(307a) IGCC Process Intensification with the Reforming Technologies for Enhanced Power Generation with CCS Technology

IGCC (Integrated gasification and combined cycle) is a pre-combustion technique which represents higher thermal efficiency with large scale implementation of CO₂ capture. On the other hand, NGCC (Natural gas combined cycle) power plants offers higher process performance compared to IGCC process with CCS technologies but the fluctuating and comparatively higher costs of natural gas limits its extensive implementation over coal based power generation systems. Therefore, process intensification of coal based gasification processes with the natural gas reforming technology has been proposed in this study to enhance the overall process performance while limiting the natural gas consumption. In this study, two IGCC based process models have been developed and evaluated in terms of both the process performance and economics with CO₂ capture. Case 1 is taken as the conventional IGCC process, whereas, case 2 presents an idea of integrating methane reforming process with an IGCC technology. Coal is used as primary fuel in both the cases for the coal gasification process, however, small amount of natural gas is used as secondary fuel only in the case 2 design. The high enthalpy steam generated during coal slurry gasification process in case 2 is used to assist the methane reforming to generate additional H₂. The integration of IGCC with methane reforming process not only supplies the heat required for the endothermic reforming process but also increases the heating value of the resulting syngas. Moreover, the H₂O generated in the gasification process in case 2 can be consequently utilized in the natural gas reforming process without utilizing any extra steam. This concept also provides an opportunity for the process economics since shared water gas shift reactors and CO₂ capture units will suffice the process needs. The net electricity generation capacity and efficiency for case 1 and case 2 is calculated as (375.08 MW_e, 472.92 MW_e) and (35.93%, 40.70%), respectively. While comparing the results, it has been seen that case 2 design offers nearly 4.77% higher efficiency compared case 1 design with CO₂ capture. The process economics analysis showed that the case 2 design requires a higher CAPEX and OPEX throughout the project life compared to the case 1 design. However, due to the higher power generation capacity of case 2 design, it has a potential to reduce the LCOE (levelized cost of electricity) by 5.81% compared to the case 1 design. Moreover, case 2 design not only requires the less CO₂ capture and avoidance costs compared to the case 1 but also exhibits higher rate of return on the investment with the less payback time. With the higher efficiency and least case 2 has been considered as the most feasible option for electricity production at an economical price compared to the case 1 design.