Is there a relationship between public expenditures in energy R&D and carbon emissions per GDP? An empirical investigation

Energy innovation plays a crucial role in the reduction of carbon emissions. In order to design climate and energy policies that promote the development, deployment and diffusion of new energy technologies, policy makers not only require a theoretical understanding of the energy innovation system, but also empirical evidence of the effects that policy actions have had. This paper focuses on public energy R&D, a traditional and controversial option among the various climate technology policies, and empirically analyses its relationship with carbon emissions per GDP (i.e. carbon intensity) and its two components: energy intensity and the carbon factor. Evidence of the causality links that have prevailed in 13 advanced economies over the 1980–2004 period has been obtained through dynamic panel models. Our findings confirm that government R&D spending is not sufficient by itself to boost the energy innovation process. Public energy R&D has been successful in improving energy efficiency at country level, but it has failed to have a significant impact on the carbon factor and carbon intensity. At the same time the formation of energy R&D budgets is found to be significantly affected by carbon trends.     

Impacts of booming economic growth and urbanization on carbon dioxide emissions in Chinese megalopolises over 1985–2010: an index decomposition analysis

Given the booming economic growth and urbanization in China, cities have become crucial to sustaining this development and curbing national emissions. Understanding the key drivers underlying the rapid emissions growth is critical to providing local solutions for national climate targets. By using index decomposition analysis, we explore the factors contributing to the carbon dioxide (CO₂) emissions in Chinese megalopolises from 1985 to 2010. An additional decomposition analysis of the industry sector is performed because of its dominant contribution to the total emissions. The booming economy and expanding urban areas are the major drivers to the increasing CO₂ emissions in Chinese megalopolises over the examined period. The significant improvement in energy intensity is the primary factor for reducing CO₂ emissions, the declining trend of which, however, has been suspended or reversed since 2000. The decoupling effect of the adjustments in the economic structure only occurred in three megalopolises, namely, the Yangtze River Delta (YRD), the Beijing-Tianjin-Heibei Megalopolis (BTJ), and the Pearl River Delta (PRD). In comparison, the impacts of urban density and carbon intensity are relatively marginal. The further disaggregated decomposition analysis in the industry sector shows that energy intensity improvements were widely achieved in 36 sub-industries in the PRD. The results also indicate the concentrations of energy-intensive industries in the PRD, posing a major challenge to local governments for a low-carbon economy. As economic growth and urbanization continue, reductions in energy intensity and clean energy therefore warrant much more policy attentions due to their crucial roles in reducing carbon emissions and satisfying the energy demand.     

Conductivity percolation in carbon–carbon supercapacitor electrodes

Composite electrodes which comprise a non-conductive activated carbon of large surface area (1420 m² g⁻¹) and a conductive carbon black (CB) of small surface area (220 m² g⁻¹) have been prepared and studied for their capacitive properties in aqueous KOH and Na₂SO₄ electrolytes. For either electrolyte, maximum capacitance exists at the composition believed to correspond to the percolation threshold for CB, the conductive phase. At a CB content less than the threshold, the capacitance is limited mainly by the electronic resistance on the electrode side. The interfacial surface area becomes the limiting factor as the threshold is exceeded. A maximum capacitance of 108 F g⁻¹ at a voltage sweep rate of 20 mV s⁻¹ is obtained in 1 M KOH aqueous electrolyte with a CB content of 25 wt.% (or ∼14 vol.%).     

