Hydrorefining generally refers to the reprocessing of certain petroleum products that do not meet the requirements for use by the hydrogenation process to achieve the specified performance targets.
- Refined raw materials:
Gasoline, diesel, kerosene, lubricating oil, petroleum wax, etc. containing more harmful impurities such as sulfur, oxygen and nitrogen.
- Refined products:
Refined and modified gasoline, diesel, kerosene, lubricating oil, petroleum wax and other products.
- Basic concepts
The hydrorefining process is a general term for catalytic upgrading of various oils under hydrogen pressure. It refers to the hydrogenolysis reaction of various non-hydrocarbon compounds in oil products under certain conditions of temperature and pressure, in the presence of catalyst and hydrogen, and then removed from the oil to achieve the purpose of refining the oil.
Hydrorefining is mainly used for the refining of oil products, and its main purpose is to improve the performance of oil products by refining.
- Production process
The hydrorefining process generally includes three parts: a reaction system, an oil-generating heat exchange, a cooling, a separation system, and a circulating hydrogen system.
Reaction system
The feedstock oil is mixed with new hydrogen and circulating hydrogen, and after heat exchange with the reaction product, it enters the heating furnace in a gas-liquid mixed phase state (this method is called pre-furnace hydrogen mixing), and is heated to the reaction temperature to enter the reactor.
The reactor feed can be in the gas phase (when refined gasoline is used) or in a gas-liquid mixed phase (refined diesel or oils heavier than diesel). The catalyst in the reactor is typically packed in layers to facilitate cold hydrogen injection to control the reaction temperature. The recycled hydrogen and oil mixture is subjected to a hydrogenation reaction through each of the catalyst beds.
- Generate oil heat exchange, cooling, separation system
The reaction product exits the bottom of the reactor, undergoes heat exchange, and is cooled to enter the high pressure separator.
High pressure wash water is injected into the product before the cooler to dissolve the ammonia and some of the hydrogen sulfide produced by the reaction.
The reaction product is subjected to oil and gas separation in a high-pressure separator, and the separated gas is recycled hydrogen, in addition to the main component hydrogen, a small amount of gaseous hydrocarbon (non-condensable gas) and water-insoluble hydrogen sulfide; the separated liquid The product is a hydrogenated oil in which a small amount of gaseous hydrocarbons and hydrogen sulfide are also dissolved;
The produced oil is depressurized and then passed to a low pressure separator to further separate components such as gaseous hydrocarbons, and the product is separated into qualified products by a fractionation system.
- Circulating hydrogen system
After the circulating hydrogen separated from the high pressure separator passes through the storage tank and the circulating hydrogen compressor, a small portion (about 30%) directly enters the reactor for cold hydrogen, and most of the remainder is sent to be mixed with the feedstock oil and recycled in the apparatus. In order to ensure the purity of circulating hydrogen and avoid the accumulation of hydrogen sulfide in the system, a hydrogen sulfide recovery system is commonly used. Generally, ethanol sulfide is used to absorb and remove hydrogen sulfide, and the rich liquid (absorbent liquid) is regenerated and recycled, and the desorbed hydrogen sulfide is sent to a sulfur-making device to recover sulfur, and the purified hydrogen is recycled.
- Heating furnace
The feedstock oil is mixed with new hydrogen and circulating hydrogen, and after heat exchange with the reaction product, it enters the heating furnace in a gas-liquid mixed phase state and is heated to the reaction temperature to enter the reactor.
- reactor
The heat exchange and post-furnace hydrogen are introduced into the reactor.
In the reactor catalyst bed reaction, sulfur, oxygen, nitrogen, and a metal compound become substances which are easily removed (by hydrogenation to hydrogen sulfide, water, ammonia, etc.), and the olefin is simultaneously saturated.
- High pressure low pressure separator
The hydrogenated oil enters the high pressure and low pressure separator after heat exchange and water cooling. More oil information oil information oil transfer technology, please pay attention to WeChat public number oil circle.
- Stripper
The hydrogenated oil from the low pressure separator exchanges heat with the stripped hydrogenated oil, enters the furnace and is heated, and then enters the stripper, which acts to strip the gas and light ends remaining in the oil. . The produced oil from the bottom of the stripper is hydrotreated after heat exchange and water cooling.
