Category Nuances for flue_gas:

• expensive,
• industrial,
• heated,
• gaseous,
• additional,
• atmospheric,
• dilute,
• appropriate,
• external,
• warm,
• electrical,
• chemical,

Simple Categories for flue_gas:

• appliance,
• unit,
• substance,
• fluid,
• gas,
• equipment,
• process,
• waste,
• medium,
• agent,
• means,
• mixture,