Fluidised Bed Reactors for the Thermochemical Conversion of Biomass and Waste

Abstract

The growing population and economic development globally has led to increasing resource consumption and waste generation. This has generated concern at local, national and international levels on environmental issues including air quality, resource scarcity, waste management (including plastics) and global warming. The resulting antipathy towards fossil fuels and waste landfilling has spurred the demand for alternative bioenergy and biofuels production methods, making use of abundant biomass and waste feedstock. Although not new concepts, there has been renewed impetus recently to develop advanced thermochemical processes such as pyrolysis and gasification to treat biomass and municipal solid waste (including refuse-derived fuel therefrom). This is because these processes have the potential to add value to cheap and abundant materials by converting them into advanced biofuels and chemicals. The work presented in this paper is concerned principally with the technical analysis and review of new-generation, state-of-the-art systems based on fluidised bed reactors operated with biomass and solid waste. A comprehensive assessment of fluidised bed reactor types and operations is considered, with particular attention given to those processes aimed at the production of clean syngas for the subsequent synthesis of high-value products, including bio-hydrogen, synthetic natural gas (SNG), and liquid fuels.

Investigation of single particle devolatilization in fluidized bed reactors by X-ray imaging techniques

“…The experimental apparatus consists of a 146 mm ID × 1000 mm high Inconel tube fitted with a stainless-steel distributor plate and is operated at atmospheric pressure and temperatures of 500, 600 and 650 °C. The temperature levels used in this work are high enough to provide devolatilization of the feedstock (above minimum devolatilization temperature mentioned above) and they fall in the typical range of pyrolysis operations [71]. The vessel was filled with a Geldart group B quartz sand (particle density 2650 kg/m 3 and average particle size 250 µm) up to a fixed bed height of 13 cm at ambient temperature.…”

Thermal plasma-aided chemical looping carbon dioxide dissociation for fuel production from aluminium particles

“…In this reactor, direct contact is established between the CO2-steam gas blend and aluminium particles to generate synthetic fuel. The fluidised bed configuration provides sufficient residence time, relatively good heat and mass transfer for solid-gas reactions [21]. The synthetic fuel produced with SFR is then cooled via a heat exchanger and is fed into a storage facility to be compressed according to the end-user specific requirement.…”

Steam - oxygen gasification of refuse derived fuel in fluidized beds: Modelling and pilot plant testing

“…One of the main advantages of a fluidised bed is a good solid mixing due to the upward gas stream that globally results in temperature homogeneity across the whole bed [47]. This is also promoted by the large contact surface and the high heat exchange rates between gas and solid particles.…”