Chemi-thermomechanical pulp (chemi-thermomechanical pulp production)

Emissions generated by the activity within the product supply chain as described in ecoinvent v3.10. The product 'chemi-thermomechanical pulp' (CTMP) is a type of unbleached mechanical wood-containing pulp. Mechanical pulp is weaker than chemical pulp (sulfate and sulfite pulp) but has a higher light-scattering coefficients and opacity. In the CTMP production process wood chips are impregnated with chemicals (sulfonation with Na2SO3) before they are mechanically defibrated in the refiner under high pressure (~about 3 bar) or at atmospheric pressure mainly in two stages. During mechanical defibration lignin is plasticised and remains in the pulp. CTMP cannot be brightened effectively by oxidative and reductive bleaching. Most of the mechanical pulp is produced at integrated pulp mills which directly process it further into (paper-) products and only a minor part of pulp production is sold on the market. CTMP is mainly used for Printing & writing papers tissue and packaging boards. The cut-off classification is allocatable product. The activity type is ordinary transforming activity. The reference product amount is 1.