Transcript TW 2002 Slide Show
CDS GROUP
Incorporating R-O2 Bio Coal Technology Technology Presentation
Presentation Overview
Technology and Patents Plant Flow, Schemes and Processes BioCoal Characteristics BioCoal Plant – Photos of Build Co-Firing with BioCoal Plant Design and EPC
52 International Patents
Unique Features
The R-O2 torrefaction technology is a patented method that uses dry SHS as the heating medium , to perform the drying and torrefaction processing The dry SHS medium is uniquely created from the water fraction contained in the wet feedstock and is used at virtual atmospheric pressure The R-O2 technology system operates on patented recirculation principles , and adopts proprietary thermal recuperative techniques, an off-gas processing system and a patented mano-metric density seal at the systems input and exit points
Temperature Profile
Technology Key Benefits
Faster initial drying times than conventional systems.
High drying / operating efficiencies .
Low supplementary energy input requirements.
Containment and use of exhaust emissions.
Low internal drying velocities to prevent ‘fly-away’ pick up of light fractions product.
Low abrasion / friction to product.
Energy recovery options.
Sterile product and condensate from the process.
Inert atmosphere drying & processing conditions, eliminating potential of product combustion.
Independent Verification
Independent Studies by the bodies listed below, have demonstrated that R-O2 Technology drying and processing technologies have demonstrated:
drying time
reductions of up to 80%.
CERAM Research
Best Practice Programme - Study
Energy Efficiency Best Practice Programme (UK)
Future Practice Final Report 58 by ETSU, Harwell, Didcot, OX11 0RA, acting on behalf of the DETR. Found: R-O2 drying offers
energy consumption
savings over industry survey averages of between 60% and 85%.
Block Flow Diagram
Superheated steam at atmospheric pressure is created and re-circulated over an indirect heater and through the feedstock, to dry and torrefy the material
Torrefaction Process
Shredding Thermal Oxidizer Purified Flue Gases / Recoverable energy source Vapor (+odour) Drying
BioCO 2 al Plant
Energy (pyrolysis gas) Energy (heat) Cooling BioCO 2 a
l
Energy (heat) Energy (heat) Fines Solid Fuel Furnace
Process Flow Sheet
Drying Phase
The patented drying technology operates by creating super heat steam (SHS) for its drying medium. This SHS is generated solely from the evaporating moisture contained within the biomass feedstock as it is dried The creation of the process SHS displaces air/oxygen from and creates the inert “low level oxygen” atmosphere for high temperature drying 150ºC
Torrefaction Phase
Directly from the drying process,the woodchip is transferred into a continuous rotary torrefaction processor via airtight sealed conveyors A mild thermal pyrolysis in a SHS atmosphere (240 280 °C) converts the wood chip/biomass into biocoal The biocoal is then “cooled” to below 130 °C before discharge to atmosphere Biocoal is ready for grinding , pulverising or densification
Thermal Recuperation and Off-gas
The off-gas from the torrefaction process is sent to a thermal oxidisation system for destruction and cleaning before being exhausted to atmosphere free from VOCs The oxidiser operates at around 750 – 800°C and the torrefaction gases are exposed to this heat source for a minimum of two seconds to effect complete destruction of the VOC’s and other organic chemicals [12] The energy recovered from the thermal oxidation of VOC’s should be used as an additional thermal source in both drying and torrefaction processes, thus reducing fuel (natural gas/oil) required to indirectly heat the re circulating drying and torrefaction gases.
Key Criteria
Capital cost less important than Operational cost Safety Efficiency Up-time Speed of repair/replacement Scaleable and modular
R-O2 Design Advantages
Energy optimization important (cost) Equipment selection Efficient - Safe (explosion hazard) - Scalable Robust - Reliable - Modular Bankable - Up time is high - Guarantees Low energy requirement in combination with recovery potential energy High thermal process efficiency Using super heat steam, a big advantage Louvre drum design is an ideal option for fast, consistent, efficient, safe drying & thermal processing Able to process larger particle sizes
Airless
TM
Louvre Drum
Different size options Same equipment type useable for all processing steps Experience with different drum design technologies Adaptation for specific conditions/requirements possible
Thermal Oxidisation
Post torrefaction VOC‘s gas thermal treatment technology Proprietary equipment design Energy Recovery using air,water, thermal fluid etc Energy re-use in drying and thermal processing Bag house for elimination of particulate emission Maximum energy recovery/re-use
Biomass Boiler
Heat recovery using thermal fluid Fuelled primarily by Biomass fines Bag house filter Classical grate stove
Emissions Management
Emissions Odour, wood gases, acids, dust emissions (ash, soot) No contaminated water Measures taken All off gases, combustible gases and vapours from drying and torrefaction are sent to Thermal Oxidiser for complete destruction/clean-up Bag houses in the effluents from Thermal Oxidiser and from boiler Emissions will observe Local Standards
Wood Reaction Characteristics
Torrefaction of wood in an inert atmosphere:
Up to 160 °C wood mainly loses its water Between 180 and 270 °C wood gives off additional moisture and begins to darken and brown, giving off cellulose, carbon dioxide and wood acids. Wood at this stage loses its hygroscopic properties and becomes more friable than untreated wood but less friable than charcoal Torrefaction occurs between 240 and 280 °C and wood at this stage in the process acquires the properties that are specific to BioCoal
BioCoal Characteristics
Has heating value close to steam coal with LHV of 20 to 22 MJ/kg Is CARBON NEUTRAL as it has no net release of CO 2 Is consistent and homogenous.
