Refining

ExxonMobil’s refinery at Slagentangen near Tønsberg, inaugurated in 1961, is located in a sheltered location by the Oslo Fjord. The refinery processes crude oil, mainly from the North Sea, into fuel products for consumption and industrial purposes.

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Refining

 

 

Refining

ExxonMobil’s refinery at Slagentangen near Tønsberg, inaugurated in 1961, is located in a sheltered location by the Oslo Fjord. The refinery processes crude oil, mainly from the North Sea, into fuel products for consumption and industrial purposes.

The annual processing capacity is 6 million tons of crude oil. The production of petroleum products represents more than half of Norway’s total consumption. The lightest products are propane and butane, followed by petrol, kerosene, gasoline (benzin), diesel and light fuel oil. The heaviest product is heavy oil. The Slagentangen refinery produces of course sulphur free diesel (less than 10 ppm sulphur), which is a prerequisite for modern, environmentally friendly cars with catalyst treatment of exhaust gases.

In 2007, the refinery installed a plant for blending of biodiesel. It supplies diesel with up to 7 per cent blend of a bio component. This low blend biodiesel may be used by all diesel cars without causing engine trouble, nor is it in conflict with guarantees given by the car manufacturers. As of January 2016, in order to comply with increased legally mandated bio portion, Slagen blends ethanol into Mogas, in accordance with car manufacturers’ specifications.

At the end of 2016 the refinery started up a new process unit for the upgrading of heavy fuel oil, which increased the value of the Slagen product portfolio. Approximately 60 percent of the refinery’s production of petroleum products are exported, which makes the refinery one of Norway’s largest onshore export businesses. All crude oil and around 90 percent of the total production is offloaded and loaded at the jetty, which can receive ships up to 190.000 ton deadweight. Every year around 700 ships call on the port.

The Slagentangen office also manages the Supply, Transportation and Distribution businesses. Transportation & Supply handles crude supplies to the Slagen refinery and conducts the trading of petroleum products from the refinery production. ExxonMobil’s trade of crude oil from the fields in the North Sea is handled from the ExxonMobil UK office in Leatherhead. The Distribution department manages the company’s three main storage terminals located in Fredrikstad, Bergen and Trondheim, and the refinery’s truck loading facilities.

Refining process

Crude oil refining is about converting the raw material into the oil products that consumers demand.

Crude oil refining is about converting the raw material into the oil products that consumers demand. Crude oil is pumped ashore from large tankers and into crude oil tanks. From there it is pumped through a heating system (heat exchangers and furnace) to the main distillation tower for a "primary sorting" of the various main components. The refining processes are monitored and controlled from a control center by means of advanced electronics and computer based control programs.

The loading and discharge of raw material and oil products are handled from a separate control room located by the pier. The control room also monitors the tank farm, the water treatment plant, and various pump operations. The refinery is operated around the clock all around the year, with highly qualified technicians keeping a vigilant eye on operations at all times. Temperatures, pressure and through-put in all parts of the plant may be monitored from the two control rooms. The operation is optimized to get an optimum value added in the form of oil products using the lowest amount of energy possible.

Crude oil

Crude oil is a mixture of hundreds of different types of chemical substances (made up of carbon and hydrogen) called hydrocarbons. No other natural raw material has to the same extent impacted the evolution of contemporary industrial society. Crude oil is fractionated and processed into the products that the market demands. Crude oil comes in all varieties, from very light (e.g. North Sea crudes) to very heavy crudes. Examples of the composition of three North Sea crudes and one Arabic are provided below, with highly qualified technicians keeping a vigilant eye on operations at all times. Temperatures, pressure and through-put in all parts of the plant may be monitored from the two control rooms. The operation is optimized to get an optimum value added in the form of oil products using the lowest amount of energy possible.

Fuel gas sulfur recovery plant

The sulfur recovery plant is required for the control of the refinery emissions of SO2 and the contribution to acid rain. Sulfur removed from the products in the desulfurization processes, has to be removed from the refinery gas before it is fired in the process furnaces. Thus one achieves that neither the products nor the refinery’s own energy consumption contribute to acidification of the environment. The hydrogen sulphide gas is converted to liquid sulphur which is sold to the paper and pulp processing industry.

Desulfurization

These processes remove sulfur from the petrol production feedstock, diesel oil and gas oil. This happens at high temperature and high pressure in the presence of hydrogen gas and a catalyst (enhances the speed of reactivity). Sulfur is removed as hydrogen sulfide gas which is fed to the sulfur treatment plant.

Visbreaking of heavy oil

The visbreaker converts 25-35% of the heavy bottoms from crude oil distillation into lighter and more valuable products (gas, naphtha and diesel). This is carried out through thermal cracking where heavy oil molecules are exposed to such high temperatures (460ยบC) in the visbreaker furnace that they crack into smaller and lighter molecules. The converted product is separated through distillation and further processing in desulfurization plants before they can be sold or processed further. The plant provides an important adjustment by bringing the refinery's product yield more in line with market demand. The bulk of the heavy fuel oil production is exported to power plants and as bunker fuel for ships.

Refining products

You can find a list over refining products here.

Slagen Refinery

Slagen Refinery is situated on the west bank of the Oslofjord about 5 n. miles south of Horten. The marine terminal consists of a pier about 500 m long with loading/discharging berths on both sides. To the south of the long pier there is a small harbour where mooring boats and oil recovery equipment are kept. The terminal and its near surroundings are owned and controlled by Esso Norge AS. It has its own Harbour Office with Marine Supervisors on duty 24 hours a day.

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