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Sanna A.,Heriot - Watt University | Wang X.,China Huaneng Group Clean Energy Research Institute | Lacinska A.,British Geological Survey | Styles M.,British Geological Survey | And 2 more authors.
Minerals Engineering | Year: 2013

Carbon capture and storage by mineralisation (CCSM) is a promising technology that sequesters CO2 from flue gases into stable mineral carbonates. Although the development of indirect pH swing processes (dissolution at acid pH and carbonation at basic pH) able to recycle the chemicals used are promising, there are still limitations in reaction rate of mineral dissolution being slow in view of a large deployment of the technology. The extraction of Mg from lizardite using magnesium bisulphate has been studied as a function of temperature, reagent concentration, solid to liquid ratio, thermal and mechanical pre-activation. Although the overall highest Mg extraction (95%) was obtained after 3 h, the reduction of the dissolution time to 1 h can consistently reduce the volumes to be treated per unit time leading to low capital costs in a hypothetical mineralisation plant. About 80% of Mg was extracted from lizardite in 1 h at 140 C, 2.8 M NH4HSO4, particles <250 μm and a solid to liquid ratio of 100 g/l. At 140 C, serpentine undergoes extensive structural modifications as indicated by XRD and FTIR analyses, producing amorphous silica and accelerating the kinetics of the reaction. Particles with diameter less than 250 μm were obtained by grinding the lizardite at 925 rpm for 10 min consuming 33 kW h/trock. © 2013 The Authors. Published by Elsevier Ltd. All rights reserved.

Yang J.,Tsinghua University | Yang J.,China Huaneng Group Clean Energy Research Institute | Hu Y.,Tsinghua University | Zuo Z.,Tsinghua University | And 2 more authors.
Applied Thermal Engineering | Year: 2012

Removal of hydration heat from mass concrete during construction is important for the quality and safety of concrete structures. In this study, a three-dimensional finite element program for thermal analysis of mass concrete embedded with double-layer staggered heterogeneous cooling water pipes was developed based on the equivalent equation of heat conduction including the effect of cooling water pipes and hydration heat of concrete. The cooling function of the double-layer staggered heterogeneous cooling pipes in a concrete slab was derived from the principle of equivalent cooling. To improve the applicability and precision of the equivalent heat conduction equation under small flow, the cooling function was revised according to its monotonicity and empirical formulas of single-phase forced-convection heat transfer in tube flow. Considering heat hydration of concrete at later age, a double exponential function was proposed to fit the adiabatic temperature rise curve of concrete. Subsequently, the temperature variation of concrete was obtained, and the outlet temperature of cooling water was estimated through the energy conservation principle. Comparing calculated results with actual measured data from a monolith of an arch dam in China, the numerical model was proven to be effective in sufficiently simulating accurate temperature variations of mass concrete. © 2011 Elsevier Ltd. All rights reserved.

Xu S.,China Huaneng Group Clean Energy Research Institute | Ren Y.,China Huaneng Group Clean Energy Research Institute | Wang B.,China Huaneng Group Clean Energy Research Institute | Xu Y.,China Huaneng Group Clean Energy Research Institute | And 4 more authors.
Applied Energy | Year: 2014

Coal-fired gasifiers are the key technology for clean power generation and coal chemical process. This paper presents a 2-stage entrained flow dry powder gasifier in which coal is entrained into the lower chamber burner with oxygen and steam to raise the temperature of the crude gas up to 1700. °C. The lower chamber is linked to the upper gasification chamber through a middle throat, where additional coal and steam is fed to cool down the slag to less than 900. °C for deslagging from the lower chamber bottom.Various coals have been characterized and gasified with this 2-stage entrained flow dry powder gasifier and comparisons made with single stage gasifiers. The results show that the 2-stage gasifier is suitable for a broad range of coal varieties and gives carbon conversion up to 98.9% with cold syngas efficiency of 83.2% at a pressure of 3.0. MPa, while the oxygen and coal consumption are lower than with the single stage gasifier. © 2013 .

Wang X.,China Huaneng Group Clean Energy Research Institute | Wang X.,University of Nottingham | Maroto-Valer M.M.,University of Nottingham
Energy | Year: 2013

Optimization of CCSM (carbon dioxide capture and storage with mineralisation) using RAS (recyclable ammonium salts) was studied here in order to minimize the energy consumption of this process. Water evaporation is required for the recycling of ammonium salts in the process, however the water evaporation technologies normally impose high energy penalty. In the optimized process, solid to liquid (S/L) ratio was increased to reduce water usage, but this change impacts dissolution efficiency, where the dissolution efficiency decreased from 100% at S/L of 50 g/l to 71% at S/L of 300 g/l. However, a 6% increase of dissolution efficiency was reported when the S/L ratio increased from 200 g/l to 300 g/l, probably due to increasing mineral inter-collisions. Besides, the optimized process employed the pressurized reactor, this change resulted in the mineral phase of product changed from hydromagnesite to magnesite. The carbon fixation efficiency was significantly improved by using (NH4)2CO3 compared to NH4HCO3, and the highest CO2 fixation efficiency achieved was 46.6% at S/L of 300 g/l. The mass balance for the optimized process was 4.9 t of serpentine, 0.6 t of NH4HSO4, 4.7 t of (NH4)2CO3 and 16 t of water required to sequester 1 t CO2. © 2013 Elsevier Ltd.

