INTEGRATION OF ELECTROLYSIS TO
PRODUCE HYDROGEN AND OXYGEN IN
A PULP MILL PROCESS
Katja Kuparinen, LUT
19.10.2015
Introduction
• Fossil fuel free pulp mill as a target
• Integration of alkaline electrolysis to produce hydrogen
and oxygen
• Favourable environment for electrolysis integration
– Use for excess electricity produced at the mill
– Hydrogen to substitute heavy fuel oil in lime kiln
– Oxygen for mill operations to replace separate oxygen
production
Case definition
• Large South American pulp mill
• Eucalyptus pulp production 1.5 million ADt/a
• Fuel oil as lime kiln fuel
• Case A: Oxygen production scaled to meet the demand
of the mill
• Case B: Hydrogen production scaled to meet the lime
kiln fuel demand or maximum amount of excess
electricity, excess oxygen to recovery boiler
The Base Case
•
•
Lime kiln heat demand 72 MW
Oxygen demand
• Delignification 16 kg/ADt
• Oxidized white liquor 2 kg/ADt
• Bleaching 2 kg/ADt
Case A: Oxygen production scaled to meet the
demand of the mill
Case B: Hydrogen production scaled to meet the
lime kiln fuel demand
Excess oxygen production
217 t/d
Variable
Unit
Base
Case A
Case B
Electrolysis power consumption
MW
0
24.2
79.1
- Hydrogen production
t/d
-
10.8
38.1
- Oxygen production
t/d
-
85.7
302.4
- Feed water flow
t/d
-
97
343
- Cooling water flow
t/d
-
5,078
14,019
- Cooling water inlet temperature
°C
-
45
45
- Cooling water outlet temperature
°C
-
75
75
- Reaction temperature
°C
-
80
80
Flow increase at the water treatment plant
%
0
3
12
Hot (75 °C) water need covered by
electrolyser cooling
%
0
12
34
MW
76
55
0
t/d
164
131
45
Electricity for sale
Oil requirement for the lime kiln
Profitability of oil replacement
with hydrogen
NEO-CARBON Energy project is one of the Tekes strategy research openings
and the project is carried out in cooperation with Technical Research Centre of
Finland VTT Ltd, Lappeenranta University of Technology LUT and
University of Turku, Finland Futures Research Centre.