J.S. Li

Multi-regional input-output analysis for China’s regional CH4 emissions

China is the largest CH4 emitter in the world. Given the importance of CH4 in greenhouse gas emission inventories, the characteristics of China’s CH4 emissions at different scales deserve to be fully understood. Presented in this paper is an interprovincial input-output embodiment analysis of China’s regional CH4 emissions in 2007, based on the most recently available multi-regional input-output table, and relevant CH4 emissions data. The results show that the eastern, central and western areas contribute to 48.2%, 28.6%, and 23.3% of the national total embodied emissions, respectively. Guangdong has the highest level of embodied CH4 emissions among all of the 30 regions. The Agriculture sector produces the most embodied CH4 emissions in final demand, followed by the Construction, Food Production and Tobacco Processing, and Other Service Activities sectors. Significant net transfers of embodied CH4 emission flows are identified from the central and western areas to the eastern area via interregional trade. Shanxi is the largest interregional exporter of embodied CH4 emissions. In contrast, Guangdong is the largest interregional importer. Energy activities, agricultural activities, and waste management comprise 65.6%, 30.7%, and 3.7% of the total embodied CH4 emissions in interregional trade, respectively. By using consumption-based accounting principles, the emission magnitudes, per capita emissions, and emission intensities of most eastern regions increase remarkably, while those of some central and western regions decrease largely. To achieve regional CH4 emission mitigation, comprehensive mitigation measures should be designed under consideration of regional transfer of emission responsibility.

Local-scale systems input-output analysis of embodied water for the Beijing economy in 2007

Using the most detailed and recent statistics available for Beijing, a local-scale embodiment analysis on water use was conducted, employing a systems input-output analysis that integrates economic systems with natural resources data. Systems analysis for water research at the local scale is a crucial part of a systems oriented water accounting framework. To our knowledge, however, related works have not been thoroughly conducted. In this paper, a set of embodied water intensity inventory data is presented, which is applicable to both intermediate input and final demand. Also, detailed analyses of Beijing’s embodied water use accounting are presented. The embodied water intensity of the Water Production and Supply Industry Sector turns out to be the highest among the 42 sectors. For water embodied in final demand, the total amount is 3.48 km3, of which the water embodied in urban household consumption makes up nearly a half proportion. As a net virtual water importer, Beijing’s water embodied in commodity trade totals 5.84×108 m3. As a result, in addition to improvements in technology and water use efficiency, adjustments in industrial structure and trade policies are also of significant importance to water conservation efforts.

Energy-dominated local carbon emissions in Beijing 2007: inventory and input-output analysis.

For greenhouse gas (GHG) emissions by Beijing economy 2007, a concrete emission inventory covering carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) is presented and associated with an input-output analysis to reveal the local GHG embodiment in final demand and trade without regard to imported emissions. The total direct GHG emissions amount to 1.06E + 08 t CO2-eq, of which energy-related CO2 emissions comprise 90.49%, non-energy-related CO2 emissions 6.35%, CH4 emissions 2.33%, and N2O emissions 0.83%, respectively. In terms of energy-related CO2 emissions, the largest source is coal with a percentage of 53.08%, followed by coke with 10.75% and kerosene with 8.44%. Sector 26 (Construction Industry) holds the top local emissions embodied in final demand of 1.86E + 07 t CO2-eq due to its considerable capital, followed by energy-intensive Sectors 27 (Transport and Storage) and 14 (Smelting and Pressing of Ferrous and Nonferrous Metals). The GHG emissions embodied in Beijings exports are 4.90E + 07 t CO2-eq, accounting for 46.01% of the total emissions embodied in final demand. The sound scientific database totally based on local emissions is an important basis to make effective environment and energy policies for local decision makers.

The rise of South–South trade and its effect on global CO 2 emissions

Economic globalization and concomitant growth in international trade since the late 1990s have profoundly reorganized global production activities and related CO2 emissions. Here we show trade among developing nations (i.e., South–South trade) has more than doubled between 2004 and 2011, which reflects a new phase of globalization. Some production activities are relocating from China and India to other developing countries, particularly raw materials and intermediate goods production in energy-intensive sectors. In turn, the growth of CO2 emissions embodied in Chinese exports has slowed or reversed, while the emissions embodied in exports from less-developed regions such as Vietnam and Bangladesh have surged. Although China’s emissions may be peaking, ever more complex supply chains are distributing energy-intensive industries and their CO2 emissions throughout the global South. This trend may seriously undermine international efforts to reduce global emissions that increasingly rely on rallying voluntary contributions of more, smaller, and less-developed nations.The rapid growth of South–South trade reflects a new phase of globalization. Here the authors show that some energy-intensive production activities, particularly raw materials and intermediate goods, and related CO2 emissions are relocating from China and India to other developing countries.

