CO2 Emission Efficiency Research Articles

Direct injection internal combustion engine with high-pressure thermochemical recuperation – Experimental study of the first prototype

The paper describes, for the first time, experimental study results of a novel direct-injection (DI) internal combustion engine (ICE) with high-pressure thermochemical recuperation (HP-TCR) fed by methanol as a primary fuel. The reported system is the first ever working prototype of ICE with HP-TCR. A detailed description of the developed novel technology, physical and chemical processes in the system is presented. HP-TCR system performance is discussed and compared to the previously published study results of the same engine fed with artificially prepared reformate from compressed gas cylinder. HP-TCR demonstrates a significant improvement over the gasoline reference case with 19%–30% relative increase in indicated efficiency and reduction in NOx, CO, HC and CO2 emissions by up to 97, 91, 96 and 15%, respectively. The system performance shows a good prospect to continue the research towards an automotive-scale system development. Further performance improvement options are discussed as well.

Botanical biofilter for indoor toluene removal and reduction of carbon dioxide emission under low light intensity by using mixed C3 and CAM plants

Abstract Botanical biofilters are an interesting technology for indoor air pollution control. However, when growing plants under indoor air conditions with low light intensity (10–50 μmole PAR m−2 s−1), they seem to emit CO2 to the environment. In order to solve this problem, a combination of C3 and CAM plants might be able to decrease the level of CO2 emission and increase pollutant-removal efficiency. Therefore, an effective botanical biofilter with mixed plants was studied. The CO2 emissions from high benzene, toluene, ethylbenzene and xylene (BTEX) removal plants including Zamioculcas zamiifolia (facultative CAM), Dracaena sanderiana (C3), Chlorophytum comosum (C3), Euphorbia milii (CAM cycling), Sansevieria kirkii (CAM), and Sansevieria trifasciata (CAM) were investigated. C. comosum and S. trifasciata emitted very low CO2 under both light (50 μmole PAR m−2 s−1) and dark conditions. These two plant species (total leaf area of 500 cm2) were used in the botanical biofilter. The results showed that the botanical biofilter with a mixture of C. comosum and S. trifasciata plants could rapidly remove 1 m3 of 1 ± 0.2 ppm (3.9–4.7 mg m−3) toluene-contaminated air within only 2–3 h. In addition, the mixed plant system also showed low CO2 emission under both light and dark conditions. The combination of C3 and CAM plants offers an alternative method to limit CO2 emissions from a botanical biofilter under low light-intensity conditions.

Shadow price of CO2 emissions in Indian thermal power sector

This paper estimates production efficiency and shadow prices of CO2 emissions for coal-fired thermal power plants in India. It employs a unique sample of 56 power plants for 2000–2013 acquired primarily by invoking the Right to Information Act 2005. It estimates parametric quadratic directional output distance function using linear programming approach. We find that CO2 intensity of electricity generation could be reduced by about 16 and 23% if the power plants were made to operate efficiently. The estimated average shadow prices of US$ 14.54 and 18.68 for a ton of CO2 emission, depending upon a plant’s strategies for enhancing electricity and reducing CO2 emissions, reflect that the prevailing Clean Energy Cess of US$ 6.15 on a ton of coal or US$ 3.81 on a ton of CO2 emissions is not enough to induce the required emission mitigation. Significant variation in the estimates of shadow prices across the thermal power plants calls for use of economic instruments to reduce the emissions.

Industrial CO2 Emissions Efficiency and its Determinants in China: Analyzing Differences Across Regions and Industry Sectors

Industrial CO2 Emissions Efficiency and its Determinants in China: Analyzing Differences Across Regions and Industry Sectors

Measuring energy use and CO2 emission performances for APEC economies

Abstract This study proposes environmental DEA-based models to measure energy use efficiency, CO2 emissions efficiency, and an environmental-economic efficiency (EEE) for the Asia-Pacific Economic Cooperation (APEC) economies for the period of 2006–2010. In our models, population and total primary energy consumption are the two inputs, while GDP and CO2 emissions represent the desirable and undesirable outputs, respectively. Empirical results from 20 APEC economies showed that Australia, Brunei, Hong Kong, and Singapore were identified as efficient countries for five consecutive years from 2006 to 2010 in terms of energy use efficiency; as for CO2 emission efficiency, Brunei, Hong Kong, and Singapore were identified as efficient countries for the five consecutive years from 2006 to 2010. As far as EEE is concerned, most countries in APEC exhibited higher economic efficiency than environmental efficiency. Moreover, both energy use efficiency and CO2 emission efficiency were found to be significantly related to the EEE value (p

