551. Kinetic analysis of Botryococcus braunii pyrolysis using model-free and model fitting methods
- Author
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Imtiaz Ali, Salman Raza Naqvi, and Ali Bahadar
- Subjects
Reaction mechanism ,biology ,Chemistry ,020209 energy ,General Chemical Engineering ,Organic Chemistry ,Kinetic analysis ,Kinetics ,Analytical chemistry ,Energy Engineering and Power Technology ,02 engineering and technology ,Activation energy ,010501 environmental sciences ,biology.organism_classification ,01 natural sciences ,Decomposition ,Fuel Technology ,0202 electrical engineering, electronic engineering, information engineering ,Botryococcus braunii ,Pyrolytic carbon ,Pyrolysis ,0105 earth and related environmental sciences - Abstract
The kinetics of Botryococcus braunii pyrolysis was studied using commonly used model-free and model-fitting methods. Differential and integral versions of iso-conversional model-free methods provide effective apparent activation energy as a function of conversion. Reaction-order and Sestak and Berggren (SB) models were considered for the estimation of global single reaction mechanism. It was shown that SB model with an empirical function f(α) = (1 − α)n·αm was the most probable reaction mechanism. The constituents namely carbohydrate, protein and lipid were found to decompose simultaneously. Average activation energy of these components were obtained from Friedman and Kissinger-Akahira-Sunose (KAS) methods. Depending on the iso-conversional method, the activation energy ranges of pseudo-carbohydrate, pseudo-protein and pseudo-lipid were found as 58.3 – 60.5 kJ · mol - 1 , 49.5 – 109 kJ · mol - 1 and 79.1 – 88.5 kJ · mol - 1 , respectively. Model-free methods when applied on biomass as whole or on separate component yielded matching results. Decomposition of pseudo-carbohydrate was 2–3 times faster than other two components. Pseudo-lipid was shown to impede the progress of pyrolytic conversion.
- Published
- 2018
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