A roadmap for China to peak carbon dioxide emissions and achieve a 20% share of non-fossil fuels in primary energy by 2030

As part of its Paris Agreement commitment, China pledged to peak carbon dioxide (CO2) emissions around 2030, striving to peak earlier, and to increase the non-fossil share of primary energy to 20% by 2030. Yet by the end of 2017, China emitted 28% of the world's energy-related CO2 emissions, 76% of which were from coal use. How China can reinvent its energy economy cost-effectively while still achieving its commitments was the focus of a three-year joint research project completed in September 2016. Overall, this analysis found that if China follows a pathway in which it aggressively adopts all cost-effective energy efficiency and CO2 emission reduction technologies while also aggressively moving away from fossil fuels to renewable and other non-fossil resources, it is possible to not only meet its Paris Agreement Nationally Determined Contribution (NDC) commitments, but also to reduce its 2050 CO2 emissions to a level that is 42% below the country's 2010 CO2 emissions. While numerous barriers exist that will need to be addressed through effective policies and programs in order to realize these potential energy use and emissions reductions, there are also significant local environmental (e.g., air quality), national and global environmental (e.g., mitigation of climate change), human health, and other unquantified benefits that will be realized if this pathway is pursued in China

A Fast Solver for Tridiagonal Toeplitz Systems with Multiple Right-Hand Sides

In this work, we introduce a novel approach for solving tridiagonal Toeplitz systems with multiple right-hand sides.Comment: 5 page

Correction: Hasanbeigi, A.; Zuberi, M.J.S. Electrification of Steam and Thermal Oil Boilers in the Textile Industry: Techno-Economic Analysis for China, Japan, and Taiwan. Energies 2022, 15, 9179

There was an error in the original publication [1]. The total annual potential energy savings from the electric steam and thermal oil boiler applications were inaccurate. A correction has been made to the Abstract: “Process heating is typically more than half of the total final energy demand in the textile industry, most of which is usually provided by fossil fuels. There is significant potential to decarbonize the textile industry by the electrification of process heating where low-carbon electricity is used. This study aims to quantify the potential for the electrification of process heating in the textile sector in three of the top textile manufacturing and exporting countries in the world. The results show that the total annual potential energy savings due to the electric steam boiler applications are estimated to be around 84, 2.2, and 2.3 PJ in China, Japan, and Taiwan, respectively, by 2050. This is equal to approximately 19% of the total boiler energy demand in the three economies. Similarly, annual potential energy savings of 35, 0.9, and 0.9 PJ can be realized if the existing fossil-fuel-fired thermal oil boilers are electrified in the textile industry in China, Japan, and Taiwan, respectively, by 2050. Moreover, the potential CO2 abatement resulting from electrification is highly dependent on the carbon intensity of the electricity used. The economic analysis shows that switching from combustion boilers to electric boilers may result in higher energy costs, primarily because the average electricity prices in all three economies are substantially higher than fossil fuel prices. Finally, some key recommendations that different stakeholders can take to scale up electrification in the textile industry are provided.” There was an error in the original publication. The annual energy savings from the electric steam boiler applications were inaccurate. A correction has been made to 3. Results and Discussion, 3.1. Electrifying the Textile Industry through Electric Steam Boilers, Paragraph 1: “Using the methods described in Section 2, potential applications of electric steam boilers in the textile industry in China, Japan, and Taiwan are investigated. The results show that the electrification of steam boilers could substantially reduce the annual final energy demand for steam generation in the textile industry in these three economies up to 2050 (Figure 4). Approximately 84, 2.2, and 2.3 PJ per year of annual boiler energy demand in the textile industry in China, Japan, and Taiwan, respectively, can be saved if the existing combustion boilers are electrified. This is equal to approximately 19% of the total boiler energy demand in the three economies. The annual energy saving potentials shown in Figure 4 are projected to remain at the same level in future years because this study assumes that the amount of textile production and, consequently, the energy and steam demand in the textile industry in each economy will remain more or less the same during 2021–2050.” There was an error in the original publication. The potential changes in annual CO2 emissions due to electric steam boiler applications were stated slightly inaccurately. A correction has been made to 3. Results and Discussion, 3.1. Electrifying the Textile Industry through Electric Steam Boilers, Paragraph 2: “If the average national grid electricity is used, the electrification of combustion steam boilers in the textile industry in China, Japan, and Taiwan could initially lead to an increase in annual CO2 emissions by around 11,000, 110, and 51 kt CO2 in 2030, respectively (assuming a 100% adoption rate), refer to Figure 5a–c.

