Any sulphur SRM scheme involves distribution of sulphur compounds into cold, low pressure air.
Naturally, you don't want to lift sulphur that's at low pressure, or you'll need some huge container to lift it with. You want to lift something nice and dense. BUT you want the sulphur to come out of the delivery vehicle at roughly ambient temperature and pressure. If there's a large pressure drop, it cools enormously, and basically ends up as snow. This falls rapidly through the air, wasting the money you've spent to lift it. If you heat the gas before lifting it, the vessel pressure ends up being absolutely bonkers. You can't practically build anything that holds it at the necessary pressure, and gets it to the stratosphere in one piece. You can use aircraft, which can have complex heaters and pressure vessels on board - thus sorting out this issue in mid air. However, for simpler technologies such as shells, hoses, etc. this is potentially a big problem. A way round this is to use a chemical reaction to put heat in any the right time (during ejection). But what to use? Sulphur burns well in air, so you can use oxygen. But liquid sulphur is hot, and liquid oxygen is very cold. Handling them together is therefore very difficult. Hydrogen peroxide might work, but the reaction isn't as exothermic. If you don't want to use molten sulphur, the fuel would have to be a sulphur powder with a fuel suspension fluid (maybe mineral oil), or maybe some kind of solid fuel rocket motor, which burns sulphur on the inside of a tube. Any help on this would be very useful. I've got a nearly-finished paper on this issue, now basically stalled for lack of a solution. A -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
