The IEA CCC 3rd Workshop on upgrading and efficiency improvements in coal-fired power plant took place on the 16-17 September 2014 in Shanghai’s International Convention Centre. The workshop was held in collaboration with China’s Electric Power Planning & Engineering Institute (EPPEI). The workshop was filmed by Chinese media and Dr Andrew Minchener, the IEA CCC General Manager, contributed to a number of articles in the Chinese press. And of course, Xi Jinping, the President of China was at the International Convention Centre at the same time, but not for our workshop (this time round).
Shanghai’s International Convention Centre
Many of the major Chinese power generation companies and research organisations participated in the event, including EPPEI, East China Electric Power Design Institute, Shanghai Waigaoqiao No.3 Power Generation Corporation, CPCEP, Northeast Electric Power Design Institute, Shanghai Jiyi Power Plant Equipment Corporation, Tsinghua University, CPECC, Zhejiang Electric Power Design Institute, Guohua Suizhong Power Generation Corporation, and Sichuan Baima CFB Demonstration Power Station. From the rest of the world, presentations were given from the IEA CCC, National Technical University of Athens, Fraunhofer and the University of Kent, all in Europe; Hanbat National University and Yonsei University of Korea; and NETL and EPRI of the USA.
Andrew’s introduction, partly in Mandarin, opened the workshop. In Europe, particularly Germany, the introduction of intermittent renewable energy has enforced the cyclic operation of coal-fired power plant; ways to do this were covered by the IEA CCC. NETL and EPRI in the USA have been assessing options to improve the efficiency of their coal fleet. In Greece, research aims to use a gas turbine alongside old lignite plant to remove excess moisture from lignite in order to increase electric capacity and efficiency at low cost. Fraunhofer in Germany have developed an analytical method, TOM, which can measure slagging behaviour of coal on high temperature components as well as quantifying creep damage. Work in Korea aims to have the IGCC/IGFC with CCS technology ready for potential use in the future. Further progress here was reviewed. Reliable online continuous measurement of pulverized coal flow using electrostatics can now be achieved at full-scale; better online closed-loop control of pulverized coal flow is under development.
Dr Andrew Minchener opening workshop
Twelve of the 20 presentations from this workshop were from the Chinese contingent. 400 GW of new coal-fired power plant is required by 2020, which equates to ~50% points additional capacity. Due to problems with air pollution, such as visibility of less than two km in Beijing, the lower emission standards of 5 mg/Nm3 PM, 35 mg/Nm3 SO2 and 50 mg/Nm3 NOx, which includes mercury for the first time, will enforce extensive flue gas cleaning technology. Additionally, new build coal-fired power plant have been banned on the east coast of China, except for WGQ IV, see below.
Research, development and deployment of upgrades and new plant have significantly improved the environmental performance of conventional technology. With new large units replacing old small units coupled with efficiency improvements throughout the fleet, the average coal consumption for China’s entire coal-fired fleet is now 321 g/kWh, down from 380 g/kWh ten years ago. This is the third lowest in the world after Japan and Germany at 290 g/kWh. Additionally, close to a third of the coal-fired fleet is fitted with CHP. Further improvements in efficiency will be met with larger units, double-reheat, and higher steam parameters, 630°C and 28 MPa superheat.
Selective Catalytic Reduction (SCR) is in operation outside of its design criteria but with longer lifetimes and uncompromised conversion efficiency of NOx to N2 of over 80%. Low NOx combustion combined with SCR achieves NOx emissions of around 30 mg/Nm3. Particulate control now reaches 99.95% of total particulates, and PM2.5 capture is high, due to the deployment of new/upgraded ESP with multiple fields and an additional small polishing ESP (wet or cold type), fabric filter or combined ESP/fabric filter after the wet FGD. Wet FGD now reaches 97.5% removal of SO2 with emissions around 12 mg/Nm3.
Interestingly, a Chinese power company has bought two 800 MW supercritical units from Russia. At some point both operated in Russia, and were then rebuilt them using new, and often fewer, components or upgrading components where possible and even reverse engineering and then rebuilding some components. New modelling methods led to some redesign of components. The plant runs safely, meets all emission regulations and each unit can reach 880MW. The payback period for the project is under 5 years.
Soot blowing has been further developed. Coal blending to lower emissions was touched on. Lower water consumption methods were covered which include: low water FGD, air cooling and new pulverised lignite USC plant are in development which require no make-up water, known as getting water from lignite (GWFL). China will soon have over 100 CFB units and a 600MW SC CFB has just successfully run for 168 hours. Work on 700°C technology continues and we will find out more about this in the second IEA CCC Workshop on advanced-ultrasupercritical coal-fired power plants (http://ausc2.coalconferences.org/ibis/2nd%20A-USC%20power%20plant%20workshop/home).
The workshop dinner was held in the International Convention Centre which had panoramic views over the Hunagpu to the Bund. The Chinese food was incredible, especially the Squirrel-Shaped Mandarin Fish. Drinks included The Great Wall red wine, Tsingtao beer and the local favourite ‘glutinous’ wine.
Dr Andrew Minchener speaking at workshop dinner