The Investigation on Application of Oxygen-Enriched Combustion in Cement Rotary Kiln

2013 ◽  
Vol 291-294 ◽  
pp. 804-808
Author(s):  
Xiao Rong Shen ◽  
Shan Qing ◽  
Xiao Jun Shi ◽  
Yi Xiao ◽  
Zhi Fang Yang

The investigation on application of oxygen-enriched combustion in cement rotary kiln shows that flame temperature in rotary kiln can be increased, which improves the utilization of coal and thermal efficiency of rotary kiln. And the fuel consumption and the cost of production can be reduced. In this situation, the objective of increasing production, improving quality and saving energy can be achieved. In the meanwhile, the requirement of air can be reduced in oxygen-enriched combustion. Thus the generation of flue gas and the products of incomplete combustion, which usually are CO, can be reduced. And then the exhaust gas loss and the generation and emission of CO2 and NOx can be accordingly reduced, which enhances to achieve the objective of reduction of pollutants and promote the environmental benefit greatly.

1998 ◽  
Vol 38 (2) ◽  
pp. 71-78
Author(s):  
Giuseppe Mininni ◽  
Vincenzo Lotito ◽  
Roberto Passino ◽  
Ludovico Spinosa

The influence of cake concentration on fuel consumption, air requirement and flue gas production in incineration of sewage sludge is discussed. Fluidized bed (FBF), multiple hearth (MHF) and rotary kiln (RKF) furnaces are considered as alternatives together with the optional use of an afterburning chamber where exhaust gases are taken at 950°C for 2 s with an oxygen concentration of 6% by volume. It clearly appears that, if an afterburning chamber is used, and total minimum fuel consumption can be achieved at an optimal value of cake concentration (45.9% for FBF and 32.5% for MHF) when autogenous conditions are reached in the furnace and air addition is no longer needed in the afterburning chamber. At higher concentrations, abundant exhaust gas productions, due to the dilution air needed in the furnace, can considerably increase fuel consumption in the afterburning chamber, especially in MHF operation. In the rotary kiln furnace, fuel requirement decreases over the whole range of cake concentration as no conditions for autogenous combustion in the furnace can be achieved.


2012 ◽  
Vol 509 ◽  
pp. 353-358
Author(s):  
Jin Shu Cheng ◽  
Zhen Lu Deng ◽  
Jing Wang

The study was carried out on the burning test-bed which was controlled by Programmable Logic Controller (PLC) model and diesel was used as the fuel. The thermodynamic characteristic of oxygen-enhanced combustion, including fuel consumption, flue gas volume, flue gas components’ volume concentration, theoretical flame temperature, flame emissivity, energy efficiency and thermal efficiency, etc, were analyzed. The results showed that: with oxygen concentration was increased from 21% to 30%, fuel consumption was decreased by 40.6% and flue gas volume was decreased by 57.5%. Additionally, higher oxygen concentration leaded to higher theoretical temperature and stronger flame blackness because of the decreasing of N2 volume in supporting air. What’s more, the decreasing of energy brought away by flue gas and the thermal efficiency were both increased with the increasing of oxygen concentration.


2017 ◽  
Vol 38 (1) ◽  
pp. 63-74 ◽  
Author(s):  
Ladislav Dzurenda ◽  
Adrián Banski

Abstract In the paper the influence of moisture content of wood on the heat losses and thermal efficiency of a boiler is analysed. The moisture content of wood has a negative effect, especially on flue gas loss. The mathematical dependence of the thermal efficiency of a boiler is presented for the following boundary conditions: the moisture content of wood 10-60%, range of temperatures of emitted flue gases from the boiler into the atmosphere 120-200 C, the emissions meeting the emission standards: carbon monoxide 250 mgm−3, fly ash 50 mgm−3 and the heat power range 30-100%.


2013 ◽  
Vol 864-867 ◽  
pp. 1798-1803 ◽  
Author(s):  
Kun Lu ◽  
Da Wei Chen ◽  
Zhuang Li

For gypsum rain phenomenon in limestone-gypsum wet desulfurization system. This article made programme that has used unit existing equipment allowance. Extracted hot secondary air to heat purified flue gas to eliminate "gypsum rain". This programme is implemented which makes temperature of purified flue gas rising to 70 °C. That almost eliminate "gypsum rain" phenomenon. While temperature of boiler exhaust gas declined, and temperature of hot air reduced, and boiler thermal efficiency declined, unit of power coal consumption rosed. Comparing to other programmes, this programme has a larger advantage in technology, economic, and security aspects.


