A study of the hydroisomerisation in a trickle bed reactor of biodiesel (palm and coconut) and n-C15 over 0.5% w/w Pt-? zeolites
- Authors
- Pazmi?o Mayorga, Isabel Cristina
- Format
- MasterThesis
- Status
- publishedVersion
- Description
Biodiesel and renewable diesel are seen as potential alternatives to fossil fuels due to the renewability of their feedstock. Their poor cold flow properties behaviour has restricted application because of potential engine damage. Several studies in the petroleum area have demonstrated that the cold flow properties can be enhanced by the presence of branched molecules. However, only a few studies have attempted cold flow improvement by applying hydroisomerisation to biodiesel and renewable diesel at high pressure and high temperature. Thus, this particular research is dedicated to study the hydroisomerisation of biodiesel (palm and coconut) and n-C15 using 0.5% w/w Pt-? catalysts 250?C and atmospheric pressure in a trickle bed reactor (TBR). It is worth mentioning that no studies have used 0.5% w/w Pt-? over these biodiesel feeds. To determine the composition of the hydroisomerisation products, a GC-MS interpretation procedure, developed in this study, lumped the products identified into five groups: paraffins, iso-paraffins, iso-FAMEs, alkyl-substituted benzenes and cyclic paraffins. These gave an indication of the dominant reaction: namely, cracking or hydroisomerisation. The main results showed that when using palm biodiesel with the most acidic zeolite (0.5% w/w Pt-? (Si/Al=12.5)), 40 % of the products corresponded to cracked compounds. Unsatisfactorily, the iso-FAMEs fraction reached only a maximum of 5%. When using the less acidic zeolite (0.5% w/w Pt-? (Si/Al=180)) with pal biodiesel, cracking and hydroisomerisation occurred at approximately the same level (around 5%). It suggested that a weaker acid catalyst suppress the degree of cracking whilst hydroisomerisation was maintained. Also, deactivation of the metallic function was apparent as the unsaturated FAMEs reappeared and reached their initial concentrations after 24 hours. Hence, the level of metal on the catalysts is clearly an area for further research. The reaction of coconut biodiesel over the less acidic zeolite (0.5% w/w Pt-? (Si/Al=180)) showed only hydrogenation of the unsaturated species (13%) throughout the 24-hour length experiment, and no isomer formation was detected. However, an indication of the potential for catalyst deactivation due to high levels of unsaturation was observed. In addition, 0.5% w/w Pt-? (Si/Al=180)) was tested. Using n-C15, and approximately 70% conversion to cracked and isomerised products was achieved. Despite its exploratory nature, this encouraging result suggested that the less acidic zeolite was a good candidate for renewable diesel treatments yielding around 30% of i-C15 and merits further research.
- Publication Year
- 2016
- Language
- eng
- Topic
- BIODIESEL
CAT?LISIS HETEROG?NEA
REACTOR DE GOTEO
CROMATOGRAF?A DE GASES
ESPECTROMETR?A DE MASAS
HIDROISOMERIZACI?N
- Repository
- Repositorio SENESCYT
- Rights
- openAccess
- License
- openAccess