Ethylene is the premier building block of the petrochemicals industry. It is used in the production of polyethylene, ethylene dichloride, ethanol, styrene, glycols and many other products.
STORAGE AND HANDLING
Ethylene is usually stored as liquid at very low temperatures (around -103°C). Cryogenic tanks are commonly employed. Pipelines are frequently used to transfer ethylene. Liquid Ethylene is transferred by trucks as well. These tanks are made of stainless steel or carbon steel for low temperatures.
Molecular weight: 28.054 g/mol
- Melting point: -169.2 °C
- Latent heat of fusion (1,013 bar, at triple point) : 119.37 kJ/kg
- Liquid density (1.013 bar at boiling point) : 567.92 kg/m3
- Liquid/gas equivalent (1.013 bar and 15 °C (59 °F)) : 482 vol/vol
- Boiling point (1.013 bar) : -103.8 °C
- Latent heat of vaporization (1.013 bar at boiling point) : 482.86 kJ/kg
- Vapour pressure (at 5 °C or 41 °F) : 47.7 bar
- Critical temperature : 9.5 °C
- Critical pressure : 50.76 bar
- Gas density (1.013 bar at boiling point) : 2.085 kg/m3
- Gas density (1.013 bar and 15 °C (59 °F)) : 1.178 kg/m3
- Compressibility Factor (Z) (1.013 bar and 15 °C (59 °F)) : 0.9935
- Specific gravity (air = 1) (1.013 bar and 0 °C (32 °F)) : 0.974
- Specific volume (1.013 bar and 21 °C (70 °F)) : 0.862 m3/kg
- Heat capacity at constant pressure (Cp) (1.013 bar and 15 °C (59 °F)) : 0.042 kJ/(mol.K)
- Heat capacity at constant volume (Cv) (1.013 bar and 15 °C (59 °F)) : 0.034 kJ/(mol.K)
- Ratio of specific heats (Gamma: Cp/Cv) (1.013 bar and 15 °C (59 °F)) : 1.242623
- Viscosity (1.013 bar and 0 °C (32 °F)) : 0.0000951 Poise
- Thermal conductivity (1.013 bar and 0 °C (32 °F)) : 16.83 mW/(m.K)
Solubility in water (1.013 bar and 0 °C (32 °F)): 0.226 vol/vol
Auto ignition temperature: 425 °C
Vapour Pressure Graph: The vapour pressure curve may be obtained from vapour pressure graph . On the graph, pressure is in bar or 0.1 MPa, temperature in K or °C. The critical point is indicated by a black spot on the liquid-vapour equilibrium curve.
Storage and Transportation of Liquid Ethylene:
Handling and Transportation guide for Ethylene is followed for above purpose.
Liquid Ethylene Storage Tank:-
We provide a variety of quality tanks and equipment including aboveground ethylene tanks.
Ethylene storage tanks of various capacities ranging from 500 Liters to 500,000 Liters.
Export of Ethylene storage tanks including competitive prices, reliable delivery, and friendly service of our team of experienced technicians, drivers, and knowledgeable customer support staff.
The unit comes with all safety features as per norms. The tanks are provided with all accessories like safety fittings, valves, pipelines etc.
Type: vertical and horizontal
MOC: Stainless steel or low temperature Carbon steel
Design code: ASME Sect VIII Div1 or 2, AD Merkblatter, PD5500, TEMA, DOT any many others
Ethylene tanks are Puf Insulated with of 250mm with 20 gauge aluminium sheet barrier or vacuum insulated tanks. Liquid Ethylene transfer pump with piping for loading and unloading of Liquid Ethylene from plants to customer storage tanks pressure temperature indicators process piping valves and fittings Differential pressure liquid level indicator to indicate liquid level in mm WC. We are providing safety valves with isolation or diverter valve as an essential tank for safety.
The vacuum insulated liquid Ethylene Storage Tank is available in different sizes. Inner tank is stainless steel and outer is carbon steel with vacuum and perlite in annular space
Large Liquid ethylene storage tanks are designed as a single wall flat bottom tank without a roof, Outer tank is a flat bottom tank, and Roof is a domed steel roof supported on the outer tank wall with a suspended deck for the Insulation.
Liquid Ethylene Transport Tank:-
Liquid ethylene transport tank used for transportation of liquid ethylene from one place to other. These tanks are equipped with safety fittings, unloading pump, valves, and other accessories as per norms. The tanks are available in various sizes from 5kl to 50kl. A 200 mm thick PUF insulation is provided on tank to prevent evaporation of liquid.
Liquid Ethylene is transported from liquefaction plants to customer storage installations in large quantities through insulted transport tank system in low Pressure form. It mainly contains insulated coded vessels, similar to storage vessel with dimensions to suit particular vehicle model. All the valves, safety fittings, liquid transfer pumps and other instruments are housed inside of a lockable back cabin. The necessary approval and documentation is provided including mounting arrangement to get statutory approval of road transport authorities. The capacity ranges from 1 MT to 25 MT depending upon customer requirement and vehicle model selected.
