Rapid pyrolysis of agricultural residues at high temperatures

Conference · Wed Nov 01 04:00:00 EST 1995

OSTI ID:115286

Zanzi, R; Sjoestroem, K; Bjoernbom, E ^[1]

---

1. Royal Institute of Technology, Stockholm (Sweden)

Agriculture plays an important role in the economy of many countries especially in Latin America. Gasification of agricultural residues such as bagasse from sugar cane for electricity production is a solution to meet energy demands with a favourable effect on the environment. Pyrolysis (heating solid biomass in absence of air to produce solid, liquid or gaseous fuels) is the first step in gasification and combustion. Depending on the conditions the solid, liquid or gaseous products are maximized. The treatment conditions in the pyrolysis determine the char yield and its reactivity in gasification. Char yield and char reactivity are important for the capacity of the gasifier. The rapid pyrolysis of biomass is performed in a free-fall reactor at 850{degrees}C. The biomass used in the study was wood (birch) and agricultural residues such as bagasse and leaves both from sugar cane and banana. The reactivity of the char obtained in pyrolysis is determined by reaction with steam in a thermobalance. The low amounts of a highly porous char and the high yield of gaseous products obtained in rapid pyrolysis of bagasse at high temperature are similar to those produced in rapid pyrolysis of wood. Bagasse gives more volatiles and less char than sugar cane residues and banana harvest residues. Bagasse produces a less reactive char after devolatilization than wood. The char obtained by rapid pyrolysis contains a fraction that can be further volatilized by slow pyrolysis. The fraction of char removed by slow pyrolysis is lower in chars from bagasse and sugar cane leaves than in chars from wood. The structures of the chars obtained from birch, bagasse, sugar cane and banana leaves were observed by scanning electron microscope. Qualitative X-ray microanalysis of the chars was made using an electron microscope supplied with an energy dispersive spectrometer. Ca, K, S, Si, Al and Mg were visible on the surface of the chars.

• Research Organization: National Renewable Energy Lab., Golden, CO (United States)
• OSTI ID: 115286
• Report Number(s): NREL/CP--200-8098; CONF-9508104--; ON: DE95009230
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
BAGASSE
BIOMASS
CHARS
COMBUSTION PROPERTIES
FEASIBILITY STUDIES
GASIFICATION
MICROANALYSIS
POWER GENERATION
PYROLYSIS
REFUSE DERIVED FUELS
SUGAR CANE