Yes, you can scrap capacitors. Aluminum capacitors offer more scrap value mainly because of the can that covers the outside of them.
There is a small amount of foil on the inside of aluminum capacitors but because of the paper that it is tightly rolled in, it is difficult to get at or gets destroyed while trying to remove it.
Capacitors come in multiple sizes and shapes. You’ll likely find decent sized ones in old televisions and various computers.
Electronic scrap recyclers buy scrap capacitors and scrap yards will accept them but to get their true value/weight remove the paper innards.
Capacitors are designed to store power. Therefore, you should not remove capacitors from electronics that have not been unplugged for at minimum 48 hours. This will allow enough time for any remaining power within the capacitors to dissipate or rundown and reduce the chances of you being shocked.
Just about all electronics have some type of capacitor within them, some big and some small but they are all worth money.
If you plan to sell the motherboard that contains the capacitors, the best way to remove them without damaging the board that I have discovered is by using a pair of pointed tin snips.
You could also use a soldering iron to reheat the solder points on the motherboard and then simply remove the capacitor.
Additionally, if you plan to sell capacitors to electronic scrap recyclers, you should invest in a cap test kit or a really good multimeter so that you are able to test each capacitor to assure that they are in working order.