Swedish Torrefaction R&D Program

Anders Nordin1, Linda Pommer1, Ingemar Olofsson1, Katarina Håkansson1, Martin Nordwaeger1, Susanne Wiklund Lindström1, Markus Broström1

Torbjörn Lestander2, Håkan Örberg2, Gunnar Kalén2

1. Energy Technology and Thermal Process Chemistry, Umeå University, Sweden 2. Unit of Biomass Technology and Chemistry, Swedish University of Agricultural Sciences, Umeå, Sweden

Energy Technology and

Thermal Process Chemistry

Umeå University

SE-901 87 Umeå, Sweden

Phone: +46 (0)70-239 26 91

E-Post: name.surname@chem.umu.se

Linda Pommer Ingemar Olofsson Susanne Wiklund LindstromAnders Nordin

1.Design, use and evaluation of a torrefaction pilot plant, production of dimensioning dataTorrefaction pilot plant (100 kW) with a capacity of 20 kg/h, (2009).

2. Equipment and instrumentation of (a) Pilot plantThe pilot plant is now equipped and instrumented. It is constructed with high control possibilities and flexibility of the process, regarding:Torrefaction temperatureResidence time at torrefaction temperatureFuel composition and sizeFuel torrefaction atmosphereProduct cooling

3. Parametric study(a) Pilot experiments

4.Fundamental sub-projects(a) Product gas composition - “green” chemicals?

6. Supply chain system analysis (a)Initiation of networkCollaboration has been initiated with the Energy system program (LiU), Logistics and Transportation (Chalmers) and Division of Energy Engineering (LTU) and an outlined plan for the system analysis was established .

(b) Model development and useThe inherent characteristics of the torrefaction process make it well suited for energy integration with other processes;Low-value excess heat could be used for the energy consuming drying stepThe torrefaction gas could be more efficiently utilized

(b) Investigation of torrefaction mechanismsThe objective is to qualitative describe the torrefaction mechanisms on a molecular/structural level by spectro-scopic analysis (NMR, NIR), GC/MS and MBMS, and couple the mechanisms to the generation of gas components.

(c) Thermal reactivity of torrefied biomass (relevance to combustion and gasification)The objective is to identify and evaluate gravimetric inst-ruments and methods (Q5000IR TGA, Q600 SDT) for determination of thermal reactivity (initiated).

(d) Model development/validation for control of ash related problemsObjectives:Deliver a validated thermo-chemical model that describes the melt behavior of typical coal- and biomass ashesSuggest and validate optimal biomass mixtures in order to obtain desired ash melt behavior.

Martin Nordwaeger

Katarina Håkansson

References1. Placid, A T. Effect of torrefied biomass on tar reduction in producer gas from gasification. Master of Science Thesis, Umeå University. ISSN 1653-0551 ETPC Report 2010-02.2. Li, C. Torrefaction and size reduction of lignocellulosic biomass. Master of Science Thesis, Umeå University. ISSN 1653-0551 ETPC Report 2010-04.3. Nordwaeger et al. Parametric study of pilot-scale biomass torrefaction. Proceedings of the 18th European Biomass Conference and Exhibition, Lyon, 3-7 May, 2010.

(b) Industrial development unit (IDU)The first large scale (25 MW) commercial

torrefaction plant has been designed, projected and is scheduled for start of operation and instrumentation in spring 2011.

AcknowledgementFinancial support from the Swedish Energy Agency and TRB Sverige are gratefully acknowledged.

4. Håkansson. K. et al. Process and system integration aspects of biomass torrefaction. Proceedings of the 18th European Biomass Conference and Exhibition, Lyon, 3-7 May, 2010.

5. Pommer. L. et al. 2010. Gas composition from biomass torrefaction. Proceedings of the 18th European Biomass Conference and Exhibition, Lyon, 3-7 May, 2010.

6. Nordin. A. et al. 2010. Design and status of the industrial-scale torrefaction plant in Örnsköldsvik, Sweden. Proceedings of the 18th European Biomass Conference and Exhibition, Lyon, 3-7 May, 2010.

7. Svanberg. M. A planning approach for supply chains of forest fuel. Proceedings of the 18th European Biomass Conference and Exhibition, Lyon, 3-7 May, 2010.

8. Svanberg. M. and Håkansson. K. Analysing the possibilities of implementing a biomass pre-treatment process in an intermodal system for a logistics perspective. 12th WCTR, July 11-15, 2010 - Lisbon, Portugal.

5. Subsequent refinementPellets have been successfully produced both in single pellet equipment and in industrial scale pellet machines.

Results from fluidized bed gasification (FBG) trials using torrefied biomass:Reactivity retained - oxygen gasificationTar generation - unchangedCO increased, H2 decreasedEntrained flow gasification (EFG) experiments planned.

Based on the positive results of a review of previous international torrefaction work and our own lab-scale batch experiments 2006-2008, an extensive R&D program was initiated in Sweden in 2009.

BackgroundRaw biomass are characterized by a number of handling and logistic challenges, which can be significantly improved by torrefaction pre-treatment.

From the gas ana-lysis, the most ab-undant compounds in the torrefaction product gas were identified.

The higher heat-ing value (HHV) in the wet torrefaction gas was thereafter calculated.

Time plan of the R&D Program

Proj.

The initial parametric study proved the concept of torrefied biomass as an efficient measure to obtain improved product propertiesMass yield 66-87 %Energy yield 78-89%Increased LHV and HHV for the torrefied biomassDecreased grinding energy for torrefied biomass (>80%).Increased hydrophobicity, less ab-sorption of moisture and faster drying.

Torrefaction integrated with a 120 MWth CHP plant. Total efficiency: 84.6 %HHV/105.2%LHV. The torrefaction gas is burned in the existing boiler and the process is heated by part of the produced heat. In this case, low-value heat is efficiently utilized.

(b) IDU experiments (to be performed)