JSE-listed Renergen reported on May 3 that it was making “strong” progress in terms of the commissioning of Phase 1 of the Virginia gas project, which comprises exploration and production rights of 187 000 ha of gasfields across Welkom, Virginia and Theunissen, in the Free State.
Cold boxes – which are self-supporting structures that protect cryogenic equipment such as heat exchangers, core-in-drums, distillation columns, piping, valves and instrumentation – are currently being purged and pre-cooled using liquid nitrogen, which is an important process in preparing the units for acceptance of gas from the field in the coming week, the company said.
Renergen stated that a significant major advantage of using nitrogen to cool the system is that it simultaneously purges the system of any oxygen-rich air, which significantly reduces risks associated with fires during startup.
Further testing is under way as part of the commissioning process.
So far, the company had completed and commissioned fire protection, instrument air systems and various smaller subsystems. The conduction oil system was noted as the next major item to be completed for process unit startup.
“The team is being extremely thorough and diligent in making sure every step in the commissioning process is done correctly. A key focus area which has been successfully completed is the testing and retesting of the fire systems, particularly in light of all the recent plant failures globally.
“Seeing the plant at cryogenic temperatures is such an amazing sight, knowing that this is soon to become the first commercial plant of its kind in South Africa,” said Renergen CEO Stefano Marani on May 3.
The source of the Virginia gas project’s natural gas is primarily microbial. It originates from deep within the Witwatersrand Supergroup through groundwater circulating through large faults and contacting bacteria deep within the earth’s crust.
Therefore, the methane is a biogenic and a continuing renewable resource, Renergen said.
Virginia’s natural gas contains one of the richest helium concentrations recorded globally, while also being very pure with an average of more than 90% methane and almost zero higher alkanes, which reduces the complexity of liquefication.
Renergen’s strategy has been to expand the Virginia gas project in stages to produce liquid helium and liquefied natural gas (LNG).
Construction of the first stage, which encompassed connecting existing wells to a new gas pipeline and building a new helium and LNG plant, was needed before the company could cease compressed natural gas production and replace it with LNG.