Carbon, Energy and Water Footprint of threeAkzoNobel Internal Sizing Chemicals : A Cradle to Gate LCA related study

Abstract: Functional chemicals are used in paper production to enhance specific characteristics in the final paper product. One functional chemicals category is internal sizing chemicals which are used to create liquid resistance hydrophobicity in the paper, at the wet end of the production process. This thesis report calculated the environmental burdens of three internal sizing chemicals produced by Eka Chemicals, a business unit of AkzoNobel. The three chemicals under study are a specific product of each of the following categories: Alkyl Ketene Dimer (AKD), Alkenyl Succinic Anhydride (ASA) and Cationic Dispersion Rosin. A Life Cycle Assessment (LCA) was performed from cradle to end customer gate. The Carbon, Energy and Water Footprint of the three products were calculated using Gabi 4 software. The functional unit used in LCA was the kilograms of dry sizing chemical required for the production of 1kg of paper. Two paper grades were used; copy paper, where AKD and ASA are mostly applied and solid board, where ASA and Rosin are applied. The Carbon Footprint for copy paper and a distribution distance 1500 km was found to be 2,5 kg CO2 eqv/ton paper for AKD, 5,1 kg CO2 eqv/ton paper for ASA and 4,9 kg CO2 eqv/ton paper for Rosin. The Energy Footprint results for the same case were 62 MJ/ton paper consumed by AKD, 136 MJ/ton paper by ASA and 228 MJ/ton paper by Rosin. The Water Footprint results for copy paper and 1500 km distribution distance were 0,1 m3 water/ton paper consumed by AKD, 0,3 m3 water/ton paper by ASA and 0,5 m3/ton paper by Rosin. Dominance analysis diagrams illustrated that for all three sizing chemicals raw material production is a hotspot both for the Carbon Footprint and the Energy Footprint. Data was evaluated and a sensitivity analysis was performed on assumptions, allocation percentages and scenarios (including and not including the emulsification of ASA). The results conclude that AKD is the best alternative according to the Carbon, Energy and Water Footprint calculated for all applications. For solid board the best choice for large distribution distances appears to be ASA.