5. Conclusions
A clean producer gas was obtained with a novel downdraft
gasifier. A modified combustion chamber that prevents the formation of cool zones inside it and increases the thermal homogenization
in this reaction zone was developed. This modification
together with an extension of the reduction zone allows
diminishing the tar content in the producer gas. The mean values of
this parameter in all the experimental tests were lower than 10 mg/
Nm3. The low tar and particle content makes the producer gas
obtained in this reactor suitable to the use in cycle Otto engines.
Acknowledgement
We are grateful to the Coordination for the Improvement of
Higher Education Personnel (CAPES) (process 5993105), from the
Brazilian Ministry of Education (MEC) and to the National Council
for Scientific and Technological Development (CNPq) (process
162633/2013-0) from the Ministry of Science and Technology
(MCT) for their generous financing support to this research.