Research in the field of CO2 capture from combustion processes (CCS-carbon capture and storage) using biomass – so-called Bio-CCS, and also with utilization of the captured CO2 – Bio-CCU.
Výzkum je specificky zaměřen na oxy-fuel spalování různých druhů biopaliv ve fluidní vrstvě, které se z pohledu nových zařízení jeví jako nejperspektivnější, a na celý technologický řetězec s ním spojený, včetně výroby kyslíku. Dalším klíčovým výzkumným směrem je oxy-zplyňování biomasy s minimalizací produkce CO2 a třetím klíčovým směrem jsou technologie využití zachyceného CO2 z oxy-fuel spalování pro výrobu kapalných biopaliv.
The research will be specifically focused on oxy-fuel combustion of various sorts of biomass in a fluidized bed, which turns out to be one of the most promising technology, and on its complete technological chain, including production of oxygen. Second major research task is oxy-gasification of biomass and the third key task is utilization of the captured CO2 to produce liquid fuels.
In the project there will be carried out associated research tasks – preparation of biomass for the oxy-fuel combustion and gasification processes, separation of condensable gases from final CO2, process modelling and process characterization with datamining. Further activities are enhancement of international cooperation, development of research team, mobility of researchers and PhD students, know-how transfer and modernization of research infrastructure at all project partners in order to significantly increase the research quality.
The research part of the project is divided into following work packages:
This research in complex focused on technology of biomass oxy-fuel combustion in a fluidized bed. It is a system, where a biomass is combusted by pure oxygen instead of conventional air. A flue gas recirculation is used in order to attain the amount of heat carrier in the fluidized bed. The output is a flue gas with high concentration of carbon dioxide (around 90 % in dry flue gas), which however contains a number of others components that need to be removed prior to CO2 storage or utilization. Those are in particular oxides of nitrogen, sulphur, water vapour and particulate matter. To this is linked the necessity of control the combustion process of biomass in an oxy-FB itself, since there arise various problems given by specific fuel properties of biomass. For example, it is a case of high fuel-N content, or low amount of ash that implies necessity of using external bed materials, or low ash fusion temperatures of biomass. In this research program there will be solved a number of particular research tasks that have been already investigated in the case of fossil fuels in conventional air combustion, but they are entirely not known for biomass in oxy-fuel combustion mode. The particular tasks will be investigated in the way to cover whole technological chain from biofuel entry into the system of oxy-fuel combustion up to outlet of pure CO2 free of unwanted components.
Work Package 2 (hereinafter referred to as WP2) focuses on progressive and modern methods of gasification and pyrolysis which produce minimum harmful substances, including carbon dioxide. Various gasification media, including recirculated flue-gas, will be used to decrease final amounts of carbon dioxide. As part of the testing, we will closely cooperate with our partners to prepare and modify the fuels. WP2 activities are linked to the WP1. The aim of the cooperation in the project is to cover the complex field of thermal processes of biomass conversion for CO2 capture.
The aim of WP3 is to design and to test such a laboratory technology, machinery and equipment, which (1) enables cleaning and upgrading CO2 and syngas to the quality required for further processing, (2) ensures efficient, energy-efficient and economically viable biochemical or thermochemical transformation of CO2 and syngas to the desired bioproducts, and finally (3) assures minimal formation of waste in solid, liquid, and especially in gaseous form, i.e. in the concept of zero-emission technology.
The research program shall be focused on the issue of preparing biomass for further energy use. The aim of the research is to prepare torrefacted biomass meeting quality requirements set for fuel and shall be consequently used for energy purposes, mainly for the oxy-fuel technology. Requirements for quality indicators of the procedural raw material shall be defined (for instance: the content of alkali, chlorine, majority elements – cellulose, lignin, hemi-cellulose, ash matter) and requirements for bio-fuel for the incineration in various types of energy equipment and oxy-fuel technology. Therefore, the influence of temperature and speed of heating shall be monitored during torrefaction on the share of siccative inflammables and fixed carbon in torrefacted carbon significantly affecting the mechanical characteristics of bio-fuel (the possibilities of compaction, pressing, hydrophobic/hydrophilic characteristics, possibilities of pressing and mechanical abrasion etc.) from the aspect of their further use (transport, storing).
Utilization of CO2 from combustion processes for further technological purposes, as well as the variant of CO2 storage, require to achieving a sufficient purity of the product. Moisture, low volatile vapours and fine aerosol particles, which may contain high concentrations of heavy metals, can be separated from the flue gas by the cleaning and condensation processes. Condensation processes are the contents of WP5. These processes can be implemented by the “traditional” way using condensing heat exchangers (WP5.1), it is possible to use an alternative approach using hollow polymeric fibres (WP5.4), but it is also necessary to consider (research) the new alternative procedures (WP 5.2). The evaluation of the various condensation cleaning approaches from the point of view of their integration in CCS/U technologies will be also a part of the programme (WP 5.3).
This WP complements the experimental activities within the project by research and development of a mathematical model of fluidized bed combustion of biomass, its numerical implementation and subsequent validation in coordination with the experiments. The goal of the program is to develop a simulation software which will provide information about the behaviour of the processes during combustion (and gasification) in fluidized bed, while requiring significantly smaller amount of time and resources compared to the experiments. The software and the simulation results may contribute to the design or control optimization of these processes.