Processes and systems for characterizing and blending refinery feedstocks

摘要

A method for characterizing and optimizing refinery feedstock blends according to their corrosivity is provided. Refinery feedstocks can be characterized based on any of: dissociation of acids in the crude, breakup of naphthenic acid molecular associations, mass changes of carbon steel samples, and/or dissociation of sulfur compounds in the feedstocks. The characterization is performed as a function of temperature via any of electrical resistivity measurement, vibrational spectroscopic analysis, voltammetry, electrochemical impedance spectroscopy, crystal microbalance measurements of weight changes, and combinations thereof. The method employs models and/or hardware to optimize the usage of refinery feedstocks in the blending and valuation of the feedstocks.

主权项

1. A method for optimizing blends of refinery feedstock, comprising:
providing a plurality of refinery feedstock samples with each feedstock sample being representative of a feedstock stream to the refinery and having a molecular association characteristic as a function of temperature; obtaining measurements from the refinery feedstock samples to quantify the molecular association characteristic of the samples as a function of temperature by electrochemical impedance spectroscopy (EIS) at 10 kHZ frequency; providing a database containing EIS measurements correlating molecular association characteristics of the refinery feedstock samples as a function of temperature with known corrosion performance of a plurality of reference refinery feedstock samples; using the EIS measurements correlating molecular association characteristics of the refinery feedstock samples and the database containing EIS measurements correlating molecular association characteristics with corrosion performance of the reference refinery feedstock samples to obtain an optimized feedstock blend having desired EIS measurements correlating with an acceptable corrosion performance.