Greenhouse gas emissions in China 2007: Inventory and input–output analysis

For greenhouse gas (GHG) emissions by the Chinese economy in 2007 with the most recent statistics availability, a concrete inventory covering CO₂, CH₄, and N₂O is composed and associated with an input–output analysis to reveal the emission embodiment in final consumption and international trade. The estimated total direct GHG emission amounts to 7456.12 Mt CO₂-eq by the commonly referred IPCC global warming potentials, with 63.39% from energy-related CO₂, 22.31% from non-energy-related CO₂, 11.15% from CH₄ and 3.15% from N₂O. Responsible for 81.32% of the total GHG emissions are the five sectors of the Electric Power/Steam and Hot Water Production and Supply, Smelting and Pressing of Ferrous and Nonferrous Metals, Nonmetal Mineral Products, Agriculture, and Coal Mining and Dressing, with distinctive emission structures. The sector of Construction holds the top GHG emissions embodied in both domestic production and consumption, and the emission embodied in gross capital formation is prominently more than those in other components of the final consumption characterized by extensive investment in contrast to limited household consumption. China is a net exporter of embodied GHG emissions, with emissions embodied in exports of 3060.18 Mt CO₂-eq, in magnitude up to 41.04% of the total direct emission.     

Price drivers and structural breaks in European carbon prices 2005–2007

This article aims at characterizing the daily price fundamentals of European Union Allowances (EUAs) traded since 2005 as part of the Emissions Trading Scheme (ETS). The presence of two structural changes on April 2006 following the disclosure of 2005 verified emissions and on October 2006 following the European Commission announcement of stricter Phase II allocation allows to isolate distinct fundamentals evolving overtime. The results extend previous literature by showing that EUA spot prices react not only to energy prices with forecast errors, but also to unanticipated temperatures changes during colder events. Besides, the sub-period decomposition of the pilot phase gives a better grasp of institutional and market events that drive allowance price changes.     

“Investments and public finance in a green,low carbon,economy”

The paper evaluates the impacts on investments and public finance of a transition to a green, low carbon, economy induced by carbon taxation. Four global tax scenarios are examined using the integrated assessment model WITCH. Taxes are levied on all greenhouse gases (GHGs) and lead to global GHG concentrations equal to 680, 560, 500 and 460 ppm CO₂-eq in 2100. Investments in the power sector increase with respect to the Reference scenario only with the two highest taxes. Investments in energy-related R&D increase in all tax scenarios, but they are a small fraction of GDP. Investments in oil upstream decline in all scenarios. As a result, total investments decline with respect to the Reference scenario. Carbon tax revenues are high in absolute terms and as share of GDP. With high carbon taxes, tax revenues follow a “carbon Laffer” curve. The model assumes that tax revenues are flawlessly recycled lump-sum into the economy. In all scenarios, the power sector becomes a net recipient of subsidies to support the absorption of GHGs. In some regions, with high carbon taxes, subsidies to GHG removal are higher than tax revenues at the end of the century.     

Combustion and emissions behaviour for methanol–gasoline blended fuels in a multipoint electronic fuel injection engine

The purpose of this study is to experimentally investigate the performance, combustion and pollutant emissions of a multipoint electronic fuel injection gasoline engine using methanol–gasoline blends. The results indicated that, with the increase in methanol (CH₃OH) content in the blends, the maximum engine torque and power are slightly decreased, the brake specific fuel consumption is evidently increased and brake thermal efficiency remains almost identical. At low engine loads and speeds, gasoline is observed to have faster combustion velocity, but the blends are faster at high engine loads and speeds. The carbon monoxide of the blends is slightly lower, hydrocarbon is slightly higher at high engine loads and nitrogen oxide is lower for M10 at low engine loads. The emissions of formaldehyde are evidently higher with the increase in CH₃OH content, but CH₃OH and acetaldehyde emissions of the blends show little variation.     

Metallic and carbonaceous –based catalysts performance in the solar catalytic decomposition of methane for hydrogen and carbon production

Solar catalytic decomposition of methane (SCDM) was investigated in a solar furnace facility with different catalysts. The aim of this exploratory study was to investigate the potential of the catalytic methane decomposition approach providing the reaction heat via solar energy at different experimental conditions. All experiments conducted pointed out to the simultaneous production of a gas phase composed only by hydrogen and un-reacted methane with a solid product deposited into the catalyst particles varying upon the catalysts used: nanostructured carbons either in form of carbon nanofibers (CNF) or multi-walled carbon nanotubes (MWCNT) were obtained with the metallic catalyst whereas amorphous carbon was produced using a carbonaceous catalyst. The use of catalysts in the solar assisted methane decomposition present some advantages as compared to the high temperature non-catalytic solar methane decomposition route, mainly derived from the use of lower temperatures (600–950 °C): SCDM yields higher reaction rates, provides an enhancement in process efficiency, avoids the formation of other hydrocarbons (100% selectivity to H₂) and increases the quality of the carbonaceous product obtained, when compared to the non-catalytic route.     

