What is bentonite-based spent bleaching earth/clay (SBE)?
The activated or neutral form of bentonite-based spent bleaching earth/clay (SBE) is a by-product generated during the bleaching process in edible oil refinery. Its untreated form is disposed of directly at landfills involving high cost and land area, and possibly causing environmental problems.
Why is activated bleaching earth used in refining edible oil?
In the process of refining edible oil, 1¨C3% w/w of activated bleaching earth is usually used to remove impurities, pigments, and harmful substances of edible oil (Loh et al. 2017 ). After the edible oil is refined, the activated bleaching earth loses its activity and becomes spent bleaching earth.
What is bleaching earth used for?
Bleaching earth is usually prepared by acid activation modification of clay minerals with good adsorption properties (Foletto et al. 2011 ). In the process of refining edible oil, 1¨C3% w/w of activated bleaching earth is usually used to remove impurities, pigments, and harmful substances of edible oil (Loh et al. 2017 ).
Is spent bleaching earth a viable alternative to clay carbon?
The reported clay carbon materials are prepared using organic compounds as carbon precursors, which makes the cost increase unsuitable for large-scale production (An et al. 2016 ), but spent bleaching earth (SBE) can solve this problem.
