The process of Refining of Crude Oil is used to separate Crude into fractions of various derived products.

For example, Crude contains fractions of gasses such as Methane, Ethane, Propane, Butane, liquids such as Gasoline and Naptha, middle-distillates such as Jet Fuel and Diesel, and heavier molecules. These are separated in a first stage fractioning column.

The heaver molecules are separated in a vacuum fractioning process, which follows the first stage.

If I understand correctly, this is used to separate various grades of fuel oil from the heaviest of compounds.

Some of these fuel oil components can be cracked into lighter molecules such as gasoline. (Usually a higher octane than the straight run gasoline from the first process.)

The remaining fuel oil components, of which there are typically three grades, are used to power large combustion engines, such as those found on ships. The heaviest of these grades is so viscous that it requires heating before it can be pumped through pipes or burned in a combustion engine.

If I understand correctly, what remains after this is bitumen, which is used in asphalt.

In terms of economics, it is not totally obvious what is categorized as "waste product". Some of these products (presumably the bitumen) have a lower economic value than the raw Crude.

I don't know what the typical value of the heavy fuel oils is compared to the Crude. Of course, the values will fluctuate as a result of economic conditions in supply and demand chains.

My question is, what happens to the waste products which cannot be converted into some saleable product? Are these products discarded? Are they buried in landfill?

I am assuming the following (I may be wrong):

• All the methane, ethane, propane and butane is either used to power the refinery itself (in the heating processes), or sold in gas cylinders, or sold to power gas fired power plants
• All the gasoline and naphtha produced from the various processes is sold, mostly as a blended commercial gasoline product
• All the diesel and kero products are blended and sold as grades of diesel or Jet Fuel
• The heavier fuel oil products are either sold and used to power large industrial equipment such as commercial and naval ships, power plants, or these products are used in the cracking process to produce lighter chain molecules
• What remains is bitumen and is considered to be waste product

Does anything else remain and is considered "waste"?

The process of refining of crude oil is used to separate crude into fractions of various derived products.

For example, crude contains fractions of gasses such as methane, ethane, propane, butane, liquids such as gasoline and naptha, middle-distillates such as jet fuel and diesel, and heavier molecules. These are separated in a first stage fractioning column.

The heaver molecules are separated in a vacuum fractioning process, which follows the first stage.

If I understand correctly, this is used to separate various grades of fuel oil from the heaviest of compounds.

Some of these fuel oil components can be cracked into lighter molecules such as gasoline. (Usually a higher octane than the straight run gasoline from the first process.)

The remaining fuel oil components, of which there are typically three grades, are used to power large combustion engines, such as those found on ships. The heaviest of these grades is so viscous that it requires heating before it can be pumped through pipes or burned in a combustion engine.

If I understand correctly, what remains after this is bitumen, which is used in asphalt.

In terms of economics, it is not totally obvious what is categorized as "waste product". Some of these products (presumably the bitumen) have a lower economic value than the raw crude.

I don't know what the typical value of the heavy fuel oils is compared to the crude. Of course, the values will fluctuate as a result of economic conditions in supply and demand chains.

My question is, what happens to the waste products which cannot be converted into some saleable product? Are these products discarded? Are they buried in landfill?

I am assuming the following (I may be wrong):

• All the methane, ethane, propane and butane is either used to power the refinery itself (in the heating processes), or sold in gas cylinders, or sold to power gas fired power plants
• All the gasoline and naphtha produced from the various processes is sold, mostly as a blended commercial gasoline product
• All the diesel and kero products are blended and sold as grades of diesel or Jet Fuel
• The heavier fuel oil products are either sold and used to power large industrial equipment such as commercial and naval ships, power plants, or these products are used in the cracking process to produce lighter chain molecules
• What remains is bitumen and is considered to be waste product

Does anything else remain and is considered "waste"?