Opposed Multi-burner Research Articles

Numerical Simulation of Industrial Opposed Multiburner Coal–Water Slurry Entrained Flow Gasifier

A comprehensive three-dimensional numerical model is developed for simulation of the industrial opposed multiburner (OMB) coal–water slurry (CWS) entrained flow gasifier. The CWS gasification process is divided into several submodels, including water evaporation, coal pyrolysis, and homogeneous and heterogeneous char reactions. The “effectiveness factor” method is used to extrapolate the intrinsic char reactivity data to industrial CWS gasifier conditions. Numerical simulations with the proposed models are performed on the industrial OMB gasifier, and the predicted temperature and gas compositions at the outlet of the gasifier are in good agreement with industrial operating data. The profiles of flow field, temperature, and gas composition in the gasifier are described. In addition, the effects of the slurry concentration and oxygen/coal ratio on the gasifier performance are also studied, which reveal that the lower oxygen/coal ratio or higher slurry concentration leads to higher cold gas efficiency, whil...

The investigations of temperature distributions in an opposed multi-burner gasifier

In a bench-scale opposed multi-burner (OMB) gasifier, the temperatures of gasification chamber and quench chamber are measured by thermocouples, and the temperature distributions of flame sections are reconstructed by the Filtered back-projection method. The results show that the temperature of gasification chamber increases slowly as the inserted distance increases in both diesel and coal–water slurry (CWS) tests. The syngas temperature decreases rapidly when it passes through the inlet of quench chamber. The impinging flames of diesel or CWS gasification all focus on the gasifier center due to restraining by each other, and can avoid scouring the refractory wall and prolong the lives of refractory. At the test conditions, the temperature distributions of diesel flames are 1650–2100 °C and those of CWS flames are 1500–2000 °C. The flame temperature distributions appear to be a typical simple peak. The investigations can provide some information for the industrial gasifier.

Numerical Study of Gas−Solid Flow in a Radial-Inlet Structure Cyclone Separator

The development of a radial-inlet structure cyclone separator is reported in this paper, which is used as a primary device for gas-particle separation in an opposed multi-burner (OMB) gasification ...

Numerical and experimental investigations on gas–particle flow behaviors of the Opposed Multi-Burner Gasifier

Numerical and experimental study on the gas–particle flow field has been carried out in the large Opposed Multi-Burner (OMB) Gasifier (I.D. 1.0 m) at high temperature and pressure. A 3D numerical model based on the Eulerian–Lagrangian model is used to simulate the gas–particle flow behaviors. The gas phase is treated as continuous phase with an Eulerian method while the Lagrangian method is applied to trace of the particles, and the interaction between gas and particles is considered. The behavior of slag/ash particle collision and its effects on particle dispersion are presented. The simulations are validated by available experimental data. The results showed that material residence time increased with the straight section height above the burner, and the deposition flux increased with the inlet velocity. The axis profiles of particle concentrations at high temperature and pressure have the similar characteristic shapes to those at ambient pressure and temperature. And the highest turbulence intensity and collision flame are converged around the centre of impingement zone. Though the inter-particle collision led to the phenomenon of particle agglomeration, the holistic distribution of particle concentration was reasonable. Finally, the effect of operating pressure and particles Stokes number were studied.

Status of domestic gasification technology in China

Five domestic gasification technologies in China were presented and reviewed, including opposed multi-burner (OMB) gasification technology of coal water slurry (CWS), oxygen staged gasification technology, two-stage dry feed entrained flow gasification, pulverized coal gasification process of HT-L, and ash agglomerating fluidized bed gasification. The former four technologies belong to pressurized entrained flow gasification technology. The process description, technology characteristics, research and development process, performance indexes and commercialization progress of these technologies were mainly discussed.

