“低碳发展”专栏征文启事

正我国提出要在2030年前实现二氧化碳排放达到峰值、2060年前实现碳中和目标之后,经济社会发展必将摆脱工业化时期对能源的资源依赖方式,全面走向绿色低碳可持续发展道路,开启一场能源领域重大技术变革。为响应"2030年碳达峰、2060年碳中和"这一国家战略需求,推进我国碳中和与生态文明建设,增进多学科协同创新和学术交流,《能源研究与管理》期刊特开辟"低碳发展"专栏,探讨我国能源、工业、建筑、交通及科技创新、生态环境建设、经济管理、政策法律等行业为实现"2030年碳达峰、2060年碳中和"目标的方法和路径。     

“低碳发展”专栏征文启事

正我国提出要在2030年前实现二氧化碳排放达到峰值、2060年前实现碳中和目标之后,经济社会发展必将摆脱工业化时期对能源的资源依赖方式,全面走向绿色低碳可持续发展道路,开启一场能源领域重大技术变革。为响应"2030年碳达峰、2060年碳中和"这一国家战略需求,推进我国碳中和与生态文明建设,增进多学科协同创新和学术交流,《能源研究与管理》期刊特开辟"低碳发展"专栏,探讨我国能源、工业、建筑、交通及科技创新、生态环境建设、经济管理、政策法律等行业为实现"2030年碳达峰、2060年碳中和"目标的方法和路径。     

“双碳”目标下氢能在我国合成氨行业的需求与减碳路径北大核心CSCD

氨(NH3)是现代社会中重要的化工产品之一,在农业和工业等领域均有重要的应用。当前我国合成氨过程中原料氢的生产以化石能源为主,为实现“双碳”目标,有效缓解高碳排放问题,电解水制氢等绿色合成氨技术与氨的清洁利用技术成为重要的突破口。本文对我国合成氨现状以及未来趋势进行研究,并基于长期能源替代规划系统(LEAP)模型,结合经济性驱动,以氢气价格和政策为主要驱动因素,考虑不同原料合成氨的替代,模拟我国合成氨行业2020—2060年的氢需求及碳排放趋势。结果表明,2060年,我国合成氨需求量将达1.2亿吨,氢气需求量达2128万吨,新增需求主要来源于船舶氨燃料、氨发电等新领域,超过合成氨的氢需求量的50%。我国合成氨行业由化石能源向可再生能源转换有着巨大的潜力,随着可再生能源制氢成本的降低,可再生能源制氢合成氨占比将会大幅度上升,超过97%。在碳排放方面,我国合成氨工业将在2030年达峰,峰值为2.2亿吨,2060年合成氨工业碳排放920万吨。为实现碳中和目标,我国应在可再生能源丰富的地区优先开展电解水制氢合成氨示范项目,加大力度开展电解制氢以及温和条件合成氨关键技术及应用,尽早实现低碳合成氨技术大规模应用,在氨应用方面,加大氨燃料发动机和掺氨发电的研究。     

江西实现碳达峰与碳中和的思考

做好碳达峰、碳中和工作是江西当前和今后一个时期全社会的一项重要任务,也是“十四五”时期推进江西经济社会高质量跨越式发展的重要抓手.面对实现2030年前碳达峰与2060年前碳中和目标的困难和挑战,江西必须坚持“绿水青山就是金山银山”生态文明理念,以战略眼光超前布局,全面部署碳达峰行动,推动产业结构转型升级、构建绿色低碳能源体系、提升能源资源利用效率、推进建筑低碳发展、推进低碳交通体系建设、加强低碳技术研发和应用,在满足当前经济增长需要的同时确保碳达峰、碳中和目标顺利实现.     

新时代可再生能源绘出“新航标”

正"习近平总书记做出系列重要讲话,明确提出我国二氧化碳排放力争于2030年前达到峰值,努力争取2060年前实现碳中和,到2030年非化石能源占一次能源消费比重达到25%左右,风电和太阳能发电总装机容量达到12亿kW以上,进一步指明了我国能源转型变革的战略方向,为我国可再生能源发展设定了新的航标"。3月30日,在国新办举行的发布会上,国家能源局局长章建华介绍中国可再生能源发展的有关情况时说。     

实现"碳达峰、碳中和"节能宣传大有可为

"力争子2030年前二氧化碳排放量达到峰值,努力争取2060年前实现碳中和"对我国节能降碳、绿色转型发展提出了更高要求.节能具有贯穿经济社会发展全过程和各领域的功能优势,因此通过节能提高能效、降低碳排放量是实现二氧化碳大规模减排的最主要途径. 节能作用能否充分发挥,推动全社会参与并"节"尽所"能"地将提高能源利用效率、促进绿色低碳可持续发展为己任是关键,因而广泛动员全社会力量参与节能,在全国范围内深入开展节能宣传工作意义重大.     

