Sequential Modular Simulation of Hydrodynamics and Reaction Kinetics in a Biomass Bubbling Fluidized-Bed Gasifier Using Aspen Plus

Abstract

A sequential modular simulation (SMS) approach was used to simulate hydrodynamics and detailed kinetics of a fluidized-bed biomass gasifier in Aspen Plus. The kinetics of tar cracking reactions was taken into account in the simulation. The effects of operating conditions including temperature, equivalence ratio (ER), and steam-to-biomass ratio (SBR) on the composition and the lower heating value (LHV) of the effluent gas were studied and compared with experimental data. The model predictions well agreed with the experimental data. The increase of the bed temperature significantly decreased the tar content and increased the hydrogen content of the product gas. At ER = 0.3, the increase of the temperature from 973 K to 1123 K resulted in the increase of H 2 molar concentration in the product gas from 7.6% to 11.3% and CO molar concentration from 13.1% to 17.0%. At a temperature of 1073 K, the optimum ER value was 0.3 and the increase in ER from 0.2 to up to 0.3 increased the amount of fuel gases but further increases in ER shifted the system kinetics toward the combustion regime. At 1073 K and ER = 0.3, with an increase in SBR from 0 to 1.0, H 2 and CO 2 concentrations increased from 9.3% and 13.3% to 10.8% and 14.7%, respectively, and CO concentration decreased from 15.8% to 12.9%. The analysis showed the SMS model with four stages gives the most satisfactory predictions, via comparison with the experimental data.

Techno-economic analysis of production of Fischer-Tropsch liquids via biomass gasification: The effects of Fischer-Tropsch catalysts and natural gas co-feeding

“…Overall process flow chart b. Process sub flowsheet for fluidized bed biomass gasification using the SMS approach [18] c. Process sub-flowsheet for gas reforming area Figure 2b gives the sub-flow chart developed in Aspen Plus ® for a fluidized bed biomass gasifier using the sequential modular-based model (SMS) in our previous study [18].…”

Process improvement analysis of pyrolysis/gasification of biomass and waste plastics with carbon capture and utilisation through process simulation

“…The normally used physical property calculation methods for simulating gasification of carbon-based material include Redlich-Kwong-Sovae (RKS) [2], Redlich-Kwong-Aspen equation (RK-Aspen) [1,32] and Redlich-Kwong-Sovae with Boston-Mathias alpha function (RKS-BM) [7]. According to the user guide of Aspen Plus®, these three methods are all suitable for processes such as gas processing, refinery and petrochemical applications.…”

“…The main reactions inside GASI-HOM contain a series of tar cracking reactions, water-gas-shift (WGS) reaction and steam-methanereforming (SMR) reaction. The reaction kinetics used in GASI-HOM are derived from Abdelouahed et al [1], Rafati et al [32], Gerun et al [19] and Jess [21]. The third reactor (i.e.…”

Simulation of two-stage automotive shredder residue pyrolysis and gasification process using the Aspen Plus model

“…Aspen Plus has been used by many researchers for designing and optimizing pyrolysis and gasification processes. Aspen Plus is favored by researchers to simulate biomass pyrolysis and gasification (Doherty et al 2009;Paviet et al 2009;Abdelouahed et al 2012;Fu et al 2012;Rafati et al 2015;Pauls et al 2016;Gagliano et al 2017;Humbird et al 2017;Liu et al 2017;Pala et al 2017;Peters et al 2017;Lan et al 2018). In these studies, the influence of parameters on the characterization of gaseous products is often considered, such as equivalent ratios (ER) (Li et al 2012), temperature, mass ratio of steam to materials, etc.…”