A design methodology for small-scale bubbling fluidized-bed furnaces

This paper deals with the prediction of ash related problems in fluidized bed boilers during co-firing of various bio-fuels. A study was performed where the slagging and fouling behavior was monitored in three different sized bubbling fluidized bed combustors, a 20 kW semi-pilot reactor, a 2 MW pilot-scale device and a 105 MW full-scale boiler. The aim of the study was to learn about how well slagging and fouling in a small-scale device compares to a full-scale boiler and to see how well the slagging and fouling can be predicted with a small-scale device. Various types of Scandinavian bio-fuels as well as peat were used both separately and mixed. From all three devices ash and deposit samples were collected during as uniform and stable conditions as possible. The fuels used in the three devices during the test campaigns were carefully chosen so that they would be as similar as possible. Bed, furnace and flue gas temperatures were monitored as well as flue gas emissions. The fuels, ashes and deposits were analyzed on their main components and deposition rates were calculated based on the deposit measurements. These data were finally used for assessing the slagging and fouling propensity of the fired fuel. The paper compares and discusses the results from the three different size classes.

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Small Scale Bubbling Fluidized Bed Gasifier for Syngas Extraction from Napier grass

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/765/1/012068 ◽

2021 ◽

Vol 765 (1) ◽

pp. 012068

Author(s):

A H Atienza ◽

A Aceituna ◽

X E Samar

Keyword(s):

Fluidized Bed ◽

Napier Grass ◽

Small Scale ◽

Bubbling Fluidized Bed ◽

Fluidized Bed Gasifier

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Scaled down Design of a Cold and Hot Flow Model Based on a Bubbling Fluidized Bed Pilot Plant Gasifier

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.786.232 ◽

2015 ◽

Vol 786 ◽

pp. 232-237 ◽

Cited By ~ 1

Author(s):

Iman Eslami Afrooz ◽

Chandra Mohan Sinnathambi ◽

Saravanan Karuppanan ◽

Dennis Ling Chuan Ching

Keyword(s):

Fluidized Bed ◽

Pilot Plant ◽

Scaling Laws ◽

Flow Model ◽

Operating Conditions ◽

Critical Parameters ◽

Small Scale ◽

Empirical Equations ◽

Cold Model ◽

Bubbling Fluidized Bed

Bubbling fluidized bed (BFB) is a vital equipment in many applications in the energy, pharmaceuticals, and chemicals process industries due to its numerous advantages such as large heat capacity inside a bed, and rapid heat and mass transfer rate. In spite of numerous research activities, achieving high fluidization performances in BFB process is still a challenge of science. This research is being conducted to study the hydrodynamic regime of a BFB pilot plant gasifier. To this end, a lab-scale cold model was first designed based on the empirical equations and scaling laws. The scaling laws was used to scale down the Tenaga Nasional Berhad-PETRONAS (TNBR-PETRONAS) pilot plant gasifier into a small scale laboratory model. Moreover, the empirical equations were utilized to determine the critical parameters such as bed pressure drop, height of the bed, number of orifices of the distributor plate and the pitch size. Finally a lab-scale hot flow model will be designed based on the cold model geometric dimensions but under a real operating conditions as that of a pilot plant.

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Empirical Design, Construction, and Experimental Test of a Small-Scale Bubbling Fluidized Bed Reactor

Sustainability ◽

10.3390/su13031061 ◽

2021 ◽

Vol 13 (3) ◽

pp. 1061 ◽

Cited By ~ 1

Author(s):

Carlos Vargas-Salgado ◽

Elías Hurtado-Pérez ◽

David Alfonso-Solar ◽

Anders Malmquist

Keyword(s):

Fluidized Bed ◽

Distribution System ◽

Experimental Tests ◽

Fluidized Bed Reactor ◽

Air Distribution ◽

Small Scale ◽

Trial And Error ◽

Integrated Methodology ◽

Bubbling Fluidized Bed ◽

Design Construction

The methods currently used for designing a fluidized bed reactor in gasification plants do not meet an integrated methodology that optimizes all the different parameters for its sizing and operational regime. In the case of small-scale (several tens of kWs biomass gasifiers), this design is especially complex, and, for this reason, they have usually been built in a very heuristic trial and error way. In this paper, an integrated methodology tailoring all the different parameters for the design and sizing of a small-scale fluidized bed gasification plants is presented. Using this methodology, a 40 kWth biomass gasification reactor was designed, including the air distribution system. Based on this design, with several simplified assumptions, a reactor was built and commissioned. Results from the experimental tests using this gasifier are also presented in this paper. As a result, it can be said the prototype works properly, and it produces syngas able to produce thermal energy or even electricity.

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Experimental Evaluation of Napier Grass Gasification in an Autothermal Bubbling Fluidized Bed Reactor

Energies ◽

10.3390/en12081517 ◽

2019 ◽

Vol 12 (8) ◽

pp. 1517 ◽

Cited By ~ 4

Author(s):

Ramin Khezri ◽

Wan Azlina Wan Ab Karim Ghani ◽

Dayang Radiah Awang Biak ◽

Robiah Yunus ◽

Kiman Silas

Keyword(s):

Fluidized Bed ◽

High Performance ◽

Maximum Yield ◽

Substantial Effect ◽

Napier Grass ◽

Small Scale ◽

Fluidized Bed Reactors ◽

Direct Combustion ◽

Bubbling Fluidized Bed ◽

Fluidized Bed Gasifier

Air gasification of Napier grass (NG) was studied with the target of producing combustible synthesis gas to be used in direct combustion for power generation. A small-scale autothermal bubbling fluidized bed gasifier was used to investigate the effect of reactor temperature, equivalence ratio (ER), and static bed height (SBH) on gasification performance and combustibility of the producer gas. The main generated species in syngas were identified through gas chromatography (GC) analysis. Minimum fluidization conditions were determined at different levels of SBH. Experiments carried out with two intentions of first, to achieve the highest composition of combustible species to ensure the maximum Lower Heating Value (LHV) of syngas and second, to obtain a high performance process with maximum yield of syngas and minimum residues. The results showed that the temperature and ER have significant effects on syngas yield and composition. SBH was found have a substantial effect on the production of H2 and CO. The results from this study was compared to other gasification studies from literature which have evaluated biomass gasification in bubbling fluidized bed reactors with different scales but almost similar method of experimentation. The purpose of verification was to demonstrate the effect of different reactor scales and heating characteristics on the results.

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