从新发展格局视角探讨民用采暖的经济可持续性问题

2060年前力争实现碳中和是我国的国家战略,各区域及各行业都需要积极回应,民用采暖属于重要的能源终端消费领域,在实现碳中和目标中肩负着较大的责任.我国民用采暖需要从清洁采暖向低碳采暖转化,在推进民用低碳采暖可持续发展过程中,面临着"地方重视短期效益""市场化困局""城市化影响"等问题,需要在综合考虑民用采暖的经济属性、...     

基于“碳中和”的氢能应用场景与发展趋势展望

氢能是可再生二次能源,具有无碳无毒、单位质量能量密度高及来源丰富等特点。中国是全球最大的能源生产国和消费国,为了应对气候变暖,减少温室气体排放,实现2060年"碳中和"目标,氢能是很好的无碳能源载体。基于"碳中和"情景,提出"零碳排放"模式下的氢能物质能量转换流程。本文通过制氢、储运、终端应用三个环节,结合储能、燃料电池、氢气内燃机、长距离输送、加氢站、发电和建筑用能七个应用场景,对氢能未来的发展趋势进行了展望。研究发现,氢能的应用存在技术或成本方面的不足。展望2060年,电能是中国能源体系构架的核心能源,氢能是有益的补充能源,建议从技术创新和成本平价两方面入手,实现基于"碳中和"的氢能应用场景。     

打造无碳绿氢产业破解碳排放约束

正面对日趋严重的能源安全和气候变化问题以及生态环境的挑战,大力发展清洁能源已经成为世界各国推动能源革命、加快能源转型、实现绿色发展的普遍共识和一致行动。随着我国提出力争二氧化碳排放2030年前达峰,力争2060年前实现碳中和,能源领域将迎来根本性调整,现代煤化工加快绿色转型已成当务之急。     

产业:乘“碳达峰、碳中和”东风打造核心竞争力

节能是大规模降碳减排的最主要途径 记者:您认为,节能工作在实现“碳达峰、碳中和”目标过程中,应该发挥怎样的作用? 孙小亮:我们认为,节能工作是实现“碳达峰、碳中和”目标的最直接、最有效、最经济的手段,也是能源系统实现二氧化碳大规模减排的最主要途径.国际能源署的分析结果显示:如果要把全球温升控制在2摄氏度以内,2050年前全球能源相关二氧化碳排放需要减少40％～70％.如果全球温室气体排放从目前的330亿吨下降到2050年的100亿吨左右,2050年前节能和提高能效对全球二氧化碳减排的贡献是37％,高于发展可再生能源、核电、二氧化碳捕获利用与封存(CCUS)等技术的贡献,位列第一.从中可以看出节能工作的极其重要性.     

计及碳税的发电权与碳排放权组合交易模型

基于发电权与碳排放权交易机制,文章构建了计及碳税的发电权与碳排放权组合交易双层规划模型。在模型中综合考虑了碳税、发电量、发电权交易价格以及碳交易价格等因素,上层模型为政府制定碳税,下层模型为发电企业确定最优的发电量及交易价格。研究表明:征收碳税不仅对发电企业碳减排起到有效的激励作用,还会对发电权交易价格与碳交易价格产生影响,随着碳税的变化,发电权交易价格与碳交易价格波动较大;征收碳税并结合发电权与碳排放权组合交易,能够实现降低碳排放与增加利润的双赢。这说明在科学合理的政府政策配置下,通过市场机制能够实现低碳环保和经济发展的和谐统一。     

