.
 
FairAndUnbiased

FairAndUnbiased

Brigadier
Registered Member
OK, would this be enough?
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or 1275 million L/day. Let's stay simple, replace 1:1 with methanol, 0.79 kg/L.

1275 million L methanol = 1007 million kg methanol per day. Carbon is 0.375 the mass of methanol. 377.625 million kg carbon per day.

Multiple by 365 days, 137.83 billion kg/year biomass required.

Annual production of biomass is
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, 1 ton = 1000 kg, total biomass production per year = 100000 billion kg.

production of total biomass required to satisfy US demands: 0.0013783 of total biomass production or 0.14% of annual biomass production.
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= 15% global energy usage. So times 7 to get world annual biomass usage, 0.98% total biomass production required.

So - yes, a hydrogen to methanol scheme with carbon source from biomass is workable - as long as you have the hydrogen.

In reality, when you have a 100% renewable economy, you don't need this much biomass:

1. passenger cars, buses and trains are electric so you don't need to fuel those with methanol
2. you can get carbon sources elsewhere i.e. chemical industry, remaining natural gas, remaining coal gasification, etc. that don't involve the horrendously high cost of concentration 400 ppm CO2 to 100% CO2.
3.
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And even ships could be converted to electric or nuclear eventually.

So in reality, you will need only ~15% of this number to fuel planes and ships. This is not that much.
 
N

Nutrient

Junior Member
Registered Member
FairAndUnbiased said:
ok, it seems that you did not understand my argument, which is from a chemical thermodynamics perspective.
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I understood your argument, such as it was, just fine. It seems you did not understand mine. The thermodynamics is irrelevant if not enough biomass is available. I demonstrated that even if all the arable and farmable land in the US were for growing biomass, and none for growing food, that would be insufficient, probably by many times. So whether biomass is thermodynamically energy-positive is completely irrelevant.
 
FairAndUnbiased

FairAndUnbiased

Brigadier
Registered Member
Nutrient said:
I understood your argument, such as it was, just fine. It seems you did not understand mine. The thermodynamics is irrelevant if not enough biomass is available. I demonstrated that even if all the arable and farmable land in the US were for growing biomass, and none for growing food, that would be insufficient, probably by many times. So whether biomass is thermodynamically energy-positive is completely irrelevant.
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I demonstrated the opposite with simple math - sufficient biomass exists.

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It is based on a historical analysis of how much biomass it takes to naturally create one gallon of gasoline. Here is the quote:

To determine how much ancient plant matter it took to eventually produce modern fossil fuels, Dukes calculated how much of the carbon in the original vegetation was lost during each stage of the multiple-step processes that create oil, gas and coal.
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OK, I accept that he is talking about ancient plant matter in a natural process. Let's read further. By what mechanism is it so inefficient?
The calculations showed that roughly one-eleventh of the carbon in the plants deposited in peat bogs ends up as coal, and that only one-10,750th of the carbon in plants deposited on ancient seafloors, deltas and lakebeds ends up as oil and natural gas.
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OK, it looks like the mechanism is loss and non-conversion of biomass into fossil fuel in natural environments. I accept that this is true.

But what does that have to do with chemical gasification in a closed reactor where the mass losses are near zero? Nothing. A chemical reactor is not a natural environment.

OK, so your paper talks about something utterly and totally different.
 
N

Nutrient

Junior Member
Registered Member
FairAndUnbiased said:
Annual production of biomass is
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, 1 ton = 1000 kg, total biomass production per year = 100000 billion kg.
production of total biomass required to satisfy US demands: 0.0013783 of total biomass production or 0.14% of annual biomass production.
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= 15% global energy usage. So times 7 to get world annual biomass usage, 0.98% total biomass production required.
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completely dissagrees with you. According to these scientists, the US could potentially produce 54 billion gallons of ethanol per year from non-food biomass. (We don't want to throw food away; we can convert the stalks of the wheat plant to energy, but we'd be foolish to use the edible wheat grains. The above article counts the stalks and other agricultural waste as part of the feedstock for ethanol production.)

According to you, the US consumes 337 million gallons of gasoline per day. I'll accept this figure, as it largely agrees with my deductions. That is 123 billion gallons of gasoline per year.

I'll adopt your shortcut, equating one gallon of ethanol to a gallon of gasoline.

Therefore, in the US the amount of usable fuel from biomass is one third of annual gasoline consumption. This is consistent with my previous conclusions: nowhere near enough biomass.

I think your problem is that you imagine being able to throw all of the world's biomass -- including your dead body -- into the digesters. This obviously inflates how much renewable biomass you think is available.
 
