Abstract
The gasification process may be utilized to transform the lignocellulosic material, in this case bagasse sugarcane, in three major products: coal, tar and gas (mixture of hydrogen, carbon monoxide, carbon dioxide and methane, mainly). The products have high potential as raw material for added-value fuels; among these fuels the hydrogen, which has lower capacity of environmental contamination (Anukam et al., 2016).
In literature, most of the work covers two scale kinds of biomass gasification processes:
a) Small-scale processes processing mass flow rate of the order of 10-1 kg / h, the most largely used kinetic data are the result of work done in this range.
b) Large-scale processes, processing 102 - 103 kg / h of biomass.
This fact has led to some phenomena, presented on the large-scale processing, which are not explained, because the kinetic in which the process is based on was conducted in a completely different scale and sometimes even the regime is not the kinetic one, mass transfer and heat phenomena are scale dependent and hence with completely different behaviours (Shen et al., 2017). In this context, this work presents a semi- pilot scale reactor, 2 kg of biomass/h as platform for investigation the main phenomena taking place in the process. Such a rig scale developed in house allows the collection of data in different operating conditions, combining ease of operation and more accurate measurements, typical of small scale, with the phenomenology of large-scale equipment.
Taking this into consideration, the reactions that occur in the biomass gasification process in a reactor with a processing capacity of 2 kg / h biomass were evaluated. The operability of the equipment, heating rates and cooling the reactor, start-up time, evaluation of the collection system and quantification of samples were identified and evaluated. After setting the operability of the equipment, optimizing the gasification process with the objective of maximizing the gaseous fraction obtained was carried out through changes in the air / biomass ratio used with respect to the same relationship required for complete combustion; this ratio is defined as ER. Varying the ER ratio, gas fractions, tar and char obtained, as well as gas composition and the amount of water in the tar were determined, allowing to identify suitable operational policies.