Correction: Hasanbeigi, A.; Zuberi, M.J.S. Electrified Process Heating in Textile Wet-Processing Industry: A Techno-Economic Analysis for China, Japan, and Taiwan. Energies 2022, 15, 8939

There was an error in the original publication [1]. The total required heating capacities of High Temperature Heat Pumps (HTHP) for the textile wet-processing industry were stated inaccurately. A correction has been made to 3.1. Electrifying the Textile Industry through Industrial Heat Pumps, Paragraph 1: “The schematic of industrial heat pump (IHP) applications and their corresponding COPs is shown in Figure 6. A high-temperature heat pump (HTHP) can be installed to preheat the makeup feed water to 82 °C before it enters the condensate tank for steam generation. The total required heating capacities of HTHPs for the textile wet-processing industry in China, Taiwan, and Japan are estimated at 142 MW, 3.3 MW, and 3.9 MW, respectively. This is a relatively low heat capacity demand compared to steam-generating heat pumps (SGHP; see later for details) because HTHP is used only to preheat make-up feed water from 25 °C to 82 °C. A larger heat demand is needed for SGHP as shown below.” There was an error in the original publication. The total required heating capacities of Steam Generating Heat Pumps (SGHP) for the textile wet-processing industry were stated inaccurately. A correction has been made to 3.1. Electrifying the Textile Industry through Industrial Heat Pumps, Paragraph 3: “Two separate SGHPs can be installed to produce process steam: (1) at 120 °C for de-sizing, scouring, mercerizing, washing, bleaching, and finishing (pad-dry-cure), and (2) at 150 °C for steam drying, dyeing, and printing. The total required heating capacities of SGHPs in China, Taiwan, and Japan are estimated at 11 gigawatts (GW), 0.30 GW, and 0.30 GW, respectively. It should be noted that the utilization of heat sources possibly available at a temperature higher than 60 °C (as assumed in this study) may result in a COP higher than currently estimated and consequently the lower electricity demand by the studied industrial heat pumps.” There was an error in the original publication. The annual final energy savings due to industrial heat pump (IHP) applications in the textile wet-processing industry were stated inaccurately. A correction has been made to 3.1. Electrifying the Textile Industry through Industrial Heat Pumps, Paragraph 4: “The change in annual final energy demand due to IHP applications for textile wet-processing in the three economies in different timeframes is shown in Figures 7–9. The figures conclude that IHP applications can substantially decrease the total annual final energy demand. More precisely, it is estimated that nearly 248, 6.6, and 6.5 PJ of the annual final energy can be saved for textile wet-processing in China, Japan, and Taiwan, respectively. The substantial reduction in annual final energy demand is due to the increase in the efficiency (measured in terms of COPs of the heat pumps) for hot water and steam generation.” There was an error in the original publication. The annual CO2 emissions reduction potentials due to IHP applications in the textile wet-processing industry were stated inaccurately. A correction has been made to 3.1. Electrifying the Textile Industry through Industrial Heat Pumps, Paragraph 6: “The change in annual CO2 emissions from the textile wet-processing industry due to industrial heat pump applications in different years is presented in Figures 10–12. The figures show up to 11, 0.3, and 0.4 Mt CO2 per year emissions reduction potential in 2030 for textile wet-processing in China, Japan, and Taiwan, respectively. This is despite the increase in electricity demand from IHPs. The CO2 reduction potential further increases to 23, 0.6, and 0.7 Mt CO2 per year in 2050, in China, Japan, and Taiwan, respectively, due to the projected rate of electricity grid decarbonization between now and 2050 in these economies (it is assumed that the electricity grid will be carbon neutral in 2050 in all three economies).” There was an error in the original publication. The annual final energy savings due to the electrification of the dyeing process were slightly inaccurate. A correction has been made to 3.2.1. Electrification of the Dyeing Process, Paragraph 3: “Electrifying the dyeing process can result in large final energy savings. In China, Japan, and Taiwan, annual energy savings of 34,000, 780, and 750 TJ per year can be achieved in 2050 (Figure 16). This is because electrified dyeing is more efficient than the conventional process, resulting in less energy consumption.” There was an error in the original publication. The annual reduction of CO2 emissions due to the electrification of the dyeing process were slightly inaccurate. A correction has been made to 3.2.1. Electrification of the Dyeing Process, Paragraph 4: “Electrification of the dyeing process in China could result in an increase in annual CO2 emissions in the short term if highly carbon-intensive grid electricity is used (Figure 17). The electrification of the dyeing process could lead to a decrease in CO2 emissions in Japan and Taiwan in 2030. Between 2030 and 2050, there will be a substantial reduction in CO2 emissions as a result of the decline in the electricity grid’s CO2 emissions factor and energy efficiency improvements. In 2050, the annual reduction of CO2 