Energy and CO2 emissions efficiency of major economies: A network DEA approach

This study extends the analysis of energy and CO2 emissions efficiency of economies from the black box to a network structure analysis realizing the fact that each economy is a network of two divisions responsible for production and distribution of economic outputs. Hence, its economic and distributive efficiencies must be taken into account while analyzing the energy and CO2 emissions efficiency. In order to analyze energy and CO2 emissions efficiency of economies in terms of economic and distributive efficiencies simultaneously, we have innovatively applied network DEA model free link case under free disposability assumption for all undesirable outputs in both divisions of economies. The results are tantalizing as we have found that in aggregate 85% of energy consumption and 89% of CO2 emissions were just because of economic and distributive inefficiencies. Although none of the economies was overall efficient but a few were efficient in one of the two divisions. China was the largest user of excess energy because of economic inefficiency and the USA was the largest user of excess energy because of distributive inefficiency. We have suggested that inefficient economies not only need rightly directed taxation laws, incentives, and penalties but also need reforms in economic structures.

A Hierarchical SBM-Tobit Approach for Examining the Influencing Factors of Industrial CO2 Emission Efficiency in the Yangtze River Delta

As the most developed region, the Yangtze River Delta (YRD) has been one of the largest CO2 emitters in China. Chinese Government has proposed the concept of YRD urban agglomeration to improve its competitiveness. To this end, we evaluate industrial CO2 emission efficiency (ICEE) of 26 cities in YRD and its space-time distribution during 2006-2015 by applying SBM-undesirable model and the method of GIS visualisation respectively. Moreover, we used Tobit model to study factors influencing ICEE. The results are as follows: 1) ICEE of YRD increases in fluctuation during our study period; 2) there is a spatial cluster in the distribution of ICEE; 3) the proportion of industrial research and development funds to regional GDP (R&D), population size (PS) and the degree of opening up to the outside world (OPEN) positively influence the ICEE, while industrial energy structure (IES) and the actual use of foreign direct investment (FDI) negatively do.

Does major agriculture production zone have higher carbon efficiency and abatement cost under climate change mitigation?

Abstract In this paper we investigate the carbon efficiency and abatement cost for different main functional regions in China, to test whether major agriculture production zone has higher carbon efficiency and abatement cost than other functional regions. For this purpose, we use a global non-radial distance function to examine the efficiency and abatement cost of carbon emissions and take China’s Poyang Lake Ecological Economics Zone (PLEEZ), one of China’s national strategy for sustainable development, as an empirical study. By using the non-radial efficiency model, the carbon emissions efficiency indicator can be constructed. By employing the dual model of the non-radial directional distance function, the shadow prices of carbon emissions, which is interpreted as marginal abatement cost can be derived. County level data from 2009 to 2013 of the PLEEZ is used as the empirical investigation. Empirical results show that the CO2 emissions of the PLEEZ are not performing efficiently and the CO2 emissions efficiency remains at a very low level with an average value of 0.279. Meanwhile, the shadow prices of CO2 emissions are calculated, with a mean value of 11.867 yuan per ton, which is relatively low compared with other previous studies of different regions or industry and indicate that carbon emissions are not strictly regulated. Moreover, significant heterogeneities in the carbon efficiency and abatement cost are found among three major functional zones in the PLEEZ remain. Major agriculture production zone shows better carbon efficiency than key ecological function zone, but lower than key economic development zone. It is also found carbon abatement cost of major agriculture production zone is lower than key economic development zone indicating the less pressure under climate change mitigation.

Marginal abatement costs of CO2 emissions in the thermal power sector: A regional empirical analysis from China

Quantifying marginal abatement costs of CO2 emissions are beneficial to estimate mitigation potentials and costs of China's regional thermal power sector. Based on the panel data of 30 provinces from 2004 to 2013, this study estimates the technical efficiency, reduction potential, and marginal abatement costs of CO2 emissions from the thermal power sector in China using a parametric quadratic directional output distance function. A regression analysis is undertaken to identify the factors that drive marginal abatement costs. The main results are: (1)The mean value of directional output distance function in China's thermal power sector is 0.0449, indicating that inefficient production of Chinese thermal power sector accounts for 4.49%. CO2 emissions could be mitigated by accumulated 1.22 billion ton in the past ten year, which is approximate 4.49% of total CO2 emissions; (2)The national weighted average marginal abatement costs of CO2 emissions are 316.51 Yuan/ton which is far higher than carbon price in the current ETS (emission trading system) pilots in China, implying that carbon price does not inflect supply and demand of carbon allowance; (3)The regression results show that the marginal abatement costs positively connect with regional power scale, namely a 1% increase in power scale will result in a 13.8% increase. Technology level, coal supply and power structure are negatively correlated with marginal abatement costs, namely a 1% increase in technology level, coal supply and power structure will result respectively in a 30.41%, 4.38% and 77.7% decrease.

