Accelerated carbonation of waste incinerator bottom ash in a rotating drum batch reactor

Publication date: Available online 11 August 2018Source: Journal of Environmental Chemical EngineeringAuthor(s): Felix Brück, Kevin Schnabel, Tim Mansfeldt, Harald WeigandAbstractAccelerated carbonation is known to improve the leaching behaviour and geotechnical properties of waste incineration bottom ash (BA). Regarding process implementation on the industrial scale dynamic reactor configurations may be particularly suited since they enhance the mass exchange between gas and solid. Here we evaluated the influence of fundamental parameters on accelerated carbonation of BA in a rotating drum batch reactor equipped with an automated CO2 supply at close to atmospheric pressure conditions. Firstly, the effect of rotation speed and reactor fill level on the solids motion was studied. Secondly, the effects of CO2-concentration, fill level, and moisture on BA carbonation were investigated. Evaluation was based on the observed CO2 uptake, self-heating, and BA leachability. The bed behaviour of BA strongly differed from that of standard materials and was more affected by fill level than by rotation speed. The fill level was not a limiting factor for BA carbonation within the tested range (7-45 vol.-%). Both the CO2 uptake rate and the final level of carbonation increased as the CO2-concentration was raised from 15 to 75 vol.-%. A close relationship between CO2 uptake and reactor temperature was confirmed by benchmarking a heat balance model against the carbonation enthalpy. Carbo...
Source: Journal of Environmental Chemical Engineering - Category: Chemistry Source Type: research