Role of CCS in a New International Climate Regime

AbstractThis paper examines the role of CCS in a new post-2012 international climate regime. Instead of the traditional 450ppm equilibrium stabilization of IPCC, a new scenario based on zero-emission and overshoot schemes was proposed recently. The scientific examinations demonstrated that the so called Z650 scenario could avoid long-term risks while meeting short term need of relatively large emissions. A numerical experiment of global energy system optimization shows the technical feasibility of the Z650 scenario not only globally but also regionally. The obtained time series total primary energy mixes suggest that the consumption of fossil energy will peak at 2030, and the clean energies, especially the renewable energy will play an essential role during the second half of the century. The resulted regional emission curves reflect the differences of financial and technical capability among areas. The industrialized countries will reduce their emissions by 50% in 2050 compared with 2005 levels, while the emissions of developing countries will increase by 10% at the same time. The cost-effective analysis based on the simulation results of the energy model shows that the Z650 scenario is economically rational. Compared with the reference case, the additional investments in Z650 scenario could be covered by the fuel savings during the following 40 years (2010-50) both globally and regionally. However, the comparison between the projection results and the national initiatives of major countries indicates that the policy measurements should be considered to promote the low carbon technology deployment and transfer. For this purpose, the existing CDM system should be enhanced on one hand, and a simpler and more efficient international scheme should be developed on the other hand.The emission reductions by sector in Z650 scenario compared with business as usual scenario indicates that CCS will be essential technology from 2030 on. It becomes the second contributing sector following the efficiency improvement both in demand and supply sides in 2050 by realizing approximate 27% of the total reduction. However, the limitation of geological sequestration capacity prevents CCS to contribute more during the second half of 21st century. Further evaluation of CCS is conducted through an additional scenario analysis in which CCS technology is not available. As a result in power sector, the share of fire power generation plant decreases remarkably. To cover the shortage, the photovoltaic plays the main alternative role up to 2050, and fuel cell becomes the key solution from then on. Less reduction contribution of power sector requests more reduction in transportation sector. As the result, more electric vehicles and fuel cell vehicles are necessary from earlier stages. Utilization of these expensive technologies destroys the cost-benefit balance that is obtained in Z650 scenario. Regional analysis suggests that the additional cost in developing countries is much more than that in industrialized countries. This experiment indicates the technological priority of CCS from economic viewpoint

Conformation of ultra-long-chain fatty acid in lipid bilayer: Molecular dynamics study

Ultra-long-chain fatty acids (ULCFAs) are biosynthesized in the restricted tissues such as retina, testis, and skin. The conformation of a single ULCFA, in which the sn-1 unsaturated chain has 32 carbons, in three types of tensionless phospholipid bilayers is studied by molecular dynamics simulations. It is found that the ultra-long tail of the ULCFA flips between two leaflets and fluctuates among an elongation into the opposite leaflet, lying between two leaflets, and turning back. As the number ratio of lipids in the opposite leaflet increases, the ratio of the elongated shape linearly decreases in all three cases. Thus, ULCFAs can sense the density differences between the two leaflets and respond to these changes

Conformations of Three Types of Ultra-Long-Chain Fatty Acids in Multicomponent Lipid Bilayers

Ultra-long-chain fatty acids (ULCFAs) are biosynthesized in certain types of tissues, but their biological roles remain unknown. Here, we report how the conformation of ULCFAs depends on the length and unsaturated-bond ratio of the ultra-long chains and the composition of the host bilayer membrane using molecular dynamics simulations. The ultra-long chain of ULCFAs flips between the two leaflets and fluctuates among three conformations: elongated, L-shaped, and turned. Furthermore, we found that the saturated ultra-long chain exhibited an elongated conformation more frequently than the unsaturated chain. In addition, the truncation of the ultra-long chain at C26 had little effect on the remaining ULCFAs. ULCFAs respond to lipid-density differences in the two leaflets, and the ratio of the elongated and turned conformations changed to reduce this difference. However, in cholesterol-containing membranes, ULCFAs exhibit no density difference after the flip–flop of cholesterol removes the difference

Conformations of Three Types of Ultra-Long-Chain Fatty Acids in Multicomponent Lipid Bilayers

Ultra-long-chain fatty acids (ULCFAs) are biosynthesized in certain types of tissues, but their biological roles remain unknown. Here, we report how the conformation of ULCFAs depends on the length and unsaturated-bond ratio of the ultra-long chains and the composition of the host bilayer membrane using molecular dynamics simulations. The ultra-long chain of ULCFAs flips between the two leaflets and fluctuates among three conformations: elongated, L-shaped, and turned. Furthermore, we found that the saturated ultra-long chain exhibited an elongated conformation more frequently than the unsaturated chain. In addition, the truncation of the ultra-long chain at C26 had little effect on the remaining ULCFAs. ULCFAs respond to lipid-density differences in the two leaflets, and the ratio of the elongated and turned conformations changed to reduce this difference. However, in cholesterol-containing membranes, ULCFAs exhibit no density difference after the flip–flop of cholesterol removes the difference