Carbon emission reduction potentials under different polices in Chinese cities: A scenario-based analysis

City is the core for carbon emission reduction. This paper examines CO2 emission efficiency and productivity in 286 Chinese cities under different production scenarios using a non-radial directional distance function approach. The examination is conducted via three scenarios, namely CO2 emission reduction (ER), emission reduction and energy conservation (EREC), and emission reduction, energy conservation, and economic growth (ERECEG). The results show substantial differences in total-factor emission efficiency and productivity across the three scenarios. We also found that total-factor emission efficiency varies considerably across regional and different-sized city groups. However, the distribution dynamics analysis provides strong evidence for the convergence of total-factor emission efficiency across Chinese cities in the long run. Efficiency change contributes of the majority of cross-city variation in productivity growth for the sample period. However, low average total-factor emission efficiency and large disparity in emission efficiency indicate great potential for future CO2 reduction. Regional development programs tend to drive economic activities into low CO2 emission performance regions. Our empirical findings provide valuable policy implications for achieving the joint targets of economic growth and CO2 emission reduction.

Investigating the learning effects of technological advancement on CO2 emissions: a regional analysis in China

Technological advancement plays a crucial role in CO2 emissions mitigation and has attracted great attention around the world. A multitude of literatures mainly focused on single technological impact on environmental issues at national level, while comprehensive studies concerning technological factors at regional level are rare. This paper employs environmental learning curve model to investigate the learning effects of different technological channels on CO2 emissions at the national and regional levels using panel data of China’s 29 provinces from 1997 to 2014. The technological advancement is disaggregated into indigenous research and development (R&D), foreign technology import and technological revolution. Furthermore, to comprehend the characteristics of various provinces with regard to CO2 emissions and emission efficiency, China’s 29 provinces are divided into four regions according to the features of “CO2 emissions-efficiency”. Empirically results manifest that technical renovation is the paramount driver to mitigate the national CO2 emissions. The CO2 learning abilities of indigenous R&D in high emissions regions are greater than those in the low ones, while boosting the investment of foreign technology import in low emission regions has significantly positive impacts on CO2 emissions, and the technical renovation is effective in abating CO2 emissions in all regions. The findings not only enrich technology innovation theories, but also deserve special attention from policymakers.

Integration of wheat-maize intercropping with conservation practices reduces CO2 emissions and enhances water use in dry areas

Crop intensification has been used as a mean to increase crop yield and secure food supplies in developing countries. However, issues about CO2 mitigation, water consumption, and the overall viability associated with the crop intensification have become a concern. The main objective of this study was to investigate how the yield related environmental factors, i.e. soil CO2 emission and crop water use would responsed to wheat-maize intercropping with conservation practices. Here we determined crop yield, plant biomass carbon, soil CO2 emission, and crop water use in various cropping systems. The field experiment was conducted at Wuwei Experimental Station in an arid oasis region (37°57′N, 102°37′E), in 2011 and 2012. Four tillage and crop residue options were applied to wheat-maize intercropping. They were (a) no-till with stubble standing (NTS), (b) no-till with stubble mulching (NTM), (c) reduced tillage with stubble incorporated into the soil (RTS), and (d) conventional tillage without stubble retention (CT). Averaged across two years, wheat-maize intercropping integrated with no-till and stubble mulching yielded 1.6tha−1 more grains and 7.1MJha−1 more energy, while emitted 1.2tha−1 less soil CO2 than conventional wheat-maize intercropping; at the same time, the system increased plant biomass carbon by 16%, and enhanced CO2 emission efficiency per unit of grain yield by 39%, compared with the conventional system. Also, the integrated system decreased soil evaporation by 11%, increased energy yield per unit of water by 19%, and lowered CO2 emission per unit of water by 9%. Among the wheat-maize intercropping systems evaluated, the treatment with no-till and crop residue mulched on the soil surface had the highest evaluation index at 0.82; this was attributable to the increases of carbon emission efficiency by 48% and water use efficiency by 22%, compared with the conventional system. Wheat-maize intercropping integrated with no-till and stubble retention can be used to increase crop yield efficiently while reducing soil CO2 emission and enhancing crop water use effectively in dry areas.

