Industrial gases include wide range of products characterized by their gaseous nature at room temperature and pressure and are primarily used in their gaseous form though they may be stored in liquid form. In scientific terms a gas is defined as state of matter which having no definite shape or volume. The gases are also classified by factors such as temperature, volume and pressure. They are known to take the volume of their container or get evaporated back into the atmosphere. They tend to form mixtures with other gases and are very compressible.
The most commonly used industrial gases are nitrogen, oxygen, carbon dioxide along with noble gases such as argon, neon, xenon and krypton. Some of the industrial gases like nitrogen, oxygen and argon are liquefied for more efficient transportation and storage. However, these liquid gases might get transformed into solids on lower temperatures. For example, carbon dioxide, which is a gas at room temperature but turns solid at cryogenic temperature known as dry gas. Some of the gases are very volatile so require specialized equipment and handling for their safe application.
Industrial gases are supplied by suppliers in both gaseous as well as liquid form. The suppliers also provide the customers with storage and other equipment needed for transportation and safe application. The equipment will typically include storage tanks, vaporizers and pressure vehicles such as cylinders and tanks. All these pressure devices are equipped with the means of controlling pressure and temperature.
How gases are stored and delivered?
The gases need to held in an air-tight container and be readily available for use at client site. There is no denying the fact that delivery is very important which includes transportation. Every detail must be in compliance with system requirements and safety standards validated by acclaimed international bodies. Industries use a wide variety of storage vessels known as cryogenic cylinders, gas cylinders, gas bottles and big storage tanks. There are many industrial gas companies that also manufactures and supplies on-site gas generation systems for oxygen, nitrogen, argon and various other gases.
What is the process of oxygen or nitrogen gas systems for on-site generation?
For persons interested in starting industrial gas business the ideal option is to install an industrial gas generation system. If you are thinking of industrial or medical oxygen gas business you must determine the size of the oxygen gas plant as also finding a reputed oxygen plant manufacturer. Once you have decides the capacity and found a reputed manufacturer the rest is easy.
The plant manufacturer will provide you with all the relevant details. However, it would be better if you get yourself an oxygen gas plant project report for getting an excellent grip on the industrial gas market including market trends, feasibility, and new innovations. In the same way, nitrogen gas plant can be set up for distributing the industrial gas to your clients.
Here the discussion will remain confined to oxygen generation system for reasons of brevity:
- Pressure swing adsorption (PSA) and cryogenic distillation process
For generation of oxygen primarily two methods are used PSA and cryogenic distillation. Both of these processes are widely used in the industry for producing high purity oxygen for industrial and medical applications. Brief information about both the processes is given below:-
- PSA oxygen gas plant
PSA oxygen gas plant uses twin towers for air separation which are composed of molecular sieves filled with Zeolites. It is can be said to be a pneumatic system comprising filters, pressure regulator and valves where oxygen purity is constantly monitored by an automatic system.
Ambient air is passed through the molecular sieves where nitrogen gets stuck in the Zeolite while oxygen is allowed to pass through as a product gas. Nitrogen is sent back into the atmosphere through the silent escape. Some of the oxygen is used for desorption of nitrogen in one vessel while other vessel generates oxygen and then the vessels are revered for the process to continue.
- Cryogenic oxygen gas plant
Cryogenic distillation process starts with the intake of the ambient air into the air separation unit (ASU) where it goes through liquefaction, air separation and distillation. The air is filtered and compressed before it is passed into a purification unit for removal of impurities like water vapors, carbon dioxide and hydrocarbons.
After being purified, the air is passed through a series of heat exchangers where liquefaction takes place. Subsequently, the air is separated into oxygen and nitrogen in the high pressure distillation column. The product gas oxygen is then put in the low pressure distillation column for achieving the required level of purity.
How industrial gases are delivered?
There are numerous modes of delivering industrial gases like oxygen, nitrogen, argon, neon, etc. Mode of delivery would largely depend on the volume, that is, bulk gas will be delivered in cryogenic tanks or trailers where the gas is in liquid form. The gases are also delivered in high pressure gas cylinders. Gas pipelines are used for supply only if the point of use is nearby the gas production plant.
- Cryogenic tanks
Cryogenic tanks are bulk carriers of industrial gases in the liquid form. They are designed with cryogenic grade materials that can withstand extreme temperatures and pressures. These tanks are vacuum insulated with outer and inner vessels. While the outer shell of the tank has specialized coating and vacuum perlite system with molecular adsorbent for achieving insulation from the surroundings.
- Gas cylinders
Gases are also supplied through gas cylinders which are fabricated in compliance with internationally approved standards. High quality materials are used in their fabrication since they are used for storing gases at high pressures.
- Cryogenic Cylinders
These are designed for storing and transporting gases in liquid form. They are constructed with double walls with vacuum space between them. The walls facing the vacuum have silvered surfaces.
- Safe Delivery System (SDS)
SDS is a state of the art system especially designed for storing and transporting gases minimizing hazards and impact on the environment. The system is used for transporting highly toxic gases. Handling of the stored gases needs precaution.