Advances in air pollution control for key industries in China during the 13th five-year plan

Industrial development is an essential foundation of the national economy,but the industry is also the largest source of air pollution,of which power plants,iron and steel,building materials,and other industries emit large amounts of pollutants.Therefore,the Chinese government has promulgated a series of stringent emission regulations,and it is against this backdrop that research into air pollution control technologies for key industrial sectors is in full swing.In particular,during the 13th Five-Year Plan,breakthroughs have been made in pollution control technology for key industrial sectors.A multi-pollutant treatment technology system of desulfurization,denitrification,and dust collection,which applies to key industries such as power plants,steel,and building materials,has been developed.High-performance materials for the treatment of different pollutants,such as denitrification catalysts and desulfurization absorbers,were developed.At the same time,multi-pollutant synergistic removal technologies for flue gas in various industries have also become a hot research topic,with important breakthroughs in the synergistic removal of NO_(x),SO_(x),and Hg.Due to the increasingly stringent emission standards and regulations in China,there is still a need to work on the development of multi-pollutant synergistic technologies and further research and development of synergistic abatement technologies for CO_(2) to meet the requirements of ultra-low emissions in industrial sectors.

Advances in air pollution control for vessels in China

Vessel emissions have contributed a great deal to air quality deterioration in China.Hence,the Chinese government has promulgated a series of stringent emission regulations.It is in this context that vessel emission control technology research is in full swing.In particular,during the 13th Five-Year Plan,the air pollution control technology of vessels has greatly improved.Vessel emission control has followed two main governance routes:source emission reduction and aftertreatment technology.Source control focuses on alternative fuels,with two main directions,the development of new fuels and the modification of existing fuels.Moreover,after-treatment technologies have also been developed,including wet desulfurization technology using seawater or alkaline liquids as wet washing liquids and selective catalytic reduction(SCR)for the control of NOx emission.Due to China’s increasingly stringent emissions standards and regulations,work on the development of clean alternative fuels and further upgrading the collaborative application of after-treatment technologies to meet the near-zero-emissions requirements of vessels is still necessary.

Advances in the treatment of multi-pollutant flue gas in China's building materials industry

In most of the world’s building material industries,the control of flue gas pollutants mainly focuses on a single pollutant.However,given the large capacity and high contribution of China’s building materials industry to global air pollution,the need to develop multipollutant emission reduction technology is urgent.Recently,China has focused on reducing the emissions of flue gas pollutants in the building materials industry,established many key research and development projects,and gradually implemented more stringent pollutant emission limits.This project focuses on the most recent advances in flue gas emission control technology in China’s building materials industry,including denitration,dust removal,desulfurization,synergistic multi-pollutant emission reduction,and the construction of pilot research and demonstration projects for pollutant removal in several building material industries.On this basis,revised pollutant limits in flue gas emitted in China’s building material industry are proposed.

Technology development and cost analysis of multiple pollutant abatement for ultra-low emission coal-fired power plants in China

The implementation of ultra-low emission(ULE)limits(SO_(2):35 mg/m3,NOx:50 mg/m3,PM:10 mg/m3)promoted the development of flue gas treatment technologies in China.Pollutant control technology development for Chinese coal-fired power plants was summarized and an analysis of the applicability and cost of pollutant control technologies was conducted.Detailed data were collected from 30 ultra-low emission coal-fired units across China.Based on a cost analysis model,the average unit power generation incremental costs were 0.0144and 0.0095 CNY/(kW·hr)for SO_(2)and NOx control technologies,respectively.The unit power generation incremental cost of twin spray tower technology was 7.2%higher than that of dual-loop spray tower technology.The effect of key parameters on operating cost was analyzed.The unit power generation incremental cost increased because of increments in the electricity price for SO_(2)control technology and the price of the reductant in NOx control technology.With high sulfur content or NOx concentration,the unit power generation incremental cost caused by pollutant control increased,whereas the unit pollutant abatement cost decreased.However,the annual operating hours or load increased,thereby leading to a decline in unit power generation incremental cost and unit pollutant abatement cost.

Preface

The serious air pollution problems in China have significantly affected the development of China’s economy and society,especially in key areas such as Beijing-Tianjin-Hebei,Yangtze River Delta,and Pearl River Delta,which has aroused widespread concern throughout society.With the launch of the MOST(Ministry Of Science and Technology)key project for Air Pollution Formation Mechanism and Control Technology during the 13thFive-Year Plan.

Experimental study and numerical simulation of the characteristics of a percussive gas-solid separator

The presence of solid particles in the flow of hypersonic wind tunnels damages the appearance of the experiment models in the wind tunnel and influences the accuracy of experimental results. The design of a highly efficient gas-solid separator was therefore undertaken, Particle trajectory imaging methods were used to measure trajectories under different conditions. The flow field and particle movement characteristics for different head angles （HAs） and separation tooth angles （STAs）, inlet velocities, and the exhaust gas outlet pressures in the separator, were calculated using simulations based on the discrete phase model. The particle separation efficiency, pressure loss, and flow loss resulting from different structural parameters were also studied. In line with experimental observations, the characteristic angle of particle movements in the separator and the separation efficiency of the separator were found to increase with decreasing HA and with increasing STA. Separation efficiency improves with increasing inlet velocity and with increasing negative pressure of the exhaust gas outlet; however, the corresponding pressure loss and the flow rate of the waste gas also increased.

Utilizing phase-shifted long-period fiber grating to suppress spectral broadening of a high-power fiber MOPA laser system

Suppressing nonlinear effects in high-power fiber lasers based on fiber gratings has become a hotspot.At present,research is mainly focused on suppressing stimulated Raman scattering in a high-power fiber laser.However,the suppression of spectral broadening,caused by self-phase modulation or four-wave mixing,is still a challenging attribute to the close distance between the broadened laser and signal laser.If using a traditional fiber grating with only one stopband to suppress the spectral broadening,the signal power will be stripped simultaneously.Confronting this challenge,we propose a novel method based on phase-shifted long-period fiber grating(PS-LPFG)to suppress spectral broadening in a high-power fiber master oscillator power amplifier(MOPA)laser system in this paper.A PS-LPFG is designed and fabricated on 10/130 passive fiber utilizing a point-by-point scanning technique.The resonant wavelength of the fabricated PS-LPFG is 1080 nm,the full width at half maximum of the passband is 5.48 nm,and stopband extinction exceeds 90%.To evaluate the performance of the PS-LPFG,the grating is inserted into the seed of a kilowattlevel continuous-wave MOPA system.Experiment results show that the 30 dB linewidth of the output spectrum is narrowed by approximately 37.97%,providing an effective and flexible way for optimizing the output linewidth of highpower fiber MOPA laser systems.

Flow behavior of high-temperature flue gas in the heat transfer chamber of a pilot-scale coal-water slurry combustion furnace

The flow characteristics of high-temperature flue gas are important in the heat transfer of coal-water slurry（CWS） combustion furnaces.The flow field of a 250 kg/h vertical-type slag tap cyclone furnace was non-intrusively investigated,using two-dimensional particle-image velocimetry（2D PIV）.The method was verified using traceable fly ash particles in high-temperature flue gas.The flow field of the flue gas was analyzed with a time-averaged method,based on which the effects of excess air ratio and loading were investigated.The flue gas separated by a gas separator maintained good rigidity near the furnace wall,rather than eroding the heating surface.Numerical simulations validated the reliability of PIV under the actual circumstances within the furnace.This study provides guidelines for applying 2D PIV in analyzing flue gas in thermal test boilers.