Nowadays, gasification is seen as a worldwide settled technique for sustainably generating energy from residues. Its final product is a synthetic gas which may be used for several purposes such as fueling engines, industry and the transport sector. This technique involves several complex reactions, different thermodynamic regimes and environments, and may be held under a myriad of operational conditions. Thus, simulation tools have become very useful to predict the optimal parameters to be applied and the heating content of the final product, therefore producing the most suitable syngas for the desired utilizations. Computational fluid dynamics (CFD) reduces the time needed to design and implement each gasification experiment, using mathematical approaches and developing specific codes regarding the type of feedstock, reactor utilized and expected atmosphere. This paper reviewed the major works on numerical methods for gasification and co-gasification of feedstocks, such as biomass, waste and fossil fuels, published in the last two decades. A thorough explanation of the solid and gaseous phases, their interconnections and behavior was presented, while relating the characteristics of the main methods to the final product obtained. Major trends were identified as well as some suggestions regarding future perspectives were done. Kinetic, thermodynamic and computational fluid dynamic models were seen to be preferred concerning the study of syngas production from distinct types of feedstocks. Also, biomass and coal were the most frequently used feedstocks, with 37% and 24% of the total share, respectively. Relative to the gasifier type, fluidized beds were used in almost 50% of the assessments, followed by entrained beds, mostly used for coal gasification. Only major trends could be identified for some of the experimental conditions applied, due to the high variances seen for different feedstocks or reactor features. This review supports the need to continue developing new models and adapting the existing ones in order to reach broader conclusions, since distinct parameters afford completely different outcomes.

Numerical approaches and comprehensive models for gasification process: A review

Influences of operating parameters on the fluidized bed coal gasification process: A coarse-grained CFD-DEM study

CFD simulation of biomass steam gasification in a fluidized bed based on a multi-composition multi-step kinetic model

Progress in CFD Simulations of Fluidized Beds for Chemical and Energy Process Engineering

A review on CFD simulation of biomass pyrolysis in fluidized bed reactors with emphasis on particle-scale models

Wood gasification in a fluidized bed reactor is regards as a promising technique to efficiently exploit the energy from biomass, which has attracted great attention. To further understand complex fluid mechanics and thermal behaviors of wood during the gasification process, a multiphase reactive model is presented, and a computational fluid dynamics (CFD) simulation of wood gasification in a bubbling fluidized bed gasifier is implemented. To account for the impact of bubble-structure on the gas–solid interaction, a revised bubble-based energy minimization multiscale (EMMS) drag model is developed and incorporated into a two-fluid model. Flow behaviors and reactive characteristics in a bubbling fluidized bed gasifier are analyzed. Profiles of temperature and concentration of gas and solid phase are also obtained. By comparisons of the outlet gas species concentrations, the prediction by a revised bubble-based EMMS drag model agrees better with experimental results than that by the conventional drag model.

CFD Simulation of a Bubbling Fluidized Bed Gasifier Using a Bubble-Based Drag Model

The dry sorbent carbon dioxide capture technology is an efficient method to remove CO2 from flue gases. In this work, a multiphase hydrodynamic model with a sorption reaction of CO2 is developed and a two-dimensional computational fluid dynamics (CFD) simulation is carried out. The potassium carbonates are used as dry sorbents. A revised multi-scale interphase drag coefficient model is incorporated into the two-fluid model to consider the influence of clusters. The non-uniform distribution of the solid concentration and CO2 concentration is captured in the reactor. The core-annular regime can be found in the reactor. Predicted results are in good agreement with experimental results. The effects of operating conditions and parameters on the CO2 removal are evaluated. Simulated results indicate that reducing the inlet gas velocity can prolong the residence time of sorbents and enhance the overall CO2 removal. Improving the particle size and solid inventory will lead to an increase of CO2 removal to some extent.

Numerical Studies for the CO2 Capture Process in a Fluidized-Bed Absorber

A 2D CFD simulation of the carbonation reactor is carried out to evaluate the performance of potassium-based dry sorbent during the CO2 capture process. A multiscale drag coefficient model is incorporated into the two-fluid model to take the effects of clusters into account. The influence of several parameters on CO2 removal is investigated. The results indicate that increasing the reactor height and reducing the gas velocity can lengthen the residence time of particles and enhance the CO2 removal. The operating pressure has a significant influence on the performance of solid sorbents. A higher pressure will decrease the CO2 removal efficiency.

CFD Modeling of a Carbonation Reactor with a K‐Based Dry Sorbent for CO2 Capture

Temperature, pressure and combustion state monitoring device of high temperature furnace

The utility model provides a milling cutter for machining carbon fiber composites. The carbon fiber composite machining efficiency and precision of existing cutters can not meet the process requirements. The milling cutter comprises a cylindrical shank (1), wherein four cutter bodies (2) are arranged on the shank; the external shapes of the cutter bodies are spherical; the four cutter bodies are uniformly distributed on the shank; the upper end faces of the cutter bodies are front cutter faces (3); the front cutter faces are 30-degree fan-shaped cutter faces; the angles of inclination of the front cutter faces are 1.5 degrees; the two sides of each cutter body are a front side cutter face (4) and a rear side cutter face (5); a rectangular blade (6) is arranged on the front cutter face at the intersection of each front cutter face and each rear side cutter face and is connected with the front cutter face via bolts (7); a chip groove (8) is formed at the intersection of the front side cutter face of one cutter body and the rear side cutter face of the adjacent cutter body and is connected with one end of one blade; and a chip storage groove (9) is formed in each rear side cutter face and is connected with each chip groove. The milling cutter is used for machining carbon fiber composites by milling.

Liu Di

Papers

CFD Simulation of a Bubbling Fluidized Bed Gasifier Using a Bubble-Based Drag Model

Numerical Studies for the CO2 Capture Process in a Fluidized-Bed Absorber

CFD Modeling of a Carbonation Reactor with a K‐Based Dry Sorbent for CO2 Capture

Temperature, pressure and combustion state monitoring device of high temperature furnace

Milling cutter for machining carbon fiber composites