Acacia Mangium is a common industrial planted woody biomass in the tropical and subtropical climates. As an economically viable, agroforestry beneficial and environmentally sustainable bio-energy form, it has the potential to generate heat for thermochemical conversion systems. This article provides a comprehensive evaluation of its characteristics, physiochemical properties, ash composition and transformation phenomena. In accordance with the ISO/DIN guides for solid fuels, the standard methods were applied. The results of analyses solid biofuel showed the significant calorific value (19-20 MJ/kg); high volatile matter, relatively low ash content; and a low S content. X-ray analyskjhgis detected high values of Ca, K, Fe, Al and Si the ash-forming elements. Ash softening and fusion phenomena were observed, with heat generated continuously at constant rates (maintained at 550 ± 10 °C for 120 minutes and practically at 850 ± 10 °C for 240 minutes). The first signs of deformation were recorded at a temperature of approximately 1220 °C, with the melting point reached at 1310 °C, which was an advantage for a woody solid biofuel.
An increasing concentration of carbon dioxide in the atmosphere is the driving force of on its utilization in different technological processes. Those processes are CCS (Carbon, Capture and Storage) and in particular in CCU (Carbon, Capture and Utilization). One of the promising CCU processes is the catalytic methanation of carbon dioxide and hydrogen. The catalytic methanation utilizes hydrogen, which can be produced using sustainable renewable energy (wind or solar) with unsteady power production. The main product of the catalytic methanation is a synthetic natural gas, consisting mainly of methane. The synthetic natural gas can be used as a substitute for natural gas in energetic applications. This paper presents results from testing of nickel catalyst (Ni/γ-Al2O3) with a variable mass fraction of nickel. Methanation reaction was tested at temperatures below 450 °C and gauge pressure of 0.5 MPa in a through-flow reactor, with a stoichiometric mixture of hydrogen and carbon dioxide. During experiments, catalytic activity, methane selectivity, hydrogen and carbon dioxide conversion were measured.
In the article are discussed the basic problems affecting flue gas desulphurisation produced in the fluidized bed boilers burning brown coal. There are compared the effects of temperature, residence time and flue gas composition in the fireplace, characteristic parameters and properties of limestone and dolomites, ratios of limestone and coal and cocombusted biomass and recirculation of by-products. The kinetics and thermodynamics of many reactions are represented here by mathematical and empirical relations.