Learnings

Outcomes

The project set out to demonstrate the benefits of a change to the current system of pneumatically driven pumps using own use gas which in turn is then vented to the atmosphere to electrically driven hydraulic diaphragm pumps. It is estimated that on average we vent 659,215 grams of carbon into the atmosphere per year just in odorant pumping activities. The project has demonstrated the functionally and resilience of the new equipment and we have made a start to reducing the amount of carbon vented into the atmosphere.

As the new electric pumping system is a lot less complex in its design with less parts, we have improved ease of maintenance, reduced maintenance costs and cut down time and related costs from alarms, faults, and callouts. Also, the new system also has a simpler and more accurate measuring system, so we believe a saving can be made on the amount of odorant used or at the very least we could be more precise about how much has been used, but this cannot be determined with the current running period and will be investigated fully over the winter months. However, the removal of the expansion tanks has drastically reduced the number of faults and callouts.

This electric pumping system from YZ Systems is new to the UK, it has been designed for today’s environmentally focused market to reduce carbon emissions and to bring ease of use and maintenance to the field. However, the use of electrically driven pumps has never been used for this type of application, and one of the aims of this project was investigate if we are swapping risk factors in the current system for others of equal, higher or lower risk. At present we haven’t seen any evidence of high-risk factors such as loss of power to the new pumps, and they have been operating within normal parameters. 

The pump itself has been specifically designed for the pumping of odorant and unlike the removed pumps has dual diaphragm redundancy built in which is a high cause of faults and so will limit process disruptions from single or even double pump failures. As the new system has only been in operation for a short time, this will be monitored as the system ages.

Currently our pumps are set to inject the same amount of odorant in every stroke, the amount of time between strokes is then varied according to the flow through site. This new design precisely calculates pump displacement and odorant usage and interfaces with the pipeline flow signal to maintain designed odorization rate by adjusting the stroke rate of the pump. This has improved accuracy of the amount of odorant injected and gives us greater visibility and monitoring capabilities.                                                                                                                     

The TRL of the project moved from 7 to 8     

Lessons Learnt

Hot-swap site works – A key objective of the project was to determine how to swap over the current LGT system with the new zero emissions system without stopping the site from flowing. The simplest and most cost effective approach was discovered to be removing the current system, relocate it on the site and utilise it as a temporary odouriser whilst installing the new system. This is possible due to the odourant saturation in the pipe which allows for a maximum of 7 hours of site flow without odourant injection. The saturation in the pipe will odourise the gas during this time. Within that 7 hour time it is feasible to remove the current LGT system, relocate it and have it up and running again as a temporary solution.

Global Supply Chain Issue – Due to the impacts of COVID the global supply chain is struggling to meet past lead times. For future projects it will be necessary to review delivery time scales.