 Here we will go over a very simple refinery flow. This is a much simpler scheme than we have included in lesson one, different types of refinery processes, separation, finishing, conversion and support. Here what we would like to do is to connect crude oil feed to these major refinery products starting with LPG, the lightest, gasoline, jet fuel, fuel oil, asphalt and coke. One point to make, look at the number of arrows that go to gasoline which really shows the significance of this product as the major product in U.S. refineries, the gasoline. Quite a few different processes just produce gasoline. Of course jet fuel and diesel also are important refinery products. So let's look at the processes that we can use to connect the crude oil to these major products. Here again crude oil goes through desalting and distillation and through the light ends unit separations we produce the first product LPG or liquefied petroleum gas that is essentially propane and butane. The light state run after coming from the light ends unit go through blending to the gasoline pool and from the atmospheric distillation unit, kerosene and light gas oil go through hydro treatment to produce jet fuel and diesel. So you can see here that using just separation and finishing processes we could produce LPG, straight run gasoline which would be low octane number and jet fuel and diesel without any conversion process. We bring in two additional separation processes, de-waxing and de-ass vaulting. You would remember de-waxing would produce lubricating oil based stock and the wax as byproduct and de-ass vaulting, treating the vacuum distillation would separate out asphalt and produce de-ass vaulted oil for further conversion. So we have pretty much exhausted our separation processes. You can see there are still quite a few arrows pointing nowhere so we need to go to our conversion processes to connect to our final products. Here are our conversion processes in color purple starting from the left hydro cracking treats the heavy vacuum gas oil to make additional jet fuel and diesel. Whisk breaking takes the VDR from the vacuum distillation process and produces fuel oil. Moving to the right catalytic cracking takes the feed from the distillation unit could be a light gas oil or heavy gas oil to produce gasoline. This is the major gasoline production path and the byproducts from cat cracking goes through alkylation to make additional gasoline, high octane number gasoline and the heavy NAFTA, straight heavy NAFTA coming from the light ends unit through hydro treatment goes through reforming to make another high octane gasoline stream. And finally the VDR from the vacuum distillation could go through coking to make additional gasoline as well as the byproduct coke. Finally we will use the two major supporting processes hydrogen production and sulfur recovery to connect all the arrows. You know that hydrogen is used to remove sulfur and the crude oil fractions as hydrogen sulfide and hydrogen sulfide is converted to elemental sulfur in the sulfur recovery unit and elemental sulfur is sold as a refinery product. So that completes our simple refinery flow.