emissions after electrification of the dyeing process will be around 4800, 115, and 125 kt CO2 per year in China, Japan, and Taiwan, respectively.” There was an error in the original publication. The annual final energy savings due to the electrification of the singeing process were slightly inaccurate. A correction has been made to 3.2.2. Electrification of Singeing Process, Paragraph 3: “Table 7 shows that electrifying the singeing process results in substantial annual final energy savings between 2030 and 2050. Electrification could lead to annual energy savings of about 18,000, 300, and 700 terajoules (TJ) per year for China, Japan, and Taiwan, respectively in 2050. This annual energy savings potential results from the higher efficiency (lower energy intensity) of electrified singeing compared with the conventional singeing process.” There was an error in the original publication. The changes in electricity loads after the electrification of the end-use wet processes were stated inaccurately. A correction has been made to 3.2.8. Total Electrification Potential in Seven Studied Wet Processes, Paragraph 3: “Furthermore, while electrification decreases net final energy demand, electricity demand increases. For example, electrifying seven textile wet-processes results in an increase in annual electricity consumption of 64, 1.5, and 1.6 TWh per year in China, Japan, and Taiwan, respectively in 2050. This translates into an increase in electricity load of 8, 0.2, and 0.2 GW in China, Japan, and Taiwan, respectively in 2050 (To estimate these additional loads, we assumed all the additional load is coming from clean renewable energy sources. We further assumed that two-thirds of this additional load is coming from solar power and one-third from wind power and assumed the capacity factor accordingly). For comparison, in 2021, China had around 2380 GW, Japan had around 313 GW, and Taiwan had around 59 GW of electricity generation capacities [45,46].” There was an error in the original publication. The total potential final energy savings due to IHP applications were slightly inaccurate. A correction has been made to 4. Discussion and Policy Recommendations, Paragraph 1: “The total potential final energy savings due to industrial heat pump applications are estimated to be around 248, 6.6, and 6.5 PJ per year in China, Japan, and Taiwan, respectively in 2050. On the other hand, electrification through end-use processes could lead to potential final energy savings of about 145, 3.5, and 3.8 PJ per year in China, Japan, and Taiwan, respectively in 2050. It must be noted that the results of the two pathways are not directly comparable because only seven end-use wet processes have been studied in the second pathway analysis mainly due to a lack of technical data for the remaining processes. Furthermore, the substantial reduction in annual final energy demand in both scenarios is due to the increase in the efficiency and lower energy intensity of the electrified heating systems.” The “country” in the paper has been changed with “country/region”. In the original publication, there was a mistake in Figure 7 as published. The annual final energy demand due to IHP applications in the textile wet-processing industry in China was inaccurate. The corrected Figure 7 appears below. In the original publication, there was a mistake in Figure 8 as published. The annual final energy demand due to IHP applications in the textile wet-processing industry in Japan was inaccurate. The corrected Figure 8 appears below. In the original publication, there was a mistake in Figure 9 as published. The annual final energy demand due to IHP applications in the textile wet-processing industry in Taiwan was inaccurate. The corrected Figure 9 appears below. In the original publication, there was a mistake in Figure 10 as published. The annual CO2 emissions reduction potentials due to IHP applications in the textile wet-processing industry in China were stated inaccurately. The corrected Figure 10 appears below. In the original publication, there was a mistake in Figure 11 as published. The annual CO2 emissions reduction potentials due to IHP applications in the textile wet-processing industry in Japan were stated inaccurately. The corrected Figure 11 appears below. In the original publication, there was a mistake in Figure 12 as published. The annual CO2 emissions reduction potentials due to IHP applications in the textile wet-processing industry in Taiwan were stated inaccurately. The corrected Figure 12 appears below. In the original publication, there was a mistake in Figure 13 as published. The energy costs per unit of production for the textile wet-processing industry in China were stated inaccurately. The corrected Figure 13 appears below. In the original publication, there was a mistake in Figure 14 as published. The energy costs per unit of production for the textile wet-processing industry in Japan were stated inaccurately. The corrected Figure 14 appears below. In the original publication, there was a mistake in Figure 15 as published. The energy costs per unit of production for the textile wet-processing industry in Taiwan were stated inaccurately. The corrected Figure 15 appears below. The authors state that the scientific conclusions are unaffected. This correction was approved by the Academic Editor. The original publication has also been updated

