Browsing by Author "Gao, Ningbo"

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Access status: Open Access ,
Biomass CO2 gasification with CaO looping for syngas production in a fixed-bed reactor
(2020) Gao, Ningbo; Śliz, Maciej; Quan, Cui; Bieniek, Artur; Magdziarz, Aneta
Wydział Inżynierii Metali i Informatyki Przemysłowej
The most important challenge in solid feedstock thermal conversion methods is minimising $CO_{2}$ emissions. In this work, the gasification of pine sawdust in a mixture of $N_{2}$ and $CO_{2}$ was investigated for the reduction of $CO_{2}$ by a calcium oxide loop. The experiments were conducted at 600, 700, and 800 °C in a fixed-bed reactor. The biomass was mixed with the calcium oxide at a ratio of 1:1. The chemical composition of the syngas was analysed using gas chromatography. Moreover, the high heating values of the received gas samples were calculated, and thermogravimetric analysis and Fourier-transform infrared spectroscopy analysis were performed to investigate the absorption of $CO_{2}$ by $CaO$. The results of the gasification process showed that the syngas contained $CO$, $CH_{4}$, $CO_{2}$, $H_{2}$, $N_{2}$, and other low hydrocarbons. The most significant results were obtained for a 2:1 ratio of $N_{2}$ to $CO_{2}$ at 700 °C, and a $CO_{2}$ reduction of 25% was observed. Moreover, the catalytic properties of $CaO$ increased the concentration of $H_{2}$ in the produced syngas by up to 10%. A temperature of 800 °C was too high for the carbonation reaction of $CaO$. This study presents a possible solution for achieving negative carbon emissions.
Access status: Open Access ,
Biomass thermochemical conversion via pyrolysis with integrated CO2 capture
(2020) Sieradzka, Małgorzata; Gao, Ningbo; Quan, Cui; Mlonka-Mędrala, Agata; Magdziarz, Aneta
Wydział Inżynierii Metali i Informatyki Przemysłowej
The presented work is focused on biomass thermochemical conversion with integrated $CO_{2}$ capture. The main aim of this study was the in-depth investigation of the impact of pyrolysis temperature (500, 600 and 700 °C) and $CaO$ sorbent addition on the chemical and physical properties of obtained char and syngas. Under the effect of the pyrolysis temperature, the properties of biomass chars were gradually changed, and this was confirmed by examination using thermal analysis, scanning electron microscopy, X-ray diffraction, and porosimetry methods. The chars were characterised by a noticeable carbon content (two times at 700 °C) resulting in a lower O/C ratio. The calculated combustion indexes indicated the better combustible properties of chars. In addition, structural morphology changes were observed. However, the increasing pyrolysis temperature resulted in changes of solid products; the differences of char properties were not significant in the range of 500 to 700 °C. Syngas was analysed using a gas chromatograph. The following main components were identified: $CO$, $CO_{2}$, $CH_{4}$, $H_{2}$ and $C_{2}H_{4}$, $C_{2}H_{6}$, $C_{3}H_{6}$, $C_{3}H_{8}$. A significant impact of $CaO$ on $CO_{2}$ adsorption was found. The concentration of $CO_{2}$ in syngas decreased with increased temperature, and the highest decrease occurred in the presence of $CaO$ from above 60% to below 30% at 600 °C.
Access status: Open Access ,
Potential of products from high-temperature pyrolysis of biomass and refuse-derived fuel pellets
(2024) Jerzak, Wojciech; Mlonka-Mędrala, Agata; Gao, Ningbo; Magdziarz, Aneta
Wydział Inżynierii Metali i Informatyki Przemysłowej
The management of energy contained in waste is an important research topic. Among many high-energy wastes, pellets are produced from refuse-derived fuels (RDF) and lignocellulosic biomass. This study investigated hightemperature pyrolysis (800 °C) of biomass and RDF pellets. Experiments were conducted in two reactors: i) on a microscale (thermogravimetric analysis) and ii) on a laboratory scale (fixed-bed reactor) to investigate the yields of the products (char, liquid fraction, and gas) and to characterise products toward their further application. The RDF char contained less carbon than the material before pyrolysis. The carbon content of the biomass char was 90%, almost twice that of the raw material. The biomass and RDF chars were chemically and physically activated to increase their specific surface areas. The chemically activated biomass char had a sorption capacity of 156.2 mg/CO2 at 25 °C and 0.1 MPa. The kinetics of CO2 sorption were also examined, and the maximum uptake was observed after 2–3 min. The higher heating value of the liquid phase, including the organic condensed phase, was 28.6 and 25.8 MJ/kg for pyrolysis of biomass and RDF pellets, respectively. The pyrolysis gas composition was analysed separately for the heating and isothermal processes. Due to the high CO, CH4, and H2 contents, the gas from the heating stage was characterised by a much higher heating value.