An in intro to WTT ThermoTreat 2.0 .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 & manufacturing Founded in 1978 Owned by Brothers Uhre & Peter Klaas Part of the Eurocon group Bicocide impregnation Vacuum drying Thermo treatment Royal Hot-Oil Ammonia treatment Fully automated 24/7 Special processes
Unique track record Experienced team Innovative engineering International 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 High Pressure, Low temperature Temperature Wood must be dried – no free water Water needed for hydrolysis – no drying < 12% Long cycle time Short cycle time Higher energy consumption & Lower energy consumption & process process emissions emissions
The new WTT ThermoTreat 2.0 .0 Patent application no. PA 201670528
WTT ThermoTreat 2.0 .0 process – whats new? 1st Generation closed system ThermoTreat 2.0 Cycle time (hrs) 24 12/8 Energy consumption 205 120 (kWh/m 3 ) Steam (kg/m 3 ) 15 1.3 Pressure in modification 8 14 phase (bar) Heat transfer coefficient 11 104 (W/mK) Nominal heating capacity 44 222 (kWh/m 3 ) Nominal cooling capacity 35 444 Pressure dynamics Unstable – quality risks Stable – risks eliminated Approximate modification 70 40 cost (EUR/m 3 )
Improved heat transfer capability Im High heat transfer capability of ThermoTreat 2.0 140,0 120,0 Heat transfer coefficent (W/mK) 100,0 80,0 Watervapour, atmospheric pressure [W/mK] 60,0 Nitrogen, 10 Bar intial pressure [W/mK] 40,0 Low heat transfer 20,0 capability of open 0,0 systems and 1st 0 20 40 60 80 100 120 140 160 180 200 220 Temperature (Celcius) generation closed
Im 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 f 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 elevated temperature, small changes in temperature.. .. causes large changes in pressure
Im Improved pressure dynamics • During the exotherm, temperature quickly 18,000 increases to over 200 °C 16,000 at the wood core 14,000 • With steam, the 12,000 atmosphere expands Pressure (Bar) Water vapour (85% 10,000 exponentially creating rm) 8,000 pressure shocks Nitrogen • This is eliminated in 2.0 6,000 4,000 2,000 0,000 0 20 40 60 80 100 120 140 160 180 200 220 Temperature (Celcius)
The new WTT ExoT process control program Patent application no. PA 2016 70531
Durability / Strength trade-off Problem: Undertreatment Optimal treatment Overtreatment • Hemicellulose content varies significantly between species and Strength (MOR) even between charges; Durability • It is practically impossible to derive the correct treatment recipe from test trials Temperature
Solution: Exploiting the differential wood component properties Hemicellulose Cellulose Lignin Modification effect on Very high low low durability Modification effect on Low High High strength Hemicellulose Cellulose Lignin Hydrolysis/low Yes No No temp Pyrolysis/high Yes Yes Yes temp Exothermic peak in Nitrogen 290 (xylan) 360 320 atmosphere ( o C)
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 250 Hemicellulose Exotherm 200 150 Temperature (Celcius) Atmosphere temperature Temperature, wood core, spruce, 32 x 100 mm 100 50 Start cooling of atmosphere 0 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 Time (minutes)
The 2.0 .0 Technology
From small to large volume with standard modules – Plug and Play installation Suitable 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 m 3 /year • Standard Ø 1800 x 11000 12/8 h cycle: 6-9,000 m 3 /year • Multiple standard modules tied together for volumes > 9,000 m 3 /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 ry overview: key fi figures & points Open 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/m 3 wood) 600 205 120 Steam (kg/m 3 wood) unknown 15 1.3 Energy for steam production (kWh/m 3 wood) unknown 11 1 Pressure in modification phase (bar) atmospheric 8 14 Modification temperature ( o C) 230 180 170 Heat transfer coefficient at 100 o C (W/mK) 11.4 11.4 101 (1 bar) (1Bar) (10 Bar) Nominal heating capacity (kWh/m 3 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 80 - 100 70 40 (EUR/m 3 ) (use class 3.2)
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