Emerging Energy-efficiency and CO{sub 2} Emission-reduction Technologies for Cement and Concrete Production

Globally, the cement industry accounts for approximately 5 percent of current anthropogenic carbon dioxide (CO{sub 2}) emissions. World cement demand and production are increasing significantly, leading to an increase in this industry's absolute energy use and CO{sub 2} emissions. Development of new energy-efficiency and CO{sub 2} emission-reduction technologies and their deployment in the market will be key for the cement industry's mid- and long-term climate change mitigation strategies. This report is an initial effort to compile available information on process description, energy savings, environmental and other benefits, costs, commercialization status, and references for emerging technologies to reduce the cement industry's energy use and CO{sub 2} emissions. Although studies from around the world identify a variety of sector-specific and cross-cutting energy-efficiency technologies for the cement industry that have already been commercialized, information is scarce and/or scattered regarding emerging or advanced energy-efficiency and low-carbon technologies that are not yet commercialized. This report consolidates available information on nineteen emerging technologies for the cement industry, with the goal of providing engineers, researchers, investors, cement companies, policy makers, and other interested parties with easy access to a well-structured database of information on these technologies

Effect of Manufacturing Parameters on the Corrosion Behavior of AZ31 Coated by Mg–Al Layered Double Hydroxide

peer reviewedAbstract: In the present study, a simple in situ hydrothermal method was used to fabricate Layered Double Hydroxide conversion coating at different treatment temperatures, times and pH values on the surface of AZ31 magnesium alloy. The films were characterized using XRD, FTIR, XPS, EDS and FESEM. The corrosion resistance of the coatings was evaluated by potentiodynamic polarization, electrochemical impedance spectroscopy and electrochemical noise techniques. The results confirmed the anion exchange ability of the LDH film. Moreover, the best results were obtained at 160 °C, 8 h and pH of 10. Dense and compact blade-like structures were obtained which exhibited appropriate corrosion resistance. The self-healing ability of the films was improved by increasing the LDH content of the film. Graphic Abstract: [Figure not available: see fulltext.

Analysis of Energy-Efficiency Opportunities for the Cement Industry in Shandong Province, China

China's cement industry, which produced 1,388 million metric tons (Mt) of cement in 2008, accounts for almost half of the world's total cement production. Nearly 40% of China's cement production is from relatively obsolete vertical shaft kiln (VSK) cement plants, with the remainder from more modern rotary kiln cement plants, including plants equipped with new suspension pre-heater and pre-calciner (NSP) kilns. Shandong Province is the largest cement-producing Province in China, producing 10% of China's total cement output in 2008. This report documents an analysis of the potential to improve the energy efficiency of NSP kiln cement plants in Shandong Province. Sixteen NSP kiln cement plants were surveyed regarding their cement production, energy consumption, and current adoption of 34 energy-efficient technologies and measures. Plant energy use was compared to both domestic (Chinese) and international best practice using the Benchmarking and Energy Saving Tool for Cement (BEST-Cement). This benchmarking exercise indicated an average technical potential primary energy savings of 12% would be possible if the surveyed plants operated at domestic best practice levels in terms of energy use per ton of cement produced. Average technical potential primary energy savings of 23% would be realized if the plants operated at international best practice levels. Energy conservation supply curves for both fuel and electricity savings were then constructed for the 16 surveyed plants. Using the bottom-up electricity conservation supply curve model, the cost-effective electricity efficiency potential for the studied cement plants in 2008 is estimated to be 373 gigawatt hours (GWh), which accounts for 16% of total electricity use in the 16 surveyed cement plants in 2008. Total technical electricity-saving potential is 915 GWh, which accounts for 40% of total electricity use in the studied plants in 2008. The fuel conservation supply curve model shows the total technical fuel efficiency potential equal to 7,949 terajoules (TJ), accounting for 8% of total fuel used in the studied cement plants in 2008. All the fuel efficiency potential is shown to be cost effective. Carbon dioxide (CO{sub 2}) emission reduction potential associated with cost-effective electricity saving is 383 kiloton (kt) CO{sub 2}, while total technical potential for CO{sub 2} emission reduction from electricity-saving is 940 ktCO{sub 2}. The CO{sub 2} emission reduction potentials associated with fuel-saving potentials is 950 ktCO{sub 2}

GeV-Scale Electron Acceleration in a Magnetized Plasma-Filled Waveguide by Twisted Electromagnetic Waves

In this paper, a test particle model is developed to study the electron acceleration in a magnetized plasma-filled waveguide by a twisted electromagnetic wave with variable amplitude and phase along the longitudinal position. With appropriately assigned initial values, the electron total energy gain is obtained using numerical analysis without calculating the dispersion relation. Numerical results show that as long as the twisted electromagnetic waves significantly affect the electron acceleration, during the passage of an electron through the waveguide, one may employ an optimum value of the external magnetic field to obtain the maximum energy gain

A Comparison of Iron and Steel Production Energy Use and Energy Intensity in China and the U.S.

