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DORSET Biomass Drying Systems

André Hermsen

Private company, grounded in 1985Aalten, The Netherlands, 120 employeesAnnual turnover € 25 million

• Biological Air Washers for pig and poultry farming• Sorting systems for selecting pigs in large groups• Feeding systems

• Animal identification• Access control and time attendance systems• Industrial reading equipment• Customer specific electronics (e.g. Pig sorting system)

• Drying systems for liquids, slurries and solids

• Chemical air cleaning systems

• Biological air cleaning systems

Drying biomass

• Liquids, slurries and solids like:

- substrates from biogas plants- (poultry) manure- sewage sludge- wood chips, sawdust, leaves, bark- grass, luzerne- paper pulp- maize- etc.

Waste heat sources

• Returned cooling water from CHP’s and ORC’s (90⁰C)

• Hot water from exhaust gas coolers (90⁰C)

• (Industrial) steam or condense water (various temperatures)

• Heat from ventilation poultry houses (20⁰C)

Reasons to dry an organic product

• Adding valuetransformation into:

- organic fertilizer- bedding for cows

- fuel- preparation for storage

• Lower transport costs- reduced weight- reduced volume

Plate belt dryerPlate belt dryer

Turning point

Dry product collection

Product flow

Air flow

Dryer in container

22.000 t/a digestate (pig manure)20%dm → 90%dm2,8 MWthDorset dryers: 2x MBD18 HTTop loaders, silos, pelleting 2t/hChemical air cleaningBiological air cleaning

Air Cleaning

Chemical Air CleanerGoal: Removing Ammonia

Biological Air CleanerGoal: reducing Smell

Combination of both

DORSET chemical air cleaner

Emissions

Dust < 10 mg/m³

Ammonia < 10 mg/m³

Smell < 500 GE/m³ (250 ouE)

Biological air cleaner

2000 m³ air/h per m² filter surface

Example (field measurement):

after dryer: 3775 GE/m³after biowasher: 170 GE/m³(target smell value: ˂ 500 GE/m³)

1 GE = 0,5 OU

Drying poultry manure

Advantages:

• Lower transport cost (up to 65% less weight)

• Dry manure is valuable product (fertilizer and fuel)

• Reduction of dust emissions by 70%

• Less smell at barn (because of less dust and dry storage)

Poultry house ventilation air →

(free energy)

Pelleting plant

manure belts

poultry houses

dryer

dryerair duct

André HermsenTelephone: +31.543472103 Mobile: +31.615559328E-mail: a.hermsen@dorset.nuWeb: www.dorset.nu

Fertilizer

layers broilers

N (Nitrogen) 4% 3%

P (Phosphorus) 3% 4%

K (Potassium) 2% 3%

Fuel 13 MJ / kg (12,300 BTU)

Dry poultry manure

Pelleting

Pelleting plant:

• Bunker

• Crusher

• Press

• Sanitation (70⁰C, 1 hr)

• Cooling

• Bagging

Capacities: 125 kg/h

400 kg/h

800 kg/h

2000 kg/h

Heat recovery

.

Wood chips, sawdust, grass, fluff

Separator

Dryer Dryer withback-mixing

85% dm

Digestate

85% dm

• Bedding material• Fuel• Fertiliser (pelleted)

• Fertiliser

Cascata(thickener)

• Storage volume reduction

2 - 5% dm 25% dm 8% dm

8 - 14% dm

Hot water 90⁰C

Back mixing

Example NPK-values

Separated Back-mixing

(screw press) (decanter)

N 18 15 26 (g/kg)

P 18 49 31 (g/kg)

K 20 23 60 (g/kg)

N - nitrogen: promotes growth of leaves and vegetationP - phosphorus: promotes root and shoot growthK - potassium: promotes flowering, fruiting and general hardiness

Example 500 kWth dryer

in: out:

8% ds 3.532 t/a 85%ds 332 t/a

25% ds 4.000 t/a 85% ds 1.176 t/a

Water: 400 t/a Ammonium Sulfate:453 t/a 292 t/a (4,24%)

Acid: 38 t/a 331 t/a (4,24%)43 t/a Water with dust:

146 t/a

165 t/a

Dryer

Air cleaner

DORSET Cascata (thickener) Product in: liquid 2 - 5%

Product out: liquid 8 - 14% (40% weight reduction)

Drying efficiency: 0,6 - 0,8 kg/kWth

Thank you for your attention !

Dorset Green Machines B.V.Weverij 26 7122 MS Aalten The Netherlands T: +31 (0) 543 472103 F: +31 (0) 543 475355 E: a.hermsen@dorset.nu