Transformation and removal of wood extractives from pulp mill sludge using wet oxidation and thermal hydrolysis.
In order to remove wood extractive compounds from pulp mill sludge and thereby enhancing anaerobic digestibility, samples were subjected to either oxidative hydrothermal treatment (wet oxidation) or non-oxidative hydrothermal treatment (thermal hydrolysis). Treatments were carried out at 220 °C with initial pressure of 20 bar. More than 90% destruction of extractive compounds was observed after 20 min of wet oxidation. Wet oxidation eliminated 95.7% of phenolics, 98.6% fatty acids, 99.8% resin acids and 100% of phytosterols in 120 min. Acetic acid concentration increased by approximately 2 g/l after 120 min of wet oxidation. This has potential for rendering sludge more amenable to anaerobic digestion. In contrast thermal hydrolysis was found to be ineffective in degrading extractive compounds. Wet oxidation is considered to be an effective process for removal of recalcitrant and inhibitive compounds through hydrothermal pre-treatment of pulp mill sludge.
Scion, Te Papa Tipu Innovation Park, 49 Sala Street, Rotorua 3010, New Zealand. Electronic address: Saeid.Baroutian@scionresearch.com.
Saeid
S
Baroutian
Scion, Te Papa Tipu Innovation Park, 49 Sala Street, Rotorua 3010, New Zealand.
Murray
M
Robinson
Scion, Te Papa Tipu Innovation Park, 49 Sala Street, Rotorua 3010, New Zealand.
Anne-Marie
AM
Smit
Scion, Te Papa Tipu Innovation Park, 49 Sala Street, Rotorua 3010, New Zealand.
Suren
S
Wijeyekoon
Scion, Te Papa Tipu Innovation Park, 49 Sala Street, Rotorua 3010, New Zealand.
Daniel
D
Gapes
D019342:Acetic Acid / Q000737:chemistry; D001673:Biodegradation, Environmental; D002244:Carbon / Q000737:chemistry; D004867:Equipment Design; D005227:Fatty Acids / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007220:Industrial Waste; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D010209:Paper; D010840:Phytosterols / Q000737:chemistry; D028223:Pinus; D011312:Pressure; D012722:Sewage; D013696:Temperature; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*; D014934:Wood / Q000737:chemistry*
D005227:Fatty Acids; D007220:Industrial Waste; D010840:Phytosterols; D012722:Sewage; D002244:Carbon; D019342:Acetic Acid; D010100:Oxygen
Pulp mill sludge; Thermal hydrolysis; Wet oxidation; Wood extractives