Abstract

It is a consensus of international community to promote the development of low carbon economy in order to face the challenges of climate change. According to the features of nuclear energy, the greenhouse gas (GHG) emission of nuclear energy chain and other energy chain are compared and analyzed, and the results indicate that the GHG emission of nuclear power chain is the least in all types of power generation. The status of nuclear power development and the potential benefit in GHGs emission reduction by developing nuclear power in China are also analyzed. Active nuclear power development is a smart choice for constructing low-carbon energy structure and for addressing global climate changes in China. Jiang, Z., 2011: Nuclear power development for greenhouse gas emission reduction in China. Adv. Clim. Change Res., 2 (2), doi: 10.3724/SP.J.1248.2011.00075.

Abstract

International shipping has finally set a target to reduce its CO2 emission by at least 50% by 2050. Despite this positive progress, this target is still not sufficient to reach Paris Agreement goals since CO2 emissions from international shipping could reach 17% of global emissions by 2050 if no measures are taken. A key factor that hampers the achievement of Paris goals is the knowledge gap in terms of what level of decarbonization it is possible to achieve using all the available technologies. This paper examines the technical possibility of achieving the 1.5° goal of the Paris Agreement and the required supporting policy measures. We project the transport demand for 6 ship types (dry bulk, container, oil tanker, gas, wet product and chemical, and general cargo) based on the Organization for Economic Co-operation and Development&rsquo s (OECD&rsquo s) global trade projection of 25 commodities. Subsequently, we test the impact of mitigation measures on CO2 emissions until 2035 using an international freight transport and emission model. We present four possible decarbonization pathways which combine all the technologies available today. We found that an 82&ndash 95% reduction in CO2 emissions could be possible by 2035. Finally, we examine the barriers and the relevant policy measures to advance the decarbonization of international maritime transport. Document type: Article

Abstract

Natural Gas (NG) leak may occur from either an above- or an under-ground pipeline, resulting in environmental and financial consequences. Although there are some relations for estimating the gas leak from an above-ground pipeline, there is no equation for the calculation of a buried pipeline leakage. The main objective of this work is to develop precise gas leak calculator equations for low- and medium-pressure buried pipelines. For this, an under-ground gas pipeline is numerically modeled considering the surrounding soil as a porous medium. Two- and three-dimensional models are used to investigate the gas leak through a hole intentionally made on the pipe. Pure methane, with a steady state, compressible and turbulent flow, is assumed through the pipe. The developed correlations are functions of the pipe diameter, the hole diameter, and the gas flow pressure. Comparison of the results with previous works in the field demonstrates that considering a one-dimensional model for the pipe and neglecting the length of the pipe after the hole causes up to 20% error. The results indicate that a two-dimensional model is not precise enough for estimating the gas leak from an under-ground pipeline (due to the soil resistance in three directions in a real situation). In addition, linear, second order and fourth order relations are observed between the amount of gas leak and the three effective parameters of the pipe entry pressure, the hole diameter, and the ratio of the hole diameter to the pipe diameter, respectively. Analysis of the results indicates that the relative difference between the results of the simulation and the results given by the developed correlations is within the range of ±7% for all cases.