Energy and environmental optimization in thermoelectrical generating processes—application of a carbon dioxide capture system

Increased thermodynamic efficiency coupled with reduced impact on the environment are fundamental aims in the generation and rational use of energy if a contribution is to be made towards sustainable development on both a local and worldwide scale. Technological developments over recent years in the field of thermal electricity generation, together with research and technologies emerging from environmentally friendly systems, are allowing increases in the efficiency of energy generating processes accompanied by a reduction in polluting gases released into the atmosphere. This work develops the methodology for defining and designing a cogeneration plant based on a combined cycle and using a computer program to provide time simulation. By way of example, the results obtained from the thermal power station of a chemical complex are given. As a novel feature, the work includes the application of a system to capture carbon dioxide, a gas that makes a significant contribution to the so-called ‘greenhouse effect’, the main cause of global warming. The work carried out allows highly accurate forecasting of future working of the cogeneration system in the proposed application, and analysis of the performance of the plant as a function of its capacity to capture carbon dioxide. The work also considers the feasibility of long-term confinement of the captured carbon dioxide in the deep ocean, and analyses its impact on plant efficiency. Finally, an economical analysis of the proposed plant is included in order to evaluate the impact of the potential carbon dioxide capture and storage system.     

The embodied energy and environmental emissions of construction projects in China: An economic input–output LCA model

A complete understanding of the resource consumption, embodied energy, and environmental emissions of civil projects in China is difficult due to the lack of comprehensive national statistics. To quantitatively assess the energy and environmental impacts of civil construction at a macro-level, this study developed a 24 sector environmental input–output life-cycle assessment model (I–O LCA) based on 2002 Chinese national economic and environmental data. The model generates an economy-wide inventory of energy use and environmental emissions. Estimates based on the level of economic activity related to planned future civil works in 2015 are made. Results indicate that the embodied energy of construction projects accounts for nearly one-sixth of the total economy's energy consumption in 2007, and may account for approximately one-fifth of the total energy use by 2015. This energy consumption is dominated by coal and oil consumptions. Energy-related emissions are the main polluters of the country's atmosphere and environment. If the industry's energy use and manufacturing techniques remain the same as in 2002, challenges to the goals for total energy consumption in China will appear in the next decade. Thus, effective implementation of efficient energy technologies and regulations are indispensable for achieving China's energy and environmental quality goals.     

Routine emissions and accidental releases of toxic air pollutants — risk,response and planning

General information on the strategies employed to address air toxics problems and a variety of activities on air toxics that are currently underway within the U.S. Environmental Protection Agency are outlined. To provide some perspective and understanding of the air toxics programs within the U.S. Environmental Protection Agency, aspects of the air toxics strategy, ongoing programs for routine emissions and programs for both responding to and planning for accidental releases are described.     

Coal utilization in industrial boilers in China —a prospect for mitigating CO2 emissions

It is estimated from GEF statistical data for 1991 that more than 500,000 industrial boilers (mostly stoker-fired) in China consume over 400 million tons of coal per year. Each year, because of low boiler efficiency, 75 million tons of coal is wasted and 130 million tons of excess CO₂ are emitted. An analysis of 250 boiler thermal-balance test certificates and 6 field visits in three provinces have shown that: (1) boilers with efficiencies of less than 70% account for 75% of the total boiler-population; (2) the main causes of the low efficiencies are high excess air and unburned carbon in the slag and fly ash. The effect of unburned carbon on CO₂ emission is a balance of positive and negative contributions: while the unburned carbon does not produce CO₂ emissions, its replacement carbon, burned at a low efficiency, contributes to a net increase in CO₂ emissions. It seems from the analysis that the average boiler efficiency can be raised to 73% by relatively simple means, such as the size grading of the coal, improved boiler operating practice and some inexpensive equipment modifications. This could then result in savings each year of 34 million tons of coal and a reduction in CO₂ emissions of 63 million tons at an estimated cost of $10 per ton of CO₂.     