Puf Insulation of 200mm with 20 gauge aluminium sheet barrier or vacuum insulated tanks.
Liquid Ethylene transfer pump with piping for loading and unloading of Liquid Ethylene from plants to customer storage tanks , pressure temperature indicators , process piping , valves and fittings Differential pressure liquid level indicator to indicate liquid level in mm WC. We also provide safety valves with isolation or diverter valve as an essential tank for safety.
Liquid Ethylene Spherical tanks:
For storage of large volumes of Liquid Ethylene we provide Spherical tanks of various capacities ranging from 500m3 Liters to 5000 m3 and above as per customers requirement . The vessel comes with all safety features as per norms. The spherical tanks are provided with all accessories like safety fittings, valves, pipelines etc.
MOC: Stainless steel or low temperature Carbon steel
Design code : ASME Sect VIII Div1 or 2 , AD Merkblatter , PD5500 , TEMA , DOT any many others
Ethylene spheres are PUF Insulated with of 200mm to 300mm with 20 gauge aluminium sheet. Liquid Ethylene transfer pump with piping for loading and unloading of Liquid Ethylene from plants to customer storage tanks pressure temperature indicators process piping valves and fittings Differential pressure liquid level indicator to indicate liquid level in mm WC. We are providing safety valves with isolation or diverter valve as an essential tank for safety.
We supply complete Ethylene plants with complete design, Drawings, P&I diagrams, Process drawings, using this technology you can achieve high reliability; trouble-free start-ups; long run-lengths; and high on-stream factors. These advantages minimize start-up costs, maximize production, ensure high profitability .FEA analysis of key components on tank including civil is also carried out for additional safety.
COMPARISON BETWEEN VACUUM INSULATED AND PUF INSULATED LIQUID ETHYLENE TANKS:
The PUF insulated Ethylene storage tanks have had an excellent history of durability and service.
The PUF insulated tanks are easy to repair and maintain with least repair cost and downtime
Easy to maintain with less maintenance cost
Less capital cost
Easy to install
PUF insulation of 8” thickness gives insulation property as good as vacuum insulated tanks
Ethylene tanks must maintain pressure between 17 to 27 bar for Ethylene storage. When Ethylene is drawn from the tank, lot of heat is also removed thereby lowering the temperature and pressure and this removal to heat must be replaced to maintain proper working pressure. Due to the increased insulation value on vacuum insulated tanks there is very little heat entry. Hence a vaporizer is required to maintain the proper operating pressure. If the pressure inside the unit is allowed to drop below critical level as indicated in the temperature –pressure curve the product can go in critical zone and can be dangerous. The unit will then have to be removed from service for a prolonged period of time to allow pressure to return to normal operating conditions. In this type of application, the heat entry into PUF insulated tanks can be very helpful.
As regards vaporizers and refrigeration systems the same is required for both PUF insulated Ethylene tanks as well as vacuum insulated Ethylene tanks. It is misinformation to say that either PUF or vacuum insulated ethylene tanks will never require a vaporizer or refrigeration system. Most importantly, the application and frequency of usage and amount of product withdrawn will determine the best type of insulation and accessories required.
Several factors should be taken into consideration, when determining the type of units. (1) Where space is limited, vertical Ethylene tanks are more readily accepted and where there are no limitations on space, horizontal Ethylene storage tanks are more economical choice. Ethylene storage tanks are generally only available in sizes from 5 tons up to 200 tons capacity.
PUF insulated Ethylene storage tanks are manufactured with a manhole and allows complete flexibility to add refrigeration if it is ever required. There has been misinformation stating that all urethane Ethylene storage tanks require a refrigeration system. For applications where vapour or a large amount of liquid Ethylene is withdrawn on a regular basis, no refrigeration system is required. External refrigeration system for those Ethylene storage tanks without an evaporator coil inside the unit are very easy to install, safe to operate and maintain
Both PUF and vacuum insulated Ethylene storage tanks have a carbon steel vessel or stainless steel construction. These pressure vessels are manufactured in compliance with various international design code like ASME SECT VIII DIV 1 , ASME SECT VII DIV 2 , PD 5500, CODAP 2000, TEMA, AD MERKBLATTER etc.
The maintenance on PUF and vacuum insulated Ethylene storage tanks differs. If a vacuum insulated unit loses its vacuum, the leak must be located and repaired and a new vacuum must be pulled on the unit. The downtime will vary depending on the extent of damage and the time required to locate the leak, make the repairs and pull a new vacuum on the unit. In most cases, on site repairs can be made. If the exterior of aluminum jacketed PUF Ethylene storage tank is damaged, the repair can be made locally with no downtime. If the outer jacket is not repaired, the insulation will eventually become saturated and the unit will have to be reinsulated.
In case of Ethylene transport tanks PUF insulated tanks have comparatively lesser dead weight as compared to Vacuum insulated tanks and so they carry more products and the payload is increased.
There is a place in today's market for both urethane and vacuum insulated Ethylene storage tanks. The customer should evaluate their particular needs and determine what type Ethylene storage unit is best for their application.
Uses of Liquid Ethylene are as follows: