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Valmet innovations in use at the Äänekoski bioproduct mill
Valmet’s delivery• Recovery boiler• Biomass dryer and gasification plant • Lime kiln• Sulfuric acid plant• Pulp drying line• Mill-wide automation system
Maximum energy efficiency with high power recovery boiler
Boiler capacity 7,200 t DS/dHigh Power RECOX – Metsä Fibre Äänekoski
October, 2018 © Valmet | Customer Days 20184
Steam parameters515°C/110 bar(a)
Black liquor dry solids 83%
Combustion air heated up to 215 °C
Feed water preheater and interheater
Vent gas heat recovery
Flue gas coolers
High power features enable the mill to produce 260 MW of electricity and sell 1.4 times more electricity than it needs for its own operation.
Without the high power features the electricity production capacity would be 206 MW
Improved safety with smelt spout cleaning robot
© Valmet | Customer Days 20185 October, 2018
Automated cleaning cycles reduce operator work and makes it safer– Reduced smelt splatter hazard– No heat hazards– No operator rodding injuries– No green liquor splash hazard
The robot ensures stable smelt flow by removing smelt deposits of all 11 spouts
Robot operation and optimization require learning and cooperation
Valmet has delivered 10 robots so far, both for new and existing boilers
October, 2018 © Valmet | Customer Days 20186
Benefits and experience of using smelt spout cleaning robot
Successful project implementation– All milestones reached as agreed – Recovery boiler was started up just as planned
Availability– 98-99% boiler availability
Production– Finetuning of the boiler together with Metsä to reach the optimal
reduction rate levels– Performance levels achieved in steam production
Emissions– Valmet ESP works well in recovery boiler circumstances – with
modern control opportunities– Boiler emission levels below the set levels – warranty tests passed
October, 2018 © Valmet | Customer Days 20187
Good performance based on 1st year operational experiences
Fossil fuel free lime kiln –with biomass gasification
Cheap fuel readily available– Saving about 100,000 €/day– Bark available at the site – reduction in need for bark storage and logistics
CO2 neutral solution Biomass dryer utilizes mill waste heat – improved energy
efficiency – no need for cooling towers Proven technology Technology and automation as one delivery from Valmet Disadvantages outweighed by benefits
– Kiln burner larger due to high gas flow– Requires back-up fuel oil or natural gas– Slightly increased dumping of lime mud
Drivers for choosing biomass gasification for the lime kiln
October, 2018 © Valmet | Customer Days 20189
Biomass dryer
Evaporation capacity: 23,700 kg/h Application: Lime kiln gasifierMaterials: Birch, pine and spruce
barkMoisture in 62%
out 8 %
Biomass gasifier
Product gas: 87 MWthApplication: Lime kilnFuels: Birch, pine and spruce bark
Lime kiln
Capacity: 1,200 t/h CaOFuels: Gasifier product gas,
tall oil pitch
October, 2018 © Valmet | Customer Days 201810
Valmet’s solutionAutomation
Performance tests approved for biomass dryer and gasifier– Fine tuning for lime kiln test ongoing
In continuous operation – Lime kiln running with 100% biogas - oil as back-up fuel– Lime kiln has been operating at 5-10% above design capacity
Challenges in optimized operation– Each unit can operate as a single island, but more challenging to
operate the whole chain from start to finish– Different bark types perform very differently in dryer, e.g. pine vs
birch
October, 2018 © Valmet | Customer Days 201811
Operational experience at Äänekoski
Savings and improved environmental performance with sulfuric acid plant
Turns sulfurous emissions into valuable products
Sulphur in odorous gases is converted to sulfuric acid– Production 13 kg H2SO4/ADt– Concentration 60 %– Conversion rate 94 %
Internally produced acid closes the mill’s Na-S chemical balance
Improved environmental performance with minimized sodium sulfate ash dumping
Showcases Valmet’s capability to develop new technologies to fulfill customer’s needs
October, 2018 © Valmet | Customer Days 201813
Metsä and Valmet jointly developed sulfuric acid plant solution
Sulfuric acid plant production process
14 October, 2018 © Valmet | Customer Days 2018
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• Sulfur compounds oxidized to SO2
• Heat transferred to water to produce MP-steam
• SO2 converted to SO3
• SO3 reacts with water and sulfuric acid is produced
• SO2 tail gas is washed
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Overall experience– Smooth start-up and high availability– High conversion efficiency– Good quality acid – well suited for mill use
No need to buy sulfuric acid from outside Sodium sulfate ash dumping is minimized Sulfuric acid is used in:
– Tall oil separation and bleaching plant– Possibly for lignin separation in the future
October, 2018 © Valmet | Customer Days 201815
Experiences gained from operating the sulfuric acid plant
With the internal acid plant the savings in chemical costs are5 EUR/ADt ** 3 kg S/Adt in CNCG converted to acid.NaOH 0,5 EUR/kg H2SO4 0,1 EUR/kg
Condition Monitoring using Industrial Internet Remote Analysis – Predictive action at the right time
Metsä Group Äänekoski bioproduct mill
The challenges at a state-of-the-art millProcess availability:
• A modern mill wants to run everything to full capacity.
