Browsing by Author "Puustinen, Maria"
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Item Elektronisesti johtavat polymeerit kemialliseen vastukseen perustuvissa kaasusensoreissa(2011) Puustinen, Maria; Annala, Minna; Kemian tekniikan korkeakoulu; Linnekoski, JuhaItem Optimizing supply chain costs by minimizing the variance in raw material composition(2018-08-28) Leivo, Jimi; Puustinen, Maria; Ruuttunen, Kyösti; Kemian tekniikan korkeakoulu; Dahl, OlliItem Sustainability aspects of crude sulfate soap acidulation to crude tall oil within the EU biofuel policy framework(2015-08-25) Puustinen, Maria; Helin, Maiju; Golam, Sarwar; Kemian tekniikan korkeakoulu; Alopaeus, VilleThe EU biofuel policy is based on two directives, the Renewable Energy Directive and the Fuel Quality Directive. These directives set sustainability criteria for biofuels and present the general rules for calculating the greenhouse gas emissions of a fuel. However, the directives have been interpreted differently in different member states, especially concerning waste and residue feedstocks. In Finland, the greenhouse gas emissions of acidulation are currently not reported in the lifecycle emissions of a biofuel based on crude tall oil (CTO), as CTO is considered a residue of pulp production. However, the residue status of CTO has been questioned, due to its alleged intentional manufacturing in the acidulation process. This thesis aims, first, to create and implement a method for calculating the greenhouse gas emissions of typical acidulation processes in line with EU policy, and second, to determine if acidulation emissions can be separated from the pulp production emissions in a kraft pulp mill. Based on the results, the work provides recommendations for the classification of CTO under EU biofuel legislation. Crude tall oil is generated when acid is added to a separated soap phase formed in pulp cooking. This soap has to be removed from the process and by means of acidulation, sulfur and sodium cooking chemicals in the soap can be recycled back to the pulping process. Acidulation is interlinked with the pulp mill chemical recovery cycle and constitutes a major intake of sulfur to the cycle. As the material streams from acidulation have effects also outside the acidulation process, emissions of acidulation were in this work calculated by considering the chemical balance of the whole pulp mill. Models for a typical pulp mill and three common acidulation processes were created based on literature and UPM-internal data. The emissions of the three most common acidulation processes were calculated and the sensitivity of these emissions was studied against the most important variables of both acidulation and chemical balance of the pulp mill. It was first observed that depending on the sulfur balance of the pulp mill and acidulation inputs, an interlinked acidulation process could either increase or decrease the total emissions of the mill. Second, it was seen that the emissions of an acidulation process are more sensitive to changes in the pulp mill sulfur balance than they are to changes in the acidulation process. Thus, due to large variations in the sulfur balances between different pulp mills, or even at the same mill at different times, the emissions of acidulation cannot be reliably determined and separated from the emissions of pulp production. Moreover, the sulfur balance, which affects the acidulation emissions the most, is optimized for pulp production, not for CTO production. This supports the conclusion that acidulation emissions should be allocated to pulp, rather than to CTO. Acidulation is an essential part of the pulp mill and an optimized way to dispose the soap. As the soap is clearly a residual stream and emissions of acidulation cannot be separated from the emissions of pulp production, no emissions can be allocated to CTO. Therefore, it is recommended that CTO is regarded as a residue in the EU biofuel legislation.
