Butane is non polar, so only non polar compounds like cannabinoids or terpenes readily dissolve in it.
Ethanol is amphiphilic (polar with a non polar tail) so it extracts the unwanted compounds (chlorophyll, waxes etc) too.
Ethanol is amphiphilic (polar with a non polar tail) so it extracts the unwanted compounds (chlorophyll, waxes etc) too.