Explain How Kuwait Refines Crude Oil Into Different Oil Products Including Gasoline and Bitumen
Basically, the product produced in this process can be categoried into 4 group, they are: light distillates, middle distillates, heavy distillates and others. The example of light distillates are liquid petroleum gas (LPG), gasoline, and kerosene. Apart from that, the products that can be classified as middle distillates are residential heating fuel and aautomoblie diesel fuels. Additionally, bunker fuel oils is an example of heavy distillataes, while petroleum cokes, lubricating oils and carban black are the other products in this distillation process.
Petroleum is a substance that occurs naturally. It is a dark liquid. It occurs beneath the earth’s surface. A large number of products like petrol, diesel, lubricating oil, etc derive from petroleum. Its compounds can be separated with the help of fractional distillation. In the year 2006, primary sources of energy consisted of petroleum 36.8%, natural gas 22.9%, and coal 26.6% share for fossil fuels in primary energy production in the world. It takes around millions of years for petroleum to form. It is formed due to the presence of decomposed carcasses of dead animals beneath the surface of the earth. These carcasses of dead animals are subjected to extreme pressure and heat. Over centuries, millions of animals lived and died to become fossilized, just in case of plant-based matter. Similarly, in the ocean, oceanic creatures drowned to the bottom of the ocean and got buried under the sand and rocks. Decayed due to the presence of bacteria, the decomposed organic matter got buried deeper and deeper over the years. Over millions of years, high temperature, high pressure, the absence of air converted the dead animals to petroleum and coal. This liquefied form of dead organic matter is petroleum or crude oil. Crude oil is extracted from oil wells, these wells can be very deep. The oil extracted is later refined to form petrol, diesel, aviation fuel, paraffin wax, lubrication oil, etc.Deposition of petroleum occurs with natural gas in the rocks called oil wells from where it is taken out by drilling. Refining is a process where the separation of various compounds of crude oil occurs. Fractional distillation is a process used to separate its compounds. Crude Oil procured from an oil well is a mixture of many liquids. Different temperature evaporates a different liquid. This temperature is the boiling point of that liquid. The crude oil is heated to a temperature of 400-degree Celcius, is fed in at the bottom of the column and heated further. The liquid with the lowest boiling point changes into vapor first and condenses. At higher temperature, the next volatile liquid changes into a vapor state and rises.
Examples of Buffer solution used on a day-to-day basis: Inside the human body, the main buffer that is in use, is in the blood stream. Carbonic Acid and Hydrogen Carbonate work together to maintain a dynamic equilibrium in the body to disallow a very acidic or alkaline solution. They maintain the pH and temperature too so cells in the mammalian body do not denature the body system failures. Another example in the body, is that the buffer solutions are used in the skeletal muscles during exercise – the Haemoglobin binds to specific proteins during contraction and dilation. With things that are used by humans; a buffer is used to balance out the alkalinity in the soap of a shampoo. During the fermentation of alcohol, a buffer is used to maintain the pH and thus produce a maximum yield of alcohol. And in the manufacturing of glue, some ingridients inside it can change the pH within solution change, the buffer here is used to withstand the changes during the manufacturing of glue. The catalyst cracking happens during the second stage of petroleum refining. This process is needed because the heaviest fractions including gas oil and residual oil are lower in value than some of the other lighter fractions (BBC Bitesize, 2019). This process is used to break apart the molecules in these heavier fractions. Through this, the end products will have a higher value. Jet fuel and gasoline are produced from the utilization of cracking that are initially heavy gas oils. Catalytic cracking is used in petroleum refining to break down long chains of hydrocarbons into simpler molecules (smaller hydrocarbons) by breaking the ‘carbon-carbon’ bonds. Large hydrocarbons are vaporised and placed over a hot catalyst. The chemical bonds within the hydrocarbons are broken down by the heat, this makes them smaller and so they’re much more efficient for during the usage (also known as thermal cracking). Catalyst cracking is a necessity in the process of Petroleum Refining as using large hydrocarbons within oils is not an efficient way to produce fuels. So by breaking it down into smaller alkanes and alkenes, it’s more useful during the production of fuels and alkanes specifically in the process of making polymers. Petroleum Refining is shown through three different stages; separation, conversion and treating. Separation is where the distillation process occurs. Distillation is when condensation occurs through the use of thermal energy for liquids. The heated crude oil enters a tall fractionating column, which (as the diagram shows, it’s warmer at the bottom- reaching 400 °C and cooler at the top, starting at 20 °C). The crude oil is heated by a furnace, in which the hydrocarbons can be separated into different boiling points (Organic Chemistry 7th Edition (2007). The lighter fractions reach the top of the tower where they condense into a liquid state; here they’re at a low boiling point. The heavier fractions stay at the bottom of the tower and have a high boiling point. Each of the fractions contain hydrocarbon molecules and a similar amount of carbon atoms.
Summing up, it's to make them clean enough to be used. Sometimes it's to turn some of the unwanted liquids into things people want to buy. The heavier liquids are in less demand from customers so are turned into lighter products that are in demand. One of the processes is called catalytic cracking. It breaks down some of the heavy liquids from the distillation column. The heavy liquids are changed into simple and more useful liquids and gases. Cracking is just one of many chemical changes in an oil refinery.
Organic Chemistry 7th Edition (2007) Distillation: Author, John E. McMurry, Organic Chemistry, Cengage Learning.
Petroleum.co.uk. (2019). Petroleum – Refining. [online] Available at: http://www.petroleum.co.uk/refining [Accessed 17 Dec 2018].
Diagram of distillation tower – https://energyeducation.ca/encyclopedia/Fractional_distillation (accessed January 2019)
BBC Bitesize. (2019). GCSE Chemistry (Single Science) – Crude oil, hydrocarbons and alkanes – AQA – Revision 5. [online] Available at: https://www.bbc.com/bitesize/guides/zshvw6f/revision/5 [Accessed 20th Dec. 2018].
Organic Chemistry 7th Edition (2007) Distillation: Author, John E. McMurry, Organic Chemistry.
What is distillation? https://www.britannica.com/science/distillation (accessed on January 2nd 2019)