Pyrolysis

About: Pyrolysis is a research topic. Over the lifetime, 34918 publications have been published within this topic receiving 833524 citations.

Catalyst studies on the hydrotreatment of fast pyrolysis oil

Abstract: Catalytic hydrotreatment is considered an attractive technology for fast pyrolysis oil upgrading to liquid transportation fuels. We here report an experimental study to gain insights in catalyst stability when using Ru/C catalysts for the hydrotreatment of fast pyrolysis oil (350 °C and 200 bar) in a batch reactor set-up. A considerable reduction in the liquid yield (55–30 wt.%), increased solids formation (3–20 wt.%), a reduction in the H/C ratio (1.24–1.08) of the liquid product and a lowering of the extent of methane in the gas phase was observed after a number of catalyst recycles. Characterization of the catalyst before and after reaction using TEM, chemo- and physisorption showed significant coke deposition and a decrease in pore volume and metal dispersion. The application of in-house prepared Ru/C catalysts for both the hydrotreatment of fast pyrolysis oil as well as phenol using different Ru-precursors (RuCl3, Ru(NO)(NO3)3 and Ru(acac)3) gave different results for the various catalysts with respect to product yield (45–56 wt.% for fast pyrolysis oil) and elemental composition of the liquid phase. A catalyst prepared from the precursor RuCl3 at a ruthenium loading of 5 wt.% showed the highest activity for the hydrogenation reaction of fast pyrolysis oil (H/C of 1.32 vs. 1.24 for the commercial Ru/C catalyst) and the lowest reduction in BET area and metal dispersion after reaction.

CVD of silicon-based ceramic materials on internal surface of a reactor

Abstract: In order to reduce the rate of coke formation during the industrial pyrolysis of hydrocarbons, the interior surface of a reactor is coated with a thin layer of a ceramic material, the layer being deposited by thermal decomposition of a non-oxygen containing silicon-nitrogen precursor in the vapor phase, in an inert or reducing gas atmosphere in order to minimize the formation of oxide ceramics.

Hydrogen production from biomass gasification with Ni/MCM-41 catalysts: Influence of Ni content

Abstract: The steam pyrolysis-gasification of biomass, wood sawdust, was carried out with a Ni/MCM-41 catalyst for hydrogen production in a two-stage fixed bed reaction system. The wood sawdust was pyrolysed in the first reactor and the derived products were gasified in the second reactor. The synthesised MCM-41 mesoporous catalyst supports were impregnated with different Ni loadings (5, 10, 20 and 40 wt.%), which were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), temperature programmed reduction (TPR), transmission electron microscopy (TEM) and temperature-programmed oxidation (TPO). NiO particles were homogeneously dispersed inside the pores of 5, 10, and 20 wt.% Ni/MCM-41 catalysts; however, more bulkly NiO particles (up to 200 nm particle size) were detected outside the pores with an increase of the Ni loading up to 40 wt.%. Gas production was increased from 40.7 to 62.8 wt.%, hydrogen production was increased from 30.1 to 50.6 vol.% of total gas composition when the Ni loading was increased from 5 to 40 wt.% during the pyrolysis-gasification of wood sawdust. This work showed low coke deposition (from 0.5 to 4.0 wt.%) with valuable bio-oil by-products using the Ni/MCM-41 catalyst. The highly efficient conversion of renewable biomass resource to hydrogen and bio-oil with very low coke deposition indicates that biomass gasification on Ni/MCM-41 catalysts via two-stage reaction is a promising method for the development of the biorefinery concept.