Search

The environmental performance of tissue paper varies greatly based on factors such as the type of fibre used as the raw material, the production process and the fuels used to meet the energy requirements. One possible strategy to decrease greenhouse gas emissions in tissue production is the integration of pulp and paper mills and their energy systems at the same site. However, the environmental trade-offs associated with this strategy are still unclear. Therefore, this study aimed (i) to assess for the first time the environmental impacts of tissue paper produced at a typical industrial site in Portugal using slush and market pulp as the main raw material, and (ii) to assess the environmental effects of the integration of bioenergy produced in the pulp mill in tissue production. A life cycle assessment was conducted from cradle to gate using real data from the production of eucalyptus wood, eucalyptus pulp and tissue paper. The results showed that energy consumption in tissue paper production is the main hotspot for most impact categories. When bioenergy is used in tissue production, the environmental impacts decrease by up to 20% for categories other than marine eutrophication and mineral resource scarcity. These results are relevant to support decision making concerning sustainable practices not only for the pulp and paper industry but also for the authorities in charge of defining environmental policies, incentives and tax regulations. [ABSTRACT FROM AUTHOR]

Tissue paper was the only paper grade whose consumption increased during 2020 in Europe. In a highly competitive context, this work explores a strategy based on bisacrylamide cross-linkers and poly(vinyl alcohol) (PVA), seeking to enhance the water uptake of pulps for tissue paper and the key properties of the resulting tissue sheets: water absorption capacity, capillarity, softness, porosity, and strength. For that, α-cellulose from cotton and a kraft hardwood pulp, in parallel, were reacted with N,N'-methylenebisacrylamide, both in the absence and in the presence of PVA. The water desorption rate of the modified polymers was monitored. Pulp blends were then mixed with a conventional softwood pulp (30%) to prepare laboratory tissue paper sheets (20 g m–2). For cotton cellulose, cross-linking with PVA more than doubled the water uptake, up to 7.3 g/g. A significant enhancement was also obtained in the case of pulps, up to 9.6 g/g, and in the case of paper, to 11.9 g/g. This improvement was consistent with a drastic increase in porosity, and it was not detrimental to paper strength. [ABSTRACT FROM AUTHOR]

The present work deals with preliminary studies concerning a new synthesis approach to prepare SAPO materials with AEL structure and evaluate their catalytic behavior in the hydroisomerization of long paraffins. The new SAPO-11 catalysts were synthesized with the help of a small amine (methylamine, MA) added during the preparation of the initial gel. As MA incorporates into the structure of the final materials, it contributes, together with DPA (dipropylamine), to an increase in Si incorporation as isolated species, which results in Brønsted acid sites. Thus, this new and original synthesis strategy allows to obtain materials with enhanced Brønsted acidity when compared with free MA materials. The catalysts were tested in n-decane hydroisomerization ( n-decane was used as a model molecule) and confirmed the effect of MA on the acidic properties of the catalysts. The samples synthesized with MA present a higher number of acid sites that increase the catalytic conversion but have a negative effect in the isomerization selectivity, i.e. a more significant amount of cracking products is formed. [ABSTRACT FROM AUTHOR]