Mechanistic Insight into Heteroatom Removal from Vacuum Gas Oil Blended with PMMA or PET Waste.

This work analyzes vacuum gas oil (VGO) and hydrocracking products of this feed blended with polymethylmethacrylate (PMMA) or polyethylene terephthalate (PET) to clarify the oxygen, nitrogen, and sulfur removal pathways in these complex mixtures. Hydrocracking reactions are conducted in a semi-batch reactor with a Pt-Pd/HY bifunctional catalyst at 400 °C and 80 bar for 300 min with 10 wt % waste plastic using 0.1 catalyst/feed weight ratio. The samples are analyzed using various techniques, including high-resolution mass spectrometry, providing an improved, more detailed analytical representation. The results demonstrate the synergistic effect of cofeeding oxygenated plastics to the VGO, altering the preferential reaction pathways of heteroatom-containing species in the following order: nitrogen, oxygen, and sulfur. We assess the nature of the species from the gathered data, establish plausible reaction mechanisms, and evaluate the catalyst's role.

Bone biopsy: indications, techniques, and complications.

Bone biopsy is the gold standard for diagnosing the type and severity of renal osteodystrophy (ROD) in end-stage renal disease (ESRD) patients. In this article we review the indications, techniques, and complications of this minimally invasive procedure. The importance of careful preparation is emphasized.