CNG or Compressed Natural gas is not new a thing anymore since all natural gas that are shipped by a pipeline are compressed. This is extensively used as fuel for transportation. It has more than 12 million vehicles for CNG worldwide that are in service. The ship transportation of this gas stored under pressure is called marine CNG. In this case, it is compressed mechanically. CNG does not require complex and expensive refrigerator compared to that of liquefied natural gas (CNG). The transportation of CNG results to having a more significant economic solution that is faster and easier to implement and permit. Other advantages of marine Compressed Natural Gas are the following:
Good economics, safe and reliable.
Small footprint at the both the unloading and loading places.
Can be utilized in a delivery/supply chain with liquid fuels, pipelines and LNG.
Using simple jetty or buoy system, flexible loading and unloading system is provided and cost effective.In order for the transport of CNG to take place, Coselle System is utilized. This system is combined with both loading and discharge facility. It also includes a number of purpose built, appropriately sized ships that utilize the system. With Coselle System that is designed specifically, project requirements are met. The components of this system includes the following:
1. Facilities for loading where gas is compressed, treated and transferred to the ship.
Loading onshore is achieved via jetty or pier.
Loading offshore is via FPSO or platform with a buoy.
2. Facilities for loading where the gas is discharged and decompressed.
Loading onshore of high and low pressure gas that will be carried out to a jetty or a pier.
Onshore loading of high and low pressure gas that will be carried to a buoy or a platform.
3. Facilities for storage
If necessary, it can be on a barge offshore.
4. Purpose-built fleet
Depending on the project parameters, the quantity and size will vary especially with the volume of the gas, marine environment as well as distance.
Using the Coselle System, customer off-take and immediate gas storage are provided. Each of the ships stays at the terminal. While waiting, the gas is being discharged or loaded using the system depending on the rate given by the customers. In order to meet the needs for a project, the fleet sized is optimized. In addition, to ensure that there will be no interruptions that would take place during the loading and delivery, shipping cycles have been designed. More reliability can be attained if desired by having more CNG storage by increasing fleet size in order to increase “slack” time or to increase ship size. Knowing the key features of Coselle System would help better understand the system. Some of its key features are the following:
It can accommodate wide range of gas composition.
Having no need for storage at the discharge or loading site since the ships can provide both transportation and storage, continuous delivery is achieved.