Comparison of greenhouse gas emission accounting for a constructed wetland wastewater treatment system

Abstract The method of systems accounting as a combination of process analysis and input–output analysis is applied to assess the greenhouse gas (GHG) emissions of Longdao River constructed wetland (LRCW), a typical constructed wetland in northern China. An improved GHG emission assessment for the constructed wetland wastewater treatment is made in this paper by using a local embodied GHG emissions intensity database for the Beijing economy 2002. Results show that the indirect GHG emission of the case constructed wetland accounts for 82.31% of the total GHG emissions. More than half of the indirect GHG emission is caused by the electricity. 64.48% of the total GHG emissions happened during the operation stage. There is a great gap between the GHG emissions of the LRCW in this study and in former study, which can be attributed to the diverse economy structures and technology levels of Beijing economy and Chinese economy.

Influence of torrefaction with Mg-based additives on the pyrolysis of cotton stalk

The study presented an approach to introduce Mg-based additives into cotton stalk for strengthening deoxygenation effect during torrefaction. Then catalytic pyrolysis of torrefied feedstock with Mg-based additives residue as catalyst was performed at 550 °C for 10 min in a fixed-bed reactor. The effects of torrefaction temperature (200, 230, 260, 290, 320, 350 °C), type of Mg-based additive (MgO and MgO-K2CO3), mass ratio of additive to biomass (0.5, 1 and 2) on pyrolysis were investigated. The results indicated that yields of bio-char and bio-oil significantly increased and decreased with torrefaction temperature rising to 350 °C. MgO inhibited pyrolysis bio-char yield increase with torrefaction severity. MgO-K2CO3 increased H2 yield a lot from 1.39 to 3.67 mmol/g. It also effectively improved the aromatic hydrocarbons in bio-oil and the reduction of acids. A maximum aromatic hydrocarbons yield of 16.05% was obtained with MgO-K2CO3 (the mass ratio of 0.5:1) at torrefaction temperature of 320 °C.

Inventory of CO2 emissions driven by energy consumption in Hubei Province: a time-series energy input-output analysis

Based on an input-output analysis, this paper compiles inventories of fuel-related CO2 emissions of Hubei economy in the years of 2002, 2005, and 2007. Results show that calculated total direct CO2 emissions rose from 114,462.69 kt (2002) to 196,650.31 kt (2005), reaching 210,419.93 kt in 2007, with an average 22.50% rate of increase. Raw coal was the dominant source of the direct emissions throughout the three years. The sector of Electric Power, Heat Production, and Supply was the main direct emissions contributor, with the largest intensities observed from 2002 (1192.97 g/CNY) to 2007 (1739.15 g/ CNY). From the industrial perspective, the secondary industry, which is characterized as manufacture of finished products, was still the pillar of the Hubei economy during this period concerned, contributing more than 80% of the total direct emissions. As a net exporter of embodied CO2 emissions in 2002 and 2007, Hubei reported net-exported emissions of 4109.00 kt and 17,871.77 kt respectively; however, Hubei was once a net importer of CO2 emissions in 2005 (2511.93 kt). The CO2 emissions embodied in export and fixed capital formation had the two leading fractions of emissions embodied in the final use. The corresponding countermeasures, such as promoting renewable and clean energy and properly reducing the exports of low value added and carbon-intensive products are suggestions for reducing CO2 emissions in Hubei.

Embodied exergy-based assessment of energy and resource consumption of buildings

As an effective approach to achieve a more unified and scientific assessment, embodied exergy-based analysis is devised to assess the energy and resource consumption of buildings. A systematic accounting of the landmark buildings in E-town, Beijing is performed, on the basis of raw project data in the Bill of Quantities (BOQ) and the most recent embodied exergy intensities for the Chinese economy in 2007 with 135 industrial sectors. The embodied exergy of the engineering structure of the case buildings is quantified as 4.95E + 14 J, corresponding to an intensity of 8.25E + 09 J/m2 floor area. Total exergy of 51.9% and 28.8% are embodied in the steel and concrete inputs, respectively, due to the fact that the case buildings are structured of reinforced-concrete. The fossil fuel source (coal, crude oil, and natural gas) is predominant among four categories of natural resources (fossil fuel, biological, mineral, and environmental), accounting for 89.9% of the embodied exergy, with coal as the dominant energy resource (75.5%). The material accounts for 89.5% of the embodied exergy, in contrast to 9.0%, 1.4%, and 0.1% for manpower, energy, and equipment respectively. This result indicates that great attention should be given to the use of various materials vs. their value of their contribution.