A boiler performs mixed-fuel combustion of a sulfur-containing fuel and ammonia as a fuel, and includes a furnace having a plurality of wall parts, a burner installed on at least one of the wall parts of the furnace, and an ammonia injection port that is configured to cause the ammonia to be burned as the fuel to flow along an inner wall surface of the wall part where the burner is not installed.

A gasifier wall is formed of a plurality of pipes through which a cooling medium flows. The plurality of pipes are made of a first material and arranged side by side. At least a part of the gasifier wall includes an outer peripheral portion stacked on a periphery of each of the pipes and made of a second material having higher corrosion resistance than the pipes; a board disposed between the outer peripheral portion and an adjacent outer peripheral portion; and a welded portion coupling the outer peripheral portion and the board. The outer peripheral portion and the board constitute a wall surface that separates an internal space and an external space from each other. The outer peripheral portion covers an entire region of the pipe in a circumferential direction.

A boiler performs mixed-fuel combustion of a sulfur-containing fuel and ammonia as a fuel, and includes a furnace having a plurality of wall parts, a burner installed on at least one of the wall parts of the furnace, and an ammonia injection port that is configured to cause the ammonia to be burned as the fuel to flow along an inner wall surface of the wall part where the burner is not installed.

A heat store component for passage of a gas flow, in particular, in heat exchangers of flue gas cleaning systems, is provided, including: a mounting forming an inlet and an outlet side of the heat store component for the gas flow fed therethrough; and a first and a second heat storage medium arranged one behind the other in the gas flow direction and each including a plurality of substantially parallel flow channels. The second heat storage medium is formed from one or more honeycomb blocks, which include a body made in one-piece manner of a plastics material and incorporating a plurality of parallel flow channels separated by channel walls, wherein the plastics material includes a plastic containing virgin polytetrafluoroethylene (PTFE) as a fraction of ca. 80% by weight or more and optionally a high performance polymer differing from the PTFE as a fraction of ca. 20% by weight or less.