Meaning
Operating intensity of a thermal decomposition furnace is defined by the temperature and residence time relationship during the production of olefins. This steam cracking severity dictates the ratio of methane to propylene in the effluent gas. It is a critical control variable for maximizing the yield of specific chemical building blocks.
Control Variables
Operators adjust the coil outlet temperature to reach the desired level of conversion for the specific feedstock in use. Higher steam cracking severity leads to a greater production of ethylene but increases the rate of coke formation on the furnace tubes. This requires a balance between output volume and the frequency of maintenance shutdowns.
Product Distribution
Light feedstocks like ethane require different conditions than heavy liquids like naphtha to achieve optimal results. When steam cracking severity is low, the process yields more heavy liquids and fewer light gases. This directly affects the availability of monomers for polymerization.
Material Impact
Changes in furnace conditions can influence the concentration of trace impurities in the monomer stream. While subsequent purification steps remove most contaminants, fluctuations in steam cracking severity can alter the cost of production for the resin manufacturer. Process stability is the goal for consistent polymer quality.
