An intro to

WTT ThermoTreat 2.0

Peter Klaas, Ph.D.

Managing Director

Wood Treatment Technology A/S

Agenda

• Introduction to Wood Treatment Technology A/S (WTT)

• Introduction to thermo modification technologies

• The new WTT ThermoTreat 2.0 process

• The new WTT ExoT process control

• The 2.0 technology

• Quality compliance and control

• Summary

WTT engineering & manufacturingFounded in 1978 Owned by Brothers Uhre & Peter KlaasPart of the Eurocon group

Bicocide impregnationVacuum dryingThermo treatmentRoyal Hot-OilAmmonia treatmentFully automated 24/7Special processes

Unique track recordExperienced team

Innovative engineeringInternational network

____________________

= Business case certainty

What is thermal modification?

• Wood consists of hemicelluloses, cellulose and lignin

• Hemicelluloses attract water and are available sugars to fungi and insects

• Hemicelluloses can be removed by two processes, Pyrolysis and Hydrolysis

• Pyrolysis is decomposition by means of high temperature without presence of oxygen

• Hydrolysis is decomposition by the addition of water

• New compounds are formed in the wood in a reaction catalyzed by acids – hence the brown color

What is the difference between the open and closed systems?

Open System Closed system

Pyrolysis Hydrolysis

Atmospheric Pressure, High Temperature

High Pressure, Low temperature

Wood must be dried – no free water Water needed for hydrolysis– no drying < 12%

Long cycle time Short cycle time

Higher energy consumption & process emissions

Lower energy consumption & processemissions

The new WTT ThermoTreat 2.0

Patent application no. PA 201670528

WTT ThermoTreat 2.0 process – whats new?1st Generation closed system ThermoTreat 2.0

Cycle time (hrs) 24 12/8

Energy consumption(kWh/m3)

205 120

Steam (kg/m3) 15 1.3

Pressure in modificationphase (bar)

8 14

Heat transfer coefficient(W/mK)

11 104

Nominal heating capacity(kWh/m3)

44 222

Nominal cooling capacity 35 444

Pressure dynamics Unstable – quality risks Stable – risks eliminated

Approximate modificationcost (EUR/m3)

70 40

Improved heat transfer capability

0,0

20,0

40,0

60,0

80,0

100,0

120,0

140,0

0 20 40 60 80 100 120 140 160 180 200 220

He

at t

ran

sfe

r co

eff

ice

nt

(W/m

K)

Temperature (Celcius)

Watervapour, atmosphericpressure [W/mK]

Nitrogen, 10 Bar intialpressure [W/mK]

High heat transfer capability of

ThermoTreat 2.0

Low heat transfer capability of open systems and 1st

generation closed

Improved heat transfer capability

• Reduced cycle time due to faster heating and cooling

• Constant heating and cooling rates cause less stress on wood and technology

Elimination of steam in the reactor atmosphere

• Reduced energy consumption• Energy not needed for turning water into

steam atmosphere• Reduced heat loss from the system due to

shorter cycle times

• Quality problems from condensates staining the wood avoided

• >90 % reduction of condensates virtually eliminates waste water

• Improved pressure dynamics…

… improved pressure dynamics

With steam at elevatedtemperature, small changes in temperature.... causes large changes in pressure

Improved pressure dynamics

0,000

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

18,000

0 20 40 60 80 100 120 140 160 180 200 220

Pre

ssu

re (

Bar

)

Temperature (Celcius)

Water vapour (85%rm)

Nitrogen

• During the exotherm, temperature quicklyincreases to over 200 °C at the wood core

• With steam, the atmosphere expandsexponentially creatingpressure shocks

• This is eliminated in 2.0

The new WTT ExoT process control programPatent application no. PA 2016 70531

Durability / Strength trade-off

Temperature

Du

rab

ility

Stre

ngt

h(M

OR

)

UndertreatmentOptimal treatment

Overtreatment

Problem:

• Hemicellulose content varies significantlybetween species and even between charges;

• It is practicallyimpossible to derive the correct treatment recipefrom test trials

Solution: Exploiting the differential wood component properties

Hemicellulose Cellulose Lignin

Hydrolysis/low

temp

Yes No No

Pyrolysis/high

temp

Yes Yes Yes

Exothermic peak

in Nitrogen

atmosphere (oC)

290 (xylan) 360 320

Hemicellulose Cellulose Lignin

Modification

effect on

durability

Very high low low

Modification

effect on

strength

Low High High

The ExoT process control strategy

• Goal: to remove as much hemicellulose, and as little cellulose and lignin, as possible to maximize durability increase and minimize strength loss

• Strategy: Use the hemicellulose exotherm as process control parameter. When the exotherm is complete, all available hemicelluloses are removed

WTT ExoT process control

0

50

100

150

200

250

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200

Tem

pe

ratu

re (

Ce

lciu

s)

Time (minutes)

Atmosphere temperature

Temperature, wood core, spruce,32 x 100 mm

Start cooling of atmosphere

HemicelluloseExotherm

The 2.0 Technology

From small to large volume with standard modules – Plug and Play installationSuitable both for small volumes with manual operation and large volumes with fully automated, 24/7 operation:

• Standard Ø 1800 x 11000 24 h cycle: 3,000 m3/year

• Standard Ø 1800 x 11000 12/8 h cycle: 6-9,000 m3/year

• Multiple standard modules tied together for volumes > 9,000 m3/year

Compliance & Quality Control

Compliance & Quality Control

• Comprehensive product tests for Scots pine, Norway spruce & Beech• EN 113 Durability, lab tests

• EN 330 Durability, field, with surface coating

• TS 12037 Durability, field

• Performed in Q3-Q4 2016

• Product Data Sheets; Scots pine, Norway spruce & beech

• Product tests and PDS for other species available on customer demand

• Quality Management System under NTR available on customer demand

• Tests and documentation of emissions Q3 2016

Summary overview: key figures & pointsOpen system Closed system

First generation 1.0 WTT 2.0

Cycle time (hrs) (use class 3.2) 42 24 12 (8)

Total energy consumption (kWh/m3 wood) 600 205 120

Steam (kg/m3 wood) unknown 15 1.3

Energy for steam production (kWh/m3 wood) unknown 11 1

Pressure in modification phase (bar) atmospheric 8 14

Modification temperature ( oC) 230 180 170

Heat transfer coefficient at 100 oC (W/mK) 11.4

(1 bar)

11.4

(1Bar)

101

(10 Bar)

Nominal heating capacity (kWh/m3 wood) 25 45 222

Initial cooling capacity (kWh/m3) N/A 35 444

Pressure dynamics N/A unstable stable

Process control system Standard recipies Standard recipies ExoT

Modification cost incl. depreciation and labour

(EUR/m3) (use class 3.2)

80 - 100 70 40

Thank You for your attention