An Influence of the Fuel Type on Element Behaviour in Domestic Boilers with Respect to the Circular Economy

Abstract

The use of waste from the regional production of waste wood, waste paper, and cardboard in the form of briquettes may be causing an increase in local emissions, both of major elements and trace elements. When burning paper and cardboard briquettes, more than 70% of Mn, Zn, As, and Pb is released into the air from the total content of trace elements in the fuel. The largest amounts of major and trace elements are released when burning paper briquettes (56 g/kg of fuel); half of these amounts are released from burning briquettes from waste wood and coal (23 g/kg of fuel). The pursuit of alternative uses for those cardboard components that are not suitable for recycling cannot be directed to the production of briquettes for residential combustion in the framework of the application of the principles of the circular economy. In particular, the high concentrations of undesirable elements in the emissions released in the gas phase into the atmosphere are an obstacle existing even when the parameters of the PM10 emissions of a boiler are met. This is related to the high ash content of the cardboard (13.5%). Waste paper or cardboard could be added to waste wood at a maximum of 10% to make the pollution produced comparable to the burning of coal briquettes.

Distribution of As within Magnetic and Non-Magnetic Fractions of Fluidized-Bed Coal Combustion Ash

“…Coal has long been a reliable energy source and currently, it is also intensively studied as the source of critical elements, such as REE and Y [1,2]; Ge and Ga [3][4][5]; Li [6]; Nb [5,7]; U, Se, and Re [6]; or Ta, Zr, and Hf [7]. However, due to the presence of minor and trace elements, it can be responsible for serious pollution problems [8][9][10][11]. In general, during coal combustion, minor and trace elements are redistributed among bottom ash (BA) or slag, fly ash (FA), and emissions.…”

“…The release of As into the environment relates not only to emissions (in the finest fly ash particles or emitted in gaseous form) [11], but is also connected with its presence in coal combustion ashes. Namely, in fly ash, arsenic could be highly enriched [3].…”