Pyrolysis of wood pellets in the presence of oxygen carriers in a fluidised bed coupled with a DBD reactor for tar quantification

Abstract

The pyrolysis of wood in the presence of chemical looping agents including Fe 2 O 3 , mayenite-supported CuO and mayenite-supported Cu 2 O was studied from 773 to 1173 K. A continuous tar quantification system, based on a DBD reactor downstream of the fluidised bed, was developed to allow quantification of the tar formed. An oxygen-containing plasma was used to convert volatiles and tars to measurable carbon-containing species, mainly CO, CH 4 , and CO 2 . It was found that pyrolysis of the wood in alumina sand produced CH 4 , CO, CO 2 , tar and char as the main products. Tar cracking was observed above 1073 K, and this mainly generated CH 4 . Both Fe 2 O 3 and mayenite-supported Cu-based oxides were effective for in situ combustion of the pyrolysis products, particularly tar, at temperatures exceeding 873 K. Mayenite-supported CuO showed the highest reactivity. The results showed the potential of using metal oxides for direct combustion of biomass, and particularly converting the tarry products during devolatisation. The better activity of mayenite-supported CuO compared to Fe 2 O 3 and Cu 2 O in these experiments was mainly due to the ability of CuO to release gaseous oxygen at higher temperatures.

Integrating anaerobic digestion and slow pyrolysis improves the product portfolio of a cocoa waste biorefinery

“…The cocoa pod husks had a relatively high ash content of 11.38 wt.% (db) ( Table 1), compared to other lignocellulosic agricultural residues like woody biomass 40 . This ash fraction constitutes the nutrients withdrawn from soil, like alkali and alkaline earth metals, but also cadmium and lead, among others.…”

Simultaneous Removal of Toluene, Naphthalene, and Phenol as Tar Surrogates in a Rotating Gliding Arc Discharge Reactor

“…Extensive researches have been carried out on tar elimination using plasma. Various types of plasma, such as dielectric barrier discharge (DBD), − microwave, , plasma torch, corona discharge, , and gliding arc plasma, , have been studied. Among different nonthermal plasmas, gliding arc plasma, as a powerful transient plasma, , is attracting increasing attention by showing comprehensive strengths of high reaction capability, high energy density (merits of thermal plasmas), high energy efficiency (merits of thermal plasmas), and high adaptability (instant on/off, adjustable energy input, etc.)…”

Chemical Looping for Combustion of Solid Biomass: A Review

“…As regards tar formation in CLC systems, the literature is rather poor: Zheng et al 114 and Boot-Handford et al 115 investigated the effectiveness of some OCs for the conversion of volatile matter. Fe 2 O 3 (pure), Fe 2 O 3 (on alumina), CuO (on mayenite), and Cu 2 O (on mayenite) were used as OCs.…”