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  1. Standard member sonhouse
    Fast and Curious
    26 May '17 14:04
    https://techxplore.com/news/2017-05-power-carbon-dioxide-steam.html

    Possible 30% increase in efficiency using supercritical CO2, apparently a difficult task but leads to a turbine 1/10th the size.
  2. 26 May '17 15:35 / 2 edits
    Originally posted by sonhouse
    https://techxplore.com/news/2017-05-power-carbon-dioxide-steam.html

    Possible 30% increase in efficiency using supercritical CO2, apparently a difficult task but leads to a turbine 1/10th the size.
    Lots of strange unexplained stuff in the article. Overall, it doesn't really make sense.
    Is the CO2 being used entirely in separate cycle like the way water is? If so, how is it compressed down without using up all the energy that comes out? Water has the wonderful property of condensing all on its own when cooled at room temperature. CO2, not so much.

    Further they seem to imply that the CO2 produced by the plant is being used up in the process - complete nonsense.
  3. 26 May '17 15:40 / 1 edit
    It seems from their website:
    https://netpower.com/technology/#prettyPhoto

    That the process is closer to a car engine (or more accurately a jet engine) than a traditional steam turbine ie it is the expansion from combustion that is being utilised.
  4. Standard member DeepThought
    Losing the Thread
    26 May '17 15:51
    Originally posted by sonhouse
    https://techxplore.com/news/2017-05-power-carbon-dioxide-steam.html

    Possible 30% increase in efficiency using supercritical CO2, apparently a difficult task but leads to a turbine 1/10th the size.
    The critical point is at 30 celcius but 7.36 MPa or 73 bars[1], so the kit will need to be able to contain pretty high pressures. So the technical difficulties will surround the high pressures, but the low temperature of the critical point means they can get a very big temperature difference which will help with efficiency.

    [1] https://en.m.wikipedia.org/wiki/Carbon_dioxide_(data_page)#Thermodynamic_Properties
  5. 26 May '17 21:17
    Originally posted by sonhouse
    https://techxplore.com/news/2017-05-power-carbon-dioxide-steam.html

    Possible 30% increase in efficiency using supercritical CO2, apparently a difficult task but leads to a turbine 1/10th the size.
    From where do you get the CO2? From some fossil source, like burning coal?
    And what do you do with it after you've used it? Let it out in the atmosphere?
  6. Standard member sonhouse
    Fast and Curious
    26 May '17 21:34
    Originally posted by FabianFnas
    From where do you get the CO2? From some fossil source, like burning coal?
    And what do you do with it after you've used it? Let it out in the atmosphere?
    Probably a closed cycle.
  7. 27 May '17 05:44 / 1 edit
    Originally posted by sonhouse
    Probably a closed cycle.
    ---deleted---
  8. 27 May '17 06:25
    Originally posted by sonhouse
    Probably a closed cycle.
    No. The CO2 comes from the fuel source and is then sold as CO2 to people that want it. Obviously that is only sustainable for small quantities. Any claim that it does not produce CO2 is bunk. Consider it a process with built in carbon capture, but it has many of the problems of other carbon capture systems including increased cost and reduced efficiency.
    The overall process is to burn natural gas then use the pressure rather than the heat. Traditional plants have an extra step which convert heat to pressure via water.
    The problems are handling the high pressures, the fact that they use pure oxygen, what to do with impurities at the end and what to do with the CO2.

    Overall, I suspect they will fail to make it work economically and will rely on development funding.

