Kazuhiro Kidoguchi

Modelling and Simulation for Extra Heavy Oil Gasification on Entrained Flow Gasifier

The objective of this study is to develop an evaluation tool for a design and performance of an extra heavy oil gasifier by a numerical simulation technique. The modelling and the numerical simulation for the extra heavy oil gasification on the 2.4 tons/day entrained flow gasifier of CRIEPI are described in this paper. The gas phase properties are calculated by three dimensional time-mean Eulerian conservation equations, in addition to the k-e turbulence model. The fuel droplet behavior is modelled via a Lagrangian particle tracking approach. Four reaction processes are modelled in the present paper: atomization (micro-explosion), pyrolysis, coke gasification reaction, and gaseous phase reaction. As a result of the simulation, in a relationship between an oxygen ratio of the gasifier and the gasifier performance, such as heating value of the product gas, carbon conversion efficiency are presented. Distribution of gas temperature and gas composition in the gasifier, and the product gas composition are also presented. Comparison between the computational and the experimental results shows that the most features of the gasifier performance have been captured accurately by the computational procedure. The numerical simulation approach is very useful for the assessment of gasification performance, operation support and optimization of the gasifier design.© 2002 ASME

Development of Oxy-Fuel IGCC System With CO2 Recirculation for CO2 Capture: Experimental Examination on Effect of Gasification Reaction Promotion by CO2 Enriched Using Bench Scale Gasifier Facility

To cope with global warming problem, utility companies are required to reduce CO2 emission from pulverized coal fired power plants. Japanese utility companies are advancing various measures to improve plant thermal efficiency and to promote utilization of biomass as a fuel. In Europe and America, CO2 capture and storage (CCS) technology is regarded as one effective approach, and various demonstration projects are planned all over the world. However, the introduction of conventional CO2 capture system to power station causes a decrease in the plant thermal efficiency and an increase in the power generating cost. In this reason, it is necessary to develop a new power generating system with high thermal efficiency. Therefore, Central Research Institute of Electric Power Industry (CRIEPI) proposed an innovative integrated coal gasification combined cycle power generating system (IGCC) with CO2 capture whose plant thermal efficiency is very high, and is working on the research and development of the new system. This is a system to combine a new oxygen-CO2 blown coal gasifier in that captured CO2 is used with the closed gas turbine in which coal gas from the gasifier is burned with the gas mixed oxygen and recycled exhaust CO2 . The system has the following features. The gasification performances improve greatly. The processes of concentrating and separating CO2 are unnecessary. It is estimated that the carbon conversion efficiency (CCE) and the cold gas efficiency (CGE) in oxygen-CO2 blown gasifier improve more than conventional oxygen blown gasifiers by the effect of the gasification reaction promotion of CO2 by gasifying coal with oxygen and CO2 . As a result, the gasifier and the char recycling system can make to compact, and the equipment cost can be reduced. This paper reports on examination of CO2 promotion effect on the gasification performances by gasification test using a bench scale gasifier facility.Copyright