(251c) Comparison of Transport Coal Gasification Process Model Focused on Coal Drying

This work addresses process models for transport coal gasifiers especially in coal drying process. In this work, two process models of the transport gasifier are developed which focus on different coal drying concepts. The first model uses additional gas for drying. The second model imports an integrated drying of feedstock feed to integrated gasification combined cycle (IGCC) plant. In this process, high pressure syngas from the gasifier is heated and is then used to dry feedstock. North Dakota Lignite (NDL) is used as feedstock coal and Peng-Robinson Equation is used for both models as physical property model.

Two simulations are run using the NDL coals and corresponding parameters listed. The ratio of syngas especially H2 and CO determines the latter process. In WTA drying model, ratio of H2 : CO = 1.16 : 1 and itâ??s suitable for hydroformylation which makes aldehyde (-CHO). In ID case, H2 : CO = 0.49 : 1. Ratio for making SNG is usually 2 : 1 and ratio which is appropriate for methanation is 3 : 1. However, the ratio of ID case is lower for making final product. Therefore, additional process such as Water Gas Shift Reaction (WGSR) process is needed to increase H2 amount.

Two process models of the transport gasifier are developed focused on different coal drying concept. The syngas of WTA model has high temperature and pressure and this energy can be applied in latter process. Integrated Drying concept is suitable for transport gasifier because of high carbon conversion rate and heat stream in gasifier.