Experimental investigations on temperature distributions of flame sections in a bench-scale opposed multi-burner gasifier

Based on a flame image processing technique, the temperature distributions of flame sections in a bench-scale opposed multi-burner (OMB) gasifier is visualized. With the assumption of the gray radiation, a charge-coupled device camera installed on the top of the gasifier is used to capture the approximately monochromatic radiant images under the visible wavelengths. To reduce the errors, the camera is calibrated by a blackbody cavity. By using the two-color method, the radiant intensity captured by the camera is calculated from the pair of red/green with reference to the calibration data. Based on the assumption of rotational symmetry, the temperature distributions of flame sections are reconstructed by the Filtered back-projection method. The results show that the temperature distributions of flame sections are consistent with the flame structure. The flame temperature distribution at the burner plane ranges from 1700 to 2100 °C. The section is farther from the burner plane, the temperature is lower. The relative errors between the calculated temperatures and the measured temperatures by a B-type thermocouple are no greater than ±6.4%. The research results establish the foundation for understanding the flame internal structure and temperature distribution in the OMB gasifier.

Release of fuel-N during entrained-flow gasification of fuel mixed with model compound

Model compound pyridine was added to diesel oil to simulate the existence of coal-N. A laboratory opposed multi-burner (OMB) gasifier was used to investigate the axial and radial concentration distribution of HCN, NH 3, NO and N 2. The maximum concentrations of nitrogen pollutants (HCN, NH 3 and NO) are produced at the nozzle plane and these concentrations decrease away from the plane. Moreover, N 2 participates in gasification and the order of concentrations of nitrogen compounds in exit is N 2>HCN>NH 3>NO. NO and N 2 increase as O 2/fuel ratio increases. HCN and NH 3 reach maximum when O 2/fuel ratio is 1.3, but largely decrease at 1.7 and 0.9. Flow field distribution make radial concentration profiles uniform toward the exit region and low near the side-wall in other axial position. The steam addition leads to increased formation of HCN and NH 3, whereas decreased formation of NO. The results may be useful for the further investigation of coal-N conversion mechanism.

Development and demonstration plant operation of an opposed multi-burner coal-water slurry gasification technology

The features of the opposed multi-burner (OMB) gasification technology, the method and process of the research, and the operation results of a pilot plant and demonstration plants have been introduced. The operation results of the demonstration plants show that when Beisu coal was used as feedstock, the OMB CWS gasification process at Yankuang Cathy Coal Co. Ltd had a higher carbon conversion of 3%, a lower specific oxygen consumption of about 8%, and a lower specific carbon consumption of 2%–3% than that of Texaco CWS gasification at the Lunan Fertilizer Plant. When Shenfu coal was used as feedstock, the OMB CWS gasification process at Hua-lu Heng-sheng Chemical Co. Ltd had a higher carbon conversion of more than 3%, a lower specific oxygen consumption of about 2%, and a lower specific coal consumption of about 8% than that of the Texaco CWS gasification process at Shanghai Coking & Chemical Corporation. The OMB CWS gasification technology is proven by industrial experience to have a high product yield, low oxygen and coal consumption and robust and safe operation.

Reaction of brown coal and lignin during briquetting

Opposed multi-burner (OMB) gasification technology is the first large-scale gasification technology developed in China with completely independent intellectual property rights. It has been widely used around the world, involving synthetic ammonia, methanol, ethylene glycol, coal liquefaction, hydrogen production and other fields. This paper summarizes the research and development process of OMB gasification technology from the perspective of the cold model experiment and process simulation, pilot-scale study and industrial demonstration. The latest progress of fundamental research in nozzle atomization and dispersion, mixing enhancement of impinging flow, multiscale reaction of different carbonaceous feedstocks, spectral characteristic of impinging flame and particle characteristics inside gasifier, and comprehensive gasification model are reviewed. The latest industrial application progress of ultra-large-scale OMB gasifier and radiant syngas cooler (RSC) combined with quenching chamber OMB gasifier are introduced, and the prospects for the future technical development are proposed as well.