View source for Homework 2:Finding a patent between 1980-1990

'''CRUDE OIL REFINING 

Patent Number: 4,565,620
 
Date of Patent: Jan. 21, 1986'''


Patent Summary: 

This patent was filed by Phillips Petroleum Company in Bartlesville, Oklahoma under the inventor Dean P. Montgomery.  This patent focuses on the catalytic cracking unit in a crude oil refinery.  The patent is intended to increase the value of the products that leave the cat cracking unit, through recyling the heavy cycle oil back into the hydrofining unit.  The purpose of the hydrofining unit is to remove detrimental components in the crude product, such as sulfur and nitrogen.  These components are found in the heavier fractions of the main distillation unit.  

Prior to this patent, the heavy cycle oil coming out of the cat cracking units were recycled back into the various cracking units to prevent wasting product.  This patent alters this cycle to having the heavy cycle oil (HCO) to be recycled back into the hydrofining unit before heading back into the various catalyst crackers.  Through a plant test, Phillips Petroleum discovered that recycling the HCO back to the hydrofining unit versus recycling the HCO back to the various catalytic crackers increased the amount of gaoline produced by 1.1%, reduced coke product in the cat cracker to 5.6%, increased API gravity of the gasoline by 1.0 deg API, reduced HCO, LCO, and carbon black feed stock, reduced the regenerator bed temperature, and reduced the air rate in the regenerator.  The result of these savings resulted in the refinery saving $2,045 per day.  

This patent covers the process of using just one catalytic cracking unit that is recycled back into the hydrofining unit, and refineries that utilize various catalytic cracking units that all recycle their heavy cycle oil back into the hydrofining unit.  

[http://www.google.com/patents?id=QwI3AAAAEBAJ&printsec=abstract&zoom=4&source=gbs_overview_r&cad=0#v=onepage&q&f=false Crude Oil Refining Patent]