Thermo and Bio-chemical Conversion Technologies OLADE

1. Thermo and Bio-chemical Conversion Technologies OLADE ALFREDO BARRIGA, PHD ESPOL – ECUADOR September2011

2. Biomass Natural Cycle

3. Biomass in Ecuador

4. RESIDUAL BIOMASS FROM PLANTS

5. BIOMASS Animal or vegetal Moist Obtained with moisture content above 60% Dry Obtained with moisture content below 60% Physical Precesses Biological Processes Thermochemical Processes Drying-Compac Chopping Mechanical Press Fermentation (alcohol) Bacterian digestion Combustion Pyrolisis Gasification Liquefaction PATHS FOR UTILIZATION OF BIOMASS FOR ENERGY

6. Typical residual Biomass • Crop residues, stalks and branches, etc. • Bagasse from the process of extracting sugar cane juice (sugar production, alcohol, etc.). • Rice hulls. • Shell and oil palm bundle branches. • Remains of wood industrialization bark, side cutting damaged planks, etc. • Sawdust and wood shavings in a production of wooden elements.

7. Biomass Characteristics

8. BiofuelsComparison Chart

9. Thermo-chemical PROCESSES Thermochemical processes (pyrolysis, gasification and combustion) consist on the organic components decomposition of biomass at high temperatures. Main thermo-chemical processes are:CombustionPyrolysisGasification

10. Thermal Decomposition Processes for Biomass

11. Lignocellulose IN AIR SCHEME COMBUSTION AIR FLAME CHAR ASH VOLATILE WOOD CHARCOAL -     DRYING -         ROASTING -         PYROLYSIS COMBUSTION

12. Pyrolysis Is the incomplete combustion of biomass at elevated temperatures in the absence of oxygen, around 500 degrees celsius. Charcoal is obtained by heating wood until its complete carbonization occurs, leaving only carbon and inorganic ash. In many parts of the world, charcoal is still produced by burning a pile of wood that has been mostly covered with mud or bricks during a lot of time, even days to relatively low temperatures (350 °C) BIOMASS+ HEATCarbon+ Liquid+ gaseous

14. Gaseous fuel combustion(Methane)

15. Liquid fuel combustion (fuel oil)

16. Biomass fuel combustion (wood)

17. Pyrolysis Technologies

18. When biomass is subjected to pyrolysis, products obtained are such as: • Solid (Charcoal) • Liquid(Bio-fuel oil) (Bio-oil) • Gases (Gaseous fuel withlowormediumcalorificvalue) • Basic products in pyrolysis depend on: • Reactor temperature. • Heatingraterelatedtotheparticlesize. • Residence time of productsinside reactor. • Technology and itsoperationalparameters.

20. COMBUSTION Combustion is a process in which biomass is oxidized to carbon dioxide (CO2), water. The overall equation of combustion reaction is the reverse of photosynthesis. BIOMASS+ O2 CO2 + H2O + HEAT + (Otherspecies)* * CO, HC, Soot, Oxidized minerals , tar, moisture and other

21. Types of Biomass Combustion Chamber Main combustion technologies for biomass

22. Biomass Combustion Technologies Grate combustion.of the following types: fixed bed, horizontal and inclined grate, mobile grate and vibrating grate. Fluidized bed: is based on the combustion reaction in a fluidized bed in which the fuel particles move similarly to those of a liquid.

23. Moving Grate Fuente: Manual de Energía Térmica con biomasa

24. Inclined Grate Furnace

25. Fluidizedbubblingbedfurnace

26. OperatingTemperature in Chamber • Operating temperature depends on several factors such as: • Fuel CalorificValue. • Biomassmoisture. • Excess Air Percentage. • Heat transfer tothechamberwalls. • Heat loss to the outside. • Combustioncompletion.

27. Humidityeffectsonbiomasscalorificvalue

28. Fluid DynamicEffects of Particles Particles to fall freely in a fluid environment (air or combustion gases for example) fall at a rate dependent upon fluid forces (drag).These drag forces depend on the viscosity fluid, and the particle shape. In the case of irregular shaped particles, as are most of the biomass "chopped" as bagasse, husks, etc.. the drag coefficient depends on the wake formed by the passage downstream of the particle.

