美国麻省理工大学Ahmed Ghoniem教授学术报告

应岑可法院士教授邀请， 美国MIT教授Ahmed Ghoniem将于近日访问实验室，并于2017年9月6日上午9:00-10:30在浙江大学能源工程学院223会议室做有关“Efficient Low-Rank Coal Gasification with ScCO2 Slurry Feed”的专题学术报告，下午2:00-3:30在浙江大学热能工程研究所205会议室作有关“Multiscale CFD Simulations of Fluidization Dynamics: Bubbles, Mixing and Reactor Scaling”的专题学术报告，欢迎老师和学生们参加！

Prof. Ahmed F. Ghoniem

Department of Mechanical Engineering

Center for Energy and Propulsion Research

Massachusetts Institute of Technology

Bio-sketch: Ahmed F. Ghoniem is a Professor in the Department of Mechanical Engineering at Massachusetts Institute of Technology. He holds the membership of American society of Mechanical Engineering, American Institute of Aeronautics and Astronautics, American Physical Society and the Combustion Institute. In 1980, he received his Ph.D. in Mechanical Engineering from University of California, Berkeley. From 1983, he worked as assistant professor, associate professor (1986), professor (1992) at Massachusetts Institute of Technology. He is a recipient of the AIAA Propellants and Combustion Award (2016), ASME James Harry Potter Gold Medal (2015), KAUST Investigator Award (2008-2013), Research Initiation Award National Science Foundation. His research interests are broadly on the energy conversion science and engineering, computational methods, combustion fundamentals and modeling, turbulent reacting flow and combustion, and renewable energy sources and conversion.

Efficient Low-Rank Coal Gasification with ScCO2 Slurry Feed

9:00AM-10:30AM Sep 6, 2017, Room 223 School of Energy Engineering, Zhejiang University

Gasification-based plants with coal-CO₂ slurry feed are predicted to be more efficient than those with coal-water slurry feed. Since the systems based on coal-water slurry feed suffer from low thermal efficiency, which is a result of the large amount of energy used in heating up and vaporizing the slurry water. This is particularly true for high moisture, low rank coal such as lignite. Liquid carbon dioxide has been suggested as an alternative to water for the preparation of coal slurry in plants with carbon capture. An up to 12%-point higher gasifier cold gas efficiency has been estimated for coal-CO₂ slurry-fed systems as a result of the lower heat capacity and enthalpy of vaporization of CO₂, relative to water. Unlike coal-water slurry, however, coal-CO₂ slurry cannot be prepared at ambient pressure: the triple point pressure of CO₂ is 5 bar so CO₂cannot exist in its liquid state at lower pressures including ambient. Various methods for preparing coal-CO₂ slurry have been suggested, all of which use lock hoppers to overcome the minimum pressure required to form CO_2(l), whereas chilling is often proposed as a way to reduce the minimum lock hopper pressure. This work presents and evaluates an alternative approach, which allows for the preparation of coal-CO₂ slurry at ambient temperature. We also introduce the Phase Inversion-based Coal-CO₂ Slurry feeding system, in which coal-CO₂ slurry is prepared at ambient temperature via coal-water slurry. The main characteristics of the LICADO process for coal beneficiation are presented, together with a brief description of the process development work conducted at the time as well as of its main findings. Next, the PHICCOS process for the preparation of coal-CO₂ slurry as a gasifier feedstock is introduced. Finally, a first estimate of the costs of the PHICCOS process is presented and compared with other feeding systems to arrive at an overall assessment of the attractiveness of this slurry preparation method and of its potential application for low and high-rank coal gasification.