Author(s):  
Maria Elena Diego ◽  
Jean-Michel Bellas ◽  
Mohamed Pourkashanian

Post-combustion CO2 capture from natural gas combined cycle (NGCC) power plants is challenging due to the large flow of flue gas with low CO2 content (∼3–4%vol.) that needs to be processed in the capture stage. A number of alternatives have been proposed to solve this issue and reduce the costs of the associated CO2 capture plant. This work focuses on the selective exhaust gas recirculation (S-EGR) configuration, which uses a membrane to selectively recirculate CO2 back to the inlet of the compressor of the turbine, thereby greatly increasing the CO2 content of the flue gas sent to the capture system. For this purpose, a parallel S-EGR NGCC system (53% S-EGR ratio) coupled to an amine capture plant using MEA 30%wt. was simulated using gCCS (gPROMS). It was benchmarked against an unabated NGCC system, a conventional NGCC coupled with an amine capture plant (NGCC+CCS), and an EGR NGCC power plant (39% EGR ratio) using amine scrubbing as the downstream capture technology. The results obtained indicate that the net power efficiency of the parallel S-EGR system can be up to 49.3% depending on the specific consumption of the auxiliary S-EGR systems, compared to the 49.0% and 49.8% values obtained for the NGCC+CCS and EGR systems, respectively. A preliminary economic study was also carried out to quantify the potential of the parallel S-EGR configuration. This high-level analysis shows that the cost of electricity for the parallel S-EGR system varies from 82.1–90.0 $/MWhe for the scenarios considered, with the cost of CO2 avoided being in the range of 79.7–105.1 $/tonne CO2. The results obtained indicate that there are potential advantages of the parallel S-EGR system in comparison to the NGCC+CCS configuration in some scenarios. However, further benefits with respect to the EGR configuration will depend on future advancements and cost reductions achieved on membrane-based systems.


Author(s):  
B. Baiju ◽  
L. M. Das ◽  
M. K. G. Babu

This paper analyses the effect of exhaust gas recirculation (EGR) on the engine performance and emissions of a compression ignition (CI) engine operating on diesel-biodiesel (rubber seed oil methyl ester) blends. Biodiesel operated engines generally produce less unburned hydrocarbon, carbon monoxide and smoke compared to diesel fuel but more NOx emissions. NOx formation is a temperature dependent phenomenon and takes place when the combustion temperature is more than 2000K. EGR is an effective method for reducing NOx emissions in CI engines because it reduces the flame temperature and the oxygen concentration in the combustion chamber. In this study both hot EGR and cold EGR (5%, 10% and 15%) are used. It was found that NOx emission decreases substantially with both hot and cold EGR but smoke and carbon monoxide emissions are increasing with higher EGR rates. Brake thermal efficiency (BTE) increases with hot egr but cold EGR gives lower thermal efficiency than hot egr. Hot EGR emits less smoke and less NOx at higher loads compared to cold EGR. It was observed that exhaust gas between 10% and 15% can be recirculated for getting better results. The use of EGR is thus considered to be one of the most effective in reducing NOx emissions.


In present days industries are growing at a rapid rate and so as the usage of the diesel. The fossil fuels are limited in nature, the increased usage of diesel is resulting in the depletion of its reserves this gives rise to the need of alternative fuels. Due to low specific fuel consumption and supreme power efficiency it has vast applications compared to other fuels but NOX and smoke has seriously causing problem to environment. For this the Palmyra oil has same properties of diesel with varying compression ratios effects the performance and emission characteristics are evaluated. In this process step wise increase of CRs from 16 initially .Then increases EGRs of 0%,5% and 10% and studied performance and emission characteristics. There is improvement in engine efficiency during EGR increment and at low load .There is simultanesly decrease in NOX emissions . The single cylinder four stroke variable compression performance and emissions can be varied.. when fuel is pure diesel,b15and b35 of Palmyra oil is examined and bear with standard automobile usable diesel was conducted at compression ratio of 16:1 at the degrees of 19 and 23 degrees. The influence of Palmyra oil like compression ratio on fuel consumption ,brake thermal efficiency and exhaust gas emissions like NOx and hc has been investigated .the overall optimum is found to be b15 biodiesel –diesel blended for compression ratio of 16 at different exhaust gas recirculation such as 0, 5 and 10. The same experimentation is done for other blends B15 and B35 with palmyra oil. All the values are compared with each other. The configuration which achieved highest Break thermal efficiency is compared to the common diesel engine configuration used and the advantages and the disadvantages are listed out


