B3 Unrefereed conference proceedings (Poster)

Use of HTC for Utilization of the Forest Industry Sludges

Open Access publication

Publication Details

Authors: Vakkilainen Esa, Kuparinen Katja, Lipiäinen Satu

Publication year: 2021

Language: English

Related journal or series: European Biomass Conference And Exhibition

Title of parent publication: 29th European Biomass Conference and Exhibition

ISBN: 978-88-89407-21-9

eISSN: 2282-5819

JUFO level of this publication: 0

Open Access: Open Access publication


The objective of this study is to discuss properties and treatment of the forest industry sludges. Primary, bio- and tertiary sludges are side streams formed in the pulp mill wastewater treatment. Their disposal and reuse is challenging due to sludge properties. Tightening legislation regarding waste treatment and disposal, and the growing need to increase efficiency in all the unit processes of a pulp mill act as driving forces to find environmental-friendly and energy-efficient ways for sludge treatment.

The study reviews current practices in newest Finnish cases where sludges are combusted in mill’s recovery and biomass boilers. This study compares the currently used methods for primary, bio- and tertiary sludge handling in kraft pulp mills and presents two potential new methods, namely, biogas production and hydrothermal carbonization (HTC) and discusses their first industrial trials.

These processes are also presented in more detail by presenting detailed mass and energy balances for typical mill example cases. The effect of sludge properties to the cost of disposal is presented. Detailed cost analysis have been done for HTC and biogas cases. The study shows that HTC process could transform the biosludge treatment process from an energy consumer into an energy producer.

Keywords: biosludge, energy efficiency, hydrothermal carbonization, forest industry, energy consumption, energy production, best available technology

Last updated on 2021-23-11 at 09:30