Revealing potential failures during warranty period:• Technical, automation and process problems must not be
allowed to develop unnoticed.
Availability and cost of expertise:• The mill’s own personnel can only do a part of the job.• Hiring more specialist workforce for the relatively short
period of time would not be economically viable.
It’s all about availability – the process and the resources
October, 2018 © Valmet | Customer Days 201817
Covering vital process areas• Turbine• Pulp dryer• Lime kiln• Recovery boiler• Evaporation plant• Fans
Typical problems that have been stopped in time from developing• Lubrication problems• Balancing problems• Bearing faults• Coupling alignment
problems• Pump impeller
contamination• Mechanical loosening• Cavitation and flow
problems• Over loading• Subprocess malfunction• Belt drive problems
October, 2018 © Valmet | Customer Days 201818
Valmet DNA Machine Monitoring with Reporting and Analysis Services
Some key figures of the Äänekoski mill
15 departments with over 600 pieces of equipment.
Over 12 000 analyzed measurements.
Weekly analysis with reporting early warnings
Approx. 300 reported findings during 08/2017–08/2018.
October, 2018 © Valmet | Customer Days 201819
Fighting back against machine efficiency and quality problems
Findings and savings examples
Case example Bearing outer race damage
Damage was found in the relative change report
October, 2018 © Valmet | Customer Days 201821
October, 2018 © Valmet | Customer Days 2018
Timely action and remedy
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Waterfall diagram shows the change after bearing changeDefect is developing quickly and the bearing damagedby current is changed
Bearing changed
Condition Analysis Expert
Using all resources efficiently
ÄÄNEKOSKI MILL’S OWN
EXPERTS
METSÄ GROUP’S
BIOPRODUCT MILL
Automation and other mill systems (MES, ERP etc.)
COLLABORATION BETWEEN EXPERTS
• Analysis support• Daily checking for alarms
and deviations• Daily/weekly reporting• Personnel training• Valmet DNA Machine
Monitoring maintenance• Shared setting of goals and
operation development
VALMET PERFORMANCE
CENTER
Mr. Vesa Onnela,Certified Condition Monitoring Specialist
Local and remote resources collaborating Sharing is essential and timing crucial
October, 2018 © Valmet | Customer Days 201824
Results at the Äänekoski mill
Emerging faults detected already during warranty period
Considerable equipment damage has been prevented
Good availability of the equipment and production line
Employee safety secured because exposure to equipment in dangerous locations has been avoided
Reduced Total Cost of Ownership through predictive maintenance
Knowledge is power. Knowing and acting in time is superpower.
October, 2018 © Valmet | Customer Days 201825
“Valmet’s machine monitoring and remote analysis service has proved invaluable during the startup phase of the mill,”
Juha Anttonen,Mill Reliability Engineer
New pulp drying features
Latest developments on the Äänekoski drying lineNominal capacity: 2,700 ADT/day, birch and softwood
© Valmet | Author / Title
Slack controlAutomatic tail
threading between presses
Advanced bale weight control
Motorized trim showers
Latest developments on the Äänekoski drying lineNominal capacity: 2,700 ADT/day, birch and softwood
Slack controlAutomatic tail
threading between presses
Advanced bale weight control
Motorized trim showers
Nominal capacity: 2,700 ADT/day, birch and softwood
Latest developments on the Äänekoski drying line
Low energy trim handling>80% energy savings in normal operation
Real case of 3,500 ADT/d HW machine, 9.5 m trim width
Patented Advanced Bale Weight Control
4
0%1%2%3%4%5%6%7%8%9%
10%11%12%13%14%
Percentage of adjusted bales at scale
Bale Weight Control - ON
Acceptable bale weight range 250+2.5 kg during this measurement
Safe operation and less variance between different shifts
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Automatic tail threading system
Tail threading robots can be installed on most
machines
27 September, 2018© Valmet | Author / Title6
Roller lists at dryer inletA simple innovation that reduces dust generation
A roller list for the dryer inlet to reduce dust formation at the inlet
Movable platforms improved for broke removal
Dry end movable platform with improved broke removal features
1) Minimum bale and unit size variation2) Low energy trim band handling3) Eliminated risk of sheet breaks4) Safe and reliable operation5) Reduced dust formation at dryer inlet6) Improved broke removal features for safe and effective
dryer cleaning
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