Cost-effective upgrading of biomass pyrolysis oil using activated dolomite as a basic catalyst

Abstract

This study deals with a continuous process on a calcined dolomite operating at atmospheric pressure and by co-feeding water for cost-effective upgrading of raw bio-oil at 400 ºC and 500 ºC. The distribution of carbon in the feed to the product fractions (gas and upgraded bio-oil) and to the dolomite (as CO2 captured and coke) was investigated with time on stream, as well as the evolution of the gas and the upgraded bio-oil composition. Acids and high-molecular weight phenols were completely removed from the raw bio-oil for 0.5 h time on stream, with the upgraded bio-oil being mainly composed of ketones (acetone, 2-butanone and cyclopentanones). Chromatographic analyses of the reaction products were combined with analysis of the dolomite characteristics by thermogravimetry and X-ray diffraction. The results are explained on the basis of possible reaction mechanisms on the dolomite basic sites (CaO, Ca(OH)2 and MgO) and the extent of dolomite carbonation with adsorbed CO2. The composition of the upgraded bio-oil is suitable for subsequent catalytic valorization for obtaining fuels and chemicals, and in particular for the production of hydrogen by steam reforming.

Production and separation of acetic acid from pyrolysis oil of lignocellulosic biomass: a review

“…During fast pyrolysis, the use of an additional catalyst could be in situ (catalyst mixed with the biomass prior to be pyrolyzed) or ex situ (separating the catalyst and biomass by physical barriers) 62 . Catalysts, in general, are used to upgrade the bio‐oil quality by reducing the acidity of the liquid phase 84 . The fast pyrolysis of white and red oak particles, in the presence and absence of a catalyst, was done to evaluate its effect on the aqueous phase.…”

“…62 Catalysts, in general, are used to upgrade the bio-oil quality by reducing the acidity of the liquid phase. 84 The fast pyrolysis of white and red oak particles, in the presence and absence of a catalyst, was done to evaluate its effect on the aqueous phase. It was found that the use of catalyst, ZSM-5, in-situ and ex-situ, decreased the acetic acid content of the aqueous phase.…”

Research progress on catalytic pyrolysis and reuse of waste plastics and petroleum sludge

“…The alkaline catalyst will remove the protons on the carbon chain to form negative carbon ions, and then the β-bit breakage will occur to form small molecules of hydrocarbons such as styrene and other useful hydrocarbons. [90,91]…”

Hydrogen Production from Catalytic Steam Reforming of Bio‐Oils: A Critical Review

“…Steam reforming of bio‐oils can be performed in the presence of natural catalysts such as dolomite, olivine, limestone, calcite, magnesite, zeolites, and so on. These materials show good activities in steam reforming and can enhance the WGS reaction and the hydrogen selectivity . Furthermore, the natural catalysts are inexpensive and abundant and can be utilized directly or with some simple pretreatments .…”

“…However, compared with other catalysts, the calcined dolomite is deactivated more easily. Besides the carbon deposition, the calcined dolomite could be saturated by the carbonation of Ca(OH) 2 and CaO to CaCO 3 and lose the ability for CO 2 capture , .…”