积极开展核电研究 开辟能源新途径

核电是一种安全、低碳、功率密度高、可大规模利用的能源,具有高效和CO₂等化学气体零排放的优点。从中国核电站建设政策推进,核电站安全性,核电技术特别是中国“华龙一号”和小型多功能模块式压水堆ACP100“玲龙一号”核电站技术的建设、运营和效益等各方面在内陆建站的概况,利用核电和H₂对有关产业实现CO₂超低排放和零排放的影响等方面进行了分析研究。研究认为,山西作为内陆省份煤炭大省,煤炭外输,发电用煤,钢铁、水泥、陶瓷和氮肥生产等工业耗能耗煤量巨大,CO₂减排压力巨大。要实现“碳达峰、碳中和”国家发展战略,成为国家能源革命排头兵,就要清醒认识能源革命就是要革矿物石油和煤炭用作燃料的命。而当今唯一能大规模代替石油和煤炭燃料,CO₂零排放的新能源——核能,具有独特的、其他能源不可取代的优势。因此,要积极开展有关核电的研究,其中重点在开始研究筹办核电站。     

Nuclear energy into the twenty-first century

The historical development of the civil nuclear power generation industry is examined in the light of the need to meet conflicting energy-supply and environmental pressures over recent decades. It is suggested that fission (thermal and fast) reactors will dominate the market up to the period 2010–2030, with fusion being relegated to the latter part of the twenty-first century. A number of issues affecting the use of nuclear electricity generation in Western Europe are considered, including its cost, industrial strategy needs, and the public acceptability of nuclear power. The contribution of nuclear power stations to achieving CO₂ targets aimed at relieving global warming is discussed in the context of alternative strategies for sustainable development, including renewable energy sources and energy-efficiency measures. Trends in the generation of nuclear electricity from fission reactors are finally considered in terms of the main geopolitical groupings that make up the world in the mid-1990s. Several recent, but somewhat conflicting, forecasts of the role of nuclear power in the fuel mix to about 2020 are reviewed. It is argued that the only major expansion in generating capacity will take place on the Asia-Pacific Rim and not in the developing countries generally. Nevertheless, the global nuclear industry overall will continue to be dominated by a small number of large nuclear electricity generating countries; principally the USA, France and Japan.     

Integrated biomass energy systems and emissions of carbon dioxide

Electric Power Research Institute (EPRI) and the US Department of Energy (DOE) have been funding a number of case studies under the initiative entitled “Economic Development through Biomass Systems Integration”, with the objective of investigate the feasibility of integrated biomass energy systems, utilizing a dedicated feedstock supply system (DFSS) for energy production. This paper deals with the full fuel cycle for four of these case studies, which have been examined with regard to the emissions of carbon dioxide, CO₂. Although the conversion of biomass to electricity in itself does not emit more CO₂ than is captured by the biomass through photosynthesis, there will be some CO₂ emissions from the DFSS. External energy is required for the production and transportation of the biomass feedstock, and this energy is mainly based on fossil fuels. By using this input energy, CO₂ and other greenhouse gases are emitted. However, by utilizing biomass with fossil fuels as external input fuels, we would get about 10–15 times more electric energy per unit fossil fuel, compared with a 100% coal power system. By introducing a DFSS on former farmland the amount of energy spent for production of crops can be reduced, the amount of fertilizers can be decreased, the soil can be improved and a significant amount of energy will be produced compared with an ordinary farm crop. Compared with traditional coal-based electricity production, the CO₂ emissions are in most cases reduced significantly by as much as 95%. The important conclusion is the great potential for reducing greenhouse gas emissions through the offset of coal by biomass.     

Mitigation assessment results and priorities for China''s energy sector

Energy-related CO₂ emission projections of China up to 2030 are given. CO₂ mitigation potential and technology options in main fields of energy conservation and energy substitution are analyzed. CO₂ reduction costs of main mitigation technologies are estimated and the multi-criteria approach is used for assessment of priority technologies.

The results of this study show (1) Given population expansion and high GDP growth, energy-related CO₂ emissions will increase in China. (2) There exists a large energy conservation potential in China. (3) Adjustment of industry structure and increase of shares of products with high added value have and will play a very important role in reducing energy intensity of GDP. (4) Energy conservation and substitution of coal by natural gas, nuclear power, hydropower and renewable energy will be the key technological measures in a long-term strategy to reduce GHG emission. (5) Identification and implementation of GHG mitigation technologies is consistent with China's targets of sustainable development and environmental protection. (6) Energy efficiency improvement is a “no-regret” option for CO₂ reduction, whereas an incremental cost is needed to develop hydropower and renewable energy.     

