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Degradation of glycerol using hydrothermal process
Lailatul Qadariyah1, Mahfud, Sumarno
1Chemical Engineering Department, Faculty of Industrial Technology, Sepuluh Nopember Institute of Technology, Indonesia.
Bioresource Technology
|July 19, 2011
Summary
Sub-critical and supercritical water efficiently degrade glycerol into valuable products like allyl alcohol. This environmentally friendly process achieves high glycerol conversion and offers insights into reaction kinetics.
Area of Science:
- Green Chemistry
- Chemical Engineering
- Reaction Engineering
Background:
- Glycerol is a byproduct of biodiesel production, necessitating efficient degradation methods.
- Water at sub-critical and supercritical conditions offers a sustainable reaction medium.
- Understanding glycerol degradation pathways is crucial for valorization.
Purpose of the Study:
- To investigate the degradation of glycerol using sub-critical and supercritical water.
- To determine the influence of temperature and reaction time on product distribution.
- To analyze the reaction kinetics and activation energy.
Main Methods:
- Batch reactor experiments were conducted at temperatures ranging from 473 to 673 K and 30 MPa pressure.
- Reaction times varied between 20 and 60 minutes.
- Product analysis included acetaldehyde, acrolein, and allyl alcohol quantification.
Main Results:
- Glycerol conversion exceeded 99.92 mol% under investigated conditions.
- Allyl alcohol was the primary product (96.69 mol%) in supercritical water.
- Acetaldehyde was predominantly formed in sub-critical water, while acrolein was produced in both.
- The global reaction kinetics followed a pseudo-first-order model with an activation energy of 39.6 kJ/mol in sub-critical water.
Conclusions:
- Glycerol degradation in sub-critical and supercritical water is a highly efficient and environmentally benign process.
- Product selectivity is influenced by water phase (sub-critical vs. supercritical).
- The established kinetics provide a basis for process optimization and scale-up.
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