Flare stack vs LN2 recondenser

• Flare stack vs LN2 recondenser by Alvian@IDN on 27 Feb, 2022 05:39
• The number of launch vehicle using methane as a fuel are growing, but I have a tricky questions
  
  Starship launch pad for example used liquid nitrogen recondenser to cool off excess boiled off methane, as a result flare stack is no longer needed (after SN4 explosion),
  
  But strangely enough McGregor site that tested Raptors still uses flare stack (maybe because it's being built earlier than Starhopper was, and changing it to recondenser would add extra costs?), also including other launch vehicles like Vulcan & New Glenn (obviously hydrogen has to have a flare stack because liquid nitrogen is too "hot" to condense boiled off hydrogen, but I'm talking about methane)
  
  Is there anyone who can provide an insight on how the consideration of using one of them vs the other?
• #1 by russianhalo117 on 27 Feb, 2022 06:41
• Quote from: Alvian@IDN on 27 Feb, 2022 05:39

  The number of launch vehicle using methane as a fuel are growing, but I have a tricky questions
  
  Starship launch pad for example used liquid nitrogen recondenser to cool off excess boiled off methane, as a result flare stack is no longer needed (after SN4 explosion),
  
  But strangely enough McGregor site that tested Raptors still uses flare stack (maybe because it's being built earlier than Starhopper was, and changing it to recondenser would add extra costs?), also including other launch vehicles like Vulcan & New Glenn (obviously hydrogen has to have a flare stack because liquid nitrogen is too "hot" to condense boiled off hydrogen, but I'm talking about methane)
  
  Is there anyone who can provide an insight on how the consideration of using one of them vs the other?
  

  You still have to have a ground flare burn off/release system regardless for emergencies and other reasons. It doesn't have to be active but it has to exist and remain functional.
  
  For starters: https://www.sciencedirect.com/topics/engineering/flare-system
  
  https://www.epa.gov/sites/default/files/2019-08/documents/flarescostmanualchapter7thedition_august2019vff.pdf
  
  https://www.energy.gov/sites/prod/files/2019/08/f65/Natural%2520Gas%2520Flaring%2520and%2520Venting%2520Report.pdf