Industrial test and techno-economic analysis of CO2 capture in Huaneng Beijing coal-fired power station

The first industrial-scale CO₂ capture plant in China has been demonstrated at Huaneng Beijing power plant has shown that this technology is a good option for the capture of CO₂ produced by commercial coal-fired power plants. The commissioning and industrial tests are introduced in this paper. The tests show that in the early stages of the passivation phase, the concentration variations of amine, anti-oxidant and Fe³⁺ are in the normal range, and the main parameters achieve the design value. The efficiency of the CO₂ capture was about 80–85%, and by the end of January 2009 about 900 tons of CO₂ (99.7%) have been captured. The equipment investment and consumptive costs, including steam, power, solution and others, have been analyzed. The results show: the cost of the absorber and the stripper account for about 50% of main equipment; the consumptive cost is about 25.3 US$ per metric tons of CO₂, of which the steam requirement accounts for about 55%; the COE increased by 0.02 US$/kW h and the electricity purchase price increased by 29%.     

Isoconversional kinetic analysis of co-combustion of sewage sludge with straw and coal

In this paper, the co-combustion behaviour of sewage sludge with straw and coal were carried out in a thermogravimetric analyzer under different atmospheres and at different heating rates (10, 20 and 40 K min⁻¹) in the temperature range from ambient temperature to 1000 °C. TG and DTG curves were analysed. The Flynn–Wall–Ozawa’s (FWO) and Kissinger–Akahira–Sunose’s (KAS) isoconversional methods were used to yield dependency of the activation energy of reduction process on the degree of conversion. The values of E_α were obtained. The results indicate that: with the increase of heating rate, the maximum weight loss rate of samples increase obviously. The activation energy is practically constant in the 0.2 ? α ? 0.9 range, with the average values of E_α = 137.27 and 132.38 kJ mol⁻¹ calculated by FWO and KAS methods, respectively.     

Relationship between the economic cost and the reliability of the electric power supply system in city: A case in Shanghai of China

This paper presents a model to quantify the impact of electric power outages on GDP by using Cobb–Douglas production function to develop an economic relationship between the reliability of the electric power supply system and the cost of electric energy unserved. Our findings show that average costs for providing a stable power supply are much lower than disruption costs, which is supported by recurring to the data available of Shanghai. Estimated by using Shanghai’s macroeconomic data of 1990–2006, this relationship indicates that the impact of electricity service disruption on Shanghai’s GDP is about 48.18 × 10⁸ CNY in 2006, matching an alternative “back-of-envelope” estimate of 50.91 × 10⁸ CNY. The estimated costs per kWh unserved are 1.81–10.26 CNY in 1990–2006, mirroring the increasing importance of electricity in the period’s economic development. These results demonstrate the usefulness of our approach for quantifying the reliability benefits of investments in electricity infrastructure.     

Forecast of oil reserves and production in Daqing oilfield of China

As China’ largest oilfield, Daqing is of great importance to China, this paper analyzes the status of the Daqing oilfield and forecasts its ultimate recoverable reserves by use of the URR model. The forecast results are presented for three scenarios which show that the ultimate recoverable reserves in Daqing oilfield are 3574.0 million tons in the optimistic scenario, 3169.3 million in the base case scenario and 3033.3 million in the pessimistic scenario, respectively. A system dynamics model is established and the quantitative relationships between variables in the model are determined. Total oil production, remaining recoverable reserves, annual newly discovered reserves, and the degree of reserves recovery before 2060 are simulated under the three scenarios by use of the system dynamics model. The forecast results show that the future oil production in Daqing oilfield will continue declining, under the base case scenario, from 41.6 million tons in 2007 to 8.0 million tons in 2060. For Chinese policy-makers, it is worth paying attention to the problem of whether oil production in new oilfields can effectively make up for the decline in production of the large, old oilfields.     

Integrated resource strategic planning: Case study of energy efficiency in the Chinese power sector

In the last quarter of the 20th century, many power companies used the integrated resource planning (IRP) approach in power expansion planning. Today, very few power companies use this approach because of the split between the power generation and distribution activities. It seems that, in some countries, long-term power system expansion planning has become a task of the central government. To help the government in this area, this paper proposes a new approach called the integrated resource strategic planning (IRSP). When combined with a smart grid, this approach can replace the IRP for the government’s power sector expansion. This paper introduces the necessity and possibility of using this new approach, presents a framework on how to use the approach, and justifies the effectiveness of this approach against the traditional power planning approach, with a case study in China. This paper concludes that if China follows the IRSP approach, it may be able to avoid or postpone up to 69 GW of power generation in the period 2009–2015. These measures could help mitigate 201.8 million tons of carbon dioxide (CO₂), 0.816 million tons of sulfur dioxide (SO₂), and 0.946 million tons of nitrogen oxide (NO_x).     

