Experimental Investigation on the Influence of Air Velocity on the Particle Dispersion Behavior of Rice Husk in a Fuel-Rich/Lean Burner

2017 ◽  
Author(s):  
Weichen Ma ◽  
Hao Zhou ◽  
Kefa Cen
Keyword(s):  
Rice Husk ◽  
Ccd Camera ◽  
Particle Dispersion ◽  
Pollutant Emissions ◽  
Pollutant Emission ◽  
Block Type ◽  
Separation Performance ◽  
Air Velocity ◽  
Large Particles ◽  
Rich Side

Recently the firing of biomass at existing power plant has drawn much attention because biomass fuels result in less pollutant emission. It is desirable to investigate the flow characteristics of biomass particles in existing combustors in order to determine whether the coal burners also have good adaptability for biomass fuel. The particle dispersion in the burner has a close relationship with pollutant emissions. In this paper, a monitoring system based on a charge-coupled device (abbreviated as CCD) camera was employed to measure the particle distribution of rice husk in a fuel-rich/lean burner. The influence of air velocity was taken into consideration. The particle-rich/lean ratio is 19.49, 16.23, 14.86, and 12.94 (corresponding to the air velocity of 9.5, 11, 12.5, and 14 m/s, respectively) at the exit of the burner model. The results indicates that the air velocity has a negative effect on the separation performance. In order to verify the particle distributions obtained by the digital imaging technique, specially designed filter bags were used to collect rice husk from both the fuel-rich side and fuel-lean side. Then mass and size distributions of the collected particles were analyzed. The results agrees with the trend above and indicates that the block-type concentrator has greater impacts on large particles. More large particles were collected from the fuel-rich side. The dispersion mechanism of rice husk particles revealed in this paper can propose solutions to the actual operation of plants that combust/co-combust the rice husk. (CSPE)

Co-Combustion of Coal With Rice Husk and Bamboo in Power Generation

2007 ◽  
Author(s):  
Christopher Y. H. Chao ◽  
Philip C. W. Kwong ◽  
J. H. Wang
Keyword(s):  
Rice Husk ◽  
Power Plants ◽  
Fuel Mixture ◽  
Volatile Matter ◽  
Pollutant Emissions ◽  
Energy Output ◽  
Pollutant Emission ◽  
Firing Process ◽  
Excess Air ◽  
Unit Energy

In many Asian countries Coal is frequently used a major fuel in power plants. Burning coal creates quite a lot of environmental problems when compared to other cleaner fuels such as natural gas. Experimental study of co-combustion of coal and biomass was conducted in a laboratory scale combustion facility to evaluate the combustion and pollutant emission performance under different operation parameters. Rice husk and bamboo were used as the biomass fuels in this study. This paper reported the influence of the biomass blending ratio in the fuel mixture and the excess air ratio on the combustion behavior. It was noted that the combustion temperature and the energy output from the co-firing process were reduced compared to coal combustion alone owing to the fact that biomass has lower heating value compared to coal. However, the high volatile matter (VM) content of biomass improved the combustion time scale so that the carbon monoxide (CO) emissions were reduced substantially. In addition, the fuel nitrogen and sulfur content in biomass were lower than that of coal and hence suppressed the formation of nitrogen oxides (NOx) and sulfur dioxide (SO2) during the cocombustion process. The increase of excess air ratio also affected most of the pollutant emissions. The pollutant emission per unit energy output at different excess air ratios and biomass blending ratios were studied in detail in this paper. Attention should be paid to the high potential of slagging and fouling in the boiler when co-firing coal with biomass.

scholarly journals Environmental Impact and External Costs Associated with Hub-and-Spoke Network in Air Transport

2021 ◽  
Vol 13 (2) ◽  
pp. 465
Author(s):  
Mengyuan Sun ◽  
Yong Tian ◽  
Yao Zhang ◽  
Muhammad Nadeem ◽  
Can Xu
Keyword(s):  
Environmental Impact ◽  
Living Environment ◽  
Strategic Decision ◽  
Air Transport ◽  
Pollutant Emissions ◽  
Pollutant Emission ◽  
Civil Aviation ◽  
External Costs ◽  
Hub And Spoke ◽  
City Network

