𝐶 𝑗 is the Bare Module Cost for equipment 𝑗. 𝐶 𝑗,𝑓𝑖𝑥 is the cost of the control system of 𝑗. 𝐿𝑀 is the cost of Labor and materials. 𝐴𝐹 is an alloy factor, which is determined by the cost of materials. 𝐶 𝑗,𝑟𝑒𝑓 is the cost for j in a reference scale, 𝑠 𝑟𝑒𝑓 . 𝑠 𝑗 is the actual scale of 𝑗. 𝑛 𝑗 is a parameter that determines the influence of a scale. The parameters in equation ( ) for each equipment, 𝑗, are given in Table with the assumption that Chemical plant cost indexes (CEPCI) is 1000. Adjustment Factor in Table is multiplied to the 𝐶 𝑗,𝑟𝑒𝑓 (j = reactor or refrigerator) in a reference scale. Stainless steel (SUS 304) was employed for the material for reactors, compressors, and heat exchangers (shell and tube) with the alloy factor, 2.75 for reactors and compressors and 2.80 for heat exchangers. It is because SUS 304 is durable for the temperature and the pressure required for the plants and is tolerant for hydrogen embrittlement. CEPCI in 2019, 607.5 was utilized.