Pulp & Paper

Pulp and paper operations present multiple challenges for air pollution control. Steam boilers produce fly-ash, process equipment creates salt cake accumulation, and in-plant processes create various kinds of dust and fumes. AAF Flanders applies the appropriate core technologies, with customized installations for the specific industry needs, to meet and exceed goals for reduced emissions and material recovery.

Contaminant Risk

The primary source for gaseous contamination in pulp and paper mills is the pulping process. In the Kraft pulping process, highly malodorous emissions of reduced sulfur compounds are produced. These compounds are measured as total reduced sulfur (TRS) and include hydrogen sulfide, methyl mercaptan, dimethyl sulfide, and dimethyl disulfide. These sulfur compounds are often described as smelling like rotten cabbage. In the sulfite pulping process, sulfur oxides are also emitted in fairly significant concentrations. Other pulping processes, such as the mechanical and thermomechanical methods, generate significantly lower quantities of air emissions.

In addition, steam and electricity-generating units using coal or fuel oil emit fly ash, sulfur oxides, and nitrogen oxides. A secondary source of corrosive gases in the pulping process is during the bleaching step. These bleaching chemicals, which often include lime, are caustic and cause corrosion to occur.

There Are Several Ways a Plant Can Produce Pulp:

The four primary processes employed in the U.S. and Canada are:

• Kraft (a chemical process)
• Sulfite (a chemical process)
• Mechanical
• Thermomechanical

Optimize Your Environment

For particulate filtration, several stages of HVAC-type air filtration products are employed to help keep the wood fiber and associated dust to a minimum. Ensuring that this dust is removed is extremely important to both the paper quality and the maintenance of the pulping equipment and paper production machines.