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The one huge aspect this article doesn't even mention are the thermodynamics of the process. Of course CO2 can be used as a building block for plastic, but it c

The one huge aspect this article doesn't even mention are the thermodynamics of the process. Of course CO2 can be used as a building block for plastic, but it contains far less energy than the plastic you want to create. That means you have to supply that energy difference somehow. The reason we use mostly oil to synthesize plastic is that someone else already put in the energy to convert CO2: the plants. Even though you can't avoid the thermodynamics here and cheat the energy difference, of course there could be more efficient, cheaper and cleaner ways to go from CO2 to plastic, and those would be interesting in terms of dealing with climate change.

Sharlin 10y ago
Given the current solar boom, we'll probably end up using the same energy source that plants use. Perhaps even a chemical process similar to photosynthesis.
- dogma1138 10y ago
  It's still would be more effective to use biomass to sequester the CO2 and then make biopolymers than it's to use an artificial process. Also solar has it's own carbon footprint, and not as small as people think. The raw materials for these panels are mined, transported, the factories in China that make those panels use likely coal as their primary energy source, then the panels are transported again and again and again, and finally installed and maintained by people who likely don't show up to work in an EV. You need to be very careful abstracting the true carbon footprint of anything and sadly too many people seem to ignore this fact. Just because the item you buy and it's use is environmentally friendly it doesn't mean that the supply chain is.
  - andrewtbham 10y ago
    This solar has a carbon footprint argument is absurd. If you used this logic we would never have renewable energy because it creates a chicken and egg problem. It would only make sense if the amount of energy used to produce solar panels exceeded the amount of energy it produced over it's lifetime, which is not the case.
    - maxerickson 10y ago
      It does make a lot of sense to examine the expected EROI when installing them though. Buying power from the other side of a mountain might be a lot greener than installing solar panels in your own backyard (that probably requires much of the transmission infrastructure to already exist, but a lot of transmission infrastructure already exists).
    - dogma1138 10y ago
      No it's not an absurd argument, you need to understand the actual carbon footprint for the entire supply chain. In this case you can easily end up releasing more carbon by building the solar panels and all the machinery needed for sequestering the CO2 than you can actually effectively sequester within the effectively lifespan of your machinery. You also need to take into account in the cost since each dollar (or any other unit of currency) has a carbon footprint on it's own based on the economy it was generated in. There is a good reason why some things are not effective, viable or just plain stupid, otherwise you end up planning your freaking solar roadways or worse building them.
  - ZeroGravitas 10y ago
    A carbon fee system takes care of most of this. The guy that commutes in a coal rolling SUV pays more so he stops and buys an EV pickup instead. The coal burning power station that he charges it with pays more so they get replaced with gas or solar or wind. The company that ships the panels chooses between different shipping methods based on price, which includes a cost of carbon. And so on. The magic of free markets (I'll end this sentence early since we're not doing politics this week.
furyg3 10y ago
This is what struck me when reading the article. The winner of the hackathon is the guy who goes out to the parking lot and plants a tree. :) In all seriousness, they gather the solar energy themselves, absorb the CO2 themselves, after a small initial investment you can walk away and the result is plenty of useful materials (including bioplastics)!
- Spooky23 10y ago
  Trees are a win-win all around, especially in urban areas. They absorb CO2 and other particulate pollution, provide shade which has measurable reductions in cooling costs, divert storm water and improve property values.
schiffern 10y ago
This. The real question is, "Can CO2 be given more value by using it to make plastics than the value of the energy used to power the process?" This is a much harder problem. A good start might be a thermodynamic analysis. Ethylene monomers have an enthalpy of formation from pure CO2 and H2O of 12.9 kWh/kg, plus losses due to process inefficiency. It's only 7.3 kWh/kg if you have a "free" source of hydrogen to provide the remaining energy, but typically industrial hydrogen comes from fossil fuels. Industrial electricity prices in the US and China are around 10c(=0.66 Yuan)/kWh, so that much electricity goes for about $1.30. But ethylene prices are only around $1.07/kg,[1] so from this admittedly simplistic analysis it would seem the answer is no, it's not worth it. This is before considering the extra energy required to concentrate CO2 from dilute form in the atmosphere or an exhaust flue. Someone else on this thread said it best -- the tree wins the technology contest. Self replicating, solar powered, soil building, carbon sequestering, water/air cleaning, etc. Oh yeah, and trees are literally[2] what makes it rain. [1] http://asia.nikkei.com/Markets/Commodities/Ethylene-prices-up-despite-cheaper-crude http://asia.nikkei.com/Markets/Commodities/Ethylene-prices-u... [2] By transpiring coastal rainfall, trees "kick it back up" and transport water to the inner parts of the continent like an irrigation system. Hence why deforestation leads to desertification. http://www.nature.com/nature/journal/v496/n7445/abs/nature11983.html http://www.nature.com/nature/journal/v496/n7445/abs/nature11...
nojvek 10y ago
Here's a crazy idea I've been thinking for a long time. Is tthere a way to artificially create a way to trap sunlight and turn it into gasoline in an artificial process. Basically what earth does in thousands of years but with human ingenuity we make it a lot faster and free reproducible in other countries. I see the core problem as. We already have great gasoline infrastructure. It's very energy dense. We just need to learn how to make green gasoline.
- abpavel 10y ago
  We make a lot of green gasoline already. It's called biofuel. The problem is that it takes farmland away from producing food for people into producing food for cars. And cars are much hungrier, filling landscapes with rapeseed https://en.m.wikipedia.org/wiki/Rapeseed https://en.m.wikipedia.org/wiki/Rapeseed
- slightleep 10y ago
  The US navy is planning on introducing the ability to generate jet fuel from seawater on its nuclear aircraft carriers in the 2020s. The process works, it just takes a tremendous amount of energy (hence the nuclear carrier part) and it requires a lot of water to create a gallon of jet fuel (20,000 gallons I believe for a singe gallon of jet fuel). The toughest part, however, is that the process would release methane gas into the air. So it's unclear if it's really greenhouse-gas neutral. In theory, though, if you could trap the methane and then sequester the hydrocarbons you made, you'd have a way to pull CO2 out of the atmosphere.
- ZeroGravitas 10y ago
  EVs are simply better than gasoline for pretty much anything with wheels. And we have a great infrastructure for that too. There's no point in producing synthetic fuels for 99% of wheeled vehicles. Planes on the other hand are a different story.

