An Experimental and Numerical Investigation of Fluidized Bed Gasification of Solid Waste

Abstract

Abstract:Gasification is a thermo-chemical process to convert carbon-based products such as biomass and coal into a gas mixture known as synthetic gas or syngas. Various types of gasification methods exist, and fluidized bed gasification is one of them which is considered more efficient than others as fuel is fluidized in oxygen, steam or air. This paper presents an experimental and numerical investigation of fluidized bed gasification of solid waste (SW) (wood). The experimental measurement of syngas composition was done using a pilot scale gasifier. A numerical model was developed using Advanced System for Process ENgineering (Aspen) Plus software. Several Aspen Plus reactor blocks were used along with user defined FORTRAN and Excel code. The model was validated with experimental results. The study found very similar performance between simulation and experimental results, with a maximum variation of 3%. The validated model was used to study the effect of air-fuel and steam-fuel ratio on syngas composition. The model will be useful to predict the various operating parameters of a pilot scale SW gasification plant, such as temperature, pressure, air-fuel ratio and steam-fuel ratio. Therefore, the model can assist researchers, professionals and industries to identify optimized conditions for SW gasification.

Understanding mineral behaviors during anthracite fluidized-bed gasification based on slag characteristics

“…The residual carbon content in the three slag samples decreases in the order S I < S D < S C . The CaO or (6) conveyer, (7) coal hopper, (8) feeder, (9) bucket elevator, (10) coal lock hopper, (11) rotary feeder, (12) gasifier, (13) ash lock hopper system, (14) heat exchanger, (15) 1st cyclone, (16) 2nd cyclone, (17) fine collection and transport system, (18) high temperature fine re-gasifier, (19) fine hopper, (20) steam/oxygen distributors, (21) oxygen supply system, (22) waste heat boiler, (23) steam and soft water pre-heater, (24) water scrubber, (25) desulphurization reactor, (26) gas burner, (27) soft water supply system, (28) washing water cleaning system.) Fe 2 O 3 content of the slag samples is much higher than that of the JC ash, whereas their trace composition of inorganic oxides (e.g., Na 2 O, K 2 O, and SO 3 ) is lower than that of JC ash because of evaporation of these constituents during AFB gasification of JC at high temperature [42].…”

“…Coal gasification is generally carried out in one of three types of reactors classified according to solid feedstock movement: fixed-bed [4,5], fluidized-bed [6,7], and entrained-flow bed reactors [8][9][10]. Among the three gasification technologies, the fluidized bed permits higher fuel flexibility with the possibility to gasify coal [11], biomass [12,13], and other municipal solid waste [14,15] at high ash fusion temperature (AFT, flow temperature (FT) of >1400°C). Thus, increasing attention has been given to its development worldwide, especially in China, where high-AFT coal accounts for more than 50% of coal reserves [16].…”

Analysis of Operation Parameters in a Dual Fluidized Bed Biomass Gasifier Integrated with a Biomass Rotary Dryer: Development and Application of a System Model

“…Integration of the DFB gasifier with the rotary dryer will increase the overall efficiency and potentially optimize the system operation. Begum et al [8,9] studied the integration of biomass drying with fixed bed and fluidized bed gasification; however, no publication has been found in literature on DFB gasification-drying integration modelling.…”

Simulation of Steam Gasification in a Fluidized Bed Reactor with Energy Self-Sufficient Condition

“…In contrast, the fixed bed system is more appropriate for a small-scale system [12]. Examples of steam gasification process studies are atmospheric fluidized bed combustor [13], biomass gasification in a fluidized bed reactor [14,15], steam blown dual fluidized bed gasification [16], and bubbling fluidized bed gasification [17]. Shehzad et al [18] studied the thermodynamic performance of a municipal solid waste (MSW) gasification system with a circulating fluidized bed gasifier under various operating conditions.…”