Capture Plant Installation

Explore each method in depth - benefits, limitations, plant and quality control on its own page.

Capture Plant Installation: step by step

1. 1

   Step 1: Fix the module split, the weights and the route

   Before fabrication starts, the project decides what gets built where. The module split is drawn against three things at once: what the technology licensor's process design needs to keep together, what the fabrication yard can build and load out, and what can physically reach the plot. That last one drives a full transport study covering quay capacity, road or barge route, bridges, culverts, overhead lines, junction geometry, headroom and the final approach through the host plant. Weights and centres of gravity are calculated properly rather than estimated, because the crane selection and the foundation design both depend on them. Once the split is agreed it is frozen, and the fabrication drawings, the foundation drawings and the lift studies are all developed from the same information. Changing it later means changing all three, which is why late module changes are among the most expensive decisions on a capture project.

2. 2

   Step 2: Receive, inspect and pre-assemble at the laydown

   Modules, columns, vessels and rack sections arrive over a period of months, usually by sea and then by road or barge, and every one of them is inspected on arrival rather than on paper. Transport damage, distortion, water ingress, missing loose items and damaged protective coatings are found now or they are found during commissioning. The laydown is run as a controlled operation with its own layout, its own lifting arrangements and its own storage requirements, since some items need protection from weather, some need preservation of internal surfaces and some need to stay upright. Pre-assembly work happens here too - joining rack sections, fitting items removed for transport, completing platforms and ladders at ground level rather than at height. Every hour of work done on the laydown is an hour not spent hanging off a column, which is the whole argument for doing it.

3. 3

   Step 3: Set the absorber and the tall columns

   The tall columns are the defining lifts of the project and they are planned as engineering exercises. A lift study covers the crane configuration, its standing position and ground bearing, the rigging, the tailing arrangement, the clearances to live plant and overhead services, and the wind conditions under which the lift may and may not proceed. The exclusion zone is agreed with the host plant, which often means shutting down or restricting parts of their operation for the duration. Foundations are re-checked against the as-built survey before the crane arrives, not after the column is airborne. The lift itself is the short part; the days around it are the difficult part - crane assembly, road closures, weather holds, and the fact that a large crawler crane parked in the middle of a retrofit plot blocks everybody else. Once set, columns are grouted, plumbed and released to the erection team.

4. 4

   Step 4: Land the equipment modules and skids

   Modules are moved onto their foundations by crane, by self-propelled transporters, or by a combination of the two, and the operation is rehearsed on paper in detail beforehand. Routes are checked for load capacity and clearance, jacking and skidding arrangements are designed, and the setting sequence is planned so that no module blocks access to the next one. Foundations, bolt groups and shim arrangements are checked against the as-built survey before the module is over them. Once landed, the unit is set to level, secured, grouted where the design calls for it and released so that the interconnecting work can begin. The tempo matters here: a well-planned module campaign runs as a repeating rhythm of deliver, position, set and release, and that rhythm is what makes the modular approach worth the design effort in the first place.

5. 5

   Step 5: Erect the pipe racks and the flue gas ducting

   The pipe rack is the spine of the plant and it goes up as the modules land, carrying process lines, utilities, steam, cabling and instrument routes between the capture island, the host plant and the compression area. Flue gas ducting is the other large-volume item and it surprises people - the ducts are big, they are structurally significant, they need their own supports and expansion arrangements, and they take up the space everyone assumed was free. Both are assembled from prefabricated sections lifted into place, joined and supported to the design. Supports, guides and expansion provisions are installed as drawn rather than adjusted to suit the fit, because they control how the system moves when it heats up. This is also the stage where the geometry between the new plant and the existing works has to be confirmed against reality, which is what the laser scan survey of the host plant was taken for.

6. 6

   Step 6: Take the tie-in during the host plant outage

   The tie-in is the one piece of work that genuinely cannot be rescheduled. Long before it, the connection points are surveyed, the new work is built up as close to them as safety allows, the spool pieces are fabricated and trial fitted, and every item, tool and person needed inside the window is staged and briefed. The host plant isolates, drains, cleans and hands over the connection points under their own permit and isolation procedures, and the working area transfers formally from operations to construction and back again. The work inside the window is planned hour by hour with a defined critical path and a contingency for the things most likely to go wrong. Inspection and testing of the new connections happens inside the window too, because handing back an untested joint is not handing back at all. When the plant restarts, the connection is either complete and proved or it waits for the next outage.

7. 7

   Step 7: Complete the mechanical works - bolting, insulation, cladding and tracing

   With the big geometry in place, the plant is finished off. Bolted joints are made up under a controlled procedure with records kept, because a joint that leaks in service on a process plant is a safety issue rather than a snag. Small-bore pipework, valves, drains, vents and sample points are installed to the drawings. Then comes the work that is always underestimated: insulation, heat tracing, cladding, painting, fireproofing and access platforms. There is a very large amount of it, it is labour-intensive, it is weather-sensitive and it sits directly on the critical path to commissioning because it cannot be completed until the pressure testing beneath it is done. Sequencing it against testing, rather than assuming both can happen at once, is one of the practical differences between a capture project that finishes on time and one that does not.

8. 8

   Step 8: Install the electrical, instrument and control systems

   The capture plant needs power, control, safety systems and a great deal of instrumentation, and most of it interfaces with systems the host plant already owns. Cable containment, tray, ladder and buried duct routes are installed, cables are pulled, terminated and tested, and field instruments are mounted, connected and calibrated. Detection systems for gas, fire and the specific hazards the designer has identified are installed to the layout drawings rather than to convenience, because their positions come from an assessment of where a release would actually go. The control system is configured, the loops are checked from the field device back to the screen, and the interfaces with the host plant's own control and protection systems are agreed, tested and documented with the operator. Getting this package finished properly is what allows commissioning to be a matter of proving the plant rather than finishing it.

How long does Capture Plant Installation take?

Typical duration: Typically 18-30 months from first delivery to mechanical completion on a full-scale retrofit, with the heavy lifts measured in weeks and the finishing trades measured in months..

Related processes

• Site Civils & Heavy Foundations
• Compression & Conditioning
• CO2 Transport Pipelines
• Injection Wells & Commissioning
• Modular - pre-assembled units built off site - method
• Stick-built on site - method
• Hybrid - modular skids with site-built interconnects - method
• Column erection - sectional or single lift - method
• Carbon Capture & Storage (CCUS) sector guide
• Utilities & Energy - group of sectors