METHOD FOR ASSESSING OF PRODUCTIONS EFFICIENCY ON CO2 EMISSION MINIMIZATION WITH ACCENT ON POWER SUPPLY SYSTEMS

The paper develops the assessment methods of CO2 emission efficiency of the combined productions and the energy supply systems, and the ways of efficiency improvement. These methods allow determining the specific indicators of the supplied products, that makes it possible to compare the efficiency of productions and energy supply systems of the different companies and countries, and to define their future target indicators. The technique is suitable for the productions with any set of equipment. Practical application of the suggested efficiency criteria will contribute to the transition to the “green” energy and economy along the most effective trajectory of their modernization. Thus, we can rank the planned measures by the efficiency and the priority of implementation. The paper can be interesting to the power engineering specialists, businesspersons and economists, and participants of the UN Paris Climate Change Agreement to determine the future specific indicators of greenhouse gases emissions. The paper presents the innovative technology of introducing the wind power plants to the energy supply systems by means of using unstabilized wind-based power for direct fuel substitution in thermal cycles of combined cycle plants. As a result, fuel consumption and CO2 emissions are reduced. The wind power plants inclusion in the electric grid through the thermal power plants allows us to avoid solving the problems of maintaining power quality and operating reserve of the wind power plants capacity in the power system and to use the wind energy at the plants of combined heat and high-quality electric power production. These the wind and fuel power complexes can replace the nuclear and fuel power plants. At the same time, the producers of the traditional power equipment get chance to expand the business instead of his reduction owing to replacement by the renewable sources and hydrogen energy.

China's CO2 emissions of a critical sector: Evidence from energy intensive industries

CO2 emissions from China's energy intensive industries increased sharply during 2000–2013 and reached around 43.84 billion tons in 2013. The large amounts of emissions make it necessary to study the CO2 emissions performance and efficiency in these industries. In this paper, we use the Shephard input distance function and nonparametric metafrontier approach to construct an index called Metafrontier Malmquist CO2 Emissions Performance Index (MMCPI) to evaluate the efficiency of CO2 emissions from China's energy intensive industries. Then we decompose the index into three components: technical efficiency change (TEC), technical change (TC) and catching-up effect. Finally, we calculate the reduction potential of CO2 emissions under both the meta-frontier and group-frontier. The results show that, the CO2 emissions efficiency in China's energy intensive industries improved in the period of 2000–2013. In addition, under the group-frontier, there is almost no CO2 emissions reduction potential for energy intensive industries in Jiangsu and Shanghai in Eastern China, while CO2 emissions reduction potential in Hebei Province is the largest. In Central China, CO2 emissions reduction potential in Shanxi is the largest and Henan has the lowest. In Western China, the potential of CO2 emissions reduction in Sichuan is the lowest, while Ningxia has the largest reduction potential.

CO2 emissions efficiency and marginal abatement costs of the regional transportation sectors in China

Nowadays, evaluating CO2 emissions efficiency and its marginal abatement cost in transportation sectors has been a hot topic. However, while evaluating the CO2 marginal abatement cost using data envelopment analysis approach, the weak disposability of CO2 may imply positive abatement cost, which undoubtedly violates our common sense. To obtain non-positive marginal abatement cost, CO2 emissions should be treated as an input. To reconcile this contradiction, this paper intends to propose a global, directional distance function model based on previous study to investigate the productivity, economic efficiency, CO2 emissions efficiency, and marginal abatement cost of the China’s regional transportation sectors during 2007–2012. The results show that: (1) the productivity, economic efficiency and CO2 emissions efficiency of different regions differ widely. More specifically, the coastal areas of south China perform better than the other areas in terms of productivity, economic efficiency, and CO2 emissions efficiency. (2) Generally, the economic efficiency is greater than CO2 emissions efficiency, which is relatively low in most areas. (3) A negative correlation is found between CO2 emissions efficiency and itsmarginal abatement cost. For a 1% increase in CO2 emissions efficiency, the CO2 marginal abatement cost declines by 102 Yuan (in 2004 constant price). The results imply that improving CO2 emissions efficiency plays an important role in marginal abatement cost reduction, and it also provides us a new approach to reduce abatement cost besides the technical progress.

