WRI’s Patented Coking Indexes Are a Set of Simple Tests that Help Refiners Gauge How Close They Are to Coke Formation.
Just as a vehicle’s fuel gauge tells a driver when the tank is nearing empty, the Coking Indexes let refiners know when the product stream is getting close to coking during petroleum distallation.
Coke forms when petroleum residua get heated beyond their individual thresholds and their carbon-rich materials are precipitated. Significant financial losses occur when heat exchangers and other refinery units must be shut down to remove coke deposits. Stop processing too soon, however, and valuable distillate production is lost.
If every residuum were the same, it would be easy to set up standard processing procedures, but every residuum is different. The Coking Indexes let refiners measure a few key properties from refinery stream samples and make a series of calculations. Comparing the results to known threshold values tells refiners how close they are to coke formation. Having a gauge lets them maximize yields and still stop the heating in time.
The process was developed by WRI with support from the U.S. Department of Energy National Energy Technology Laboratory and the oil industry. The Coking Indexes are patented as “Predicting Proximity to Coke Formation” under U.S. Patent Number 6,773,921.
A Green Light for U.S. Petroleum Production
Conservatively, at approximately 1.5 million barrels per day of heavy ends and a price differential of about $10 per barrel between distillate and residual oils, a 1 percent increase in efficiency from the Coking Indexes could mean an average increase of approximately $150,000 per day. With widespread use, the Coking Indexes could mean greater production, bigger profits, greater resource efficiency and environmental benefits.