Forskningsoutput per år
Forskningsoutput per år
Forskningsoutput: Tidskriftsbidrag › Artikel i vetenskaplig tidskrift › Peer review
Polyphenolic compounds in bark are resources of great interest to produce renewable chemicals and several different technologies are available or under early development for the extraction of these types of compounds. Since critical environmental effects of a product are often set during the design phase, it is important to use life cycle assessment (LCA) to identify the steps resulting in the largest environmental burdens and the overall performance of the various technologies at an early stage during technology development. In addition, for a better understanding of the environmental impact of the future system, it is needed to consider an up-scaled process already in early process development. In the current study, LCAs of three different technologies; hot water extraction (HWE), ultrasound assisted extraction (UAE), and supercritical fluid extraction (SFE) for the extraction of phenolic compounds from spruce bark were compared in a large-scale production scenario. The study includes industrially relevant heat sources and heating technologies, downstream separations, solvent recovery, and heat recovery within the processes. The LCA shows that the simpler HWE process has a lower environmental impact per amount of phenolic compound extracted than UAE and SFE unless the extraction yields of the latter are more than about 5 times that of HWE. The reason for this result is mainly the environmental burden caused by the consumption of ethanol in the UAE and SFE processes, which accounts for more than 70% of the total environmental burden in most impact categories. Even if bioethanol produced with a particularly low carbon footprint would be used, the impact from ethanol use in the extractions would be considerable. UAE and SFE were also more dependent on the use of electricity. In the base case scenario, electricity produced with a low share of fossil resources was used, and electricity was in this case not one of the main contributors to the environmental impact of the processes. However, if the production of electricity is largely fossil-based, it comes out as a significant factor. Furthermore, the heat recovery in an up-scaled process is very important and accounts for a reduction of 35–60% net heat demand. As a complement to LCAs, future studies of promising polyphenolic compound production systems should also include economic aspects and performance.
Forskningsoutput: Avhandling › Doktorsavhandling (sammanläggning)