**2.4 Transport**

246 Fossil Fuel and the Environment

making its separation more feasible. As a result, the oxy-combustion process must be associated with at least one of the other separation processes. The Figure 9 shows a diagram

The Carbon Capture and Low Emission Coal Research program mandated by the American Recovery and Reinvestment Act (ARRA), signed into law by President Obama in February 2009, calls for investment of US\$ 3.4 billion for research aimed to make burning or gasification of coal an activity with low GHG emissions. One of the simplest ways to modernize a coal power plant is to introduce O2 separation units to feed the

The objective of dehydration is to reduce the level of moisture of the CO2 as much as possible so that it will be less prone to cause erosion in the mechanical elements involved in

To be transported, CO2 needs to be compressed. The compression range depends on how it will be transported. For pipeline transport, the CO2 needs to be compressed in the range between 1100 and 3100 psi to assure single phase flow, because above 1100 psi, CO2 remains in single phase within a broad range of temperatures. Since pipelines are subject to great temperature variations, it is important to avoid the formation of two phases, which can

The pressure required is much lower for transport in tank trucks, railcars or ships, because the temperature can be kept low through thermal insulation, something that is uneconomic in the case of pipelines. Therefore, pressures of 250 to 400 psi are sufficient to keep the CO2

of oxy-combustion system in a pulverized coal power plant.

Fig. 9. Oxy-combustion system in a pulverized coal power plant

cause pressure spikes that can in turn rupture pipes (Barrie et al., 2004).

burners of the boilers.

Source: Alstom Power (2011)

**2.2 Dehydration** 

the injection process.

**2.3 Compression** 

in the liquid phase.

As indicated above, there are four ways of transporting CO2 between the emission source and the underground injection site:


Of these four transport means, only pipelines are viable for EOR projects, where the distances can run into the hundreds of kilometers and the volumes of CO2 are in the millions of tonnes per year. This high carrying capacity compensates for the high costs of building, maintaining and operating a carbon pipeline.

Because of the high initial investments and operating expenses of a carbon pipeline and the large damages that could be caused by a rupture, as well as the fact it may cross land held by many owners, special attention must be given to the commercial, legal and insurance aspects to minimize the economic risks. Suppliers and consumers of the CO2 carried by pipeline along with the line operator must participate in detailed multilateral agreements with well-defined rights and obligations. The other types of transport are feasible for industrial processes that use CO2 as an input, in cases where the quantity is small and does not compensate the cost of building and operating a pipeline and/or when the production and consumption sites are very close.