Under the background of economic globalization, the air transport industry developed rapidly. It turns out that the city-to-city network has not been able to adapt well to the development of the society, and the hub-and-spoke network came into being. The hub-and-spoke network demonstrates the advantages of reducing the operating costs of airlines to keep a competitive advantage, and by maintaining the interests of airlines in the rapidly developing context. However, during the operation of aircrafts, they consume fuel and spew a great deal of harmful pollutants into the air, which has an adverse impact on the living environment. This paper explores the impact and external costs associated with hub-and-spoke network in air transport from an environmental perspective. With some mathematical models, we construct a hub-and-spoke network and take a quantitative study on the environmental impact of air transport. For calculating pollutant emissions, meteorological conditions were considered to revise the pollutant emission factors of the Engine Emissions Data Base (EEDB) published by International Civil Aviation Organization (ICAO). The environmental external costs measurement model is employed to calculate the externality of toxic gas and greenhouse gas (GHG). In order to make the study more convincing, two alternative networks are computed: hub-and-spoke network and city-to-city network. It is found that the hub-and-spoke network is associated with poorer environmental impact and environmental external costs because of the different network characteristics and the scale of the fleets. Therefore, under the general trend of green aviation, the environmental impact and environmental external costs associated with hub-and-spoke network in air transport provides a certain reference for airlines’ strategic decision-making.

scholarly journals Estimating the open biomass burning emissions in Central and Eastern China from 2003 to 2015 based on satellite observation

2018 ◽  
Author(s):  
Jian Wu ◽  
Shaofei Kong ◽  
Fangqi Wu ◽  
Yi Cheng ◽  
Shurui Zheng ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Annual Variation ◽  
Eastern China ◽  
Satellite Observation ◽  
Pollutant Emissions ◽  
Pollutant Emission ◽  
Burned Area ◽  
Management Policies ◽  
Straw Burning ◽  
Grassland Fire

Abstract. Open biomass burning (OBB) has significant impacts on air pollution, climate change and potential human health. OBB has raised wide attention but with few focus on the annual variation of pollutant emission. Central and Eastern China (CEC) is one of the most polluted regions in China. This study aims to provide a state-of the-art estimation of the pollutant emissions from OBB in CEC from 2003 to 2015, by adopting the satellite observation dataset (the burned area product (MCD64Al) and the active fire product (MCD14 ML)), local biomass data (updated biomass loading data and high-resolution vegetation data) and local emission factors. Monthly emissions of pollutants were estimated and allocated into a 1 × 1 km spatial grid for four types of OBB including grassland, shrubland, forest and cropland. From 2003 to 2015, the emissions from forest, shrubland and grassland fire burning had a minor annual variation whereas the emissions from crop straw burning steadily increased. The cumulative emissions of OC, EC, CH4, NOX, NMVOC, SO2, NH3, CO, CO2 and PM2.5 were 3.64 × 103, 2.87 × 102, 3.05 × 103, 1.82 × 103, 6.4 × 103, 2.12 × 102, 4.67 × 103, 4.59 × 104, 9.39 × 105 and 4.13 × 102 Gg in these years, respectively. For cropland, corn straw burning was the largest contributor for all pollutant emissions, by 84 %–96 %. Among the forest, shrubland, grassland fire burning, forest fire burning emissions contributed the most and emissions from grassland fire was negligible due to few grass coverage in this region. High pollutant emissions were populated in the connection area of Shandong, Henan, Jiangsu and Anhui, with emission intensity higher than 100 ton per pixel, which was related to the frequent agricultural activities in these regions. The monthly emission peak of pollutants occurred in summer and autumn harvest periods including May, June, September and October, at which period ~ 50 % of pollutants were emitted for OBB. This study highlights the importance in controlling the crops straw burning emission. From December to March of the next year, the crop residue burning emissions decreased, while the emissions from forest, shrubland and grassland exhibited their highest values, leading to another small peak emissions of pollutants. Obvious regional differences in seasonal variations of OBB were observed due to different local biomass types and environmental conditions. Rural population, agricultural output, local burning habits, anthropological activities and management policies are all influence factors for OBB emissions. The successful adoption of double satellite dataset for long term estimation of pollutants from OBB with a high spatial resolution can support the assessing of OBB on regional air-quality, especially for harvest periods or dry seasons. It is also useful to evaluate the effects of annual OBB management policies in different regions.

scholarly journals Carbon and air pollutant emissions from China's cement industry 1990–2015: trends, evolution of technologies and drivers

