A gasifier 
system is provided that includes a gasification chamber spool that has a 
ceramic matrix composite (CMC) liner adapted to form a solidified 
slag protective layer on an interior surface of the liner from 
molten slag flowing through the gasification chamber spool. The gasification 
system additionally includes a 
heat exchanger (HEX) quench spool that also includes a CMC liner adapted to form a solidified 
slag protective layer on an interior surface of the liner from 
molten slag flowing through the HEX quench spool. Additionally, the HEX quench spool includes a 
parallel plate HEX core having a plurality of CMC panels. The CMC panels are adapted to form a solidified 
slag protective layer on exterior surfaces of each respective CMC panel from 
molten slag flowing through the HEX quench spool. Furthermore, each CMC panel includes a plurality of internal 
coolant channels adapted to exchange sensible 
waste heat from the hot product flowing through the HEX quench spool with a 
coolant flowing through the internal 
coolant channels. The sensible 
waste heat absorbed by the coolant is recovered by the gasification 
system by utilizing the heated coolant in various operational phases of the gasification system.