Evaluation of the Energy Efficiency Improvement Potential through Back-End Heat Recovery in the Kraft Recovery Boiler
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 moistu...
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doaj-caebd6f0db284c5099a0251ddfb7798f2021-03-12T00:03:19ZengMDPI AGEnergies1996-10732021-03-01141550155010.3390/en14061550Evaluation of the Energy Efficiency Improvement Potential through Back-End Heat Recovery in the Kraft Recovery BoilerJussi Saari0Ekaterina Sermyagina1Juha Kaikko2Markus Haider3Marcelo Hamaguchi4Esa Vakkilainen5School of Energy Systems, Lappeenranta-Lahti University of Technology LUT, 53850 Lappeenranta, FinlandSchool of Energy Systems, Lappeenranta-Lahti University of Technology LUT, 53850 Lappeenranta, FinlandSchool of Energy Systems, Lappeenranta-Lahti University of Technology LUT, 53850 Lappeenranta, FinlandInstitute for Energy Systems and Thermodynamics, TU Wien, 1060 Wien, AustriaStora Enso International Oy, 55400 Imatra, FinlandSchool of Energy Systems, Lappeenranta-Lahti University of Technology LUT, 53850 Lappeenranta, FinlandSustainability 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.https://www.mdpi.com/1996-1073/14/6/1550flue gas condensationscrubberscombustion air humidificationkraft recovery boilerenergy efficiencyheat pumps |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Jussi Saari Ekaterina Sermyagina Juha Kaikko Markus Haider Marcelo Hamaguchi Esa Vakkilainen |
spellingShingle |
Jussi Saari Ekaterina Sermyagina Juha Kaikko Markus Haider Marcelo Hamaguchi Esa Vakkilainen Evaluation of the Energy Efficiency Improvement Potential through Back-End Heat Recovery in the Kraft Recovery Boiler Energies flue gas condensation scrubbers combustion air humidification kraft recovery boiler energy efficiency heat pumps |
author_facet |
Jussi Saari Ekaterina Sermyagina Juha Kaikko Markus Haider Marcelo Hamaguchi Esa Vakkilainen |
author_sort |
Jussi Saari |
title |
Evaluation of the Energy Efficiency Improvement Potential through Back-End Heat Recovery in the Kraft Recovery Boiler |
title_short |
Evaluation of the Energy Efficiency Improvement Potential through Back-End Heat Recovery in the Kraft Recovery Boiler |
title_full |
Evaluation of the Energy Efficiency Improvement Potential through Back-End Heat Recovery in the Kraft Recovery Boiler |
title_fullStr |
Evaluation of the Energy Efficiency Improvement Potential through Back-End Heat Recovery in the Kraft Recovery Boiler |
title_full_unstemmed |
Evaluation of the Energy Efficiency Improvement Potential through Back-End Heat Recovery in the Kraft Recovery Boiler |
title_sort |
evaluation of the energy efficiency improvement potential through back-end heat recovery in the kraft recovery boiler |
publisher |
MDPI AG |
series |
Energies |
issn |
1996-1073 |
publishDate |
2021-03-01 |
description |
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. |
topic |
flue gas condensation scrubbers combustion air humidification kraft recovery boiler energy efficiency heat pumps |
url |
https://www.mdpi.com/1996-1073/14/6/1550 |
work_keys_str_mv |
AT jussisaari evaluationoftheenergyefficiencyimprovementpotentialthroughbackendheatrecoveryinthekraftrecoveryboiler AT ekaterinasermyagina evaluationoftheenergyefficiencyimprovementpotentialthroughbackendheatrecoveryinthekraftrecoveryboiler AT juhakaikko evaluationoftheenergyefficiencyimprovementpotentialthroughbackendheatrecoveryinthekraftrecoveryboiler AT markushaider evaluationoftheenergyefficiencyimprovementpotentialthroughbackendheatrecoveryinthekraftrecoveryboiler AT marcelohamaguchi evaluationoftheenergyefficiencyimprovementpotentialthroughbackendheatrecoveryinthekraftrecoveryboiler AT esavakkilainen evaluationoftheenergyefficiencyimprovementpotentialthroughbackendheatrecoveryinthekraftrecoveryboiler |
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