We produced bioplastic sustainably from natural materials that are not very useful nowadays, namely coffee dregs, dried leaves, annual plants, acorns, lupine seed peels and acacia seeds and leaves. Promoting a circular economy, from rice grains discarded by large industries, we produced a bioplastic that can be used in the manufacture of packaging and biofilters capable to remove heavy metals in aqueous solution. We also produced bioplastic from surplus cooked rice in order to combat food waste. We used commercial glycerin, but also glycerin in excess of biodiesel production from used cooking oil. The bioplastics obtained are flexible and resistant. We performed mechanical and biodegradation tests, too. We also made bioplastic articles, such as bags and packaging.