Preparation and Characterization of Sorbents from Food Waste

Creating usable products from left over coffee grinds.

(De Gruyter) – Food waste is a major global problem, with most biomass winding up in landfills. Organic matter from fruits, vegetables, teas, coffees, etc. can instead be recycled to produce new products. Chemical and gas sorbents are porous materials that aid in the purification of liquids and gasses and can be produced from food waste.

The authors describe two methods of using coffee waste to form sorbents. In one case the coffee was treated by pyrolysis at 800 °C. The second method treated waste material to microwave pyrolysis. Solid residues from both treatments were potentially further activated with potassium hydroxide.

In both cases the activated sorbents had much better sorption properties than the non-activated masses, which had almost zero sorption properties. The surface area of sorbents prepared by microwave pyrolysis was much lower than from conventional pyrolysis, however treatment time for microwave pyrolysis was only 20 minutes compared to several hours in the case of conventional pyrolysis. The authors noted despite the decrease in sorption abilities the reduced power consumption for microwave pyrolysis could be beneficial when performing an analysis of the benefits versus energy costs.

The authors concluded that waste coffee, which is mostly disposed of by landfilling, could be used for preparation of sorbents.


Edited for Content and Length by Dr. Matthew A. Hood.

The original full article can be found at De Gruyter in the journal Green Proccessing and Synthesis.

DOI: 10.1515/gps-2016-0182

Green Processing and Synthesis 2017, 6, 287–29.

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