Improvement of enzyme transport in wood chips for thermomechanical pulp refining

Abstract Spruce wood chips were produced under well-controlled conditions in a laboratory wood chipper at spout angles of 30°, 40°, and 50° at a cutting rate of 20 m s-1 and with a nominal chip length of 25 mm. The chips were then refined under thermomechanical pulp (TMP) conditions in a pilot refiner plant. The pulp properties such as freeness, average fiber length, and shives content were determined and evaluated as a function of specific energy consumption. For a first stage refining and for a freeness value of 350 ml, a decrease in specific electrical energy consumption could be achieved by performing the wood chipping at a spout angle of 50° as compared to 30° which is the spout angle commonly used. A patent application regarding this method has been filed and is pending. It is realized that a freeness value is not directly indicative of any quality measure, such as, for example tensile index and light scattering coefficient but the obtained results can be interpreted to be promising. Further studies are needed regarding the impact of the modified chipping process.

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Pilot trials of hemicelluloses extraction prior to thermomechanical pulp production: Part 1

TAPPI Journal ◽

10.32964/tj10.5.21 ◽

2011 ◽

Vol 10 (5) ◽

pp. 21-28 ◽

Cited By ~ 13

Author(s):

CARL HOUTMAN ◽

ERIC HORN

Keyword(s):

Oxalic Acid ◽

Energy Savings ◽

Wood Chip ◽

Strength Properties ◽

Thermomechanical Pulp ◽

Sugar Solution ◽

Bisulfite Treatment ◽

Pilot Trials ◽

Pulp Production ◽

Production Part

Pilot data indicate that wood chip pretreatment with oxalic acid reduced the specific energy required to make thermomechanical pulp. A combined oxalic acid/bisulfite treatment resulted in 21% refiner energy savings and 13% increase in brightness for aspen. A low level of oxalic acid treatment was effective for spruce. Energy savings of 30% was observed with no significant change in strength properties. Adding bisulfite did not significantly increase the brightness of the spruce pulp. For pine, the optimum treatment was a moderate level of oxalic acid, which resulted in 34% energy savings and an increase in strength properties. For all of these treatments 1–3 w/w % carbohydrates were recovered, which can be fermented to produce ethanol. The extract sugar solution contained significant quantities of arabinose.

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Use of thermomechanical pulp fibers from waste woods for making eco-friendly cushioning material

TAPPI Journal ◽

10.32964/tj9.7.15 ◽

2010 ◽

Vol 9 (7) ◽

pp. 15-21 ◽

Cited By ~ 1

Author(s):

JI-YOUNG LEE ◽

CHUL-HWAN KIM ◽

JEONG-MIN SEO ◽

HO-KYUNG CHUNG ◽

KYUNG-KIL BACK ◽

...

Keyword(s):

Impact Test ◽

Product Distribution ◽

Expanded Polystyrene ◽

Thermomechanical Pulp ◽

Fiber Structure ◽

Pulp Fibers ◽

Cationic Starch ◽

Thermal Insulating ◽

Surface Sizing ◽

The Impact

Eco-friendly cushioning materials were made with thermomechanical pulps (TMPs) from waste woods collected from local mountains in Korea, using a suction-forming method without physical pressing. The TMP cushions had superior shock-absorbing performance, with lower elastic moduli than expanded polystyrene (EPS) or molded pulp. Even though the TMP cushions made using various suction times had many voids in their inner fiber structure, their apparent densities were a little higher than that of EPS and much lower than that of molded pulp. The addition of cationic starch contributed to an increase in the elastic modulus of the TMP cushions without increasing the apparent density, an effect which was different from that of surface sizing with starch. In the impact test, the TMP cushions showed a more ductile pattern than the brittle EPS. The porosity of the TMP cushion was a little less than that of EPS and much greater than that of molded pulp. The porous structure of the TMP cushions contributed to their excellent thermal insulating capacity, which was equivalent to that of EPS. In summary, the TMP packing cushions showed great potential for surviving external impacts during product distribution.

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Storage Problems of Poplar Chips from Short Rotation Plantations with Special Emphasis on Fungal Development

Acta Silvatica et Lignaria Hungarica ◽

10.2478/v10303-012-0010-7 ◽

2012 ◽

Vol 8 (1) ◽

pp. 123-132 ◽

Cited By ~ 9

Author(s):

Zsuzsanna Horváth ◽

Béla Marosvölgyi ◽

Christine Idler ◽

Ralf Pecenka ◽

Hannes Lenz

Keyword(s):

Particle Size ◽

Health Risk ◽

Dry Matter ◽

Ph Value ◽

Wood Chips ◽

Raw Material ◽

Special Focus ◽

Fungal Development ◽

Short Rotation ◽

Fungal Particles

Abstract - There are several problems in storing wood chips freshly harvested from short rotation plantations, which result in quality losses as well as in dry matter and energy losses. The factors influencing the degradation of raw material are examined in this paper with special focus on fungal development. An excessive growth of fungi is connected to dry matter losses and also to an increased health risk during raw material handling. The following factors were measured during 6 months storage of poplar wood chips depending on particle size: box temperature, moisture content, pH-value, appearance of fungi in the storage and the concentration of fungal particles in the air. The results show a close connection between particle size, temperature and attack of fungi. During the storage mesophilic and termophilic species of the genera Alternaria, Aspergillus, Cladosporium, Mucor and Penicillium appeared. The concentration of fungal particles is the highest for fine chips and decreases in bigger particles. There was a special focus on the investigation of the properties of coarse chips (G 50), which represent a good compromise between handling, storage losses and health risk due to fungal development.

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