• Energy Research

Abstract This manuscript attempted to analyze the influencing factors of coal consumption growth in China using the logarithmic mean Divisia index (LMDI) decomposition method developed based on the physical processes of coal utilization from raw coal to the end-use sectors. By mapping the energy allocation diagram of coal flows, we built a method to balance the energy allocation of coal flows and derived several technical influencing factors. These factors were used to develop an LMDI decomposition method suitable for analyzing the coal consumption growth of complex coal-use systems, such as that of China. The method is subsequently applied to analyze the influencing factors of China's coal consumption growth from 2001 to 2011. The results indicate the rapid growth of GDP (gross domestic production) per capita, which heavily relied on the expansion of heavy industry as the dominant factor driving coal consumption growth. Improvement in the energy efficiency of coal power generation and coal end-use combustion were the primary factors reducing coal consumption.

Malaysia is a rapidly developing country in Southeast Asia that aims to achieve high-income country status by 2020; its economic growth is highly dependent on its abundant energy resources, especially natural gas and crude oil. In this paper, a complete picture of Malaysia’s energy use from primary source to end use is presented by mapping a Sankey diagram of Malaysia’s energy flows, together with ongoing trends analysis of the main factors influencing the energy flows. The results indicate that Malaysia’s energy use depends heavily on fossil fuels, including oil, gas and coal. In the past 30 years, Malaysia has successfully diversified its energy structure by introducing more natural gas and coal into its power generation. To sustainably feed the rapidly growing energy demand in end-use sectors with the challenge of global climate change, Malaysia must pay more attention to the development of renewable energy, green technology and energy conservation in the future.

Abstract Coal–water slurry (CWS) preheating vaporization technology is an important new technology for the future development of Integrated Gasification Combined Cycle (IGCC) systems, providing an opportunity to improve the energy efficiency of wet feed gasification processes. This manuscript systematically analyzed the influence of integration of this technology on the energy efficiency performance of wet feed IGCC systems with or without carbon capture. We designed, simulated and compared ten cases of IGCC systems, including three wet feed IGCC systems with distinct integration modes for CWS preheating technology, one traditional wet feed IGCC and one dry feed IGCC as reference cases, all of which have one case with carbon capture and another case without carbon capture. The results indicate that, without carbon capture, the overall energy efficiencies of wet feed IGCC systems integrated with this technology are 1–5 percentage points (1%–5%) higher than that of the original wet feed IGCC system, depending on the integration mode. When carbon capture is introduced, the overall energy efficiencies of wet feed IGCC systems integrated with this technology are close to or even higher than that of the dry feed IGCC system.

The input–output table and input–output method have been widely used to understand complex economic structures and are often used in cross-disciplinary research between economics and other disciplines, such as analysis of embodied energy, carbon footprints, the water–food nexus, etc. However, when researchers present these results to audiences, especially policymakers, they often lack an effective visualization tool to present (1) the full picture of the input–output table; (2) the complicated upstream–downstream nexus, and (3) the input–output relationships between the economic sectors. Therefore, a better visualization method is developed to solve this problem. We propose mapping an input–output table into a Sankey diagram, a so-called monetary allocation Sankey diagram. We first designed the mapping structure of a monetary allocation Sankey diagram according to the general structure of an economic monetary input–output table to establish the correspondence nexus between the table and diagram. We used China as a case study to demonstrate the usage of the monetary allocation Sankey diagram. The purpose of the monetary allocation Sankey diagram is to help people understand the input–output table in a short time and quickly grasp the big picture of the economic system. To verify whether this goal is achieved, we presented and applied these Sankey diagrams on different occasions and obtained evaluations from scholars from different academic backgrounds. The evaluation shows that the monetary allocation Sankey diagram is not only a visualization result of the input–output table but also a miniature model of the economic system, which allows people to “truly observe” the complex input–output relationship and upstream–downstream nexus in the economic system. Researchers can quickly grasp the main features of the economic system by observing the miniature model, or they can use this miniature model as an auxiliary tool to introduce the economic system and its inherent complex relationships to the audience.

Abstract A new concept of ‘low-carbon towns’ (LCTs) has emerged in the urban planning and development of China in recent years to face the challenge of global climate change. This manuscript presents the current status, basic concepts, and town practices for the development of LCTs in China. First, we summarize the driving forces and regional activities for the development of LCTs in China; then, we introduce the town types and related programs. We propose the definition of a Chinese LCT and the main approaches to developing Chinese LCTs through a system analysis revealing what they are and how they may be developed in a Chinese context. The proposed approaches to develop Chinese LCTs include economic, social, layout, technology, and reuse approaches, each of which is introduced in the context of typical town planning and management in China.

Abstract China's power sector has experienced rapid development over the past decade. With the clean energy targets and carbon mitigation objectives proposed by the government as well as rapid development of power transmission infrastructure, future potential pathways for the expansion of China's power sector are worth assessing. In this paper, a mathematical model, named the Long-term Multi-region Load-dispatch Grid-structure-based (LoMLoG) has been developed and a “most-likely” scenario has been created that delivers insights into optimal regional power generation, transmission and emissions profiles. The results confirm the importance of clean energy targets in driving deployment of renewable energy and maximizing its contribution to carbon mitigation of China’s power sector. In addition, the development of power transmission infrastructure will significantly influence regional power generation and transmission profiles. Last but not least, carbon mitigation approaches in the long term are discussed, and rational methods of allocating future carbon caps are presented.

Abstract The utilization scale of biomass solid densified fuel (BSDF) in China is still far from reaching the 2020 target of the national plan. Promoting the utilization of pellet fuel from corn straw (CSPF) is an effective way to increase the utilization of BSDF considering its resource potential and convenience for distributed use. To enhance scientific support for the corresponding policy research, this manuscript presents a life cycle assessment (LCA) and economic evaluation of CSPF through a case study in Jilin Province. The results indicate that the utilization of CSPF in this case study can eliminate 90.46% of the life cycle GHG emissions by replacing coal burning. A CSPF project designed with a production capacity of 50,000 tons/year based on corn straw resources of five neighboring villages can be economically viable, but a smaller project with a capacity of 10,000 tons/year based on corn straw resources of a single village will have a poor economic outcome. Further encouraging the use of CSPF among industrial and commercial users and applying carbon trading mechanism for CSPF projects can effectively improve the economy of smaller projects to further promote the deployment of CSPF technologies.

Greenhouse gas emissions in China have been increasing in line with its energy consumption and economic growth. Major means for energy-related greenhouse gases mitigation in the foreseeable future are transition to less carbon intensive energy supplies and structural changes in energy consumption. In this paper, a bottom-up model is built to examine typical projected scenarios for energy supply and demand, with which trends of energy-related carbon dioxide emissions by 2050 can be analyzed. Results show that low-carbon technologies remain essential contributors to reducing emissions and altering emissions trends up to 2050. By pushing the limit of current practicality, emissions reduction can reach 20 to 28 percent and the advent of carbon peaking could shift from 2040 to 2030. In addition, the effect of electrification at end-use sectors is studied. Results show that electrifying transport could reduce emissions and bring the advent of carbon peaking forward, but the effect is less significant compared with low-carbon technologies. Moreover, it implies the importance of decarbonizing power supply before electrifying end-use sectors.