Nombre: ANTÔNIO CARLOS OLIVEIRA SANTOS
Tipo: MSc dissertation
Fecha de publicación: 23/03/2020
Supervisor:
Nombre |
Rol |
|---|---|
| MARCELO SILVEIRA BACELOS | Advisor * |
Junta de examinadores:
| Nombre |
Rol |
|---|---|
| LEONARDO DA SILVA ARRIECHE | External Examiner * |
| MARCELO SILVEIRA BACELOS | Advisor * |
| PAULO SÉRGIO DA SILVA PORTO | Internal Examiner * |
| YURI NASCIMENTO NARIYOSHI | Co advisor * |
Resumen: With the accelerated population growth experienced today, solid waste generation is
increasing. Aiming at a better energy use, thermo-chemical routes for waste treatment
are being sought. In the carton packaging waste sector, pyrolysis is the only route that
allows the recovery of aluminum on an industrial scale - due to the devolatization of
polyethylene. The fluidized bed reactor is an alternative for rapid pyrolysis of the
polyethylene and aluminum composite (LDPE/Al). However, the use of a bed
composed of binary mixture of sand and composite polyethylene and aluminum, can
generate segregation of particles. Particulate segregation can cause defluidization of
the bed and reduce the heat transfer rate and compromise the recovery of aluminum
via LDPE/Al pyrolysis. To evaluate the segregation of binary mixtures of sand and
LDPE/Al, experiments were conducted in a cylindrical column of 10 cm in diameter and
17 cm in height. The bed was composed of mixtures of sand particles with a diameter
of 0.45 mm and LDPE/AL with a range of 0.3 to 2.85 mm. Thus, the objective of this
study was to perform a planning of factor 33 experiments, with three central points, to
evaluate the effect of the mixing mass fraction factors (XC% w/w), air velocity (V/Vmf)
and sand particle diameter ratio and LDPE/AL (dC/dS) on the mixing index (IM). The
composite ratios in the mixture were 10 to 30% w/w. Under the investigated conditions,
air velocity in a range of 10 to 40% above the minimum fluidization was employed. The
use of the planning of experiments made it possible to adjust a statistical model to
predict the mixing index. The statistical analysis of the data revealed that only the
factors dC/dS and V/Vmf had an effect on IM. The optimal operational conditions (with IM
1) were achieved with values of 0.667 of composite and sand diameter ratio, 10% of
air velocity and 15% w/w of composite mass fraction. The statistical model obtained
was adequate to predict the values of the mixture index with an error lower than 15%.
With the low levels of segregation achieved by the bed in the optimal operational
conditions, this contact system can be indicated for the pyrolysis of LDPE/Al, thus
allowing the recovery of aluminum.
