Retrofitting 25T/h Pulverized Coal-Fired Boiler Into 35T/h Circulating Fluidized Bed Boiler for Burning Mixture of Coal and Bagasse

2005 ◽  
Author(s):  
Han-Ping Chen ◽  
Xian-Hua Wang ◽  
Shi-Hong Zhang ◽  
De-Chang Liu ◽  
Yu-Hua Lai ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Combustion Efficiency ◽  
Economic Benefits ◽  
Pulverized Coal ◽  
Industrial Wastes ◽  
Pollutant Emission ◽  
Fluidized Bed Combustion ◽  
Circulating Fluidized Bed Boiler ◽  
Combustion Technology

In China, there are a large number of pulverized coal-fired industrial boilers, whose steam capacities are usually relatively small. These boilers can burn only high-grade coal and have low combustion efficiency. Furthermore, the combustion emissions, such as SO2 and NOx, pollute the environment severely. Therefore it is very important and urgent to adopt economically efficient and environmentally friendly technologies to retrofit these boilers. At the same time, there are many industrial wastes, such as bagasse, wood waste, rubbish, petroleum coke and so on, need burning disposal in China. Fluidized bed combustion technology is a kind of clear combustion technology, which has many advantages, such as excellence fuel flexibility, high combustion efficiency, low pollutant emission and good turndown capability etc. So, adopting fluidized bed combustion technology, retrofitting pulverized coal-fired boiler into fluidized bed boiler can realize pure burning various wastes or co-firing with coal, which should have great economic benefits and social benefits. And the application prospect of the method is also extensive. The State Key Laboratory of Coal Combustion has successfully retrofitted a 25t/h pulverized coal-fired boiler into circulating fluidized bed boiler with in-bed tubes and downward exhaust cyclone. The retrofitted boiler can burn mixture of coal and bagasse and the steam capacity reaches 35t/h. This paper presents the retrofitting measures and the operation status of the boiler after retrofitting.

Experimental Study of CFB Modification Fly Ash in Concrete

2014 ◽  
Vol 1051 ◽  
pp. 743-747 ◽  
Author(s):  
Rong Jin Xu ◽  
Yan Kai Huo ◽  
Bin Teng ◽  
Si Hai Song
Keyword(s):  
Experimental Study ◽  
Fly Ash ◽  
Carbon Content ◽  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Pulverized Coal ◽  
Experimental Results ◽  
Unburned Carbon ◽  
Fluidized Bed Combustion ◽  
Effective Use

The character of the Fly ash of Circulating Fluidized Bed Boiler (CFB Fly ash) is greatly different from that of Pulverized coal furnace for its high unburned carbon. In order to make effective use of CFB Fly ash in concrete, carbon content was decreased by simulated fluidized bed combustion in laboratory and a series of concerned experiments were carried out on CFB Fly ash. The experimental results indicate that CFB modification Fly ash is possible to be used in concrete to partially replaced cement. It is a valuable reference for CFB Fly ash technical engineers.

scholarly journals Development of Methane and Nitrous Oxide Emission Factors for the Biomass Fired Circulating Fluidized Bed Combustion Power Plant

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Chang-Sang Cho ◽  
Jae-Hwan Sa ◽  
Ki-Kyo Lim ◽  
Tae-Mi Youk ◽  
Seung-Jin Kim ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Fluidized Bed ◽  
Emission Factor ◽  
Circulating Fluidized Bed ◽  
Wood Chip ◽  
Emission Factors ◽  
Fluidized Bed Combustion ◽  
Cfb Boiler ◽  
Combustion Technology ◽  
The Subject

