CHARACTERIZATION OF VOLATILE CONSTITUENTS IN RADIATA PINE HIGH-TEMPERATURE MECHANICAL PULP SCREW PRESS EFFLUENT

Results are presented arising from an investigation to characterize vo latile constituents released from radiata pine in the manufacture of h igh temperature thermomechanical pulp, prior to refining, by analysis of the screw press effluent. Effluent samples were taken from commerci al operations and pilot plant trials at the post presteaming and prehe ating stages. The volatile constituents in the effluents were determin ed after extraction by GCMS analysis. The main compounds identified we re alpha-pinene, beta-pinene, limonene, furfural, 1,4-terpineol, alpha -terpineol, pimarinal, and resin acid methyl esters. The total concent rations of extractable components were 200-1000 mg/kg for the post pre steamer effluent and 60-130 mg/kg for the post preheater effluent. Con centrations of formaldehyde, acetic acid and methanol were also determ ined. Chemical oxygen demand values for the presteamer effluent were i n the range 11-20 g/L and for biochemical oxygen demand 3.6-9.9 g/L.