The shortfall in gas supply to production facilities on Trinidad’s Point Lisas Estate has been a topic of national discussion for the past few years. Energy Now caught up with some of the leaders of key Point Lisas plants to find out how these shortfalls have impacted on their operations.
Each of the petrochemical companies on the estate requiring natural gas for their production, negotiates a contract with the National Gas Company (NGC) for a daily contracted quantity. Plants are also designed to run at full capacity and therefore the gas demand at full capacity usually corresponds to the daily contract quantity. However, curtailments have resulted in several companies receiving up to 15% reductions in their daily contract quantity.
NGC does provide quarterly forecasts to the companies to facilitate their production planning and budget forecasts. The companies on the estate, to get a better sense of the supply, update each other at their bimonthly Point Lisas Energy Association (PLEA) meetings on when there would be planned plant shut-downs or turnarounds for maintenance. NGC is also present at these meetings and the updates are factored into the company’s quarterly projections.
Charles Percy, Managing Director and President of Methanex’s operation in Trinidad, agrees that this gives a fair indication of what the supply would be like. However, this does not guarantee that supply will be what it is forecasted to be, since other unforeseen issues may arise to affect supply, including unplanned outages and issues with upstream production.
Operational issues coming out of gas curtailment exist, not necessarily because the gas is less than expected daily contract rate, but because of the variability in supply on a daily basis. Percy indicates that chasing methanol molecules in an environment of frequent plant rate adjustments appears to adversely impact catalyst performance. Catalyst deterioration shortens the time span between turnarounds and can increase turnaround costs by approximately 15%.
Similarly, Yara Trinidad President, Richard de La Bastide says that varying loads, stopping and starting plants, exposes equipment to cycles in pressure and temperature, accelerating wear and tear and also increasing costs due to unproductive gas consumed during start and stop sequences. De La Bastide goes on to say that since the plants operate at unfavourable efficiency levels at lower rates, unit production costs increase significantly. Also, the cycling of high pressure and high temperature equipment leads to higher maintenance costs.
Percy admits that when a plant is running at full capacity, it is in a stable state of operation. However, with variable gas supply, constant and more manual operator intervention is required to prevent plant trips. He notes that Methanex has managed to do this safely and have gotten a lot better at holding the plants steady in responding to plant rate change requests by the NGC.
Percy urges that something should be done now to deal with gas curtailment since there will be a lag time for additional gas to come into the system. He says that the quickest way to deal with the shortfall in gas in the short term is through cross-border gas. As consumers of natural gas, PLEA members are considering proposals to put forward to government and others on how to engage the Venezuelan government to help close the gap and bring some stability to the gas supply to the estate.