Life Cycle Inventory of Woodfree Paper Containing Nonwood Pulp or Deinked Pulp

Life cycle environmental loads for woodfree paper containing nonwood pulp or deinked pulp were investigated (Environmental loads: CO2, SOx, NOx, and incineration ash). In this study, inventory data concerning wood pulp and deinked pulp were collected at Mitsubishi paper mill in Hachinohe. With regard to the inventory for nonwood pulp, data for bagasse pulp produced in Colombia and data for kenaf pulp produced in Japan were used. Environmental loads for woodfree paper made from the mixture of wood pulp and nonwood pulp or deinked pulp was compared with those for woodfree paper made from 100% wood pulp.CO2 emission for life cycle of woodfree paper containing bagasse pulp (except CO2 emission from the pith burning) was as large as that of woodfree paper made from 100% wood pulp, because the pith contained in bagasse may be regarded as the agricultural by-product. Since kenaf pulp was produced at the small pulping plant that has no energy recovery system from black liquor, CO2 emission for woodfree paper containing kenaf pulp was larger than that of other kinds of woodfree paper. In case of deinked pulp, the increase in content of deinked pulp in woodfree paper increased the consumption of fossil fuel, resulted in the increase of CO2 emission from fossil fuel. SOx emission for woodfree paper containing deinked pulp was smaller than that of other kinds of woodfree paper. There were observed little differences in NOx emission for these four kinds of woodfree paper. Incineration ash emission for woodfree paper was almost caused by coal used in the process of the woodfree paper production and by waste paper burning in the incineration process.For more detailed study, it is desirable to analyze a life cycle inventory by taking the land use for wood afforestation or non-wood cultivation and the value of agricultural by-products into account.