Biocharproduction: Basics, Facilities and Potentials Biochar: Climate Savior or Bluff Package Symposium October 5th and 6th 2011 Winfried Sehn
Contents: Introduction Charcoal pits Retort pits Gasification Pyrolysis Syngas
http://earthobservatory.nasa.gov/features/carboncycle/carbon_cycle4.php
Slasch and Burn Agriculture in Madagaskar Shot by Marlis Kees in Madagaskar. GTZ / Marlis Kees.
Charcoalburner in Madagaskar GTZ-Pressefotos Umwelt und Ressourcen-management Shot by Martin Egbert in Madagaskar. GTZ / Martin Egbert.
Wood Drying 100-150 C Steam Abs. dry wood Pyrolysis 150 500 C Charcoal High temp.pyrolysis 500-800 C Burning gas Air Exhaustgas 500-1600 C Dry Charcoal Steam-Carbon-Reaction Oxidation
Charcoalpit http://www.schwarzwald.com/bildergalerie
Longitudinal Section of a Schilling Buntescher Gasification-furnace
Charcoalproduction near Sosa by Jörg Behmann
Charcoalproduction by burnig rice chaff to heat up wood in oil barrels.
Fixed Bed Reactor upstream gasification Thermal Output up to 10 MW Fixed Bed Reactor downstream gasification Thermal Output up to 5 MW Advantages: Advantages: Humid feedstocks up to 50% water and fine grained feedstocks can be -Low content of tars used Low gas temperatures at reactor Disadvatages: exit -High feedstock quality needed Disadvantages: Formation of tars and organic -High gastemperature at reactor compounds exit Until now no series production
Woodgas Generator Drying T< 200 C Pyrolysis 200< T< 500 C dissociation Air Charcoal Ashes Oxidation: 500 < T < 1200 C heating process Reduction: T < 550 C gasforming process Gas exit Kramb Jan: Technologieforum og e o zur Biomasseverstromung e s o 11-5-2006 Wartenberg
Electric power Thermal power hot water Thermal power other appl. Wood demand Fragmented size Humidity Area height
Economics calculation Kuntschar HGK 150 (100-150 kw el.) 7000 h operation hours 05.05.2011 Spending Investment Consumption Maintenance Personal Insurance 274.240 Earnings Electricity Heat 282.702 Anual rate of return 18%
Yield: 100 kg wood result in 34-40 m³ gas and 25-30 kg Charcoal, Additional products: 4-5 kg tar and 40-55 kg pyroligneous acid. Composition Charcoal gas (acc.mothermik) Carbon ca. 83% Carbondioxid 12% Hydrogen 3% Carbonmonoxid 19% Oxigen 6% Hydrogen 11% Nitrogen 1% Methan and complex Water 6% Hydrocarbons 4% Ashes 1% Nitrogen 54%
Functional Scheme of the Pyreg Plant
Conditions for Fast Pyrolysis -Very high heating and heat transfer rates at the reaction interface -Carefully controlled pyrolysis reaction temperature of around 500 C -vapour phase temperatures of 400-450 C, -short vapour residence times of typically y less than 2 seconds and -rapid cooling of the pyrolysed vapours to give the bio-oil product.
Mode Conditions Liquid Char Gas Wt% Wt% Wt% Fast Pyrolysis ~500 C ~1s 75 12 13 Intermediate Essential Pyrolysis features of ~500 C the fast pyrolysis process 50 are: 25 25 very high heating and ~10-30s heat transfer rates at the reaction interface, Slow which Torrefaction usually requires ~290 C a finely ground biomass - feed 82 18 carefully controlled pyrolysis ~30 minsreaction temperature of around 500?C Slow and Carbonisation vapour phase temperature ~400 C 400-450?C, 30 35 35 short vapour residence hrs times to days of typically less than 2 seconds rapid cooling of the pyrolysis vapours to give the bio-oil product. Gasification ~800 C 5 10 85
1 Feedstock, 2,3 Transport, 4 fluidized bed reactor, 5 cyclone 6h heat exchanger, 7 cooler, 8filter, 9flare 10 compressor, 11,12 burner, 13 overflow tank
PYTEC: continuously working ablative reaktor evaporating biomass on a rotating,heated disk 1 biomass feedstock, 2 elimination of impurities, 3 dryer, 4 Transportbelt, 5 reactor, 6 coalbox, 7 gasifier, 8 burner, 9 cyclone, 10 condenser, 11 biooil tank, 12 filter, 13 combustion engine, 14 heat exchanger
Low temperature catalytic converter condenser Feedstock Low temperature catalytic converter Gas Biochar Residual Water Bio Oil
Process according Choren Drying Pyrolysis Oxidation of Carbon and Hydrogen with pure oxygen to heat the process: Reduction of CO2 and H2O; 200 C < T < 500 C, 500 C < T < 2.000 C 500 C < T < 1.000 C) Balance reactions for gasification: I. C + CO2 < > 2CO II. C + H2O < > CO + H2 III. CO + H2O < > CO2 + H2 IV. C + 2H2 < > CH4 growing temperatures shift the equilibrium of reaction I. and II. to the rigth side forming CO and H2. ReactionsIII. and IV. generate more of CO and H2O resp. C and H2.
Conclusion The Processes should be able to use waste biomass that isn t in conflict with food All generated products should be used for further applications Processe with timber, oil and fat should possibliy conserve the naturally synthysized molecules The processes have to be designed for low flow capacities Biomass utilisation must become part of the carbon cycle and must not destroy this cycle
04.10.2011 Berlin