2020 ◽  
Author(s):  
Jun Liu ◽  
Dan Tong ◽  
Yixuan Zheng ◽  
Jing Cheng ◽  
Xinying Qin ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Large Scale ◽  
Air Pollutant ◽  
Cement Industry ◽  
Pollutant Emissions ◽  
Pollutant Emission ◽  
Climate Mitigation ◽  
Nox Emissions ◽  
Cement Production ◽  
Control Technologies

Abstract. China is the largest cement producer and consumer in the world. Cement manufacturing is highly energy-intensive, and is one of the major contributors to carbon dioxide (CO2) and air pollutant emissions, which threatens climate mitigation and air quality improvement. In this study, we investigated the decadal changes of carbon dioxide and air pollutant emissions for the period of 1990–2015, based on intensive unit-based information on activity rates, production capacity, operation status, and control technologies, which improved the accuracy of the cement emissions in China. We found that, from 1990 to 2015, accompanied by a 10.9-fold increase in cement production, CO2, SO2, and NOx emissions from China's cement industry increased by 626 %, 59 %, and 658 %, whereas CO, PM2.5 and PM10 emissions decreased by 9 %, 66 %, and 63 %, respectively. In the 1990s, driven by the rapid growth of cement production, CO2 and air pollutant emissions increased constantly. Then, the production technology innovation of replacing traditional shaft kilns with the new precalciner kilns in the 2000s markedly reduced SO2, CO and PM emissions from the cement industry. Since 2010, the growing trend of emissions has been further curbed by a combination of measures, including promoting large-scale precalciner production lines and phasing out small ones, upgrading emission standards, installing low-NOx burners (LNB) and selective noncatalytic reduction (SNCR) to reduce NOx emissions, as well as adopting more advanced particulate matter control technologies. Our study highlighted the effectiveness of advanced technologies on air pollutant emission control, however, CO2 emissions from China's cement industry kept growing throughout the period, posing challenges to future carbon emission mitigation in China.

scholarly journals Health Risk Assessment of Toxic and Harmful Air Pollutants Discharged by a Petrochemical Company in the Beijing-Tianjin-Hebei Region of China

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1604
Author(s):  
Tao Zhu ◽  
Furong Li ◽  
Wenfeng Niu ◽  
Zijun Gao ◽  
Yiwei Han ◽  
...  
Keyword(s):  
Air Pollutants ◽  
Solid Phase ◽  
Carcinogenic Risk ◽  
Pollutant Emissions ◽  
Oil Refining ◽  
Pollutant Emission ◽  
Gas Chromatography Mass Spectrometry ◽  
Hazardous Air Pollutants ◽  
Petrochemical Company ◽  
The Impact

Monitoring of toxic and hazardous air pollutants (HAPs) in a petrochemical company in the Beijing-Tianjin-Hebei region of China to assess the impact of HAPs on the health risks of workers in the petrochemical company. The samples were tested by solid-phase adsorption thermal desorption/gas chromatography-mass spectrometry (HJ734-2014), and the pollutant emission list was obtained. According to the pollutant emission inventory, it can be seen that benzene, toluene and xylene are the main components of toxic and harmful air pollutants emitted by the petrochemical enterprise. The method of combining actual monitoring and CALPUFF model prediction was used to evaluate the impact of the toxic and harmful air pollutants emitted by the enterprise on the health of workers. The risk characterization results show that when benzene is the maximum concentration value predicted by the model, it will pose a carcinogenic risk to the factory workers. Therefore, based on the results of this study, it is recommended not to allow residents to live within the predicted concentration range of the model. The results of this study can enable China’s oil refining industry to better understand the characteristics of pollutant emissions from petrochemical companies in the Beijing-Tianjin-Hebei region. Moreover, the results of this study can be used as a policy basis for improving the health of workers in petrochemical enterprises, and are of great significance to the protection of public health.

scholarly journals Multi-Objective Optimization of a Regional Water–Energy–Food System Considering Environmental Constraints: A Case Study of Inner Mongolia, China

2020 ◽  
Vol 17 (18) ◽  
pp. 6834
Author(s):  
Junfei Chen ◽  
Tonghui Ding ◽  
Ming Li ◽  
Huimin Wang
Keyword(s):  
Natural Gas ◽  
Water Consumption ◽  
Inner Mongolia ◽  
Food System ◽  
Gas Production ◽  
Pollutant Emissions ◽  
Pollutant Emission ◽  
Basic Material ◽  
Multi Objective ◽  
Multi Objective Programming