29. Influx of chipped biomass through inlet

30. FlameShape in BiomassCombustion • Flameshapedependson: • Ratio of gas-phase combustion of pyrolysis products to rate of burning of the carbonaceous residue. • Relative position of the biomass at the time of combustion. • Geometry and distribution of air supply: from below the grate, and • above it. • Presence of vortex effects which are induced by tangential entry of air.

33. Efficiency of various thermal processes with Biomass

34. Industrial Combustion Problems of Residual Biomass • The main problems of residual biomass operation are: • Formation of agglomerates and slag on the grate (slagging). • Fouling on interior surfaces. • Metal surfaces corrosion.

35. Slag formed in Biomass Combustion

36. Fouling on boiler tubes

37. Control and Emissions Combustionplants produce effluent gases, solids and liquids. Particles are one of themostimportantemissionsonbiomasscombustion. • GAS TREATMENT SYSTEMS • CYCLONIC SYSTEMS • BAG FILTERS • WET SCRUBBER • ELECTROSTATIC FILTERS

39. BIOGAS Biogas is the gaseous product of anaerobic digestion of organic waste under appropriate conditions of temperature, dilution, residence time, and others. It comprises approximately 60% of CH4 and CO2 rest, with small amounts of other gases. Organic substrates are used such as manure mixed with straw and agricultural residues and agro-industrial production.

40. BIOGAS GENERATION PROCESS The raw material for biogas generation can be processed in either batch or semi continuous production. Reactors are built using metal, plastic or masonry components. Gas begins to appear a short time after initial loading of the reactor, first slowly, and not always generating combustible gases., Methane starts to appear under the right conditions, along with carbon dioxide in the form of biogas.The biogas generated is stored within the digester or in a separate container (GASHOLDER) which can be use outside the digester. The effluent contains some of the organic compounds and nutrients, which can be used as fertilizer. It also forms some bottom sludge, which need to be removed periodically.

41. STEPS IN THE PRODUCTION OF BIOGAS

42. CHARACTERICTICS OF Biogas • Flash Point 700 º C (350 º C Diesel, gasoline and propane close to 500 º C).The flame temperature reaches 870 º C.Biogas typically contains: • 60% methane (CH4)40% of carbon dioxide (CO2).The longer the retention time, the higher the methane content, and that the calorific value.

43. PARAMETERS AFFECTING THE OPERATION OF BIODIGESTOR • Daily amount of total solids. • Retention time. • Specific production of gas per day, depending on the raw material. • Mass temperature of the digester agitation. • Physical and chemical characteristics of the raw material. • Level of pH. • Presence of harmful elements.

44. PRODUCTIVITY OF BIOGAS SYSTEM withoutagitation * Based on volatile solids Reference: Methane generation from human, animal, and agricultural waste. USA, Academy of Science, 1977

45. CompaRISON OF PRODUCTIVITY AND RETENTION TIME WITH CATTLE MANURE MIXTURES AGRICULTURAL WASTE Reference: Methane generation from human, animal, and agricultural waste. USA, Academy of Science, 1977

46. BIOGAS PRODUCTION FROM COW MANURE: Temperature and retention time Author’s own elaboration based on data from multiple sources

47. NITROGEN CONTENT AND C/N Reference: Methane generation from human, animal, and agricultural waste.

48. NITROGEN CONTENT AND C/N All materials are composed of fermentation mostly of carbon (C) and contain nitrogen (N). The C / N ratio influences the production of gas, this is optimal when C / N ranges between 20:1 and 30: 1. For example, chicken manure (high N) mixed with rice chaff, is a high gas production. If you suspect that digestion is being disturbed by toxic substances, add water or fermenting material, thus decreasing the concentration.

49. PREPARATION OF THE MIXTURE SOURCE: ENYA

50. Auxiliaryelementsfor BIOGAS SOURCE: ENYA