On November 19 this year was officially opened a dew point of methane in Uniszki Zawadzkie, which belongs to the SPV UNIMOT SA. During the event, representatives of local authorities were present as well as quests from gas and liquid fuels industry and media.
The installation has its own connection to network of Gaz-System and is one of four natural gas liquefaction plants in Poland. The installation was built on the basis of compressors and operates according to Joula-Thomson gas liquefaction technology. In this process, part of gas is decompressed in a device called turboexpander and later cooled to very low temperatures. The cooled gas is then used to condense another portion of the gas flowing through the installation. This technology does not require an external supply of energy when it is used during the production process. Energy is required only for cooling the inlet gas and its tensioning in order to increase the power of condensation and numerous control and measurement devices. The source of Methane-rich gas which is used for the installation is the connection to network of Gaz-System.
Part of the system is also suitable for the production of CNG (compressed natural gas) with a capacity of up to 600 m3 / hr, used to supply end users within a distance of 200 km. The combination of two plants in one production process, will reduce costs and allow component parts to work more flexible.
Description of technological process
The main component of natural gas is methane. The composition includes also: ethane, propane and heavier hydrocarbons as well as nitrogen, oxygen, carbon dioxide and sulfur. During the liquefaction, natural gas must be purified from water and carbon dioxide, this step is required in order to prevent the formation of solid particles during cooling to a temperature of approx. -160 ° C. In consequence, LNG is a very clean gas and consists of 95% of methane and only 5% other components.
After purification, natural gas goes through the process line into heat exchanger where it is cooled to lower the enthalpy of the system. Next, at vapours pressure is being throttled in the orifice, then temperature is lowered and is performed partial condensatio. Condensed gas is directed to the cryogenic tank, where it takes direct loading into auto-tankers.
Thanks to its own natural gas liquefaction plant, the Company UNIMOT SA will increase the flexibility of its distribution. It will also make the company independent from external suppliers and it will be possible to supply our own regasification stations, which were launched this year in three different regions of the country. The collection of additional quantities of natural gas will improve the flexibility of the existing and newly constructed gas network and further the costs associated with the operation will be lower. The expansion of the gas distribution network will help in the future to gain new gas customers.
Estimated capacity of the instalation is the production of LNG in the amount of up to 750 kg per hour. Construction and assembly works related to the start-up lasted from May 2014 and the first condensations were made at the end of October.