Water, energy, and food, as the basic material resources of human production and life, play a prominent role in social and economic development. As the imbalance between the supply and demand of water, energy, and food increases, a highly sensitive and fragile relationship gradually forms among water, energy, and food. In this paper, Inner Mongolia in China is selected as a research area. Firstly, synergy theory is applied to establish the framework of a water–energy–food system. Then, a multi-objective programming model is constructed, where the objective functions are defined to minimize the integrated deviation degree and pollutant emissions of the water–energy–food system. Meanwhile, maximization of the water benefit, energy production, and food production is also considered. In addition, the model takes economy, environment, water, energy, and food as constraints. Finally, a genetic algorithm is designed for accurately assessing the most promising results. The results show that the cooperation degree of the water–energy–food system in Inner Mongolia is getting better and better, and the pollutant emission from the water–energy–food system is decreasing. In 2020, the proportion of agricultural water consumption fell by 1%, while that of industrial water consumption rose by 0.48%. The production of coal, natural gas, and power are all showing an increasing trend. Among them, the increase of natural gas production is as high as 38,947,730 tons of standard coal. However, the proportions of coal, natural gas, and power change inconsistently, where the proportions of coal and natural gas increase while that of power decreases. Corn production accounts for more than 80% of the total, which is in the eldest brother position in the food industry structure. Besides, there are differences between the planned values and optimal values of decision variables. Finally, suggestions are put forward to improve the sustainable development of water–energy–food in Inner Mongolia.

scholarly journals Fuel-Water emulsion impact on miniature gas turbine pollutant emission

2019 ◽  
Vol 137 ◽  
pp. 01046 ◽  
Author(s):  
Maciej Chmielewski ◽  
Marian Gieras ◽  
Paweł Niszczota
Keyword(s):  
Gas Turbine ◽  
Theoretical Background ◽  
Pollutant Emissions ◽  
Water Phase ◽  
Pollutant Emission ◽  
Combustion Mechanism ◽  
Water Emulsion ◽  
Theoretical Predictions ◽  
Numerical Research ◽  
Distributed Energy Generation

The innovative use of the Fuel-Water emulsion in a small gas turbine for distributed energy generation is proposed. The FWE in this situation is considered as a nonhomogeneous mix of water and fuel, where water is a dispersed phase in the continuous fuel phase with an addition of surfactants. The Fuel-Water emulsion has a great mainly due to two mechanisms: temperature reduction due to heat absorption by the water phase and enhanced homogeneity of the fuel-air mixture due to micro-explosion of the superheated water phase inside the emulsion droplet. Proposed paper presents theoretical background on Fuel-Water emulsion combustion mechanism. Finally initial results of numerical research of fuel-water emulsion injection to miniature gas turbine are presented. Theoretical predictions of NOX pollutant emissions are compared with accuracy of the gas analyzer planned to be used during experimental research.

scholarly journals Evaluation of Road Transport Pollutant Emissions from Transporting Building Materials to the Construction Site by Replacing Old Vehicles

2020 ◽  
Vol 17 (24) ◽  
pp. 9316
Author(s):  
Sehee Han ◽  
Seunguk Na ◽  
Nam-Gi Lim
Keyword(s):  
Construction Industry ◽  
Building Materials ◽  
Maintenance Phase ◽  
Road Transport ◽  
Pollutant Emissions ◽  
Pollutant Emission ◽  
Construction Site ◽  
The Road ◽  
Diesel Vehicles ◽  
Material Transportation

Since the life cycle of a building spans more than 50 years, studies of the environmental impacts in the construction industry have focused on reducing the energy consumption and greenhouse gas emissions during the operation and maintenance phase. The products of the construction industry are assembled using various building materials manufactured outside of the construction site. Consequently, it is essential that the manufactured building materials be transported to the construction site using various types of transportation methods. However, there is a lack of studies that assess the pollutant emissions of road transport while executing a construction project. The purpose of this study is to investigate the changes in the road pollutant emissions when the old diesel vehicles for transporting building materials are replaced according to enhanced pollutant emission regulations. In this study, we found that approximately 89, 64, 77, and 64% of NOx, VOC, PM, and CO, respectively, were emitted during transportation of building materials as a proportion of the emissions during the construction of the structure. The analyzed results also show that about 10, 35, 23, and 35% of NOx, VOC, PM, and CO, respectively, were generated from material transportation as a proportion of the emissions from finishing the work. It is expected that a reduction in pollutant emissions from transporting building materials of up to approximately 64, 39, 49, and 27% of NOx, VOC, PM, and CO, respectively, can be achieved when vehicles registered before 2003 are replaced with ones that adhere to the tightened regulations.