Can envelope codes reduce electricity and CO2 emissions in different types of buildings in the hot climate of Bahrain?

The depletion of non-renewable resources and the environmental impact of energy consumption, particularly energy use in buildings, have awakened considerable interest in energy efficiency. Building energy codes have recently become effective techniques to achieve efficiency targets. The Electricity and Water Authority in Bahrain has set a target of 40% reduction of building electricity consumption and CO₂ emissions to be achieved by using envelope thermal insulation codes. This paper investigates the ability of the current codes to achieve such a benchmark and evaluates their impact on building energy consumption. The results of a simulation study are employed to investigate the impact of the Bahraini codes on the energy and environmental performance of buildings. The study focuses on air-conditioned commercial buildings and concludes that envelope codes, at best, are likely to reduce the energy use of the commercial sector by 25% if the building envelope is well-insulated and efficient glazing is used. Bahraini net CO₂ emissions could drop to around 7.1%. The simulation results show that the current energy codes alone are not sufficient to achieve a 40% reduction benchmark, and therefore, more effort should be spent on moving towards a more comprehensive approach.     

How ambitious are China and India’s emissions intensity targets?

Several developing economies have announced carbon emissions targets for 2020 as part of the negotiating process for a post-Kyoto climate policy regime. China and India’s commitments are framed as reductions in the emissions intensity of the economy by 40–45% and 20–25%, respectively, between 2005 and 2020. How feasible are the proposed reductions in emissions intensity for China and India, and how do they compare with the targeted reductions in the US and the EU? In this paper, we use a stochastic frontier model of energy intensity to decompose energy intensity into the effects of input and output mix, climate, and a residual technology variable. We use the model to produce emissions projections for China and India under a number of scenarios regarding the pace of technological change and changes in the share of non-fossil energy. We find that China is likely to need to adopt ambitious carbon mitigation policies in order to achieve its stated target, and that its targeted reductions in emissions intensity are on par with those implicit in the US and EU targets. India’s target is less ambitious and might be met with only limited or even no dedicated mitigation policies.     

Electroactivity of high performance unsupported Pt–Ru nanoparticles in the presence of hydrogen and carbon monoxide

The electrochemical activity of high performance unsupported (1:1) Pt–Ru electrocatalyst in the presence of hydrogen and carbon monoxide has been studied using the thin-film rotating disk electrode (RDE) technique. The kinetic parameters of these reactions were determined in H₂- and CO-saturated 0.5 M H₂SO₄ solutions by means of cyclic voltammetry, including CO stripping, and RDE voltammetry. Pt–Ru/Nafion inks were prepared in one step with different Nafion mass fractions, allowing determining the ionomer influence in electrocatalytic response and obtaining the kinetic current density in absence of mass-transfer effects, being 41 and 12 mA cm² (geometrical area), for H₂ and CO oxidation, respectively. These values correspond to mass activities of 1.37 and 0.40 A mg_Pt¹ and to specific activities of 1.52 and 0.44 mA cm_Pt². The Tafel analysis confirmed that hydrogen oxidation was a two-electron reversible reaction, while CO oxidation exhibited an irreversible behavior with a charge-transfer coefficient of 0.42. The kinetic results for CO oxidation are in agreement with the bifunctional theory, in which the reaction between Pt–CO and Ru–OH is the rate-determining step. The exchange current density for hydrogen reaction was 0.28 mA cm² (active surface area), thus showing similar kinetics to those found for carbon-supported Pt and Pt–Ru electrocatalyst nanoparticles.     

