|Using Automated Flocculation Titrimetry to Reduce Fouling from Heat-Induced Deposition and Coking
|Analytical challenges in addressing new generation FuelFeedstocks and renewables
|Dr Raj Shah
|Mr Yuya Baba
Mr Stanley Zhang
|Koehler Instrument Company, Inc.
Abstract Information :
Flocculation is a process in which flocs are formed by clustering together particles that are suspended in fluids and mixtures. These flocs are usually formed with an addition of a chemical called flocculants. This process is commonly used and known for cleaning and filtering dirty, contaminated water to make drinkable, clean water. We see similar concepts and problems in the petrochemical industry. Mixing incompatible oils can cause asphaltene precipitation. Polar asphaltene is suspended in crude oil, which has a lower polarity, by resins that have intermediate polarity. These suspensions can be deconstructed irreversibly by pyrolysis as the solvent is heated over 340 C. However, heating such solvents can cause undesired coke formation and fouling. Since the point at which coking begins cannot be predicted, refiners tend to stop the process short which causes a reduction in distillate yield. The Automated Flocculation Titrimeter, or AFT, is a useful tool to predict when coking and heat-induced fouling will occur and determine whether heavy oils are compatible for mixing. Compatibility of high- and low-grade crude oils is important to reach target specifications while using the minimal amount of high-grade crude oil. The AFT can be used to perform Automated Heithaus Titrimetry, as per ASTM D6703. This test method measures the state of the dispersed particle system and calculates predictive parameters for heavy oils. It can also be used to provide valuable information about the internal stability of heavy oils, the proximity of a pyrolyzed oil to coke formation, and to design blending protocols for oils mixtures to prevent asphaltene precipitation.