scholarly journals Development of a Variable Valve Actuation Control to Improve Diesel Oxidation Catalyst Efficiency and Emissions in a Light Duty Diesel Engine

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4561 ◽  
Author(s):  
José R. Serrano ◽  
Francisco J. Arnau ◽  
Jaime Martín ◽  
Ángel Auñón
Keyword(s):  
Diesel Oxidation Catalyst ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Oxidation Catalyst ◽  
Pollutant Emission ◽  
Engine Model ◽  
Light Duty ◽  
Diesel Oxidation ◽  
Variable Valve ◽  
Catalyst Efficiency

Growing interest has arisen to adopt Variable Valve Timing (VVT) technology for automotive engines due to the need to fulfill the pollutant emission regulations. Several VVT strategies, such as the exhaust re-opening and the late exhaust closing, can be used to achieve an increment in the after-treatment upstream temperature by increasing the residual gas amount. In this study, a one-dimensional gas dynamics engine model has been used to simulate several VVT strategies and develop a control system to actuate over the valves timing in order to increase diesel oxidation catalyst efficiency and reduce the exhaust pollutant emissions. A transient operating conditions comparison, taking the Worldwide Harmonized Light-Duty Vehicles Test Cycle (WLTC) as a reference, has been done by analyzing fuel economy, HC and CO pollutant emissions levels. The results conclude that the combination of an early exhaust and a late intake valve events leads to a 20% reduction in CO emissions with a fuel penalty of 6% over the low speed stage of the WLTC, during the warm-up of the oxidation catalyst. The same set-up is able to reduce HC emissions down to 16% and NOx emission by 13%.

scholarly journals Enhanced atmospheric oxidizing capacity in simulating air quality with updated emission inventories for power plants especially for haze periods over East China

2017 ◽  
Author(s):  
Lei Zhang ◽  
Tianliang Zhao ◽  
Sunling Gong ◽  
Shaofei Kong ◽  
Lili Tang ◽  
...  
Keyword(s):  
Air Quality ◽  
Power Plants ◽  
Emission Inventory ◽  
Environmental Changes ◽  
Air Pollutant ◽  
Pollutant Emissions ◽  
Atmospheric Environment ◽  
Pollutant Emission ◽  
East China ◽  
Emission Inventories

Abstract. Air pollutant emissions play a determinant role in deteriorating air quality. However, an uncertainty in emission inventories is still the key problem for modeling air pollution. In this study, an updated emission inventory of coal-fired power plants (UEIPP) based on online monitoring data in Jiangsu province of East China for the year of 2012 was implemented in the widely used Multi-resolution Emission Inventory for China (MEIC). By employing the Weather Research and Forecasting Model with Chemistry (WRF-Chem), two simulations were executed to assess the atmospheric environmental change by using the original MEIC emission inventory and the MEIC inventory with the UEIPP. A synthetic analysis shows that (1) compared to the power emissions of MEIC, PM2.5, PM10, SO2 and NOx were lower, and CO, black carbon (BC), organic carbon (OC) and NMVOCs were higher in the UEIPP, reflecting a large discrepancy in the power emissions over East China; (2) In accordance with the changes of UEIPP, the modeled concentrations were reduced for SO2 and NO2, and increased for most areas of primary OC, BC and CO, whose concentrations in atmosphere are highly dependent on emission changes. (3) Interestingly, when the UEIPP was used, the atmospheric oxidizing capacity significantly reinforced, reflecting by increased oxidizing agents, e.g. O3 and OH, thus directly strengthened the chemical production from SO2 and NOx to sulfate and nitrate, which offset the reduction of primary PM2.5 emissions especially in the haze days. This study indicated the importance of updating air pollutant emission inventories in simulating the complex atmospheric environment changes with the implications on air quality and environmental changes.

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