A study of the development of bio-energy resources and the status of eco-society in China

Industrialization of bio-energy relies on the supply of resources on a large scale. The theoretical biomass resources could reach 2.61–3.51 billion tce (tons of coal equivalent)/a in China, while the available feedstock is about 440–640 million tce/a, however, among this only 1.5–2.5% has been transferred into energy at present. Marginal land utilization has great prospects of supplying bio-energy resources in China, with co-benefits, such as carbon sequestration, water/soil conservation, and wind erosion protection. There is a large area of marginal land in China, especially in northern China, including about 263 million ha of desertification land, 173 million ha of sand-land, and 17 million ha of salinizatin land. The plant species suitable to be grown in marginal lands, including some species in Salix, Hippophae, Tamarix, Caragana, and Prunus is also abundant Biomass feedstock in marginal lands would be 100 million tce/a in 2020, and 200 million tce/a in 2050. As a result, a win–win situation of eco-society and bio-energy development could be realized, with an expected 4–5% reduction of total CO₂ emission in China in 2020–2050. Although much progress has been made in the field of bio-energy research in China, yet significant efforts should be taken in the future to fulfill large-scale industrialization of bio-energy.     

An overview of energy consumption of the globalized world economy

For the globalized world economy with intensive international trade, an overview of energy consumption is presented by an embodied energy analysis to track both direct and indirect energy uses based on a systems input–output simulation. In 2004, the total amounts of energy embodied in household consumption, government consumption, and investment are 7749, 874, and 2009 Mtoe (million tons of oil equivalent), respectively. The United States is shown as the world’s biggest embodied energy importer (683 Mtoe) and embodied energy surplus receiver (290 Mtoe), in contrast to China as the biggest exporter (662 Mtoe) and deficit receiver (274 Mtoe). Energy embodied in consumption per capita varies from 0.05 (Uganda) to 19.54 toe (Rest of North America). Based on a forecast for 2005–2035, China is to replace the United States as the world’s leading embodied energy consumer in 2027, when its per capita energy consumption will be one quarter of that of the United States.     

Cost of energy and environmental policy in Portuguese CO2 abatement—scenario analysis to 2020

This paper quantifies the contribution of Portuguese energy policies for total and marginal abatement costs (MAC) for CO₂ emissions for 2020. The TIMES_PT optimisation model was used to derive MAC curves from a set of policy scenarios including one or more of the following policies: ban on nuclear power; ban on new coal power plants without carbon sequestration and storage; incentives to natural gas power plants; and a cap on biomass use. The different MAC shows the policies’ effects in the potential for CO₂ abatement. In 2020, in the most encompassing policy scenario, with all current and planned policies, is possible to abate only up to +35% of 1990 emissions at a cost below 23 € t/CO₂. In the more flexible policy scenarios, it is possible to abate up to −10% of 1990 emissions below the same cost. The total energy system costs are 10–13% higher if all policies are implemented—76 to 101 B€—roughly the equivalent to 2.01–2.65% of the 2005 GDP. Thus, from a CO₂ emission mitigation perspective, the existing policies introduce significant inefficiencies, possibly related to other policy goals. The ban on nuclear power is the instrument that has the most significant effect in MAC.     

Energy efficiency standards for refrigerators in Brazil: A methodology for impact evaluation

In Brazil energy efficiency standards for cold appliances was established in 2007. A specified single set of MEPS (minimum energy performance standards) for refrigerators, freezers and freezer refrigerators was implemented without evaluating its impacts and estimation of potential electricity savings. This paper presents a methodology for assessing the impacts of the Brazilian MEPS for cold appliances. It uses a bottom-up approach to estimate residential end-use consumption and to evaluate the energy saving potential for refrigerators. The household electricity consumption is projected by modeling appliance ownership using an econometric approach based on the recent household survey data. A cost–benefit analysis for more stringent standards is presented from the perspective of the society and electricity customers. The results showed that even considering the current market conditions (high discount rate for financing new efficient equipment) some MEPS options are advantageous for customers. The analysis also demonstrates significant cost-effective saving potential from the society perspective that could reach 21 TWh throughout the period of 2010–2030—about 25% of current residential consumption.     