This study makes use of this distinction to analyze the exhaust gas concentration and fuel of the circulating fluidized bed (CFB) boiler that mainly uses wood biomass, and to develop the emission factors of Methane (CH4), Nitrous oxide (N2O). The fuels used as energy sources in the subject working sites are Wood Chip Fuel (WCF), RDF and Refused Plastic Fuel (RPF) of which heating values are 11.9 TJ/Gg, 17.1 TJ/Gg, and 31.2 TJ/Gg, respectively. The average concentrations of CH4and N2O were measured to be 2.78 ppm and 7.68 ppm, respectively. The analyzed values and data collected from the field survey were used to calculate the emission factor of CH4and N2O exhausted from the CFB boiler. As a result, the emission factors of CH4and N2O are 1.4 kg/TJ (0.9–1.9 kg/TJ) and 4.0 kg/TJ (2.9–5.3 kg/TJ) within a 95% confidence interval. Biomass combined with the combustion technology for the CFB boiler proved to be more effective in reducing the N2O emission, compared to the emission factor of the CFB boiler using fossil fuel.

scholarly journals Experimental Study of Stabilized Soil Utilizing Circulating Fluidized Bed Combustion Desulfurization Ash with Carbide Slag and Desulfurization Gypsum

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Dezhi Shao ◽  
Jinlong Liu ◽  
Xin Huang
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Composite Foundation ◽  
Industrial Wastes ◽  
Fluidized Bed Combustion ◽  
Soil Mixing ◽  
Carbide Slag ◽  
Stabilized Soil ◽  
Cement Soil ◽  
Circulating Fluidized Bed Combustion

This paper discusses the feasibility of preparing soil stabilizer which is circulating fluidized bed combustion ash-based, supplemented with carbide slag and desulfurization gypsum, composed entirely of complete industrial wastes. The results show that CFBC ash has better pozzolanic activity than fly ash. When stabilizer total content is 10% and the ratio of CFBC ash : carbide slag : desulfurization gypsum is 7.2 : 1.8 : 1, compressive strength of stabilized soil can reach the maximum of 2.12 MPa at the age of 28 d of curing. Stabilizer can meet the strength requirements of cement-soil mixing pile composite foundation and cement-soil mixing pile waterproof curtain.

Fluidized Bed Technologies for Biomass Combustion

2009 ◽  
Author(s):  
Aku Rainio ◽  
Vinod Sharma ◽  
Markus Bolha`r-Nordenkampf ◽  
Christian Brunner ◽  
Johannes Lind ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Distribution System ◽  
Circulating Fluidized Bed ◽  
Close Contact ◽  
Combustion Efficiency ◽  
Biomass Combustion ◽  
Fluidized Bed Combustion ◽  
Biomass Fuels ◽  
So2 Emissions ◽  
Gas Treatment

Biomass, a renewable fuel source for generating energy, is available in large quantities in the USA. Typical biomass consists of wood chips, construction and demolition wood, bark, residual logging debris, saw dust, paper rejects, and paper and sewage sludge. Composition and moisture content of biomass vary greatly and affect its heating value. There are several combustion technologies available to generate power from biomass. Fluidized bed boilers are preferred, because of their ability to burn a wide variety of biomass fuels while achieving high combustion efficiency and low emissions. This paper discusses basic design and operation features of bubbling (BFB) and circulating fluidized bed (CFB) boilers, both offering high fuel flexibility. In fluidized bed combustion, reactive biomass fuels are almost completely burned out because of close contact between the hot bed material and the fuel. In advanced BFB and CFB boilers, an open bottom design is used for ash and coarse material removal through the fluidizing air distribution system. This allows combustion of fuels containing large inert particles, such as rocks and metal pieces. If limestone is added to the bed, SO2 emissions are reduced. By using ammonia or urea in high temperature areas, NOx emissions are reduced. In order to achieve very low emissions, back-end flue gas treatment for SO2, NOx, HCl, HF, and Hg is required. To treat flue gases, several technologies can be used — such as activated carbon and sodium bicarbonate or Trona injection, Turbosorp® circulating dry scrubber, and SCR. Normally the preferred particulate matter cleaning device is a baghouse since the filter cake allows further reactions between pollutants and sorbents. Different fluidized bed designs are shown and recommended for various biomass fuels. This paper describes design, fuels, and emissions for an advanced BFB boiler producing steam at a rate of 230,000 lb/hr/930 psig/860°F (29.0 kg/s/64 barg/460°C).