集成小型堆和可再生能源的超临界CO2循环发电系统

  [目的]  小型模块化压水堆(小型堆)核电站由于温度参数低,其发电效率不到30%,为了提高小型堆的核能利用效率,可将小型堆与可再生能源组合,并以先进的超临界CO₂循环作为热能转换为电能的装置。  [方法]  基于简单回热模式的超临界CO₂循环,并在此基础上增加一次间冷和一次再热,将小型堆与太阳能、生物质能热源集成为新型混合发电系统,对其发电效率进行了分析。  [结果]  结果表明:对于高压透平入口温度390 ℃的系统,发电效率34.13%,对于高压透平入口温度550 ℃的系统,发电效率41.22%。此外,对系统的安全性分析表明:CO₂本身是具备核安全属性的工质,并且超临界CO₂循环还可以作为反应堆的非能动余热排出系统,确保在严重事故工况下,反应堆持续排出衰变热。  [结论]  集成小型堆和可再生能源的超临界CO₂循环发电系统具备良好的发电效率和核安全性。     

燃气-超临界CO2联合循环发电系统

  [目的]  燃气轮机排气温度高,可增加底循环,利用排气的余热发电,从而提高燃料总的能量利用率。鉴于超临界CO₂循环热效率高,并且具有系统简单、结构紧凑、运行灵活等潜在优势,可与燃气轮机组成新型的燃气-超临界CO₂联合循环。  [方法]  为了充分利用燃气轮机排气余热,提出在简单回热超临界CO₂循环的基础上,再嵌套一个简单回热循环的布置方式,并以PG9351(FA)型燃气轮机为例,对其热效率进行了计算分析。同时,在系统中增加余热利用装置,可将剩余热量用于供热、转换为冷量或发电。  [结果]  结果表明:对于选定的燃气轮机,超临界CO₂循环最高温度可达约600 ℃,循环发电效率约32%,获得余热温度为170 ℃以上,余热热量占燃气轮机排气热量9%,联合循环发电效率约54%。  [结论]  燃气-超临界CO₂联合循环发电系统具有较高的热效率,并且保留部分较高品位的余热,可进一步用于电厂运行。     

Multi-objective optimization of an advanced combined cycle power plant including CO2 separation options

This paper illustrates a methodology developed to facilitate the analysis of complex systems characterized by a large number of technical, economical and environmental parameters. Thermo-economic modeling of a natural gas combined cycle including CO₂ separation options has been coupled within a multi-objective evolutionary algorithm to characterize the economic and environmental performances of such complex systems within various contexts.

The method has been applied to a case of power generation in Germany. The optimum options for system integration under different boundary conditions are revealed by the Pareto Optimal Frontiers. Results show the influence of the configuration and technical parameters on the electrical efficiencies of the Pareto optimal plants and their sub-systems. The results provide information on the relationship between power generation cost and CO₂ emissions, and allow sensitivity analyses of important economical parameters like natural gas and electricity prices. Such a tool is of interest for power generation technology suppliers, for utility owners or for project investors, and for policy makers in the context of CO₂ mitigation schemes including emission trading.     

A coal-fired power plant integrated with biomass co-firing and CO2 capture for zero carbon emission

A promising scheme for coal-fired power plants in which biomass co-firing and carbon dioxide capture technologies are adopted and the low-temperature waste heat from the CO₂ capture process is recycled to heat the condensed water to achieve zero carbon emission is proposed in this paper. Based on a 660 MW supercritical coal-fired power plant, the thermal performance, emission performance, and economic performance of the proposed scheme are evaluated. In addition, a sensitivity analysis is conducted to show the effects of several key parameters on the performance of the proposed system. The results show that when the biomass mass mixing ratio is 15.40% and the CO₂ capture rate is 90%, the CO₂ emission of the coal-fired power plant can reach zero, indicating that the technical route proposed in this paper can indeed achieve zero carbon emission in coal-fired power plants. The net thermal efficiency decreases by 10.31%, due to the huge energy consumption of the CO₂ capture unit. Besides, the cost of electricity (COE) and the cost of CO₂ avoided (COA) of the proposed system are 80.37 $/MWh and 41.63 $/tCO₂, respectively. The sensitivity analysis demonstrates that with the energy consumption of the reboiler decreasing from 3.22 GJ/tCO₂ to 2.40 GJ/ tCO₂, the efficiency penalty is reduced to 8.67%. This paper may provide reference for promoting the early realization of carbon neutrality in the power generation industry.     