Energy-efficiency standards for electric motors in Brazilian industry

The first regulation of the “Energy Efficient Act” for electric motors, launched in 2002, established two sets of minimum efficiency performance standards (MEPS), for ‘standard’ (mandatory) and ‘high efficiency’ (voluntary) motors. An updated regulation, from the end of 2005 (Edict 553/2005), established the previous high-efficiency MEPS as mandatory for all motors in the Brazilian market. This paper analyses the consequences of this new regulation, which is foreseen to take effect in 2010. These new Brazilian MEPS are compatible with those implemented in other countries. The cost–benefit analysis, considered for different scenarios for industrial consumers, showed that motor substitution (from standard to high efficiency) is generally advantageous. A sample of nine thousand industrial motors has been used, with measured operation in actual conditions, to analyze the investment cost–benefit in three different scenarios. This analysis also demonstrated the benefit of motor substitution, with an average MWh cost from 20 to 35 US$, and with only a few substitutions presenting an unfavorable cost–benefit relationship to the user. We assess that Edict 553 avoided construction of 350 MW of hydroelectric capacity. Nevertheless, since the cost of conserved energy for this energy-saving measure is generally below the marginal cost of expansion of the Brazilian electric system, we propose mechanisms to share investment costs among the society as a whole, including demand-side bidding.     

Experimental determination and analysis of CO2, SO2 and NOx emission factors in Iran’s thermal power plants

Emission factors of CO₂, SO₂ and NO_x emitted from Iran’s thermal power plants are fully covered in this paper. To start with, emission factors of flue gases were calculated for fifty thermal power plants with the total installed capacity of 34,863 MW over the period 2007–2008 with regard to the power plants’ operation characteristics including generation capacity, fuel type and amount and the corresponding alterations, stack specifications, analysis of flue gases and physical details of combustion gases in terms of g kWh⁻¹. This factor was calculated as 620, 2.57 and 2.31 g kWh⁻¹ for CO₂, SO₂ and NO_x respectively. Regarding these results, total emissions of CO₂, SO₂ and NO_x were found to be 125.34, 0.552 and 0.465 Tg in turn. To achieve an accurate comparison, these values were compared with their alternatives in North American countries. According to this comparison, emission factor of flue gases emitted from Iran’s thermal power plants will experience an intensive decline if renewable, hydroelectric and nuclear types of energy are more used, power plants’ efficiency is increased and continuous emission monitoring systems and power plant pollution reduction systems are utilized.     

CO2 emissions structure of Indian economy

This paper analyses carbon dioxide (CO₂) emissions of the Indian economy by producing sectors and due to household final consumption. The analysis is based on an Input–Output (IO) table and Social Accounting Matrix (SAM) for the year 2003–04 that distinguishes 25 sectors and 10 household classes. Total emissions of the Indian economy in 2003–04 are estimated to be 1217 million tons (MT) of CO₂, of which 57% is due to the use of coal and lignite. The per capita emissions turn out to be about 1.14 tons. The highest direct emissions are due to electricity sector followed by manufacturing, steel and road transportation. Final demands for construction and manufacturing sectors account for the highest emissions considering both direct and indirect emissions as the outputs from almost all the energy-intensive sectors go into the production process of these two sectors. In terms of life style differences across income classes, the urban top 10% accounts for emissions of 3416 kg per year while rural bottom 10% class accounts for only 141 kg per year. The CO₂ emission embodied in the consumption basket of top 10% of the population in urban India is one-sixth of the per capita emission generated in the US.     

Economic and environmental implications of demand-side management options

End-use electricity efficiency improvements offer an inexpensive way to reduce power shortages. The present study estimates the potential of demand-side management efficiency improvement targeted at (1) short-term efficiency improvement (agricultural pump rectification) that can provide immediate relief, and (2) long-term efficiency improvement (appliance standards such as AC and refrigerator, new agricultural pump purchase and pump replacement) for Gujarat state in India. The methodology includes the calculation of cost of conserved energy for each technology, which works out to be (−1.18) US$ cents/kW h for new agriculture pump sets, 1.03 US$ cents/kW h for refrigerators and 5.21 US$ cents/kW h for air conditioners. The price of power varies around 1.13 US$ cents to 12.1 cents/kW h in Gujarat. The annual energy savings from the selected energy-efficient technologies are approximately 8767 GW h over a period of 10 yr, while the estimated peak power savings are about 1814 MW, large enough to eliminate one-fourth of the state's electricity shortages. Also, the estimated CO₂ emissions savings are about 7715 Giga grams (Gg) from implementation of the selected energy efficiency measures over a period of 10 yr.     

