One of the key aspects relating to the transportation of anthropogenic carbon dioxide (CO2) for climate change mitigation as part of Carbon Capture and Storage (CCS) schemes is the composition of the CO2 stream to be transported. The specification of this stream has both technical and economic implications and, as CCS schemes start to become realised, the requirement to specify the CO2 stream quality is becoming more important.The aim of this work has been to analyse the effects of the composition of the CO2 stream from post-combustion, pre-combustion and oxyfuel capture processes on the hydraulic network design and the relative costs of the network. Several key conclusions have been drawn to inform the process of specifying the CO2 purity and to guide pipeline operators on the specification of a CO2 stream, for dense phase pipeline operation, on the basis of hydraulic design.The analysis has shown that impurity additions up to 2mol% did not affect the relative cost/km for the networks when compared to a pure CO2 equivalent in terms of the pipeline internal diameter and length. However, the inlet pressure to the network is increased for all of the compositions studied and in this respect, levels of hydrogen in particular should be limited to less than 1mol% to reduce inlet pressure and thereby compression costs.It has been demonstrated that direct connection pipelines from source to sink are the most expensive network options however, when designing a pipeline network, the size of the emitters, the phasing of entry into the network and the stability of the network in the event of interruptions in flow needs to be considered

The impurities present in carbon dioxide (CO2) streams for Carbon Capture and Storage (CCS) schemes are extremely important for CO2 pipeline and ship transportation affecting, for instance, the range of operation, safety considerations, fracture, cracking, corrosion control, dispersion in the event of a release, fluid density, operating pressure and temperature and the quantity of CO2 that can be transported. The range and levels of potential impurities present in captured CO2 from CO2 capture facilities will differ between sources and also between the capture technologies installed at the CO2 emission sources. However, the potential CO2 specifications that could enter the transport and storage systems, particularly from industrial sources, remain relatively under-researched. Consequently, the effect of these potential impurities in CO2 streams on CO2 transportation also needs to be understood. This paper summarises the main findings of an IEAGHG study, “Impact of CO2 Impurity on CO2 Compression, Liquefaction and Transportation”, commissioned to identify potential impurities and address the consequences of their impact on CO2 transportation

We use the non-normalizable complex deformations to describe the stringy realizations of the metastable vacua in $\mathcal{N}=1$, $SU(N_c)$ SUSY theories with $N_f>N_c$ massive fundamental flavors. The consideration of the non-normalizable deformations requires a modified toric duality. The new approach considers the tachyon condensation between pairs of wrapped D5 branes and anti-D5 branes and the resulting mixing between some cycles in the geometry. We enlarge the class of metastable vacua to the case of branes-antibranes wrapped on cycles of deformed $A_n$ singularities.

The maritime industry will continue to see increasing regulatory requirements to reduce carbon emissions from ships’ operations. Improving the energy efficiency of ships with waste heat recovery systems based on the organic Rankine cycle (ORC) is an attractive way to meet these tightening requirements. The operational profile of a ship has a huge influence on the feasibility of installing ORC onboard as it affects the waste heat source profile from the diesel engines. However, to date, scant attention has been paid to examining the effects that the operational profile has on the marine application of ORC as it is both difficult and expensive to obtain. The present paper aims to describe a methodology that can overcome this problem by developing a generic ship speed profile that defines the ship’s operational profile. This speed profile works together with a fit-for-purpose diesel engine waste heat model to derive a waste heat source profile that is used as the input to a thermoeconomic analysis that can justify the installation of ORC. The proposed methodology allows for an objective comparison of the feasibility of ORC subjected to variations in the operational profile. Furthermore, the optimum ORC design can be identified to meet payback time expectations of different shipowners.