Presentation Profile
Development of an ASTM Method to Reliably Predict Which Heavy Crudes or Petroleum Residua can be Mixed Without Causing Phase Separation
Currently Scheduled: 1/19/2018 - 9:50 AM - 10:10 AM
Room: Exhibit Hall
Main Author
Dr. Raj Shah - Koehler Instrument Company
- Cindy Galdamez - Koehler Instrument Company
Abstract:
The newly updated Automated Flocculation Titrimeter (AFT) automates the collection of Heithaus values and predicts flocculation for various crudes. It also allows users to easily and reliably predict which heavy oils and petroleum residua (including asphalts) can be mixed without causing phase separation.
Typically, refiners all around the world have stopped processing crudes too soon because they couldn’t predict precisely when coking would occur. They’ve stopped well short of coke formation to avoid fouling in heavy oil processing equipment, tanks, and transfer lines but have reduced the distillate yield. That is now history due to the development of the advanced AFT. This advanced laboratory tool is also capable of reverse titration and can be used for flocculation kinetic studies.
This expanded AFT methodology, now allows any refinery using this tool to recover additional distillate without fear of fouling. One can predict the refinery conditions for coking and stop processing before fouling occurs but not sooner than necessary by using the Coking Indexes pioneered by Western Research Institute. The AFT lets the user quickly and easily collect the data needed for analysis.
The theory behind this innovative technique is discussed in this poster as well. Petroleum residua consists of ordered structures of associated polar asphaltene complexes that are dispersed in a lower polarity solvent phase by intermediate polarity material commonly referred to as resins. When the residuum is heated to temperatures above 340 degrees Celsius, this suspended structure is systematically and irreversibly destroyed during pyrolysis. A common problem in the refining industry is to ascertain how close a pyrolysis system is to forming coke on the coke induction period timeline. A certain amount of pyrolysis typically occurs and can be tolerated in a distillation unit, since there is an induction period prior to the appearance of coke.
The automated flocculation titrimeter has been developed to perform ASTM D6703, the official test method for automated Heithaus titrimetry. This helps to measure the state of the dispersed particle system and calculates predictive parameters for heavy oils.
The advanced AFT can now be used to provide valuable information about the internal stability of a heavy oil, the proximity of a pyrolyzed oil to coke formation, and to design blending protocols for oils mixtures related to prevent asphaltene precipitation, as well as study flocculation kinetics. It is an extremely versatile tool for the petroleum industry in both upstream and downstream operations.