A comparison of CO2 emissions from fossil and solar power plants in the United States

We present estimates of the lifetime carbon dioxide emissions from coal-fired, photovoltaic, and solar thermal power plants in the United States. These CO₂ estimates are based on a net energy analysis derived from both operational systems and detailed design studies. It appears that energy-conservation measures and shifting from fossil to renewable energy sources have significant long-term potential to reduce CO₂ production caused by energy generation. The implications of these results for a national energy policy are discussed.     

A model analysis of clean development mechanisms to reduce both CO2 and SO2 emissions between Japan and China

It is necessary for Japan to support the development of desulfurization policies of China to solve global and local environmental problems. This study proposes a “double clean development mechanism” to reduce both CO₂ and SO₂ emissions at the same time. The purpose of this study is to investigate the consequences for both countries' energy economies of following double clean development mechanism between Japan and China. A dynamic optimization model is developed to estimate the effects of Japanese investments in China for carbon dioxide recovery-disposal and emission desulfurization technologies. The simulation results suggest that a double clean development mechanism can effectively mitigate the damage caused by SO₂ emissions because the clean development mechanism itself can reduce SO₂ emissions, e.g. by switching to fuels. However, China might not be willing to accept restrictions on SO₂ emissions. This study also examines whether China will be able to maintain high growth rates with a clean development mechanism under the CO₂ and SO₂ restriction. The analysis shows that increasing the upper limit of investment from Japan to China can enhance the economies of the both nations. The effect of nuclear power installation on economic performance is also investigated for the both nations.     

Cost effective integration of hydrogen in energy systems with CO2 constraints

The integration of hydrogen in national energy systems is illustrated in four extreme scenarios, reflecting four technological mainstreams (energy conservation, renewables, nuclear and CO₂ removal) to reduce C emissions. Hydrogen is cost-effective in all scenarios with higher CO₂ reduction targets. Hydrogen would be produced from fossil fuels, or from water and electricity or heat, depending upon the scenario. Hydrogen would be used in the residential and commercial sectors and for transport vehicles, industry, and electricity generation in fuel cells. At severe (50–70%) CO₂ reduction targets, hydrogen would cost-effectively supply more than half of the total useful energy demands in three out of four scenarios. The marginal emission reduction costs in the CO₂ removal scenario at severe CO₂ reduction targets are DFL 200/tCO₂ (ca $ 100/t). In the nuclear, renewable and energy conservation scenarios these costs are much higher. Whilst the fossil fuel scenario would be less expensive than the other scenarios, the possibility of CO₂ storage in depleted gas reservoirs is a conditio sine qua non.     

Will Germany move into a situation with unsecured power supply?

Together with a huge number of other countries, Germany signed the Paris Agreements in 2015 to prevent global temperature increase above 2°C. Within this agreement, all countries defined their own national contributions to CO₂ reduction. Since that, it was visible that CO₂ emissions in Germany decreased, but not so fast than proposed in this German nationally determined contribution to the Paris Agreement. Due to increasing traffic, CO₂ emissions from this mobility sector increased and CO₂ emission from German power generation is nearly constant for the past 20 years, even a renewable generation capacity of 112 GW was built up in 2017, which is much higher than the peak load of 84 GW in Germany. That is why the German National Government has implemented a commission (often called “The German Coal Commission”) to propose a time line: how Germany can move out of coal-fired power stations. This “Coal Commission” started its work in the late spring of 2018 and handed over its final report with 336 pages to the government on January 26th, 2019. Within this report the following proposals were made: ① Until 2022: Due to a former decision of the German Government, the actual remaining nuclear power generation capacity of about 10 GW has to be switched off in 2022. Besides, the “Coal Commission” proposed to switch off additionally in total 12.5 GW of both, hard coal and lignite-fired power plants, so that Germany should reduce its conventional generation capacity by 22.5 GW in 2022. ② Until 2030: Another 13 GW of German hard coal or lignite-fired power plants should be switched off. ③ Until 2038: The final 17 GW of German hard coal or lignite-fired power plants should be switched off until 2038 latest. Unfortunately the “Coal Commission” has not investigated the relevant technical parameter to ensure a secured electric power supply, based on German’s own national resources. Because German Energy Revolution mainly is based on wind energy and photovoltaic, this paper will describe the negligible contribution of these sources to the secured generation capacity, which will be needed for a reliable power supply. In addition, it will discuss several technical options to integrate wind energy and photovoltaic into a secured power supply system with an overall reduced CO₂ emission.     

