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

Author(s):  
Christopher Y. H. Chao ◽  
Philip C. W. Kwong ◽  
J. H. Wang

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.

Author(s):  
A. P. Shaikin ◽  
I. R. Galiev

The article analyzes the influence of chemical composition of hythane (a mixture of natural gas with hydrogen) on pressure in an engine combustion chamber. A review of the literature has showed the relevance of using hythane in transport energy industry, and also revealed a number of scientific papers devoted to studying the effect of hythane on environmental and traction-dynamic characteristics of the engine. We have studied a single-cylinder spark-ignited internal combustion engine. In the experiments, the varying factors are: engine speed (600 and 900 min-1), excess air ratio and hydrogen concentration in natural gas which are 29, 47 and 58% (volume).The article shows that at idling engine speed maximum pressure in combustion chamber depends on excess air ratio and proportion hydrogen in the air-fuel mixture – the poorer air-fuel mixture and greater addition of hydrogen is, the more intense pressure increases. The positive effect of hydrogen on pressure is explained by the fact that addition of hydrogen contributes to increase in heat of combustion fuel and rate propagation of the flame. As a result, during combustion, more heat is released, and the fuel itself burns in a smaller volume. Thus, the addition of hydrogen can ensure stable combustion of a lean air-fuel mixture without loss of engine power. Moreover, the article shows that, despite the change in engine speed, addition of hydrogen, excess air ratio, type of fuel (natural gas and gasoline), there is a power-law dependence of the maximum pressure in engine cylinder on combustion chamber volume. Processing and analysis of the results of the foreign and domestic researchers have showed that patterns we discovered are applicable to engines of different designs, operating at different speeds and using different hydrocarbon fuels. The results research presented allow us to reduce the time and material costs when creating new power plants using hythane and meeting modern requirements for power, economy and toxicity.


Author(s):  
Weichen Ma ◽  
Hao Zhou ◽  
Kefa Cen

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)


2017 ◽  
Author(s):  
Lei Zhang ◽  
Tianliang Zhao ◽  
Sunling Gong ◽  
Shaofei Kong ◽  
Lili Tang ◽  
...  

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.


2014 ◽  
Vol 1073-1076 ◽  
pp. 2719-2727
Author(s):  
Bing Qiao ◽  
Yi Chao Liu ◽  
Wei Jian He ◽  
Yu Jun Tian ◽  
Yue Li ◽  
...  

Based on methods of the fuel consumption, statistical and analogy analysis, the throughput amount method was established to calculate the emissions from port handling, and the minimum mileage method was established to estimate emissions from port cargo highway distributing. In the methods, some coefficients were used obtained by investigations: the current container handling emission factors of NOx, VOCs, CO, PM2.5 and SOx are 1.64, 0.21, 0.42, 0.01 and 0.29 t/TEU; the energy consumption of the unit throughput is 4.12 tons of standard coal per 104tons; the ratios of the unit non container cargoe handling energy consumption for coastal and inland river ports to those of container cargo are 0.631 and 0.405; the ratio of the unit non container cargoe highway distributing energy consumption to those of container cargo is 0.365. The calculation results show that the total emissions from the cargo handling and highway distributing of 2013 in China for NOx, VOCs, CO, PM2.5 and SOx are 54.365, 14.821, 24.631, 5.599 and 16.802 104tons, and the emissions from highway distributing are 4.21, 10.02, 8.24, 8.22 and 8.19 times of the emissions from port handling facilities. According to energy saving and emission reduction measures, formulas were established to calculate air pollutant emissions after the new added measures. Analyzing the real performance of the measures implemented since 2001 and predicting its trend of development, a scenario was designed, in which the Chinese port throughput continuously rises while the energy saving and emission reduction efforts gradually increase by 2020: the popularities of the energy saving measure of "oil changing to electricity" and the clean fuel measure of "oil changing to gas" reach 100% and 83%; the proportion of power plants with 95% desulfurization and denitrification reaches 100%; the energy saving and emission reduction efficiency of port cargo distributing optimization measures reaches 40%. Under this scenario, the prediction shows that during the port throughput increasing approximately 4.2 times from 2005 to 2020, the air pollutant emissions will be reduced significantly, returning to a lower level compared with 2005. The above methods and results can be used to support the decision-making and the implementation of emission reduction measures for the national, regional and port enterprises.


