Enhanced BTEX formation via catalytic fast pyrolysis of styrene-butadiene rubber: Comparison of different catalysts
FUEL
Authors: Wang, Jia; Jiang, Jianchun; Wang, Xiaobo; Pang, Shusheng; Sun, Yunjuan; Meng, Xianzhi; Li, Mi; Ruan, Roger; Ragauskas, Arthur J.
Abstract
Catalytic degradation of styrene-butadiene rubber (SBR) to produce value-added BTEXs (i.e., benzene, toluene, ethylbenzene, and xylenes) is a promising approach to dispose of solid wastes. In this work, the effects of catalyst contact mode (in-situ or ex-situ), catalyst type, and reaction conditions on desirable BTEXs production were investigated. Experimental results indicated that a limited amount of BTEXs with selectivity of 11.1% was obtained in the non-catalytic run, while a similar to 6-fold content increase was attained upon employing ultrastable Y (USY) zeolite as a catalyst in the in-situ catalytic trial. The USY catalyzed run also produced more C-4 olefin, C5-6 linear alkanes and alkenes, and C9+ aromatic hydrocarbons. A comparison between in-situ and ex-situ catalytic pyrolysis suggesting that the former was more beneficial to the generation of BTEXs as the enhanced factor was 11.5% higher than that of the ex-situ catalytic pyrolysis. Catalyst type played a critical role in the catalytic degradation of SBR, and the BTEXs formation was highly dependent on the acidic property of the employed catalyst. The Y type zeolites with a higher content of acid sites, larger surface area, and moderate pore size, generated more targeted BTEXs than H beta, HZSM-5, and SAPO-34. The optimized reaction conditions to promote the formation of BETXs in the catalytic degradation of SBR over USY, including heating rate, pyrolysis temperature, and catalyst to feedstock mass ratio, were determined to be at 10 degrees C/ms, 700 degrees C, and 3:1, respectively.
Thrombocytopenia and thromboses in a young woman
ZEITSCHRIFT FUR RHEUMATOLOGIE
Authors: Tatsis, S.; Malkowski, L.; Guldenzoph, B.
Abstract
This article reports the case of a 34-year-old female patient with multiple thrombotic events (cerebral venous sinus thrombosis, ischemic duodenitis) with simultaneous thrombocytopenia (ca. 70/nl). A paroxysmal nocturnal hemoglobinuria without detectable hemolysis and with simultaneous myelodysplastic syndrome was causative for these symptoms. This rare disease is important to consider in the differential diagnosis of chronic inflammatory rheumatic diseases, such as systemic lupus erythematosus, antiphospholipid antibody syndrome and vasculitis.