Different types of feedstocks have similar physical and chemical properties after torrefaction, which is important for process optimization and control Can be pelletised / densified dust for distant shipments at costs much lower than even saw Is densifiable to sub-bituminous coal level (16-17 GJ/m3) - higher than bio-pellets (~10 GJ/m3) Is friable and has greatly improved grinding properties, when compared to raw biomass or wood pellets Becomes hyrdophobic to atmosphere moisture re-absorbtion (ideal for external stock piling)
BioCoal (Woodchips) Analysis
Sample Ref: 21576 Lab Ref:
Moisture % Fixed Carbon %* Sulphur % Volatile Matter % Gross Calorific Value kJ/kg Calorific Value kJ/kg (DAF)* Gross Calorific Value Btu/lb Ash % Volatile Matter % (DAF)*
Torrefied Wood TES Bretby
2.1
21.3
0.12
73.5
17945 22350 9609 0.7
76.1
Test Results calculated to 'As Received' moisture basis. * calculated using determined values
BioCoal (Pellets) Analysis
RWE 10/5/2008
Method As Reference calP/01 cplP/05 calP/03 calP/01 calP/02 calP/04 calP/26 calP/01 calP/06 astmD5373 astmD5373 calP/25 astmD5373 calP/07 calP/25 calP/25 Moisture Proximate Ultimate Calorific Value Total Free Inherent Analysis Ash Volatile Matter Fixed Carbon Total Sulphur Chlorine Carbon Hydrogen Hydrogen (calc.) Nitrogen Gross Net(H calc.) Net(H det.) Energy % % % % % Units % % % % % % % % kJ/kg kJ/kg kJ/kg MWh/t Received 4.0
0.89
0.6
69.8
25.6
0.04
<0.01
54.5
4.62
5.31
0.04
21098 19866 20013 5.560
Results Basis As Analysed Dry 3.16
3.15
0.6
70.4
0.6
72.7
25.8
0.04
<0.01
55.0
4.66
5.36
0.04
21290 26.7
0.04
<0.01
56.8
4.81
5.53
0.04
21982 Dry Ash Free 73.2
26.8
0.04
<0.01
57.1
4.84
5.57
0.04
22117 -
BioCoal Pellets
address the drawbacks encountered with the durability and biological degradation of biopellets (storage of biocoal pellets is therefore simplified) can be applied to wide variety of biomass (sawdust, willow, larch, verge grass, wood, energy crops, straw etc) yielding similar qualities, thus increasing the feedstock range for pellet production offer a solution to low volumetric energy density of torrefied biomass [2]
BioCoal Pellets vs Wood Pellets
Properties p-BioCoal p-Wood
Density (kg/m3) 750 - 850 500 - 650 Net Calorific Value (MJ/kg) 22 Energy Density (GJ/m3) Pellet Strength 18.5
Very Good Hydroscopic Nature Biological Degradation 17 10 Good Hydrophobic Water up-take Unlikely Very Likely
BioCoal Pellets Production
Operational Benefits:
the energy consumption of the biocoal pelleting process is lower than the conventional pelletisation, due to lower energy consumption used for material sizing and pelletisation (despite increased energy consumption used for torrefaction) the desired plant production capacity with much smaller equipment [3] can be established The torrefaction gases can be recovered and used for drying , instead of using fossil fuel as utility fuel
Co-Firing with BioCoal
Co-Firing at Essent
30 tonnes of torrefied BioCoal was manufactured using the R-O2 technology and was test co-fired with coal at EPZ's 400 MWe PC-plant unit BS12, located at Borssele, The Netherlands, operated by Essent Energie (for co-pulverization and co-firing testing) At the plant, BioCoal was fed into a single coal pulverizer, a CE model with conical rollers and rotating classifier, with 100 MWe capacity Biocoal was mixed with coal up to 9% (energy basis) and injected to the boilers
There is a capacity for increasing the co-firing ratio, as the pulverizer’s limits were not reached
[7]
That ‘the significance of torrefied biofuels is that it will allow a much wider slate of biomasses (both woody and otherwise) to be conditioned for direct co-pulverizing and co firing ’ [
7]
Essent Energie, Borssele, The Netherlands
Institute for Energy findings
By far the most economical option for co-firing of coal and biomass is to co-mix the fuel stocks prior to grinding and injection into the fuel combustors at maximum ratios This avoids the need to retro-fit dedicated biomass injectors to the plant By contrast, the tough, fibrous nature and higher MC of raw biomass means that the biomass proportion is limited, typically to <7% by weight Institute for Energy, Petten (the Netherlands)
Institute for Energy findings continued
Attempts to increase the BioMass proportion beyond this limit typically lead to problems: insufficient throughput overheating and failure of the grinding mills clogging of pneumatic fuel transfer systems an unacceptable proportion of over-size particles reaching the injectors, and unpredictable thermal transients in the combustion chamber
[1]
Institute for Energy, Petten (the Netherlands)
Institute for Energy findings continued
Torreffied Biocoal however: destroys the fibrous structure biomass of the raw reduces the MC and provides a narrow range of calorific content thereby allowing a much greater biomass proportion to be combusted in existing installations
[1]
Institute for Energy, Petten (the Netherlands)
Torrefaction and Grindability
‘…it is concluded that the grindability of raw biomass can be improved [using torrefaction] to the level of coal using the temperature range of 260 – 280 0 C…’ Ref: Torrefaction for biomass co-firing in existing coal fired power stations ‘P.C.A. Bergman, et el July 2005