Are renewables an alternative to nuclear power? An analysis of the Austria/Slovakia discussions

Politicians and publics throughout Europe have different views on nuclear power and renewable energy sources. Countries such as Austria and Denmark which have no nuclear power are rather hostile towards this energy source, and at the same time view renewable energy sources as one of the solutions in curbing CO₂ emissions. Other countries, such as Slovakia, which is less endowed in terms of renewables, view nuclear power as a electricity-generating source that can reduce dependency on fossil fuels and thereby CO₂. This paper focuses on the confrontation between two nations with different sets of electricity policies, namely Austria and Slovakia. Of particular interest for this study include an evaluation of Austria's anti-nuclear policy towards its Slovakian neighbour and an analysis of Austria's attempts to promote renewable energy sources in both Austria and Slovakia. In conclusion, a number of recommendations are put forward with regard to how Austria's future energy dialogue with Slovakia should look like and what types of projects Austria should consider funding.     

Scenario analysis on CO2 emissions reduction potential in China''s electricity sector

With the approach of the year 2012, a new round of international negotiations has energized the entire climate change community. With this, analyses on sector-based emissions reduction and mitigation options will provide the necessary information to form the debate. In order to assess the CO₂ emissions reduction potential of China's electricity sector, this research employs three scenarios based on the “long-range energy alternative planning system” (LEAP) model to simulate the different development paths in this sector. The baseline scenario, the current policy scenario, and the new policy scenario seek to gradually increase the extent of industrial restructuring and technical advancement. Results imply that energy consumption and CO₂ emission in China's electricity sector will rise rapidly in all scenarios until 2030—triple or quadruple the 2000 level; however, through structural adjustment in China's electricity sector, and through implementing technical mitigation measures, various degrees of abatement can be achieved. These reductions range from 85 to 350 million tons CO₂ per year—figures that correspond to different degrees of cost and investment. Demand side management and circulating fluidized bed combustion (CFBC) (ranked in order) are employed prior to use to realize emissions reduction, followed by supercritical plants and the renovation of conventional thermal power plants. In the long term, nuclear and hydropower will play the dominant role in contributing to emissions reduction. It is also suggested that a “self-restraint” reduction commitment should be employed to help contribute to the reduction of emission intensity, an avenue that is more practical for China in light of its current development phase. Setting the year 2000 as the base year, the intensity reduction target could possibly range from 4.2% to 19.4%, dependent on the implementation effectiveness of various mitigation options.     

Effects of future fossil fuel use on CO2 levels in the atmosphere

A model based on fossil fuel use per capita and United Nations population predictions has been developed to predict global fossil fuel use and the resulting levels of CO₂ in the atmosphere. The results suggest levels of CO₂ will increase to between 415 and 421 ppm by 2025. Countries with energy-intensive economies will be responsible for the majority of CO₂ emissions, while nations with large populations but low energy consumption per capita will have less of an effect. A major increase in nuclear power generation will not have a significant impact on CO₂ levels over this time scale.     

Environmental assessment and extended exergy analysis of a “zero CO2 emission”, high-efficiency steam power plant

Aim of this paper is to analyze the performance of an innovative high-efficiency steam power plant by means of two “life cycle approach” methodologies, the life cycle assessment (LCA) and the “extended exergy analysis” (EEA).

The plant object of the analysis is a hydrogen-fed steam power plant in which the H₂ is produced by a “zero CO₂ emission” coal gasification process (the ZECOTECH^© cycle). The CO₂ capture system is a standard humid-CaO absorbing process and produces CaCO₃ as a by-product, which is then regenerated to CaO releasing the CO₂ for a downstream mineral sequestration process.

The steam power plant is based on an innovative combined-cycle process: the hydrogen is used as a fuel to produce high-temperature, medium-pressure steam that powers the steam turbine in the topping section, whose exhaust is used in a heat recovery boiler to feed a traditional steam power plant.

The environmental performance of the ZECOTECH^© cycle is assessed by comparison with four different processes: power plant fed by H₂ from natural gas steam reforming, two conventional coal- and natural gas power plants and a wind power plant.     

