Publication
Sustainable polymer solutions through biomass liquefaction processes
| datacite.subject.fos | Ciências Naturais::Ciências Químicas | pt_PT |
| dc.contributor.advisor | Barreiro, M.F. | |
| dc.contributor.advisor | Fernandes, Isabel P. | |
| dc.contributor.advisor | El Aissi, Radhia | |
| dc.contributor.author | Bourogaa, Intissar | |
| dc.date.accessioned | 2019-10-16T15:49:16Z | |
| dc.date.available | 2019-10-16T15:49:16Z | |
| dc.date.issued | 2019 | |
| dc.date.submitted | 2018 | |
| dc.description | Dupla diplomação com a Université Libre de Tunis | pt_PT |
| dc.description.abstract | In a context of better management of land resources and development of renewable biomass-based chemicals, lignin offers excellent alternative to replace certain fossil-based derivatives. Through the integration of green chemistry into biorefineries, and the use of low environmental impact technologies, we can establish future supply chains for genuinely green and sustainable chemical products. Indeed, lignin can be converted into polyols via several processes, mainly liquefaction. Liquefaction is considered an efficient method to generate polyols with high content of reactive hydroxyl groups. These final products can be used as raw materials for polymer synthesis, like in the production of polyurethanes and polyesters. In our study this alternative has been adopted; namely by using conventional heating system and microwave heating. The difference between the two is essentially based on energetic terms, given that liquefaction processes are usually carried out at high temperatures, using different types of liquefaction solvents and in the presence of acid catalysts. The use of microwave heating system has various advantages in terms of speed and consumed energy. The objective of this study was to compare the liquefaction of sodium lignosulphonate lignin by conventional heating system and microwave system. The liquefaction was carried out using polyethylene glycol (Mw 400) and glycerol as solvents, and sulphuric acid as catalyst, and the conversion yield determined, aiming at achieve the best liquefaction conditions. In fact, several process conditions were tested namely the catalyst content (1, 2 and 3%, (w/w, solvent-basis) and liquefaction temperature (140, 160 and 180°C). The obtained polyols were characterized in terms of their most relevant technical properties: hydroxyl number (IOH), viscosity, and unreacted biomass. The chemical structure, which was evaluated by Fourier Transform Infrared analysis (FTIR) was also checked. Finally, the properties of the generated polyols were compared in order to evaluate the efficiency of both systems. | pt_PT |
| dc.identifier.tid | 202289591 | pt_PT |
| dc.identifier.uri | http://hdl.handle.net/10198/19677 | |
| dc.language.iso | eng | pt_PT |
| dc.rights.uri | http://creativecommons.org/licenses/by-nc/4.0/ | pt_PT |
| dc.subject | Lignin | pt_PT |
| dc.subject | Liquefaction | pt_PT |
| dc.subject | Microwave | pt_PT |
| dc.subject | Conventional reactor | pt_PT |
| dc.subject | Biopolyols | pt_PT |
| dc.title | Sustainable polymer solutions through biomass liquefaction processes | pt_PT |
| dc.type | master thesis | |
| dspace.entity.type | Publication | |
| rcaap.rights | openAccess | pt_PT |
| rcaap.type | masterThesis | pt_PT |
| thesis.degree.name | Engenharia Química | pt_PT |