A study on optimum insulation thicknesses of external walls in hot summer and cold winter zone of China

The employ of thermal insulation is one of the most effective ways of building energy conservation for cooling and heating. Therefore, the selection of a proper insulation material and the determination of optimum insulation thickness are particularly vital. Four typical cities of Shanghai, Changsha, Shaoguan and Chengdu are selected to represent A, B, C and D subzone of hot summer and cold winter zone in China, respectively. The optimum thicknesses of five insulation materials including expanded polystyrene, extruded polystyrene, foamed polyurethane, perlite and foamed polyvinyl chloride are calculated with a typical residential wall using solar-air cooling and heating degree-days analysis and P₁–P₂ economic model. And then, life cycle total costs, life cycle savings and payback periods are calculated based on life cycle cost analysis. Considering different orientations, surface colors, insulation materials and climates, optimum thicknesses of the five insulations vary from 0.053 to 0.236 m, and the payback periods vary from 1.9 to 4.7 years over a lifetime of 20 years. The maximum life cycle savings are 54.4 $/m² in Shanghai, 54.8 $/m² in Changsha and 41.5 $/m² in Shaoguan (with a deep-colored northeast wall), and 39.0 $/m² in Chengdu (with a light-colored northwest wall). Finally, an approach to analyze economical efficiency of insulation materials is developed, result shows that expanded polystyrene is the most economic insulation material of the five because of the highest life cycle saving and lowest payback period.     

Fabrication of Ni nanowires for hydrogen evolution reaction in a neutral electrolyte

Hydrogen evolution reaction in 1 M Na₂SO₄ was investigated using Ni nanowires in diameter of 250 nm with exposed lengths of 20, 35, and 45 μm, respectively. The Ni nanowires were fabricated by a direct-current pulse electrodeposition technique using an anodic aluminum oxide template, followed by selective removal of the supporting pore walls. Scanning Electron Microscope images revealed structural stabilities and X-ray diffraction pattern indicated a polycrystalline fcc phase. In current–potential (i–V) polarizations, the Ni nanowires with longer exposed lengths demonstrated larger current responses. Analysis from impedance spectroscopy confirmed increasing double-layer capacitances with longer Ni nanowires. In galvanostatic lifetime experiments, the free-standing Ni nanowires exhibited a reduced overpotential over that of supported ones. Similar procedures were performed for the oxygen evolution reaction in both i–V and lifetime measurements. For the Ni nanowires of 45 μm length, we estimated the energy cost for hydrogen production was 5.24 × 10⁵ J/mole.     

Optimal household refrigerator replacement policy for life cycle energy,greenhouse gas emissions,and cost

Although the last decade witnessed dramatic progress in refrigerator efficiencies, inefficient, outdated refrigerators are still in operation, sometimes consuming more than twice as much electricity per year compared with modern, efficient models. Replacing old refrigerators before their designed lifetime could be a useful policy to conserve electric energy and greenhouse gas emissions. However, from a life cycle perspective, product replacement decisions also induce additional economic and environmental burdens associated with disposal of old models and production of new models. This paper discusses optimal lifetimes of mid-sized refrigerator models in the US, using a life cycle optimization model based on dynamic programming. Model runs were conducted to find optimal lifetimes that minimize energy, global warming potential (GWP), and cost objectives over a time horizon between 1985 and 2020. The baseline results show that depending on model years, optimal lifetimes range 2–7 years for the energy objective, and 2–11 years for the GWP objective. On the other hand, an 18-year of lifetime minimizes the economic cost incurred during the time horizon. Model runs with a time horizon between 2004 and 2020 show that current owners should replace refrigerators that consume more than 1000 kWh/year of electricity (typical mid-sized 1994 models and older) as an efficient strategy from both cost and energy perspectives.     

Potential energy savings and environmental impact by implementing energy efficiency standard for household refrigerators in China

With the rapid economic growth and improvement in standard of living, Chinese people are employing more and more household appliances to make their living convenient and comfortable, of which refrigerators are indispensable. Because refrigerators operate continuously irrespective of seasons and regions, the total electricity consumption of refrigerators is huge and consequently causes severe energy-related environmental issues. China has been paying more and more attention to this and issued a national energy efficiency standard, GB12021.2-2003, for refrigerators. This paper first describes the standard briefly. Then it develops a mathematic model to evaluate the potential energy savings and environmental impacts of the standard. The estimated results indicate implementing the standard will save large energy, as well as benefit greatly to environment. Thus, it is very necessary to implement energy efficiency standard for refrigerators in China.     

