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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.

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.

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.

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.

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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