10.4 Direct connection optimization

The different scenarios for development of a direct connection between an emitter and sink were presented, but not yet compared to each other. To illustrate the impact of the discussed variables, distance and capacity, the scenario with the lowest cost is presented in Table 29 for different combinations of onshore transport distance, offshore transport distance and capacity.

Table 29: Configuration comparison for different capacities

The influence of capacity on the selection of the preferred configuration is limited. Although the impact on the actual cost per tonne CO₂ transported decreases with increased capacity. The main conclusion is that for longer distances ship transport is preferred, both onshore as offshore. The application of barge or ship transport of liquefied CO₂ is competitive to pipeline transport, not only on flexibility, but also on costs at transport distances of approximately 150 – 200 kilometers (see Figure 79 and Figure 80).

Checks have been performed with pipeline systems with only a 10 instead of a 100 bar pressure drop: the outcome was identical meaning that apparently the lower compressor costs compensated the high pipeline costs.

For the specific case of injection of CO₂ in depleted reservoirs in the Dutch waters of the North Sea, Figure 78 shows that the majority of these fields are located between 150 to 250 kilometers from the port of Rotterdam. Ship transport for these fields would be competitive to pipeline transport with regard to costs. This also shows that the location of the terminal is an important factor in the configuration of a CO₂ network.

Figure 78: Oil and gas fields in the Dutch area of the North Sea and their distance to the Rotterdam harbor

Distance intervals of 50 kilometers are used in this study. For industrial areas like the Rotterdam area, distances from the emitters to the terminal can be much shorter than the 50 kilometers taken here as the minimum. This is the reason that the “pipe → ship”-scenario is not in the results presented in Table 29. This configuration will be a competitive configuration for the Rotterdam area for cases where onshore transport distances are small.

Reviewing the cost for onshore and offshore transport by pipeline or by barge/ship is complicated, since it is very depending on the assumptions. In Figure 79 the transport costs for barge and pipeline serviced emitters is presented. The cost include all assets and operational costs required to transport the CO₂ from the emitter to a terminal either by pipeline or barge. For pipeline transport the compression costs, drying and pipeline cost are included. For barge transport the liquefaction, barge, barge terminal and hub terminal costs are included. The results show that the preferred option is depending on capacity and distance, but breakeven distances for barge versus pipeline transport are around 200 km.

Figure 79: Barge versus onshore pipeline cost comparison

For offshore a similar comparison is done. The transport tariff for pipeline transport is very sensitive to transport distance and breakeven distances with ship transport are increasing with capacity. Included cost for shipping are the liquefier, hub, ship and offloading system. For the offshore pipeline costs the compression plant and pipeline are taken into account.

Figure 80: Ship versus offshore pipeline cost comparison