Microwave-assisted Production of Activated Carbon from Pulp Mill Sludge with White Liquor

This work establishes the technical feasibility of producing a value added product ,activated carbon, from a waste stream, pulp mill sludge, using white liquor as the activating agent and microwaves as the energy source. The work also demonstrates the potential of the sludge-derived activated carbon in removing bioactive compounds in pulp mill effluents that affect fish production. Readily available at Kraft mills, white liquor is able to convert sludge into activated carbon with a specific surface area (SSA) of 650 m2/g. While NaOH in white liquor creates pores in the carbon from sludge, other two components of white liquor, Na2S and Na2CO3, inhibit the activation process. Porosities of activated carbon produced with microwave oven and conventional furnace are comparable. The use of microwaves reduces the activation time from hours to minutes. However, strong microwave absorbers, such as NaOH and KOH, are needed for pyrolysis and activation, since pulp mill sludge and wood polymers are weak microwave absorbers with tan δPh.D.2017-06-16 00:00:0