OP-II-3

OP-III-A-5Waxes have been collected in a set of filters controled by manual valves at differenttimes and quantified by weight.Weight loss (g g -1 )1.00.80.60.40.20.00 20 40 60 80 100t (s)550 є C600 єC700 єCa)Volatile formation rate (g g -1 s -1 )0.100.080.060.040.020.000 20 40 60 80t (s)550 єC600 єC650 єCFigure 2. Polymer weight loss (a) and volatile formation rate (b).b)Figure 2 shows the good performance of the reactor for this process. Due to the lowconductivity of the polymer fed as pellets, the reaction begins after 10 s at 550 °C,whereas this initial period is shortened to 6 and 4 s at 600 and 650 °C, respectively.However, high heat transfer rates between phases in the CSBR avoid defluidizationproblems, which are common in fluidized bed reactors [4]. The polymer uniformly coatsthe sand particles thanks to their cyclic movement. The vigorous solid flow and theaction of the spout avoid the formation of agglomerates and the reaction rate increasesvery fast once the polymer has been melted. Temperature has a great influence onreaction rate. Thus, at 550 °C the reaction finishes at around 70 s and volatile formationrate peaks around 30 s; at 600 °C, the reaction finishes at around 50 s and themaximum rate is located at 18 s, whereas at 650 °C these values correspond to 30 and13 s, respectively. The wax fractions prevails at 550 and 600 °C, accounting for 60 and49 wt% in each case. At 650 °C, diesel fraction components are the main lump (35wt%), followed by the wax and gasoline fractions (25 wt%).The simple design of a CSBR makes its scaling-up straightforward. Furthermore,its throughput by reactor volume unit is higher than that of a bubbling fluidized beddue to the lower amount of solid (sand) required for fluidization enhancement.References[1]. Plastics Europe’s Annual Report, Plastics Europe, Association of Plastic Manufacturers, 2007, p.26.[2]. Kaminsky, W.; Predel, M.; Sadiki, A. Polym. Degrad. Stab. 2004, 85, 1045-1050.[3]. Olazar, M.; San Jose, M.J.; Aguado, R.; Gaisan, B. Ind. Eng. Chem. Res. 1999, 38, 4120.[4]. Arena, U.; Mastellone, M.L. Chem. Eng. Sci. 2000, 55, 2849.160