A1 Journal article (refereed), original research

Evaluation of the Energy Efficiency Improvement Potential through Back-End Heat Recovery in the Kraft Recovery Boiler


Open Access publication

Publication Details
Authors: Saari Jussi, Sermyagina Ekaterina, Kaikko Juha, Haider Markus, Hamaguchi Marcelo, Vakkilainen Esa
Publisher: MDPI
Publication year: 2021
Language: English
Related Journal or Series Information: Energies
Journal name in source: Energies
Volume number: 14
Issue number: 6
ISSN: 1996-1073
JUFO-Level of this publication: 1
Permanent website address: https://www.mdpi.com/1996-1073/14/6/1550
Open Access: Open Access publication

Abstract
Sustainability and energy efficiency have become important factors for many industrial processes, including chemical pulping. Recently complex back-end heat recovery solutions have been applied to biomass-fired boilers, lowering stack temperatures and recovering some of the latent heat of the moisture by condensation. Modern kraft recovery boiler flue gas offers still unutilized heat recovery possibilities. Scrubbers have been used, but the focus has been on gas cleaning; heat recovery implementations remain simple. The goal of this study is to evaluate the potential to increase the power generation and efficiency of chemical pulping by improved back-end heat recovery from the recovery boiler. Different configurations of heat recovery schemes and different heat sink options are considered, including heat pumps. IPSEpro simulation software is used to model the boiler and steam cycle of a modern Nordic pulp mill. When heat pumps are used to upgrade some of the recovered low-grade heat, up to +23 MW gross and +16.7 MW net power generation increase was observed when the whole pulp mill in addition to the boiler and steam cycle is considered as heat consumer. Combustion air humidification proved to yield a benefit only when assuming the largest heat sink scenario for the pulp mill.

Last updated on 2021-22-03 at 07:49