CO2 emission during the combustion of Orhaneli lignite coal

2017 ◽  
Vol 14 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Mehmet Ozkaymak ◽  
Mehmet Ali Ceylan ◽  
Hasancan Okutan ◽  
Hüsnü Atakul ◽  
Engin Berrin ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Combustion Efficiency ◽  
Side Reactions ◽  
Content Type ◽  
Positive Effects ◽  
Bed Temperature ◽  
Combustion Technology ◽  
Combustion Experiment ◽  
Lignite Coal

Purpose In Turkey, dependence on foreign countries for energy is a problem which upsets all economic balances. Turkey’s biggest fossil energy source is lignite coal. Therefore, energy conversion of lignite in thermal plants, causing minimum environmental effect is extremely important. The basic problem in terms of the combustion technology is to improve the combustion technology that can burn the low-qualified fuels that do not have standard fuel features (lignite, peat, schist). The most suitable technology today for the efficient and clean combustion of nonstandard low-qualified fuels is the combustion at fluidized-bed technology. In this study, CO2 emission that occurs during the combustion of Orhaneli coal that is one of our native low-qualified lignite, has been investigated according to the experimental study. Design/methodology/approach For this combustion experiment, laboratory-scaled circulating fluidized-bed (CFB) process that exists at TÜBITAK-MAM Energy Institute which has been designed and used before has been used. The effect of excess-air coefficient, combustion type and bed temperature to the greenhouse gas formation and CO2 emission has been investigated experimentally. In terms of flue gas emissions, it has been detected that the decrease of the amount of CO2 that has occurred has no positive effects on combustion efficiency, water vapor, SO2, NOx, CO and other gases which occur during deficient combustion must be thought as a whole and each reaction affects each other similar to complex reactions. Findings As a consequence of measuring CO2 emissions over 10 minute periods, CO2 emissions are 12.43 percent average, CO2 decreases at different air coefficient values; Often form undesirable side reactions such as CO, NOx with back and forth reactions. Originality/value The importance of aerodynamic structure of the system, and the losses and leakages forming in the system has been observed experimental and affected parameters are evaluated.

scholarly journals Fluidized bed combustion with the use of Greek solid fuels

2003 ◽  
Vol 7 (2) ◽  
pp. 33-42
Author(s):  
Emmanuel Kakaras ◽  
Panagiotis Grammelis ◽  
George Skodras ◽  
Panagiotis Vourliotis
Keyword(s):  
Fluidized Bed ◽  
Brown Coal ◽  
Circulating Fluidized Bed ◽  
Pilot Scale ◽  
Thermal Capacity ◽  
Low Rank ◽  
Fluidized Bed Combustion ◽  
Bubbling Fluidized Bed ◽  
Combustion Technology ◽  
Combustion Tests

The paper is an overview of the results obtained up to date from the combustion and co-combustion activities with Greek brown coal in different installations, both in semi-industrial and laboratory scale. Combustion tests with Greek lignite were realized in three different Circulating Fluidized Bed Combustion (CFBC) facilities. Low rank lignite was burned in a pilot scale facility of approx. 100kW thermal capacity, located in Athens (NTUA) and a semi-industrial scale of 1.2 MW thermal capacity, located at RWE's power station Niederaussem in Germany. Co-combustion tests with Greek xylitic lignite and waste wood were carried out in the 1 MWth CFBC installation of AE&E, in Austria. Lab-scale co-combustion tests of Greek pre-dried lignite with biomass were accomplished in a bubbling fluidized bed in order to investigate ash melting problems. The obtained results of all aforementioned activities showed that fluidized bed is the appropriate combustion technology to efficiently exploit the low quality Greek brown coal either alone or in conjunction with biomass species.

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