Sharlin 10y ago

Given the current solar boom, we'll probably end up using the same energy source that plants use. Perhaps even a chemical process similar to photosynthesis.

dogma1138 10y ago
It's still would be more effective to use biomass to sequester the CO2 and then make biopolymers than it's to use an artificial process. Also solar has it's own carbon footprint, and not as small as people think. The raw materials for these panels are mined, transported, the factories in China that make those panels use likely coal as their primary energy source, then the panels are transported again and again and again, and finally installed and maintained by people who likely don't show up to work in an EV. You need to be very careful abstracting the true carbon footprint of anything and sadly too many people seem to ignore this fact. Just because the item you buy and it's use is environmentally friendly it doesn't mean that the supply chain is.
- andrewtbham 10y ago
  This solar has a carbon footprint argument is absurd. If you used this logic we would never have renewable energy because it creates a chicken and egg problem. It would only make sense if the amount of energy used to produce solar panels exceeded the amount of energy it produced over it's lifetime, which is not the case.
  - maxerickson 10y ago
    It does make a lot of sense to examine the expected EROI when installing them though. Buying power from the other side of a mountain might be a lot greener than installing solar panels in your own backyard (that probably requires much of the transmission infrastructure to already exist, but a lot of transmission infrastructure already exists).
  - dogma1138 10y ago
    No it's not an absurd argument, you need to understand the actual carbon footprint for the entire supply chain. In this case you can easily end up releasing more carbon by building the solar panels and all the machinery needed for sequestering the CO2 than you can actually effectively sequester within the effectively lifespan of your machinery. You also need to take into account in the cost since each dollar (or any other unit of currency) has a carbon footprint on it's own based on the economy it was generated in. There is a good reason why some things are not effective, viable or just plain stupid, otherwise you end up planning your freaking solar roadways or worse building them.
- ZeroGravitas 10y ago
  A carbon fee system takes care of most of this. The guy that commutes in a coal rolling SUV pays more so he stops and buys an EV pickup instead. The coal burning power station that he charges it with pays more so they get replaced with gas or solar or wind. The company that ships the panels chooses between different shipping methods based on price, which includes a cost of carbon. And so on. The magic of free markets (I'll end this sentence early since we're not doing politics this week.