    At the very best, it is a more efficient fossil fuel power plant with built in carbon capture.
  9. Standard member sonhouse
    Fast and Curious
    28 May '17 15:44
    Originally posted by twhitehead
    No. The CO2 comes from the fuel source and is then sold as CO2 to people that want it. Obviously that is only sustainable for small quantities. Any claim that it does not produce CO2 is bunk. Consider it a process with built in carbon capture, but it has many of the problems of other carbon capture systems including increased cost and reduced efficiency. ...[text shortened]...
    At the very best, it is a more efficient fossil fuel power plant with built in carbon capture.
    Well it probably has a better chance of success than cold fusion
  10. 28 May '17 19:14
    Originally posted by sonhouse
    Well it probably has a better chance of success than cold fusion
    I see no reason why it couldn't be done. That doesn't mean it should be done. But if they can do it at competitive pricing and do manage to store the CO2 somewhere, then it would be better than a traditional natural gas plant.
    But given that wind and solar are cheaper, its not a good investment.
  11. Standard member sonhouse
    Fast and Curious
    28 May '17 19:21
    Originally posted by twhitehead
    I see no reason why it couldn't be done. That doesn't mean it should be done. But if they can do it at competitive pricing and do manage to store the CO2 somewhere, then it would be better than a traditional natural gas plant.
    But given that wind and solar are cheaper, its not a good investment.
    They are building it so SOMEONE thinks it's a good idea. Of course 5 years from now it might just be shut down and a pile of scrap.
  12. 28 May '17 19:26 / 2 edits
    Originally posted by sonhouse
    They are building it so SOMEONE thinks it's a good idea.
    As I said, it probably based on government funding or something like that. Your government is in the pocket of Saudi Arabia and the fossil fuel industries.

    Back in the days of Bush it was all about he 'hydrogen economy'. When I saw Scientific American do a whole issue on it I knew that politics had even gone into science. What was funny was how the articles themselves mostly admitted it was stupid idea, yet they still acted like it was inevitable.
  13. Standard member sonhouse
    Fast and Curious
    29 May '17 13:17
    Originally posted by twhitehead
    As I said, it probably based on government funding or something like that. Your government is in the pocket of Saudi Arabia and the fossil fuel industries.

    Back in the days of Bush it was all about he 'hydrogen economy'. When I saw Scientific American do a whole issue on it I knew that politics had even gone into science. What was funny was how the art ...[text shortened]... cles themselves mostly admitted it was stupid idea, yet they still acted like it was inevitable.
    And there is STILL a push for H2 since the infrastructure is mostly the same as petrol stations, same kind of idea just a different fluid with different technological costs.

    H2 + electric seems better than petrol + electric though.

    That would pitch H2 as a secondary source not primary.

    If photocells get up to 60% like people are saying, then cells on cars also can extend the range of pure electrics without needing H2 OR petrol. The advantage there is paint the whole car with photocells and park in the sunlight and that alone will go a long way to extend range.

    So the future of electrics looks bright and the better they look like the less drive there will be for H2 stuff, fuel cells and all that.
  14. 29 May '17 14:02 / 1 edit
    Originally posted by sonhouse
    And there is STILL a push for H2 since the infrastructure is mostly the same as petrol stations, same kind of idea just a different fluid with different technological costs.
    The push has largely died down with only a few small pockets of people trying desperately to hold on to what is obviously a failed idea (and was stupid 20 years ago, but arguably less so than now).

    H2 + electric seems better than petrol + electric though.
    Except it isn't. Right now, we are not quite a the point where pure electric beats petrol for all circumstances. But in 10 years, electric will rule supreme. It would be stupid to build H2 stations country wide for a <10 year use.

    If photocells get up to 60% like people are saying, then cells on cars also can extend the range of pure electrics without needing H2 OR petrol.
    Higher capacity batteries and faster charging are the real solution. Solar cells on cars are a highly unlikely possible future technology - but will play no part in the transition to electric cars.

    The advantage there is paint the whole car with photocells and park in the sunlight and that alone will go a long way to extend range.
    That makes no sense. I can understand solar panels that charge while driving, but solar panels intended for use when parked, is illogical. Simply plug it in when parked.

    So the future of electrics looks bright and the better they look like the less drive there will be for H2 stuff, fuel cells and all that.
    The drive for H2 comes from two sources:
    1. the fossil fuel / automotive industry trying to slow down the advent of electric.
    2. Scammers trying to get funding for new technology ideas.