Plasma-assisted Pt and Pt–Pd nano-particles deposition on carbon carriers for application in PEM electrochemical cells

Plasma-assisted deposition of platinum and platinum-palladium nano-particles at the surface of carbonaceous electronic carriers for application in proton-exchange membrane (PEM) electrochemical cells has been carried out using a conventional DC magnetron sputtering system. Different types of carrier have been used for that purpose: carbon powder (Vulcan XC-72), carbon nanotubes and carbon nano-fibers. The interest of initial chemical pretreatment or metallization of the electronic carrier to improve surface adhesion of catalyst nano-particles has been analyzed. Nanostructured catalytic powders thus obtained have been analyzed and characterized using TGA, SEM, TEM, XRD, XRF and cyclic voltammetry. The electrochemical performances of Pt/C and Pt–Pd/C electrodes have been measured in single-cell PEM fuel cell (PEMFC), water electrolyzer (PEMWE) and unitized regenerative fuel cell (URFC). Results show a high active surface area (up to 44 m² g⁻¹) and high electrochemical activity for a number of synthesized samples. A qualitative correlation has been established between sputtering parameters, type of carbon carrier and performances as electrocatalyst.     

How does tax system on energy industries affect energy demand,CO2 emissions,and economy in China?

Energy savings and CO₂ emission reduction have become a major issue in recent years. Taxes on energy production sectors may be an effective way to save energy, reduce CO₂ emissions, and improve environmental quality. This paper constructs a dynamic recursive Computable General Equilibrium (CGE) model to analyze the impact of the energy tax on energy, economy, and environment from the perspective of tax rates and tax forms (specific tax and ad valorem tax). The results show that adjusting the tax system and the tax rate has important implications for energy conservation while having minor impacts on the output of other industries. The impact of an increasing energy tax on the energy demand is greater than the impact on sectoral output, indicating that energy efficiency will be increased to some extent. The CO₂ reduction will increase over time when an ad valorem tax is implemented on enterprises. We found that ad valorem tax has greater elasticity of economic output, energy demand, and CO₂ emission reduction. The results support the direction of China's resource tax reform. However, we argue that it is better to increase the tax rate relatively and relax the control on energy prices so that energy efficiency will increase.     

Combustion and emissions performance of a hybrid hydrogen–gasoline engine at idle and lean conditions

Due to the narrow flammability of gasoline, pure gasoline-fueled spark-ignited (SI) engines always encounter partial burning or even misfire at lean conditions. Gasoline engines tend to suffer poor combustion and expel large emissions at idle conditions because of the high variation in the intake charge and low combustion temperature. Comparatively, hybrid hydrogen engines (HHE) fueled with the mixtures of hydrocarbon fuels and hydrogen seem to achieve lower emissions and gain higher thermal efficiencies than the original hydrocarbon-fueled engines due to the wide flammability and high flame speed of hydrogen. Since a HHE only requires a small amount of hydrogen, it also removes concerns about the high production and storage costs of hydrogen. This paper introduced an experiment conducted on a four-cylinder SI gasoline engine equipped with a hydrogen port-injection system to explore the performance of a hybrid hydrogen–gasoline engine (HHGE) at idle and lean conditions. The injection timings and durations of hydrogen and gasoline were governed by a hybrid electronic control unit (HECU) developed by the authors, which can be adjusted freely according to the commands from a calibration computer. During the test, hydrogen flow rate was varied to ensure that hydrogen volume fraction in the intake was constantly kept at 3%. For the specified hydrogen addition level, gasoline flow rate was reduced to make the engine operate at idle and lean conditions with various excess air ratios. The test results demonstrated that cyclic variations in engine idle speed and indicated mean effective pressure were eased with hydrogen enrichment. The indicated thermal efficiency was obviously higher for the HHGE than that for the original gasoline engine at idle and lean conditions. The indicated thermal efficiency at an excess air ratio of 1.37 was increased from 13.81% for the original gasoline engine to 20.20% for the HHGE with a 3% hydrogen blending level. Flame development and propagation periods were also evidently shortened after hydrogen blending. Moreover, HC, CO and NOx emissions were all improved after hydrogen enrichment at idle and lean conditions. Therefore, the HHE methodology is an effective and promising way for improving engine idle performance at lean conditions.