furyg3 10y ago

This is what struck me when reading the article. The winner of the hackathon is the guy who goes out to the parking lot and plants a tree. :) In all seriousness, they gather the solar energy themselves, absorb the CO2 themselves, after a small initial investment you can walk away and the result is plenty of useful materials (including bioplastics)!

Spooky23 10y ago
Trees are a win-win all around, especially in urban areas. They absorb CO2 and other particulate pollution, provide shade which has measurable reductions in cooling costs, divert storm water and improve property values.

schiffern 10y ago

This. The real question is, "Can CO2 be given more value by using it to make plastics than the value of the energy used to power the process?" This is a much harder problem. A good start might be a thermodynamic analysis. Ethylene monomers have an enthalpy of formation from pure CO2 and H2O of 12.9 kWh/kg, plus losses due to process inefficiency. It's only 7.3 kWh/kg if you have a "free" source of hydrogen to provide the remaining energy, but typically industrial hydrogen comes from fossil fuels. Industrial electricity prices in the US and China are around 10c(=0.66 Yuan)/kWh, so that much electricity goes for about $1.30. But ethylene prices are only around $1.07/kg,[1] so from this admittedly simplistic analysis it would seem the answer is no, it's not worth it. This is before considering the extra energy required to concentrate CO2 from dilute form in the atmosphere or an exhaust flue. Someone else on this thread said it best -- the tree wins the technology contest. Self replicating, solar powered, soil building, carbon sequestering, water/air cleaning, etc. Oh yeah, and trees are literally[2] what makes it rain. [1] http://asia.nikkei.com/Markets/Commodities/Ethylene-prices-up-despite-cheaper-crude http://asia.nikkei.com/Markets/Commodities/Ethylene-prices-u... [2] By transpiring coastal rainfall, trees "kick it back up" and transport water to the inner parts of the continent like an irrigation system. Hence why deforestation leads to desertification. http://www.nature.com/nature/journal/v496/n7445/abs/nature11983.html http://www.nature.com/nature/journal/v496/n7445/abs/nature11...

nojvek 10y ago

Here's a crazy idea I've been thinking for a long time. Is tthere a way to artificially create a way to trap sunlight and turn it into gasoline in an artificial process. Basically what earth does in thousands of years but with human ingenuity we make it a lot faster and free reproducible in other countries. I see the core problem as. We already have great gasoline infrastructure. It's very energy dense. We just need to learn how to make green gasoline.

abpavel 10y ago
We make a lot of green gasoline already. It's called biofuel. The problem is that it takes farmland away from producing food for people into producing food for cars. And cars are much hungrier, filling landscapes with rapeseed https://en.m.wikipedia.org/wiki/Rapeseed https://en.m.wikipedia.org/wiki/Rapeseed
slightleep 10y ago
The US navy is planning on introducing the ability to generate jet fuel from seawater on its nuclear aircraft carriers in the 2020s. The process works, it just takes a tremendous amount of energy (hence the nuclear carrier part) and it requires a lot of water to create a gallon of jet fuel (20,000 gallons I believe for a singe gallon of jet fuel). The toughest part, however, is that the process would release methane gas into the air. So it's unclear if it's really greenhouse-gas neutral. In theory, though, if you could trap the methane and then sequester the hydrocarbons you made, you'd have a way to pull CO2 out of the atmosphere.
ZeroGravitas 10y ago
EVs are simply better than gasoline for pretty much anything with wheels. And we have a great infrastructure for that too. There's no point in producing synthetic fuels for 99% of wheeled vehicles. Planes on the other hand are a different story.