Current status and perspectives of accelerated carbonation processes on municipal waste combustion residues.
The increasing volumes of municipal solid waste produced worldwide are encouraging the development of processes to reduce the environmental impact of this waste stream. Combustion technology can facilitate volume reduction of up to 90%, with the inorganic contaminants being captured in furnace bottom ash, and fly ash/APC residues. The disposal or reuse of these residues is however governed by the potential release of constituent contaminants into the environment. Accelerated carbonation has been shown to have a potential for improving the chemical stability and leaching behaviour of both bottom ash and fly ash/APC residues. However, the efficacy of carbonation depends on whether the method of gas application is direct or indirect. Also important are the mineralogy, chemistry and physical properties of the fresh ash, the carbonation reaction conditions such as temperature, contact time, CO(2) partial pressure and relative humidity. This paper reviews the main issues pertaining to the application of accelerated carbonation to municipal waste combustion residues to elucidate the potential benefits on the stabilization of such residues and for reducing CO(2) emissions. In particular, the modification of ash properties that occur upon carbonation and the CO(2) sequestration potential possible under different conditions are discussed. Although accelerated carbonation is a developing technology, it could be introduced in new incinerator facilities as a "finishing step" for both ash treatment and reduction of CO(2) emissions.
Costa
Giulia
G
Department of Civil Engineering, University of Rome Tor Vergata, Via del Politecnico 1, 00133, Rome, Italy. costa@ing.uniroma2.it
Baciocchi
Renato
R
Polettini
Alessandra
A
Pomi
Raffaella
R
Hills
Colin D
CD
Carey
Paula J
PJ
D000392:Air Movements; D000393:Air Pollutants / Q000302:isolation & purification*; D017610:Calcium Compounds / Q000737:chemistry; D002244:Carbon / Q000737:chemistry / Q000302:isolation & purification; D002245:Carbon Dioxide / Q000737:chemistry / Q000302:isolation & purification*; D002947:Cities; D060729:Coal Ash; D004784:Environmental Monitoring; D006813:Humidity; D017745:Incineration; D052638:Particulate Matter / Q000737:chemistry / Q000302:isolation & purification; D012037:Refuse Disposal / Q000379:methods* / Q000706:statistics & numerical data; D018570:Risk Assessment; D017655:Silicon Compounds / Q000737:chemistry; D013997:Time Factors; D018505:Waste Management / Q000379:methods* / Q000706:statistics & numerical data
D000393:Air Pollutants; D017610:Calcium Compounds; D060729:Coal Ash; D052638:Particulate Matter; D017655:Silicon Compounds; D002245:Carbon Dioxide; D002244:Carbon