Conceptual study of distributed CO2 capture and the sustainable carbon economy

Capture of carbon dioxide from distributed sources is often neglected as a viable solution to the global problem of CO₂ emissions management. Small scale power plants, including those applicable to the transportation sector, can be designed to capture their CO₂ exhaust stream, provided it is not heavily diluted with air. Liquefaction of carbon dioxide allows the captured CO₂ to be stored densely, with a minimal energetic penalty and space requirement, until it can be permanently sequestered. In this short-term solution, the energetic penalty for CO₂ capture can be further offset by exploiting novel energy conversion processes involving regeneration of the reaction product stream – a simple strategy that is not exploited in conventional systems. More importantly, in the long-term, as the renewable energy infrastructure is built up, the collected CO₂ can be recycled into synthetic carbon-based liquid fuels which act as energy carriers in the sustainable carbon economy.     

Internalisation of external cost in the power generation sector: Analysis with Global Multi-regional MARKAL model

The Global MARKAL-Model (GMM), a multi-regional “bottom-up” partial equilibrium model of the global energy system with endogenous technological learning, is used to address impacts of internalisation of external costs from power production. This modelling approach imposes additional charges on electricity generation, which reflect the costs of environmental and health damages from local pollutants (SO₂, NO_x) and climate change, wastes, occupational health, risk of accidents, noise and other burdens. Technologies allowing abatement of pollutants emitted from power plants are rapidly introduced into the energy system, for example, desulphurisation, NO_x removal, and CO₂ scrubbers. The modelling results indicate substantial changes in the electricity production system in favour of natural gas combined cycle, nuclear power and renewables induced by internalisation of external costs and also efficiency loss due to the use of scrubbers. Structural changes and fuel switching in the electricity sector result in significant reduction of emissions of both local pollution and CO₂ over the modelled time period. Strong decarbonisation impact of internalising local externalities suggests that ancillary benefits can be expected from policies directly addressing other issues then CO₂ mitigation. Finally, the detailed analysis of the total generation cost of different technologies points out that inclusion of external cost in the price of electricity increases competitiveness of non-fossil generation sources and fossil power plants with emission control.     

Coal gasification system using nuclear heat for ammonia production

Utilization of nuclear energy is an effective way of solving the global warming resulting from CO₂ emissions. Thermal energy accounts for more than two thirds of total energy utilization at present and therefore it is significant to extend the utilization of nuclear heat for the effective reduction of CO₂ emissions in the world. This paper describes a coal gasification system using HTGR nuclear heat in an ammonia production plant in terms of industrial utilization of the nuclear heat. The system uses the nuclear heat directly in addition to generating electricity. A steam reforming method using a two-stage coal gasifier is employed: it improves the heat utilization efficiency of the secondary helium gas from the HTGR. Finally, the paper clarifies that the nuclear gasification system can reduce CO₂ emissions by about five hundred thousand tons per year from that of a conventional system using fossil fuel.     

Short-term impact of green certificates and CO2 emissions trading in the Swedish district heating sector

Swedish district-heating (DH) systems use a wide range of energy sources and technologies for heat-and-power generation. This provides the DH utilities with major flexibility in changing their fuel and technology mix when the economic conditions for generation change. Two recently introduced policy instruments have changed the DH utilities’ costs for generation considerably; the tradable green-certificate (TGC) scheme introduced in 2003 in Sweden, and the tradable greenhouse-gas emission permit (TEP) scheme introduced in the EU on January 1, 2005. The objective of this study is to analyse how these two trading schemes impact on the operation of the Swedish DH sector in terms of changes in CHP generation, CO₂ emissions, and operating costs. The analysis was carried out by comparing the most cost-effective operation for the DH utilities, with and without, the two trading schemes applied, using a model that handles the Swedish DH-sector system-by-system. It was found that the volume of renewable power generated in CHP plants only increased slightly owing to the TGC scheme. The TGC and the TEP schemes in force together, however, nearly doubled the renewable power-generation. CO₂ emissions from the DH sector may either increase or decrease depending on the combination of TGC and TEP prices. The overall CO₂ emissions from the European power-generation sector would, however, be reduced for all price combinations assuming that increased Swedish CHP generation replaces coal-condensing power (coal-fired plants with power generation only) in other European countries. The trading schemes also lower the operational costs of the DH sector since the cost increase owing to the use of more expensive fuels and the purchase of TEPs is outweighed by the increased revenues from sales of electricity and TGCs.