Heavy oil

Heavy oil is after gasoline and diesel oil extraction of remaining heavy oil, its characteristic is high molecular weight, viscosity.The proportion of heavy oil in commonly 0.82 ~ 0.95, calorific value in 10000-11000 kcal/kg.Its composition is mainly of hydrocarbons, also contains some sulfur and trace inorganic compounds.

Crude oil is also called fuel oil, black liquid, according to the international convention for the classification method of heavy oil is called persistent oil, as the name suggests, this oil is more viscous, difficult to volatilize.So once on shore, it is difficult to remove.Mainly in processing crude oil atmospheric oil, vacuum residuum, cracked residue, such as diesel and catalytic cracking diesel oil as a raw material blending.Its heavy weight more than 0.91, viscosity, contain large amounts of nitrogen, sulfur, wax, and metal, basic flow, and tar sands is can't flow.During mining, some need to underground heat injection, such as injecting steam, hot water, or some hydrocarbons dissolved it, increase its liquidity, or a similar coal mining method.

For of heavy oil used as fuel, in addition to the requirements with high calorific value, also requires:

(1) low viscosity.Injection atomization for pipeline, and is helpful to improve combustion efficiency;Heavy oil viscosity by paraffin content more big, should be preheated when using, make up to 100 ℃ or 100 ℃ above, in order to reduce the viscosity.

(2) the lower freezing point.General heavy oil solidification temperature is 22 ~ 36 ℃;Quantity of paraffin, the high freezing point of crude oil, proper heating measures should be taken, in order to facilitate transportation and handling.

(3) the high flash point temperature.Can use higher preheating temperature, easy to transport and atomization, general heavy oil flash point in 180 ~ 330 ℃, were higher than needs preheating temperature.

(4) the mechanical impurity and water content in the oil.Impurity and high water content, not only reduces the calorific value of heavy oil, and use can cause nozzle clogging and flame, so need to filter, such as oil and water of emulsion formation, can improve the combustion effect.

(5) to low sulfur.General sulphur content is 0.15% ~ 0.15%, but there are a few heavy oil is as high as 2%, sulfur used in adverse consequences.

Crude oil can be used as fuel injection in the blast furnace in a steel plant, heating furnace, the iron ore sintering and iron ore pellets method of ignition, roasting, etc.However, after the second oil crisis in the 1970 s, the rise in oil prices, coupled with the crude oil and other chemical raw materials can be produced, so the number of steel mills using heavy oil decreases, and the generation of pulverized coal.