flapbreaker":328iz1hg said:
Not sure if this makes any difference or not but they only get 9 gallons of diesel out of a barrel of oil compared to 19 gallons of gasoline.
http://www.eia.doe.gov/kids/energyfacts ... ml#Howused
This diagram only illustrates the amount of Diesel produced in the US based on the production characteristic of our refineries.
U.S. refineries serve a market demand heavily weighted toward automotive gasoline. European refineries are more focused on diesel fuel production.
LCO (Light Cycle Oil) and Fuel Quality
June 1, 2008
Demand for diesel in China is driving up prices for diesel fuel everywhere. U.S. Refiners are going where the money is, switching as much of their production as possible from gasoline to diesel. But without major refinery changes, only 2-3% of their production can be switched into diesel.
As they stretch this capacity to the limit, ULSD (Ultra Low Diesel) is expected to experience an increase in sludge and varnish at the end user level. Why? A little thing called LCO (Light Cycle Oil). Here is what your customers can do about it to protect their tanks from sludge and their equipment from varnish.
During crude oil refining, crude is heated under pressure and passed through a distillation column. Different fractions are drawn off at different locations in the column. Light gasses like Butane evaporate quickly (<90F) and are drawn off at the top of the column. Straight Run Gasoline is next, followed by Naphtha (which is gasoline that is sent to catalytic reforming to increase yield), kerosene, Light Gas Oil, Heavy Gas Oil and Straight Run Residue (800F+) is drawn off at the bottom of the column.
In the United States, most gas oils are fed to the cat cracker for gasoline production. In other countries, the bulk of the gas oils go to distillate fuel oil. In the U.S., the ratio of gasoline to diesel production is 55% gasoline to 12% diesel. The difference is that the U.S. with its large car population has a healthy appetite for gasoline production: the cat cracker, above all else, is a gasoline maker.
As the gas oils are fed to the cat cracker for gasoline production, the catalyst cracks the bulk of the molecules into gasoline. The other molecules are cracked into Light Gas Oil (LGO) and Heavy Gas Oil (HGO). The LGO goes to light distillate fuel blending (diesel, kerosene). The HGO goes to heavy distillate fuel (Bunker C, #6 Fuel Oil). The remainder is called Light Cycle Oil (LCO) and it makes up about 10% of the cat cracker yields. Because it doesn't crack well, it is sent back to the reactor feed where it re-cracked and recycled to extinction.
And therein lies the problem with American diesel fuel. Light Cycle Oil (LCO) is recycled into the reactor feed where it is cracked again. Eventually the LCO that does not crack is typically worked off into the Light Gas Oil (LGO) that is used to make light distillate (diesel and kerosene). Even small amounts of LCO will increase gum and varnish that typically plugs injector spray tips resulting in uneven fuel burn, loss of power and fuel economy.
Excessive amounts hurt thermal and storage stability and cause sludge buildup in the lines and can even plug filters, especially when it mixes with moisture in the fuel tank. LCO also reduces Cetane. LCO in diesel fuel increases the need to treat with Cetane Improvers.
Schaeffer Fuel Additives are one way to provide Premium Diesel that combats the effects of LCO in diesel fuel – eliminating gum, varnish and sludge build up. The Fuel Dr. can diagnose fuel problems and identify bacteria and moisture. Using Fuel Shock and Tank Dry periodically should be a regular program to provide clean and dry tank maintenance.