Thermal Degradation of Starch in Production of Environmentally Benign Flocculants, 2. Experiments and Process Identification
  • Metaadatok
Tartalom: http://real.mtak.hu/5845/
Archívum: MTA Könyvtár
Gyűjtemény: Status = Published


Type = Article
Cím:
Thermal Degradation of Starch in Production of Environmentally Benign Flocculants, 2. Experiments and Process Identification
Létrehozó:
Gyenis, János
Dencs, Judit
Nős, Gábor
Marton, Gyula
Kiadó:
American Chemical Society
Dátum:
2007
Téma:
QD Chemistry / kémia
TP Chemical technology / vegyipar, vegyészeti technológia
Tartalmi leírás:
Experiments were carried out to produce biodegradable flocculants by phophorylation and heat treatment of
corn starch at elevated temperatures in the dry state. The temporal change of molecular weight distribution
was measured by HPSEC/MALLS/RI. To elucidate the mechanism and kinetics of degradation during this
treatment a Markov-chain stochastic model was used. For this, five molecular weight intervals were defined
between >32 million and 2 million Da with exponentially decreasing spans. The probabilities of mass fraction
transitions among these intervals at different processing temperatures were determined by fitting the calculated
molecular weight distributions to the experimental data. Examining the transition probabilities between various
MW intervals, it was concluded that degradation took place gradually by multiple splits of molecules, resulting
in stepwise transition of fragments from higher intervals to lower ones. From the values of the transition
probabilities between different molecular weight intervals, and considering the evolution of molecular weight
distributions during the process, it was concluded that an end-scission mechanism did not play a role in the
studied system under the applied conditions. The degradation probability of starch molecules diminished
with decreasing molecular weight and increased with the temperature of treatment. These dependences were
described by an exponential relationship.
Típus:
Article
PeerReviewed
Formátum:
text
Azonosító:
Gyenis, János and Dencs, Judit and Nős, Gábor and Marton, Gyula (2007) Thermal Degradation of Starch in Production of Environmentally Benign Flocculants, 2. Experiments and Process Identification. INDUSTRIAL and ENGINEERING CHEMISTRY RESEARCH, 46 (24). pp. 7908-7914. ISSN 0888-5885
Kapcsolat: