The variety of products derived from crude oil and natural gas such as jet fuel, diesel, liquified petroleum gas, propane, and butane are vital to many daily activities around the world.
The process of extracting and refining natural gas and oil requires the installation of complex industrial components carefully installed and optimized by engineers. The components regularly found in a gas or oil plant processing system include high-grade and well-tested drills, pumps, hydraulic systems, valves, filters, and pipes.
Before crude oil and natural gas can be used it has to be refined into its more useful components. For this to take place the raw fuels have to go through certain chemical processes that involve lots of heat and pressure. A plant process system ensures all the components of a refinery are working safely and tracks fuel as it goes through the processes of separation, conversion, and recovery.
For oil and gas enthusiasts or those looking to get into the industry, here is a short guide to the main functions of the key components in a gas refinery’s plant process system and how they can be improved in the future.
Separation of Gas and Oil
After extraction, natural gas is transported to storage tanks at a refinery, this requires miles of pipes to be laid as well as a provider of valves to install several high-grade transfer valves around the plant. Next, the natural gas is sent from storage tanks to a separator.
Once natural gas has been extracted and transported to the refinery it will be piped to a separator, a large closed tank that uses gravity to separate gases and liquids. To further assist with the separation of the gas and oil, separators also cool the gas under high pressure which also separates water and any other impurities or useful by-products.
Removal of Hydrogen Sulfide and Carbon Dioxide
After the separator removes oil, water, and other compounds that can be condensed from the natural gas, it is time to remove any carbon dioxide and hydrogen sulfide that may be present. The removal of hydrogen sulfide is a vital step in the production process as it is a potentially lethal, corrosive, and harmful chemical.
The process of removing carbon dioxide and most importantly, hydrogen sulfide, from natural gas is known as “sweetening” in the industry, as natural gas containing hydrogen sulfide creates a sour smell due to the sulfur present in the gas. Removing hydrogen sulfide and carbon dioxide is done by forcing the cooled liquid gas through industrial-sized membranes.
Dehydration of Natural Gas
After the removal of carbon dioxide and hydrogen sulfide is the process of dehydration. All excess water must be removed from the gas to avoid hydrates that can cause issues of corrosion and freezing in the system or when in storage.
Natural gas can be dehydrated by using two processes, adsorption and absorption, both of which can be facilitated using computer-assisted and monitored dehydration systems.
Adsorption is the process of collecting and condensing water vapor on a cool surface possible with dry desiccant dehydrators. Absorption processes on the other hand use a dehydrating agent to remove water vapor.
Recovery of Natural Gas Liquids
Butane, ethane, and propane are all examples of natural gas liquids (NGLs), a valuable by-product in natural gas production. NGLs are recovered by first separating them from natural gas in a process that involves lowering the gas temperature which converts the vapor into a liquid for easy collection.
After the separation of natural gas and NGLs, the process of fractionation takes place using a piece of machinery called a fractionator train. At this stage, NGLs are divided up into individual compounds needed for specialized products.
Skilled Engineers Are Required
The work of skilled and well-trained plant process engineers is vital to the effective, efficient, and most importantly safe production of oil and gas. Engineers will work in teams to design, install and monitor the equipment and systems in a natural gas refinery.
How Can the Process Be Improved
One stage in the production that may be considered for improvement is the process of absorption, the removal of water vapor from natural gas using dehydrating agents which may be harmful to the environment, however dry desiccant dehydrators provide a greener option for dehydrating natural gas.
Another consideration for the future of plant process systems is cybersecurity. Although computers make oil and gas plants safer, more efficient, and easier to manage, however since most plant process systems connect to the Internet there are security risks engineering companies need to be aware of. To mitigate the risk of getting hacked, engineering companies often promote the use of closed networks and strong security measures.
The installation of a plant processing system used in the production of natural gas and oil products is a mammoth task requiring lots of planning, high-grade industrial equipment, teams of engineers, and lots of capital. Plant process systems are crucial to producing the sources of energy we need, however, companies are continuing to look for improvements in efficiency and reductions in environmental impacts.