The aforementioned recycling alternatives are only interesting
for coffee producing countries while in importing countries,
where roast of green processed beans is performed, the wastes are
mainly associated with roasting and consumption: coffee silverskin
and spent grounds, respectively. The last example consists in
the remains of ground roasted coffee after beverage preparation.
Recently, a lot of attention is being given to their recycling, namely,
as a possible fertilizer after composting, a versatile barrier in reducing
pesticide leaching through soil, a source of oil for biodiesel or
biomass for bunker fuel substitution