The use of a alkaline hydroxide (Mg) can be utilised in an appropriate reactor to produce a carbonate in the presence of CO2. This effective sequestration technique could have large implications for National Grid's compressor fleet.
The programme will look to test the trial unit to validate the initial claims.
Benefits
The CCC technology has considerable potential for reducing CO2 emissions from NG’s compressor fleet.
Learnings
Outcomes
Progress 2018/2019:
The project is currently ongoing and still in the infancy of its progress, so no outcomes are currently delivered.
Progress 2019/2020:
The project has made some considerable progress over the last year; yet has faced several challenging issues. Several of these issues have led to the project being paused until the right course of action for the project can be decided. More details are listed further on in this report.
However, there have been some key accomplishments to date:
Following a selection matrix and numerous surveys, a candidate site has been chosen for the trial.
Site layout design is in a mature state.
Health, safety and environmental factors have been fully considered.
The demonstrator is in a part-built state.
HAZID & HAZOP studies have been started.
Technology Readiness Level
The technology readiness level (TRL) targeted at commencement of the project, TRL 7, requires a system prototype in an operational environment.
The technology remains at TRL 4 having been validated as a subsystem in a laboratory environment and not currently tested at scale on an operational site.
Closure 2020/2021:
The project has been ended early. By partly completing the design processes and reviews to National Grid standards, the interfaces, implications and challenges (safety and technical) have been more greatly understood.
Ultimately to continue the project would far exceed the original budget, especially with the vastly increased budget requirements for all the civil work required to comply with all environmental and safety regulations on a site National Grid share with a third party. This, coupled with a weakened business case for the adoption of this specific technology on an operational gas site, has resulted in the project concluding before all the outcomes could be delivered.
It is possible that a containerised carbon capture unit could be a viable solution to tackle a challenge such as emission levels on a smaller gas site, but upscaling the technology for use on larger scale sites such as compressor stations and the associated civils, logistics and power requirements would need comprehensive consideration prior to a project of this nature being developed in the future.
Lessons Learnt
Progress 2018/2019:
For future projects, which require Operational staff involvement, it would be best practice to engage them at the earliest opportunity. This main issue is due to availability of the operational personnel – the more notice we can provide them the better the chance of them being able to accommodate our requests. Operational staff are an extremely valuable resource to this type of innovation work and have provided a lot of constructive feedback which has helped influence the direction of the project to date.
Progress 2019/2020:
There have been a number of key lessons to date:
Design of site layout in parallel with the unit design and unit operation philosophies posed some challenges in terms of changing design requirements. Ideally a fixed unit design would have been used as a basis of design for the site layout. This would have reduced the uncertainty in the design required and therefore the number of site layout design iterations required.
Early stage construction cost estimates at the start of the project proved to be largely inaccurate considering the eventual evolution of the site design. This highlighted the challenge in estimating construction costs with an inherently unclear scope such as those faced at the start of an innovation project. Similarly, operational costs were not sufficiently allowed for in the project budget. For example, the cost of having SCO/91 competent personnel on site was not catered for and only became apparent after the safety studies.
Closure 2020/2021:
There have been a few additional lessons to the ones listed above:
Laser scanning proved to be useful tool for design and review purposes. The point cloud data obtained from the laser scan allowed the site to be modelled quickly and efficiently. Development and distribution of site models as Navisworks files proved to be a useful method of updating key project stakeholders and provided a useful visual aid during design review meetings.
It may be beneficial as a proof of concept to trial the demonstrator unit at a non-operational location first to test process and systems. This would in turn mitigate the issues with on-site perimetry and site modifications until the technology is proven at a larger scale.
