Simulation of Coal Gasification in a Low-Temperature, High-Pressure Entrained-Bed Reactor with a Volatiles Condensation and Re-Evaporation Model +
Footnote †: journal: Applied Physics Letters  
[PERSON]  
1 Mechanical and System Engineering Program, Institute of Nuclear Energy Research, Atomic Energy Council, Longtan, Taoyuan 32546, Taiwan; [EMAIL_ADDRESS]  
[PERSON]  
2 Chemistry Division, Institute of Nuclear Energy Research, Atomic Energy Council, Longtan, Taoyuan 32546, Taiwan  
the emission of greenhouse gas are crucial issues for the development of a sustainable environment. Coal is still the most abundant source in traditional fossil fuels, and it is expected to be utilized for more than 110 years [1]. Due to its low cost and stable supply, the USA and other industrial countries have proposed the concept of Clean Coal Technology (CCT). Coal gasification is an important means of CCT that can not only convert clean energy from conventional coal resources, but also produce various fuels and chemicals. Popular coal-derived fuels include gaseous fuels such as CO, H\({}_{2}\), synthetic (or substitute) natural gas (SNG), etc., and liquid fuels such as diesel, jet fuels, and methanol. The coal-derived chemicals, in turn, are as broad as petroleum-derived chemicals. The most popular chemicals are ammonia, urea, dimethyl ether, ethylene, and propylene. Among various options of CCT, Integrated Gasification Combined-Cycle (IGCC) is an environmentally friendly coal utilization technology for power generation, which has been gradually commercialized, and more advanced developments continue globally. With a multi-fuel feeding feature, IGCC can be employed to produce power more efficiently with less pollution than traditional coal-fired power plants. Combining with carbon capture and storage (CCS) technology, it will also be an essential option for base-loaded power and sustainable development. If integrated with hydrogen technologies, i.e., hydrogen turbine and fuel cell, the said combination can achieve the vision of zero emission. There have been five major IGCC demo plants globally since mid-1990s, i.e., Wabash River and Tampa in USA, Buggenum (Nuon) in Netherlands, Puertollano (Elcogas) in Spain, and CCP in Japan. Abundant operating experience has been accumulated from these five demo plants. All the gasifiers used in these demo plants are entrained-bed gasifiers, and each has its individual pros and cons. Besides the air-blown methods used by MHI, Japan, the oxygen-blown method is employed for the rest of the four plants. The gasifiers of Wabash River (E-Gas\({}^{\text{TM}}\) gasifier) and Tampa (GE gasifier) employed coal-slurry feeding, while those of Buggenum (Shell gasifier), Puertollano (Prenflo gasifier) and CCP (MHI gasifier) all used dry-fed option. The downdraft flow condition is only employed in the GE gasifier in Tampa. The E-Gas\({}^{\text{TM}}\) and MHI gasifiers feed coal in two-stages, while the Shell, GE, and Prenflo use only one-stage feed. Coal gasification is an extremely complex process. It will take many years of continuous efforts to achieve meaningful and practical results, and for continuous improvements afterwards. The Institute of Nuclear Energy Research (INER) in Taiwan has developed Computational Fluid Dynamics (CFD) models for years to simulate gasification process. Previous studies have successfully established the CFD capability to analyze the gasification process in an E-Gas\({}^{\text{TM}}\) type entrained-flow gasifier to produce syngas for power generation [2]. To further investigate the different products that can be produced by coal gasification, the gasification model needs to be continuously expanded and improved by incorporating more complex and detailed sub-models. It has been reported that a newly introduced Entrained Slagging Transport Reactor (E-STR) gasifier can reduce capital and operating costs, while improve operability [3]. E-STR is a product modified from the existing E-Gasifier design, and the configuration can be seen in Slide 6 of Ref. [3].