2021 ◽  
Vol 15 (3) ◽  
pp. 8300-8309
Author(s):  
SIVABALAN KANIAPAN ◽  
H. Suhaimi ◽  
Y. Hamdan ◽  
Jagadeesh Pasupuleti

It has been a necessary option for most developing countries moving towards renewable energy options as part of the Paris Agreement, which minimizes conventional energy sources’ reliance. In Malaysia, biomass is a profitable renewable option compared to solar and hydro sources for energy production due to the abundance of agricultural biomass availability for immediate use. However, most of the biomass power plants in Malaysia depend on empty fruit bunch as fuel, causing problems when there is a shortage of fuel supply and other circumstances. Variations in the fuels’ properties provide a new challenge to the power plant output; however, mixing biomass fuels can overcome the issue. Hence, this article aims to study the empty fruit bunch (EFB) with other abundant biomass fuels like “palm kernel shell (PKS),” “rice husk (RH),” and “coconut shell (CS)” for biomass boiler fuel. Therefore, the biomass’s composition and characteristics need to be known, which was done through the proximate analysis (PA), ultimate analysis (UA), and high heating value (HHV). As a result of PA, UA, and HHV, RH is the least favourable fuel due to lowest ((moisture (4.92%), volatile matter (63.20%), carbon (42.50%), hydrogen (5.42%), nitrogen (0.43%) and sulphur (0.01%)) and highest ash content (18.19%), whereas CS exhibits the most favourable option with highest (carbon (50.25%) and oxygen (42.57%)) and second highest in HHV (20.53%) compared with PKS. Thus, the experiments have provided the least and highest favourable feedstock ratios option for biomass boiler fuel application.


2021 ◽  
Vol 13 (2) ◽  
pp. 465
Author(s):  
Mengyuan Sun ◽  
Yong Tian ◽  
Yao Zhang ◽  
Muhammad Nadeem ◽  
Can Xu

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.


Author(s):  
Kavitha E ◽  
Karthik S ◽  
Eithya B ◽  
Seenirajan M

The quantity of fly ash produced from thermal power plants in India is approximately 80 million tons each year, and its percentage utilization is less than 10%. An attempt has been made to utilize these cheaper materials in concrete production. This thesis aims at investigating the characteristics of fresh concrete and various strengths of hardened concrete made with various mineral admixtures such as fly ash. GGBFS, silica fume. Rice husk ash along with polypropylene fibres in various proportions.  M20 grade concrete is considered for experimental studies with 53grade Ordinary Portland Cement blended with varying percentages of mineral admixtures. The maximum size of coarse aggregate used is 20mm.  Various mineral admixtures such as fly ash. GGBFS.Silica fume. Rice Husk Ash were added concrete in various percentages by partially replacing cement and the optimum percentage of the mineral admixtures will be found.  Based on the obtained values, the admixture with maximum mechanical strength is determined and to this polypropylene fibre is added by varying 0 to 0.5 % by weight of cement to the mix.  The test results obtained were compared and discussed with conventional concrete.


Author(s):  
Yong Tian ◽  
Wen-Jing Liu ◽  
Qi-jie Jiang ◽  
Xin-Ying Xu

With the development of biomass power generation technology, biomass waste has a more excellent recycling value. The article establishes a biomass waste inventory model based on the material flow analysis method and predicts raw material waste’s energy utilization potential. The results show that the amount of biomass waste generated from 2016 to 2020 is on the rise. In 2020, biomass waste’s energy utilization can reach 107,802,300 tons, equivalent to 1,955.28PJ of energy. Through biomass energy analysis and emission analysis, the results show that the biomass waste can generate 182.02 billion kW⋅h in 2020, which can replace 35.9% of the region’s total power consumption, which is compared with the traditional power generation method under the same power generation capacity. Power generation can reduce SO2 emissions by 250,400 tons, NOx emissions by 399,300 tons, and PM10 emissions by 49,700 tons. Reduce direct economic losses by 712 million yuan. Therefore, Chinese promotion of the recycling of biomass waste and the acceleration of the biomass energy industry’s development is of great significance for reducing pollutant emissions and alleviating energy pressure.


2018 ◽  
Author(s):  
Jian Wu ◽  
Shaofei Kong ◽  
Fangqi Wu ◽  
Yi Cheng ◽  
Shurui Zheng ◽  
...  

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.


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