Sun X.,China Huaneng Group Clean Energy Research Institute
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2014

Based on research and manufacture and engineering application experience of 330 MW and 600 MW circulating fluidized bed (CFB) boiler, the plan design of 350 MW Ultra-supercritical CFB boiler with 700℃ steam parameters was performed, the water-steam process and key components of advanced Ultra-supercritical (AUSC) 350 MW CFB boiler were also analytical calculated and designed. The AUSC 350 MW CFB boiler adopted H-shaped configuration with four steam-coated cyclones placed on both sides of the furnace. The cyclone is connected to a compact pneumatic uniform-flow heat exchangers through a stand pipe. The membrane water walls of the boiler are vertical tube panels with low-mass flow rate, and two loops feeding coal system can assure the fuel be supply into furnace reliably and uniformly. © 2014 Chinese Society for Electrical Engineering.

Wang J.,China Huaneng Group Clean Energy Research Institute | Xu S.,China Huaneng Group Clean Energy Research Institute
International Journal of Coal Science and Technology | Year: 2014

CO2 capture is an important carbon management route to mitigate the greenhouse gas emission in power sector. In recent years, China Huaneng Group (CHNG) has paid more attention on CO2 capture technology development and launched a series of R&D and demonstration projects. In the area of pre-combustion CO2 capture technology, GreenGen project initiated by CHNG is the first integrated gasification combined cycle (IGCC) power plant in China. Located in Tianjin, GreenGen aims at the development, demonstration and promotion of a near-zero emissions power plant. An IGCC plant of 250 MW has successfully passed full-scale trial operation. In the next phase, a pre-combustion CO2 capture unit will be integrated into the system. Pre-combustion process based on coal chemical process has been developed with lower costs successfully. Regarding to post-combustion CO2 capture (PCC), in 2008, CHNG built a 3,000 tpa CO2 capture plant, which was the first CO2 capture demonstration plant in China. In 2009, CHNG launched a PCC project in Shanghai with a capture capacity of 120,000 tpa CO2. Recently, Huaneng Clean Energy Research Institute (CERI) and Powerspan formed a joint venture, Huaneng-CERI-Powerspan (HCP). HCP has completed the technology qualification program to supply carbon capture technology for the CO2 capture Mongstad project. Besides these activities mentioned above, feasibility studies and system design for large scale PCC system, have been undertaken by CERI and its partners from Australia, US and Europe. © 2014, The Author(s).

Jiang M.,China Huaneng Group Clean Energy Research Institute | Huang B.,China Huaneng Group Clean Energy Research Institute
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2012

Coal-fired power generation will be still the most important power generation technology for a long time in China. Resource, environment and climate change have been taking with the serious challenges for the sustainable development of coal-fired power generation. Large-capacity and high parameter units, which have many advantages including higher efficiency, easier to control pollutants emission and to deploy, higher reliability and lower cost, will be the most important technology for coal-fired power generation. Although it has the disadvantages of complex system and expensive cost, the large-scale IGCC unit will still be an important technology being worth developing for its bigger potential to enhance the efficiency and reduce the pollutants emission. CFB is a kind of clean combustion technology and is good at burning low-grade coal, which will play a complementary role for coal-fired power generation in China. It will be required to develop further the technologies of dedust, deSOx, deNOx and deHg to meet the new emission standards. CCUS is an important option to reduce the carbon emission massively, but high energy penalty and safety for long-time storage both are the big challenges for this technology. © 2012 China. Soc. for Elec. Eng.

Xu S.,China Huaneng Group Clean Energy Research Institute
30th Annual International Pittsburgh Coal Conference 2013, PCC 2013 | Year: 2013

• CHNG had developed PCC process both for coal and natural gas combustion flue gas, and one of them has been operated 5 years. • CHNG is doing Pre-CC demonstration pant. • Improving efficiency and reducing cost is most important in the future.

China Huaneng Group Clean Energy Research Institute | Date: 2011-11-11

The disclosure provides an M-type pulverized coal boiler suitable for ultrahigh steam temperature. The pulverized coal boiler comprises a hearth of which the bottom is provided with a slag hole and a tail downward flue of which the lower part is provided with a flue gas outlet. The pulverized coal boiler further comprises a middle flue communicated between the hearth and the tail downward flue, wherein the middle flue comprises an upward flue and a hearth outlet downward flue of which the bottoms are mutually communicated and the upper ends are respectively communicated with the upper end of the hearth and the upper end of the tail downward flue to form a U-shaped circulation channel. In the pulverized coal boiler provided by the disclosure, the middle flue which extends downwards and can make flue gas flow along the U-shaped circulation channel is arranged between the outlet of the hearth and the tail downward flue, so that high-temperature flue gas from the hearth can be introduced into a position with low elevation through the downward flue, and final-stage convection heating surfaces (such as a high-temperature superheater and a high-temperature reheater) can be arranged at positions with low height, and the length of ultrahigh-temperature steam pipelines between the high-temperature superheater and a steam turbine, and between the high-temperature reheater and the steam turbine can be greatly reduced. Therefore, the manufacturing cost of a boiler unit is obviously reduced.

China Huaneng Group Clean Energy Research Institute | Date: 2011-11-18

The disclosure provides an arrangement structure suitable for an inverted pulverized coal boiler with ultra-high steam temperature steam parameters, including a hearth, wherein the hearth is communicated with a middle uplink flue, and the top of the middle uplink flue is communicated with that of a tail downlink flue. In the arrangement structure suitable for an inverted pulverized coal boiler with ultra-high steam temperature steam parameters, the hearth is connected with the middle uplink flue by a hearth outlet horizontal flue at the bottom, so that the high-temperature gas at the hearth outlet is drained to a low elevation and then flows upwards through the middle uplink flue; a final heating surface may be arranged at the low position of the hearth outlet horizontal flue and the middle uplink flue so as to reduce the length of the high-temperature steam pipeline between the final heating surface and the steam turbine, lower the manufacturing cost of the boiler as well as the frication and radiation loss of the pipe, improve the efficiency of the power generating unit and make the power generating unit possible to adopt ultra-high steam temperature steam parameters and/or double reheat system.

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