Pilot implementation of marine CNG technology is here considered to transport gas from Gresik facilities to a receiving point located in Lombok (about 300 Nautical Miles from Gresik). The gas will be utilized as feed gas to power plant in order to cope with peak electricity demand in the evening time (from 14:00 to 20:00) and, therefore, the gas shall be decompressed by pressure regulating system in order to fulfill pressure requirement at Lombok Power Plant.
Among all possibilities, compressed natural gas (CNG) technology seems to be an effective way for limited distance transport of gas like the case under exam. Technically this technology is quite easy to deploy and with limited requirements for facilities and infrastructure.
In the proposed project, gas from PLN line in Gresik will be taken from gas supply line and having a maximum forecasted availability of 40 MMSCFD. Gas should be compressed and transported to Lombok by means of CNG Carrier.
At the receiving/offloading point in Lombok, gas will be decompressed by a pressure regulating plant to fulfill pressure and temperature requirements, before it is delivered via pipeline to the power plant.
Gresik CNG Compression Plant processes gas from COMPANY pipeline to CNG ship and Power Plant. The gas is received from pipeline at a flow rate of 46 MMSCFD through 10” header at 22 barg and 30 °C. The plant is designed for 55 MMSCFD of maximum gas flowrate.
The gas flow to inlet gas scrubber (V-100), where gas and liquid are separated, this scrubber is also intended to trap any dirt material which may come with gas and potentially leading to scale or plugging the tube of downstream equipments. The gas coming out from the scrubber is passed to Gas Drier (D-100 A/B/C/D) and goes to metering (M-001). Gas drier will absorb any water content on the inlet gas so that the gas will suitable for further using at power plant. Outlet gas drier will be routed to Compressor package and around 1.4 MMSCFD of the gas from outlet Gas drier will be routed to fuel gas system.
The marine CNG transportation system will consist of the following main facilities:
- Electrical installation connecting to 6.3 kV and 380 V from electrical existing in Gresik with distance of about 1000 meter from CNG Plant
- Connection with existing pipeline in Gresik
- Compression station in Gresik
- CNG Storage in Gresik – as needed
- Gas supply from storage to existing power plant in Gresik for peaking operations
- CNG Carrier Loading Facilities
- CNG marine transportation by means of CNG Carrier(s)
- CNG Carrier Offloading Facilities
- CNG Storage in Lombok – as needed
- Decompression Station in Lombok
- Connection with Lombok Power Plant
- Remove and demolish piping, firefighting. oil pipe, metering system and accessories, electrical, instrument, etc.in Gresik
- Instrument & Control by PLC System for CNG storage in Gresik and unloading-storage in Lombok.