FairAndUnbiased

FairAndUnbiased

Brigadier
Registered Member
Nutrient said:
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completely dissagrees with you. According to these scientists, the US could potentially produce 54 billion gallons of ethanol per year from non-food biomass. (We don't want to throw food away; we can convert the stalks of the wheat plant to energy, but we'd be foolish to use the edible wheat grains. The above article counts the stalks and other agricultural waste as part of the feedstock for ethanol production.)

According to you, the US consumes 337 million gallons of gasoline per day. I'll accept this figure, as it largely agrees with my deductions. That is 123 billion gallons of gasoline per year.

I'll adopt your shortcut, equating one gallon of ethanol to a gallon of gasoline.

Therefore, in the US the amount of usable fuel from biomass is one third of annual gasoline consumption. This is consistent with my previous conclusions: nowhere near enough biomass.

I think your problem is that you imagine being able to throw all of the world's biomass -- including your dead body -- into the digesters. This obviously inflates how much biomass you think is available.
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No, not according to me, according to the EPA which I have conveniently linked for you.

54 billion gallons from a bioethanol process. Who said anything about bioethanol? The process proposed was a gasification + hydrogenation process. that's not bioethanol by any means.

Here is what you said:

Yes, you could burn the methanol directly. But methanol (CH3-OH) has carbon in it. Are there any scalable sources of renewable carbon? (There's a reason the English switched to coal: they probably preferred to burn wood, but their forests were almost gone.) Getting carbon from the atmosphere is impractically slow: I believe I said upthread that carbon dioxide is 0.04% of air.
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My response is yes, there is a scalable source of renewable carbon: biomass. You gasify and hydrogenate the biomass to produce methanol. This is an energy positive process. It was demonstrated to be so with 1. a plausible pathway using known reactions and 2. a simple thermodynamics calculation. You then talk about bioethanol, ancient natural processes and pretty much every single thing that has nothing to do with this, because it seems like you saw 'biomass' and started thinking that it had something to do with 'biofuels' when this was in fact a response to a very specific technical question: what is a reneweable source of carbon to convert hydrogen to sustainable methanol?
 
N

Nutrient

Junior Member
Registered Member
FairAndUnbiased said:
I demonstrated the opposite with simple math - sufficient biomass exists.
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You did not demonstrate how much of that biomass is actually accessible, yielding an energy profit. There's no point in saying that we could harvest the gigantic amount of bacteria underground, not if the effort of harvesting would cost more energy than we would recover from using that bacteria.


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It is based on a historical analysis of how much biomass it takes to naturally create one gallon of gasoline. Here is the quote:
To determine how much ancient plant matter it took to eventually produce modern fossil fuels, Dukes calculated how much of the carbon in the original vegetation was lost during each stage of the multiple-step processes that create oil, gas and coal.
Click to expand...
Click to expand...
I have already said
The article goes on to say, "we would need to harvest 22 percent of all land plants just to equal the fossil fuel energy used in 1997". This calculation is for using plant material directly, not as prehistoric biomass. [Emphasis added.]
Click to expand...
I went on to demonstrate that the US doesn't have anywhere near enough accessible biomass to support its gasoline habit.
 
FairAndUnbiased

FairAndUnbiased

Brigadier
Registered Member
Nutrient said:
You did not demonstrate how much of that biomass is actually accessible, yielding an energy profit. There's no point in saying that we could harvest the gigantic amount of bacteria underground, not if the effort of harvesting would cost more energy than we would recover from using that bacteria.



I have already said

I went on to demonstrate that the US doesn't have anywhere near enough accessible biomass to support its gasoline habit.
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But this is where you demonstrate that you don't understand that the biomass here is not the primary energy source nor is it lossy like in bioethanol or natural processes. The biomass here is used as a carbon source.

It is the same as a flue gas capture + hydrogenation scheme without the fossil fuels. There's literally no difference between gasifying biomass and "gasifying" fossil fuels by lighting it on fire. Both are already exothermic, both have high atom efficiency of converting feedstock to carbon gases. the only 2 difference is that flue gas here is taken from renewable plant matter and instead of uselessly pumps it into the ground this process reduces the gas with hydrogen from renewables to act as a stored energy supply.
 
Bellum_Romanum

Bellum_Romanum

Brigadier
Registered Member

Comparison Of Source Codes Proves Xpeng Didn't Use Tesla IP​

XMotors and the former Tesla employee at the center of the allegations both issue statements.​


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Of Source Codes Proves Xpeng Didn't Use Tesla IPXMotors and the former Tesla employee at the center of the allegations both issue statements.

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