Gasification of biomass and solid recovered fuels (SRFs) for the synthesis of liquid fuels

Identifier:  TDX:2579

Handle: https://hdl.handle.net/20.500.11797/TDX2579

Authors:  Recari Ansa, Javier

Abstract:
Gasification is a promising technology for energy exploitation of biomass and waste, converting carbonaceous fuels into a synthesis gas (syngas) with multiple applications. However, technical obstacles hinder the full implementation of this technology at industrial scale, particularly for the production of liquid fuels through Fischer-Tropsch (FT) synthesis. Those challenges are mainly related to the syngas quality, such as a low H2/CO ratio and the presence of impurities (tar and minor contaminants), strongly influenced by the nature of the feedstock and the operating conditions of the gasification process. This thesis focuses on the improvement of the syngas quality from gasification of biomass and solid recovered fuels (SRFs) aiming to produce liquid fuels. The present work is divided in two main blocks. The first block corresponds to biomass and SRFs gasification experiments in a lab-scale fluidized bed reactor in order to study the influence of key operating conditions (temperature, bed materials, gasification agents, etc.) on the gasification performance and gas composition. Since SRF materials contain higher amounts of contaminants precursors than biomass, a method to assess the concentration of HCl, H2S, HCN and NH3 in the syngas by means of ion-selective potentiometry was developed. The application of a thermal pretreatment (torrefaction) to the gasification feedstocks is proposed as a way to upgrade the feedstock properties and abate the release of contaminants in the syngas. The second part of this work consists in a techno-economic analysis that estimates capital and production costs of FT liquid fuel plants based on biomass and waste gasification, using as input the experimental results.