Continuous Hydrothermal Carbonization of Olive Pomace and Orange Peels for the Production of Pellets as an Intermediate Energy Carrier

Published February 5, 2024 | Version v1

Journal article Open

The ever-increasing volumes of food waste generated and the associated environmental

issues require the development of new processing methods for these difficult waste streams. One of

the technologies that can treat these waste streams directly is hydrothermal carbonization. In this

work, olive pomace and orange peels were treated via a mild hydrothermal carbonization process

(TORWASH®) in a continuous-flow pilot plant. For olive pomace, a solid yield of 46 wt% and a

dry matter content of 58% for the solid press cakes were obtained during continuous operation for

18 days. For orange peels, the values were lower with 31 wt% solid yield and a 42% dry matter content

during 28 days of continuous operation. These values corresponded fully with initial laboratory-scale

batch experiments, showing the successful transformation from batch to continuous processing.

The obtained hydrochar from both feedstocks showed an increase in higher heating value (HHV)

and a significant reduction in ash content. Pellets produced from the solids met the requirements

for industrial use, demonstrating a large increase in the deformation temperature and a significant

reduction in the potassium and chlorine content compared to the original feedstock. These results

indicate the excellent potential of these pellets for combustion applications.

Files

Name	Size	Download all
sustainability-16-00850.pdf md5:ac242fcd471d8d1acd3207de5daea828	1.3 MB	Preview Download