I think what you are missing is perspective. What you are not seeing is the piles of grounds that would be needed and the tangle of logistics to get the grounds from where they are produced to where they can be used.
Why do you think lifting and transporting 1t of grounds takes less energy than lifting and transporting 1t of sand?
Only sand is already conveniently placed in bulk and very dense and does not require pyrolysis to be usable, etc. Almost every process related to sand I can imagine (I am not an expert at making cement in volume) will cost more for coffee grounds.
> What you are not seeing is the piles of grounds that would be needed and the tangle of logistics to get the grounds from where they are produced to where they can be used.
so many of these ideas seem to hand wave over “we’ll need to implement a whole new waste stream worldwide. don’t mind that we can hardly manage >1 stream as it is”
Why do you think lifting and transporting 1t of grounds takes less energy than lifting and transporting 1t of sand?
Only sand is already conveniently placed in bulk and very dense and does not require pyrolysis to be usable, etc. Almost every process related to sand I can imagine (I am not an expert at making cement in volume) will cost more for coffee grounds.