Biomass

Biomass is organic matter of vegetable or animal origin. These are (dead or living) bodies of all organisms – i.e. animals, plants, fungi, bacteria and cyanobacteria. Biomass can be obtained as waste from agriculture, industry, forestry, food industry, such as municipal waste, or arises as the result of deliberate production activities (growing trees and plants). Biomass includes materials such as wood chips, shavings, sawdust, wood waste pellets, briquettes, straw or herbs.

Biomass can be “dry” (e.g. wood) or “wet” (e.g. manure – liquid and solid livestock manure mixed with water). The basic processing technology is divided into dry and wet processes. The dry process (thermochemical conversion) includes incineration, gasification and pyrolysis. The wet process (biochemical conversion) includes anaerobic digestion (methane fermentation), alcohol fermentation and the production of bio hydrogen. There is also a special subset of oil extraction and subsequent treatment, which is essentially a mechanical-chemical conversion (e.g. production of biodiesel and natural lubricants).

SMART BOILERS OPERATING DATA
Technical data of the boiler  
Marking   150 180 200 220 250 300 350 400 450 500
Nominal power Pn kW 150 180 199 220 250 300 350 400 450 500
Partial load (power) Pp kW 40 45 50 55 65 75 90 100 115 140
Boiler efficiency at Pn % >95  >95  >95  >95  >95  >95  >95  >95  >95  >95 
Boiler class   5 5 5 5 5 5 5 5 5 5
Water  
Water volume l  380 420 460 460 500 690 740 790 850 900
Diameter of water connection 3 3 3 3 3 4 4 4 4 4
Diameter of water connection DN  80 80 80 80 80 100 100 100 100 100
Hydraulic-pressure drop of the boiler
at the temperature fall 20°
mbar   65 73 80 80 87 95 102 110 122 130
Boiler temperature °C  60–90° 60–90° 60–90° 60–90° 60–90° 60–90° 60–90° 60–90° 60–90° 60–90°
Minimal temperature of returnable water °C  55 55 55 55 55 55 55 55 55 55
Maximal operational pressure bar 3,5 3,5 3,5 3,5 3,5 3,5 3,5 3,5 3,5 3,5
Test pressure bar 6,5 6,5 6,5 6,5 6,5 6,5 6,5 6,5 6,5 6,5
Temperature of furnace °C  900–1100         
Pressure of furmace  mbar  -0,04 -0,04 -0,04 -0,04 -0,04 -0,04 -0,04 -0,04 -0,04 -0,04
Required draught of the chimney  mbar  0,2 0,2 0,2 0,2 0,2 0,2 0,2 0,2 0,2 0,2
Requirement for the forced draught   Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes
Combustion temperature at Pn °C 96,6 97,2 104,9 98 96,6 99,6 99,3 98,9 98,2 97,2
Combustion temperature at Pp °C 63,1 63,1 72,4 63,1 63,1 63,1 62,9 62,7 62,4 62,2
Diameter of flue gas duct mm 220 220 220 220 220 300 300 300 300 300
Diameter of chimney mm 250 250 250 250 250 350 350 350 350 350
Fuel clasification according to norm EN 14961  
Wood pellets – C1 Tested
fuel 
D6, M10, A1,5, DU90,0
Wood chips – B1 P45, M30, A3.0

 

Important concepts

Calorific value – specifies the energy resulting from fuel combustion per unit of fuel (usually 1 kg) of fuel to produce combustion products that contain water in the form of steam. 

Combustion heat – there is so much heat that the unit burns fuel to produce combustion products and it is assumed that water released by combustion condenses (e.g. condensing heat in condensing boilers). Gross calorific value is always greater than or equal to the calorific value.

Efficiency – the ratio between supplied and consumed energy [%]        

η = P / Q [%]

η … efficiency, dimensionless, or in %

P … boiler output [kW]

Q … boiler heat input [kW]

 

Fuel efficiency – SMART Boiler

Conversion

1 GJ = 1000 MJ

1 GJ = 277.78 kWh

1 GJ = 238 846 kcal

1 kg – wood pellets – 16.5 to 18.5 MJ = 4.6 to 5.1 kWh

1 kg – brown coal – 10.5 to 17.2 MJ = 2.9 to 4.8 kWh

1 kg – chips with 10% humidity = 16.4 MJ = 4.6 kWh

1 kg – chips with 20% humidity = 14.3 MJ = 4.0 kWh

1 kg – chips with 30% humidity = 12.2 MJ = 3.4 kWh

1 kg – chips with 40% humidity = 10.1 MJ = 2.8 kWh

1 m3 – natural gas = 37.82 MJ = 10.5 kWh