Production of iron and steel is an energy-intensive manufacturing process. In 2006, the iron and steel industry accounted for 13.6% and 1.4% of primary energy consumption in China and the U.S., respectively (U.S. DOE/EIA, 2010a; Zhang et al., 2010). The energy efficiency of steel production has a direct impact on overall energy consumption and related carbon dioxide (CO2) emissions. The goal of this study is to develop a methodology for making an accurate comparison of the energy intensity (energy use per unit of steel produced) of steel production. The methodology is applied to the steel industry in China and the U.S. The methodology addresses issues related to boundary definitions, conversion factors, and indicators in order to develop a common framework for comparing steel industry energy use. This study uses a bottom-up, physical-based method to compare the energy intensity of China and U.S. crude steel production in 2006. This year was chosen in order to maximize the availability of comparable steel-sector data. However, data published in China and the U.S. are not always consistent in terms of analytical scope, conversion factors, and information on adoption of energy-saving technologies. This study is primarily based on published annual data from the China Iron & Steel Association and National Bureau of Statistics in China and the Energy Information Agency in the U.S. This report found that the energy intensity of steel production is lower in the United States than China primarily due to structural differences in the steel industry in these two countries. In order to understand the differences in energy intensity of steel production in both countries, this report identified key determinants of sector energy use in both countries. Five determinants analyzed in this report include: share of electric arc furnaces in total steel production, sector penetration of energy-efficiency technologies, scale of production equipment, fuel shares in the iron and steel industry, and final steel product mix in both countries. The share of lower energy intensity electric arc furnace production in each country was a key determinant of total steel sector energy efficiency. Overall steel sector structure, in terms of average plant vintage and production capacity, is also an important variable though data were not available to quantify this in a scenario. The methodology developed in this report, along with the accompanying quantitative and qualitative analyses, provides a foundation for comparative international assessment of steel sector energy intensity

China Energy and Emissions Paths to 2030

After over two decades of staggering economic growth and soaring energy demand, China has started taking serious actions to reduce its economic energy and carbon intensity by setting short and medium-term intensity reduction targets, renewable generation targets and various supporting policies and programs. In better understanding how further policies and actions can be taken to shape China's future energy and emissions trajectory, it is important to first identify where the largest opportunities for efficiency gains and emission reduction lie from sectoral and end-use perspectives. Besides contextualizing China's progress towards reaching the highest possible efficiency levels through the adoption of the most advanced technologies from a bottom-up perspective, the actual economic costs and benefits of adopting efficiency measures are also assessed in this study. This study presents two modeling methodologies that evaluate both the technical and economic potential of raising China's efficiency levels to the technical maximum across sectors and the subsequent carbon and energy emission implications through 2030. The technical savings potential by efficiency measure and remaining gap for improvements are identified by comparing a reference scenario in which China continues the current pace of with a Max Tech scenario in which the highest technically feasible efficiencies and advanced technologies are adopted irrespective of costs. In addition, from an economic perspective, a cost analysis of selected measures in the key industries of cement and iron and steel help quantify the actual costs and benefits of achieving the highest efficiency levels through the development of cost of conserved energy curves for the sectors. The results of this study show that total annual energy savings potential of over one billion tonne of coal equivalent exists beyond the expected reference pathway under Max Tech pathway in 2030. CO2 emissions will also peak earlier under Max Tech, though the 2020s is a likely turning point for both emission trajectories. Both emission pathways must meet all announced and planned policies, targets and non-fossil generation targets, or an even wider efficiency gap will exist. The savings potential under Max Tech varies by sector, but the industrial sector appears to hold the largest energy savings and emission reduction potential. The primary source of savings is from electricity rather than fuel, and electricity savings are magnified by power sector decarbonization through increasing renewable generation and coal generation efficiency improvement. In order to achieve the maximum energy savings and emission reduction potential, efficiency improvements and technology switching must be undertaken across demand sectors as well as in the growing power sector. From an economic perspective, the cost of conserved energy analysis indicates that nearly all measures for the iron and steel and cement industry are cost-effective. All 23 efficiency measures analyzed for the cement industry are cost-effective, with combined CO2 emission reduction potential of 448 Mt CO2. All of the electricity savings measures in the iron and steel industry are cost-effective, but the cost-effective savings potential for fuel savings measures is slightly lower than total technical savings potential. The total potential savings from these measures confirm the magnitude of savings in the scenario models, and illustrate the remaining efficiency gap in the cement and iron and steel industries