2020 ◽  
Vol 10 (2) ◽  
pp. 183-190
Author(s):  
Viet Dung Tran ◽  
Anh Tuan Le ◽  
Anh Tuan Hoang

As a rule, the highest permissible sulfur content in the marine fuel must drop below 0.5% from 1 January 2020 for global fleets. As such, ships operating in emission control areas must use low sulfur or non-sulfur fuel to limit sulfur emissions as a source of acid rain. However, that fact has revealed two challenges for the operating fleet: the very high cost of ultra-low sulfur diesel (ULSD) and the installation of the fuel conversion system and the ULSD cooling system. Therefore, a solution that blends ULSD and biodiesel (BO) into a homogeneous fuel with properties equivalent to that of mineral fuels is considered to be significantly effective. In the current work, an advanced ultrasonic energy blending technology has been applied to assist in the production of homogeneous ULSD-BO blends (ULSD, B10, B20, B30, and B50 with blends of coconut oil methyl ester with ULSD of 10%, 20%, 30% and 50% by volume) which is supplied to a small marine diesel engine on a dynamo test bench to evaluate the power and torque characteristics, also to consider the effect of BO fuel on specific fuel consumption exhaust gas temperature and brake thermal efficiency. The use of the ultrasonic mixing system has yielded impressive results for the homogeneous blend of ULSD and BO, which has contributed to improved combustion quality and thermal efficiency. The results have shown that the power, torque, and the exhaust gas temperature, decrease by approximately 9%, 2%, and 4% respectively with regarding the increase of the blended biodiesel rate while the specific fuel consumption and brake thermal efficiency tends to increase of around 6% and 11% with those blending ratios.


2020 ◽  
Vol 12 (12) ◽  
pp. 168781402097552
Author(s):  
Youssef A. Attai ◽  
Osayed S. Abu-Elyazeed ◽  
Mohamed R. ElBeshbeshy ◽  
Mohamed A. Ramadan ◽  
Mohamed S. Gad

Castor biodiesel (CBD) was manufactured by slow pyrolysis of oil from highly yielded seeds with anhydrous sodium hydroxide catalyst. An experimental study of engine’s performance, emissions and combustion characteristics using biodiesel blended with gas oil in volumetric ratios of 0, 10, 25, 50, 75, and 100% at different loads was performed. Increase of CBD percentage in the blend led to a reduction in engine’s thermal efficiency, cylinder pressure, net heat release rate, and smoke emission. The exhaust gas temperature, specific fuel consumption, unburned hydrocarbon, CO, and nitrogen oxide emissions were increased with the increase of CBD ratio. Biodiesel showed the maximum increase in specific fuel consumption by 10% and the thermal efficiency was decreased by 10.5% about pure diesel. Smoke emissions were decreased for CBD100 by 12% about gas oil. The maximum increases in NOx, CO, HC emissions, and exhaust gas temperature for CBD 100 were 22, 34, 48, and 11%, respectively related to diesel oil. The maximum reductions in cylinder pressure and net heat release rate were 5 and 13% for CBD100 about gas oil, respectively. Biodiesel percentage of 10% showed near values of performance parameters and emissions to gas oil, so, it is recommended as the optimum percentage.


Author(s):  
Vahid Vandadi ◽  
Chanwoo Park ◽  
Massoud Kaviany

The thermal efficiency of radiant porous burners is less than 25% because most of the combustion heat is lost by flue gas. Here, we present a new radiant burner design to recuperate the heat of the exit flue gas using a preheater to increase the inlet air temperature and raise the flame temperature locally above adiabatic temperature (superadiabatic) at fuel-lean conditions. The superadiabatic heat is then conducted through embedded radiation corridors and is radiated, at a higher temperature than the flue gas, to target. This paper presents the results of the superadiabatic radiant porous burner from a numerical analysis using a zero-order combustion reaction model for methane/air mixture and non-thermal equilibrium formulation. The thermal efficiency over 40% is predicted.


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