Pyrolysis of Solid Recovered Fuel Using Fixed and Fluidized Bed Reactors.

Currently, most plastic waste stems from packaging materials, with a large proportion of this waste either discarded by incineration or used to derive fuel. Accordingly, there is growing interest in the use of pyrolysis to chemically recycle non-recyclable (i.e., via mechanical means) plastic waste into petrochemical feedstock. This comparative study compared pyrolysis characteristics of two types of reactors, namely fixed and fluidized bed reactors. Kinetic analysis for pyrolysis of SRF was also performed. Based on the kinetic analysis of the pyrolytic reactions using differential and integral methods applied to the TGA results, it was seen that the activation energy was lower in the initial stage of pyrolysis. This trend can be mainly attributed to the initial decomposition of PP components, which was subsequently followed by the decomposition of PE. From the kinetic analysis, the activation energy corresponding to the rate of pyrolysis reaction conversion was obtained. In conclusion, pyrolysis carried out using the fluidized bed reactor resulted in a more active decomposition of SRF. The relatively superior performance of this reactor can be attributed to the increased mass and heat transfer effects caused by fluidizing gases, which result in greater gas yields. Regarding the characteristics of liquid products generated during pyrolysis, it was seen that the hydrogen content in the liquid products obtained from the fluidized bed reactor decreased, leading to the formation of oils with higher molecular weights and higher C/H ratios, because the pyrolysis of SRF in the fluidized bed reactor progressed more rapidly than that in the fixed bed reactor.

Fracture of an ossified tibialis anterior tendon.

Fractures of ossified tibialis anterior tendon have been successfully managed by the excision of the ossified tendon and transfer of the extensor hallucis longus tendon. A 64-year-old man sustained an injury during mountain hiking 2 weeks prior to presentation, falling down on his heels with his ankle fully plantarflexed. Two tender and bony hard masses were palpable along the course of the tibialis anterior tendon, one at the anteromedial aspect of the ankle and another at the dorsum of the talonavicular joint. Radiographs of the ankle demonstrated an approximately 2x1-cm ovoid-shaped bony mass at the anterior aspect of the ankle joint and another bony mass of similar size and shape at the dorsal aspect of the talonavicular joint. He underwent operative exploration, and complete rupture of the tendon through a bony mass was observed. The gap between the torn ends of the tendon after excision of the mass was too long to be repaired directly. Extensor hallucis longus tendon was retrieved 1 cm proximal to the metatarsophalangeal joint and was passed through the insertion of the anterior tibial tendon and pulled proximally and sutured to itself with the ankle in neutral. At 1 year after surgery, plain radiographs and ultrasonography showed no recurrence of calcification or ossification in the tendon and good mobility of the tibialis anterior muscle was observed.