We report the applicability of ZrO 2 /ZnO impregnated onto a variety of MgO:SiO 2 materials as heterogeneous catalysts for the conversion of ethanol to 1,3-butadiene. The selectivity to 1,3-butadiene is affected by the ratio of the basic MgO to the acidic SiO 2 , with higher selectivities being observed as the mole fraction of MgO increases. The catalysts have been characterised by SEM, XPS, pXRD, BET surface area measurements and 29 Si solid-state NMR spectroscopy.
One of the most efficient
among the methods of managing waste tire
rubber is the pyrolysis process which allows for obtaining pyrolysis
oil. The as-received, raw tire pyrolysis oil (rTPO) is a complex mixture
whose components exhibit a wide boiling temperature range, reflected
in the physicochemical properties influencing injection, combustion,
performance, and emission. The present contribution is aimed at producing
TPO via steam-assisted pyrolysis followed by its fractionation by
vacuum distillation. The resultant TPO fractions were analyzed in
terms of composition as well as physicochemical parameters. The products
are liquids with a relatively high density, poor volatility, and satisfactory
low-temperature properties. They exhibit a mutually similar chemical
composition reflected in a roughly the same Watson factor. The dominant
components are cyclic and aromatic compounds, as was proven by gas
chromatography coupled to mass spectrometry analysis and mid-infrared
Fourier transform spectroscopy. Such a characteristic of the TPO fractions
opens the way to utilize them either as additives to conventional
automotive fuels or for heat and power generation. In particular,
the two lightest fractions demonstrate high potential as fuel additives.
Among the advantages of the fractionation of rTPO, one of the most
important is the effect of the accumulation of sulfur-containing compounds
in the highest boiling fractions, namely, vacuum fractionation allowed
for reduction of the S content by 69.6 and 43.5 wt % (with regard
to the rTPO) for the fractions boiling up to 180 and 180–250
°C, respectively. Thus, fractionation of pyrolysis oils could
be used also as an ingenious and effective pretreatment method prior
to exact desulfurization.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.