Influence of Seasonal Variations on Energy-Saving Opportunities in a Pulp Mill
Journal article, 2009

Significant energy savings can be achieved in the pulp and paper industry through process integration. The aim of this paper was to investigate how much seasonal variations in the process influence the potential for making energy savings. The hot and warm water system in a market pulp mill has been evaluated from an energy point of view, using pinch analysis. Considerable energy-saving potential was found, 40.7 MW, of which 16.5 MW was in the form of steam savings. The steam savings represent 7% of the total steam consumption at the mill. New heat exchanger networks were redesigned using different approaches. The influence of seasonal variations was estimated from the calculated energy savings when monthly averages were used in the new heat exchanger networks. When seasonal variations were taken into account, the energy-saving opportunities fell by 2.5–5.0 MW, depending on heat exchanger network design, compared with a steady-state scenario. Consequently, 88–94% of the theoretical energy savings could be realised. An economic evaluation indicates positive earnings from investment in a new heat exchanger network when seasonal variations were taken into account, even with low prices for the extracted steam and excess heat (5 €/MWh) and with an annuity factor of 0.2.

Process integration

Energy saving

Seasonal variations

Pulp mill

Pinch analysis


Jörgen Lars Persson

Industrial Energy Systems and Technologies

Thore Berntsson

Industrial Energy Systems and Technologies


0360-5442 (ISSN)

Vol. 34 10 1705-1714

Subject Categories

Energy Engineering

Chemical Process Engineering

Chemical Engineering



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