Climate trade-off between black carbon and carbon dioxide emissions

There are various difficulties involved with comparing the effects of short-lived and long-lived atmospheric species on climate. Global warming potentials (GWPs) can be computed for pulse emissions of short-lived species. However, if the focus is on the long-term effect of a pulse emission occurring today, GWPs do not factor in the fact that if a radiative forcing is applied for a short period, the climate system has time to relax back to equilibrium. The concept of global temperature change potential (GTP) at a time horizon for an emission pulse has been proposed to circumvent this problem. Here we show how GTPs can be used to compare black carbon (BC) and CO₂ emissions and the methodology is illustrated with two concrete examples. In particular we discuss a trade-off situation where a decrease in BC emissions is associated with a fuel penalty and therefore an additional CO₂ emission. A parameter—which depends on the BC radiative effects, the BC emission reduction and the additional CO₂ emission—is defined and can be compared to a critical parameter to assess whether or not the BC emission reduction wins over the fuel penalty for various time horizons. We show how this concept can be generalised to compare the climate effects of carbon dioxide against a set of short-lived species and to account for differences in climate efficacy. Finally, the need for additional research is discussed in the light of current uncertainties.     

The reactions of hydrogen and carbon monoxide with surface-bound oxides on carbon

The stability of surface oxides formed on exposure of Spherocarb to oxygen has been investigated in various atmospheres (Ar, CO, and H₂) through gravimetry and mass spectrometry. Oxide complexes, formed in oxygen (2.67 Pa) at 973 or 1073 K, were exposed to 2.67 Pa of the bath gas in the temperature range 923 to 1073 K. Changes in the population of surface complexes were identified through analysis of gas evolution (principally CO) profiles during temperature-programmed desorption (TPD) of the oxides in an inert atmosphere. Oxides formed in this work display a distribution of activation energies for their decomposition, E_des, from 300 to 420 kJ mol⁻¹. Soaking of these oxides in Ar showed the frequency factor for their thermal decomposition to be 10^{14.3 ± 0.3} s⁻¹, independent of E_des. The effect of soaking in CO was essentially the same as that of Ar, and it is concluded that no significant reaction occurs under these conditions between surface oxides and CO. However, on soaking in H₂, H₂O was evolved as a result of reaction between hydrogen and the surface oxide complex

Abstract

The kinetics of the reaction between hydrogen and surface complexes are dependent on the reaction temperature and on the thermal stability of the reacting surface oxide. Less stable oxides react more readily than do more stable oxides. If all the reaction rate variation between complexes of differing thermal stability is attributed to changes in the activation energy of the reaction, the activation energy for the reaction of H₂ with complexes may be expressed as E_H = 0.5E_des − 50 kJ mol⁻¹, 348 < E_des < 408 kJ mol⁻¹. Comparison of the apparent preexponential factor for the reaction with the expected frequency factor for gas–surface-complex collision under the experimental conditions suggests that direct reaction of hydrogen with the oxygen complex may be the limiting step in the overall reaction.     

Biomass and China's carbon emissions: A missing piece of carbon decomposition

A number of previous studies on China's carbon emissions have mainly focused on two facts: (1) the continuous growth in emissions up till the middle of the 1990s; (2) the recent stability of emissions from 1996 to 2001. Decomposition analysis has been widely used to explore the driving forces behind these phenomena. However, since 2002, China's carbon emissions have resumed their growth at an even greater rate. This paper investigates China's carbon emissions during 1971–2003, with particular focus on the role of biomass, and the fall and resurgence in emissions since the mid-1990s. We use an extended Kaya identity and the well-established logarithmic mean Divisia index (LMDI I) method. Carbon emissions are decomposed into effects of various driving forces. We find that (1) a shift from biomass to commercial energy increases carbon emissions by a magnitude comparable to that of the increase in emissions due to population growth, (2) the technological effect and scale effect due to per-capita gross domestic products (GDP) growth are different in the pre-reform period versus the post-reform period, (3) the positive effect of population growth has been decreasing over the entire period, and (4) the fall in emissions in the late 1990s and resurgence in the early 2000s may be overstated due to inaccurate statistics.     

Catalysis and oxidation of carbon in a hybrid direct carbon fuel cell

The hybrid direct carbon fuel cell (HDCFC), combining molten carbonate fuel cell and solid oxide fuel cell technology, is capable of converting solid carbon directly into electrical energy without intermediate reforming. Here, we report the investigation of the HDCFC with yttria stabilized zirconia (YSZ) electrolyte, NiO-YSZ anode and lanthanum strontium manganite (LSM) cathode using the eutectic mixture of 62 mol% Li₂CO₃ and 38 mol% K₂CO₃. An open circuit voltage (OCV) of 0.71 V at 800 °C is recorded without the carbonate which increases to 1.15-1.23 V in the presence of the carbonate at the same temperature. In addition, the cell's OCV is enhanced not only by the thermal history but also by the carbonate, which is in excess of 1.57 V after the high temperature treatment. Electrochemical performance analysis indicates a suitable amount of the carbonate enhanced the carbon oxidation. With 1 mm robust thick electrolyte and commercial carbon, the cell (1.13 cm² active area) generates the peak density of 50 mW cm⁻² at 800 °C. There are significant losses from electrolyte resistance, which would be overcome by the application of a thinner electrolyte.     

