The pyrolysis of coconut shell, coconut shell residue and de-ashed coconut shell residue was studied with the thermogravimetric technique, and the pyrolysis kinetics models were established.It was found that for coconut shell residue and de-ashed coconut shell residue, pyrolysis mainly occurred between 280—370℃, and there was only a single peak in their DTG curves.But in the case of raw coconut shell, two stages of 230—300℃ and 300—350℃, were involved in the pyrolysis process, which resulted in two peaks in the DTG curve.Apparent activation energies for the pyrolysis of these three materials were estimated, and the difference of apparent activation energies in the low temperature range was more evident than in the high temperature range and the highest reaction rate appeared in the high temperature stage.When used for making activated carbon, coconut shell residue and de-ashed coconut shell residue have more advantages than coconut shell.The pyrolysis temperature is in a narrow range.The pyrolysis process is easy to control and is noted for energy saving.
The effects of reaction time,reaction temperature and acid concentration on xylose concentration in coconut shell hydrolysate were investigated.The acid hydrolysis mechanism for coconut shell was discussed.As a homogeneous irreversible series reactions system,first-order reaction rate models for coconut shell acid hydrolysis were established.The activation energy,kinetic coefficient for xylooligosaccharides hydrolysis and kinetic coefficient for xylose decomposition were estimated.According to the rate equations,the favorable acid hydrolysis conditions were predicted,the drawn conclusions can be used to industrial production.