Energy,economic and environmental benefits of using high-efficiency motors to replace standard motors for the Malaysian industries

Electric motors use major share (i.e. about 30–80% of total industrial energy consumption) of total industrial energy use around the world. Experiences from other countries show that government intervention in the form of regulations such as mandatory and voluntary approaches can save sizeable amount of energy along with the reduction in emissions associated with energy savings. This paper presents potential energy savings by introducing high-efficiency motors as a case study in Malaysian industrial sector. Emission reductions associated with the energy savings has been estimated and presented as well. It was also estimated that a cumulative amount of 1940 and 892 GWh of energy can be saved for 20 and 120 kW motors, respectively, in Malaysia relative to BAU over the next 10 years. Similarly, a cumulative amount of USD 100 million and USD 60 million can be saved as utility bills for the same motor categories. It has been found that the payback period of different capacities of motors are less than a year. Based on results, it was found that 1789 million kg of CO₂ emission can be avoided by replacing standard motors with high-efficiency motors.     

Synthesis and electrochemistry of cubic rocksalt Li–Ni–Ti–O compounds in the phase diagram of LiNiO2–LiTiO2–Li[Li1/3Ti2/3]O2

On the basis of extreme similarity between the triangle phase diagrams of LiNiO₂–LiTiO₂–Li[Li_1/3Ti_2/3]O₂ and LiNiO₂–LiMnO₂–Li[Li_1/3Mn_2/3]O₂, new Li–Ni–Ti–O series with a nominal composition of Li_1+z/3Ni_1/2−z/2Ti_1/2+z/6O₂ (0 ≤ z ≤ 0.5) was designed and attempted to prepare via a spray-drying method. XRD identified that new Li–Ni–Ti–O compounds had cubic rocksalt structure, in which Li, Ni and Ti were evenly distributed on the octahedral sites in cubic closely packed lattice of oxygen ions. They can be considered as the solid solution between cubic LiNi_1/2Ti_1/2O₂ and Li[Li_1/3Ti_2/3]O₂ (high temperature form). Charge–discharge tests showed that Li–Ni–Ti–O compounds with appropriate compositions could display a considerable capacity (more than 80 mAh g⁻¹ for 0.2 ≤ z ≤ 0.27) at room temperature in the voltage range of 4.5–2.5 V and good electrochemical properties within respect to capacity (more than 150 mAh g⁻¹ for 0 ≤ z ≤ 0.27), cycleability and rate capability at an elevated temperature of 50 °C. These suggest that the disordered cubic structure in some cases may function as a good host structure for intercalation/deintercalation of Li⁺. A preliminary electrochemical comparison between Li_1+z/3Ni_1/2−z/2Ti_1/2+z/6O₂ (0 ≤ z ≤ 0.5) and Li_6/5Ni_2/5Ti_2/5O₂ indicated that charge–discharge mechanism based on Ni redox at the voltage of >3.0 V behaved somewhat differently, that is, Ni could be reduced to +2 in Li_1+z/3Ni_1/2−z/2Ti_1/2+z/6O₂ while +3 in Li_6/5Ni_2/5Ti_2/5O₂. Reduction of Ti⁴⁺ at a plateau of around 2.3 V could be clearly detected in Li_1+z/3Ni_1/2−z/2Ti_1/2+z/6O₂ with 0.27 ≤ z ≤ 0.5 at 50 °C after a deep charge associated with charge compensation from oxygen ion during initial cycle.     

Preparation and electrochemical properties of composite LaNix/Ni–S–Co alloy film

The composite LaNi_x/Ni–S–Co film with considerable stability and high HER activity (η₁₅₀ = 70 mV, 353 K) was obtained by molten salt electrolysis combined with aquatic electrodeposition. LaNi_x film was prepared by galvanostatic electrolysis at 100 mA cm⁻² under 1273 K. The results showed that the La³⁺ ions could be reduced on the nickel cathode and the LaNi_x film could form, i.e. La³⁺ + 3e + xNi = LaNi_x (x = 5 or 3) at ca. −0.6 V, which is much lower than that of the decomposition potential of lanthanum, due to the strong depolarization effect of nickel. Furthermore, compared with the traditional amorphous Ni–S film, the composite LaNi_x/Ni–S–Co film could absorb large amount of H atoms, which would be oxidized and avoid the dissolution of the Ni–S–Co film under the state of open-circuit effectively and increase the HER activity.