Effects of carbon sources and carbonized carbon contents during carbon riveting process on the stability of Pt/C catalyst

Effects of different carbon sources and carbonized carbon contents during carbon riveting process (CRP) on the stability of Pt/C catalysts have been systematically studied. X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), cyclic voltammograms (CV), and accelerated potential cycling tests (APCT) have been carried out to characterize the catalysts. Experimental results show that the carbon riveted Pt/C catalysts treated by different carbon sources have different stability due to different properties of Pt and carbon after the CRP. The best carbon source for the carbon riveted Pt/C catalysts is glucose and is ascribed to the most content of Pt (0) and sp³-C after the CRP. APCT results indicate that the stability of Pt/C catalysts carbon-riveted by glucose exhibits the increasing trend with the increase of carbonized carbon contents because of increasing anchor effect to Pt nanoparticles. However, a larger carbon content from the carbonization of glucose can also reduce the electrochemically active specific surface areas (ESA) of the carbon riveted Pt/C catalyst by covering the active sites of Pt nanoparticles. Taking into account both activity and stability of the carbon riveted Pt/C catalysts, 6% carbon from the carbonization of glucose is the optimized content.     

Structure and electrochemical properties of activated polyacrylonitrile based carbon fibers containing carbon nanotubes

Solution spun polyacrylonitrile (PAN), PAN/multi-wall carbon nanotube (MWCNT), and PAN/single-wall carbon nanotube (SWCNT) fibers containing 5 wt.% carbon nanotubes were stabilized in air and activated using CO₂ and KOH. The surface area as determined by nitrogen gas adsorption was an order of magnitude higher for KOH activated fibers as compared to the CO₂ activated fibers. The specific capacitance of KOH activated PAN/SWCNT samples was as high as 250 F g⁻¹ in 6 M KOH electrolyte. Under the comparable KOH activation conditions, PAN and PAN/SWCNT fibers had comparable surface areas (BET surface area about 2200 m² g⁻¹) with pore size predominantly in the range of 1–5 nm, while surface area of PAN/MWCNT samples was significantly lower (BET surface area 970 m² g⁻¹). The highest capacitance and energy density was obtained for PAN/SWCNT samples, suggesting SWCNT advantage in charge storage. The capacitance behavior of these electrodes has also been tested in ionic liquids, and the energy density in ionic liquid is about twice the value obtained using KOH electrolyte.     

Fabrication and electrochemical performances of porous carbon nanotubes/polyaniline-modified carbon nanotube fiber

通过低电压电泳沉积的方法在碳纳米管纤维（CNF）表面沉积多孔碳纳米管（CNTs）,然后在其表面电化学沉积一层聚苯胺（PANI）,得到CNTs@PANI三维多孔网络结构修饰的核-鞘型纤维电极材料。通过扫描电镜、透射电镜和拉曼光谱表征电极材料表面形貌和微观结构,并利用电化学工作站测试电化学性能,研究结果表明,沉积的多孔CNTs结构可以为PANI提供更多的氧化还原反应活性位点,而PANI也具有固定CNTs的作用,在电流密度为1 mA/cm²时,CNTs和PANI修饰的电极面积比电容达77.28 mF/cm²。以聚二甲基硅氧烷薄膜为基底、PVA-H₃PO₄为电解质制备的对称型固态柔性超级电容器在电流密度为0.25 mA/cm²时,面积比电容为61.25 mF/cm²,恒流充放电4000次后,电容值仍维持在80%,并且串联两个电容器可以点亮电压为1.8 V的LED灯泡。     

Studies and characterisations of various activated carbons used for carbon/carbon supercapacitors

Various activated carbons from the PICA Company have been tested in supercapacitor cells in order to compare their performances. The differences measured in terms of specific capacitance and cell resistance are presented. Porosity measurements made on activated carbon powders and electrode allowed a better understanding of the electrochemical behaviour of these activated carbons. In this way, the PICACTIF SC carbon was found to be an interesting active material for supercapacitors, with a specific capacitance as high as 125 F/g.