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


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


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


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


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


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


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


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


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


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.


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



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


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.


“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

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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

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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Valmet innovations in use at the Äänekoski bioproduct mill · 2018. 10. 10. · Biomass dryer...

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Transcript of Valmet innovations in use at the Äänekoski bioproduct mill · 2018. 10. 10. · Biomass dryer...