Effects of Variables on a Soaker-Stripper Reactor for Thermal Cracking of Deasphalted Oil
Date
2014-10-16
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Abstract
Vast resources of heavy oils like Canadian bitumen are available and processed through many different schemes to bring a synthetic crude oil to markets. One effective scheme in use employs Solvent Deasphalting (SDA), a versatile upgrading process that uses light alkanes to precipitate the asphaltic phase from the feedstock, producing Deasphalted Oil (DAO), a stream with reduced asphaltenes and metal content. In that industrial scheme DAO is thermally cracked to generate distillates with conversion of the 553 °C+ fraction over 50%. One important current challenge is to increase that conversion level by optimization of the reactor and the flow regime inside it.
In this work, a pilot plant was designed, procured and built to investigate the thermal cracking of DAO with steam in a counter-current flow pattern reactor. The effect of a Raschig rings packed bed and variables such as reaction temperature and space velocity were studied. Among different techniques, Simulated Distillation (SD) was used for product characterization. The product characterization and reactor performance showed a limited effect of the Raschig rings and enhanced heat distribution due to the steam counter-current flow, which allows better performance at a lower temperature.
A parametric study along with the corresponding product distributions for each experiment made possible the use of a kinetic model to describe the reaction network taking place. The model includes 5 lumps: residue (R), vacuum gas oil (VGO), distillates (D), naphtha (N) and gases (G). Thermal cracking of the residue followed first order kinetics with activation energies ranging from 172 to 250 kJ/kmol. Gases were found to be produced almost exclusively from residue, and naphtha was found to be a secondary product of the reaction scheme.
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Engineering--Chemical
Citation
Gutierrez Aldana, N. D. (2014). Effects of Variables on a Soaker-Stripper Reactor for Thermal Cracking of Deasphalted Oil (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/25838