Gasificación de resíduos agricolas

Electo Eduardo Silva LoraUniversidade Federal de Itajubá

MINIFORUM CYTED

GASIFICATION

CONCEPT• Conversion

• BIOMASS GASEOUS FUEL (CO, H2, CH4)

• HIGH TEMPERATURE

• In sub-stoichiometric conditions

FACTOR INFLUENCING THE GASIFIER OPERATION AND OBTAINED GAS QUALITY.

5

Biomass characteristics ElementaL composition Heating value Size Distribution Moisture

Gasification fluid Air Oxygen Steam

ER REACTOR temperature

Flow and velocity of

the gasification fluid

Biomass flow

Operation pressure

STUDY ON SEWAGE SLUDGE GASIFICATION Hajime Takahashi

INDIRECT OF ALLOTHERMAL GASIFIER

Gasification applications:Electricity generation using engines

Combustion in boilers

Gasifiers coupled to internal combustion engines:

Experience and related problems

Influence parameters in ICE fuelled with producer gas

• Energy density or heating value of the producer gas/air mixture,

• Displacement volume of the engine,

• Methane or octane number of the fuel and flame speed of the fuel/air mixture, autoignition delay time,

• Compression ratio of the engine (factors directly associated with the knock tendency),

• Spark timing, that have a significant influence on the performance of the RICE.

Compression ratio of the engine (factors directly associated with the knock tendency),

• The engine operation is found to be smooth at compression ratio of 17 without any evidence of knock when is fuelled with a producer gas with 19 ± 1% H2; 19 ± 1% CO; 2% CH4; 12 ± 1% CO2; 2 ± 0:5% H2O and rest, N2 (Sridhar et al. [17] )

Spark timing - influence on the performance of the ICE.

• According to Sridhar [40] the considerably hydrogen concentration in the producer gas makes necessary lower advancement (retarding) in the spark timing for a better performance of the engine when operating with producer gas, that is, spark ignition nearest to the top dead center.

• This makes sense when it is considering the significance hydrogen concentration (20%) in the producer gas and its higher flame speed (2.7 m/s at ambient conditions [58]).

• In addition to the flame speed, spark timing also depends on other variables such as load and the rotational engine speed among others.

Main gasifier manufacturers

Succesfully projects in small scale biomass gasification in 1980-1990

• - Open top gasifier of the Indian Institute of Science. Efficiency 80%. Gas LHV 4,7 MJ/Nm3 and tar /particulate content 50 / 80 mg/Nm3.

• - Comercial chinese rice husk gasifier, Specific fuel consumption 3,75 – 4,0 kg /kWh, reprted data in the range 2,0 – 2,5 kg/kWh.

EQTEC gasifierBubbling fluidized bed

Karlovo facility in BulgariaGE/EQTEC• General Electric is to supply a three fuel flexible Jenbacher engines to

a 5 MW organic waste to energy combined heat and power facility.• One J612 and two J620 units which will be powered by syngas

derived from straw and wood chip waste.• A typical Rankine thermal cycle-based plant -electrical efficiency of

18% to 20% from converting biomass to electricity compared to using GE’s Jenbacher gas engines that offer approximately 28% electrical efficiency and almost 70% total combined heat and power efficiency.

ANKUR GASIFIERS

GASIFIER/ENGINE SET FROM XYLOWATT

Source: Laborelec, 2004

Gas LCV – 5,2 MJ/m3

CO – 25 %H2 -14 %CH4 -2 %

Gasifier efficiency – 70-80 %

Electric Power

XW 300- 300-350 kWeXW 900 – 900-1050 kWeElectric efficiency – 25 %

XYLOWATT GASIFIERS

Gasification Projects all over the world

GASEIFICADORENAMORA

GUASCOR BIOENERGIA

Gaseificadores alotérmicosPlanta de Gussing, Áustria

Nexterra and GE plants