Technology gap and CO2 emission reduction potential by technical efficiency measures: A meta-frontier modeling for the Chinese agricultural sector

The purpose of this paper is to explore CO2 emission efficiency in china’s agricultural sector during the period 2001–2012. We also analyze the CO2 emission reduction potential as well as its two main contributors (i.e. technology gap inefficiency and managerial failure). The meta-frontier framework is adopted to reflect technology heterogeneities in China’s agricultural sector among the eastern, central and western regions. Based on the DEA (data envelopment analysis) method, the models are estimated by means of linear programming. Empirical results indicate that CO2 emission efficiency of the agricultural sector in western China is the lowest compared with eastern and central China; stemming from the fact that most provinces in western China generally fall behind in terms of technology. The total potential agricultural CO2 emissions reduction is estimated at 1161.33 million tons, which can be attributed to managerial failure in the case of eastern and central China. For western China, it can be attributed to both technological gap inefficiency and managerial failure.

The environmental emission efficiency of larger and heavier vehicles – A case study of road transportation in Finnish forest industry

Road freight transportation is the most common mode of long-distance timber transportation. This study assesses the environmental impacts of the larger and heavier vehicles on emission efficiency for 76 t vehicles using the synchronized calculation method. The method took account of two factors: load mass and the migration of loads to heavier vehicles. The method was successfully tested to calculate emission efficiency after the short-term adaptation process. Calculations were made for four mass limits (60, 64, 68 and 76 t) year after the mass limits were raised. Based on Enterprise Resource Planning data, efficiency of CO2 emissions (measured in relation to trip) increased 15.8% for 76 t vehicles. Respectively, CO2 emissions reduced 6.2% to 42.8 g/tkm. The results show that increase in maximum vehicle mass yields cleaner wood procurement chain in pulp production process. This study confirms that the synchronized calculation method can be used in real-world transport systems and local wood supply chains to determine and solve emission efficiencies of larger and heavier vehicle combinations.

Energy and CO2 emissions efficiency of major economies: A non-parametric analysis

Excessive energy consumption and carbon dioxide emissions are long lasting issues and need continuous research to improve efficiency evaluation and performance monitoring of economies. The static and dynamic aspects of efficiency need to be dealt with simultaneously to thoroughly analyze the performance of economies. This paper aims at conducting a static and dynamic analysis of energy and CO2 emissions efficiency of major economies. In this paper, we applied slacks based model of Tone (2001) with the treatment of undesirable output in objective function and constraint assuming free disposability of undesirable output and built a dashboard. The results can be summarized by saying that the larger economies with intensive production strategy, larger secondary industry, and weaker carbon tax laws are more likely to be inefficient. China, India, and Russia have the greatest potential for improvement in both energy efficiency and carbon dioxide emissions efficiency. The suggested dashboard has the ability to dig out the potential for efficiency improvement of countries like the USA, which mostly appear at the efficient frontier with other techniques. Concluding it can be suggested that economies in lower ranks of dashboard need stricter policy measures to cut energy consumption, carbon dioxide emissions and encourage a shift from fossil fuels to other renewable resources of energy.

Analysis of CO2 Emission Performance and Abatement Potential for Municipal Industrial Sectors in Jiangsu, China

As the main source of CO2 emissions in China, the industrial sector has faced pressure for reducing emissions. To achieve the target of 50% reduction of industrial carbon intensity by 2020 based on the 2005 level, it is urgent to formulate specific CO2 emission mitigation strategies in the provincial industrial sector. In order to provide decision-making support for the development and implementation of mitigation policy, our undesirable slack based measure (SBM) model is firstly applied to evaluate the industrial CO2 emission efficiency under total-factor frame (TFICEE) in 13 prefecture-level cities of Jiangsu Province, the largest CO2 emitter in China. Then, we analyze space-time distribution and distributional evolution tendency of TFICEE by using the GIS visualization method and kernel density estimation, respectively. Finally, we utilize the industrial abatement model to estimate the CO2 abatement potential of Jiangsu’s industrial sector. The empirical results show that there exists a significant spatial inequality of TFICEE across various regions in Jiangsu, but the regional disparity has been narrowing during our study period. Additionally, average annual industrial CO2 emission reductions in Jiangsu Province can attain 15,654.00 (ten thousand tons), accounting for 28.2% of its average annual actual emissions, which can be achieved by improving production technology, adjusting industrial structure and raising the level of industry concentration.

The greenness of Chinese cities: carbon dioxide emission and its determinants

This paper investigates carbon dioxide (CO2) emission and its determinants in 286 Chinese cities. The findings strongly support an inverted U-shaped relationship between per capita CO2 emission (PCE) and urban development. However, the realization of this relationship depends on stringent governmental policy interventions. The regression analysis in this paper shows that city size is positively correlated with CO2 emission efficiency, but negatively correlated with PCE. This result suggests that population restrictions in large cities tend to increase CO2 emission. It is also shown that regional development programs are likely to encourage economic activities in regions with low CO2 emission efficiency and may have significant environmental consequences in the future.