Isopropyl Alcohol Production from RG Propylene | Economic Analysis
Isopropanol Production — Technology Description & Economic Analysis
The main raw materials for Isopropanol manufacture are propylene and acetone. Propylene is reacted with water directly, or indirectly (in the presence of sulfuric acid), to form Isopropanol. Acetone, in turn, passes though a hydrogenation process.
This article aims to present a brief process description and a condensed cost analysis of Isopropyl Alcohol Production from RG Propylene.
Process Description
The process under analysis is comprised of three major sections: (1) Isopropanol synthesis; (2) propylene recovery; and (3) purification.
Isopropanol synthesis. Refinery grade (RG) propylene (70 wt%) is converted into Isopropanol through two consecutive reaction steps. First, gaseous propylene is contacted with weak sulfuric acid in a reactive absorber, forming isopropyl sulfates. Then, the sulfates are hydrolyzed by steam addition in a stripper reactor, generating isopropanol. The stripper gaseous product is absorbed in caustic solution for residual acid neutralization and sent to the purification section. The stripper liquid effluent, containing dilute sulfuric acid, is treated in an acid reconcentration unit for further reuse in the process.
Propylene recovery. The reactive absorber gaseous effluent is treated in a caustic scrubber for residual acid removal and fed to a column for recovery of unreacted propylene. Propane contained in the RG propylene is withdrawn from this column as oveheads product and purged from the process. Recovered propylene is recycled to the Isopropanol synthesis section.
Purification. The crude isopropanol from both the caustic scrubber and the stripper reactor are directed to an ether separation step, where diisopropyl ether (generated in side reactions) is separated and recycled to the absorber reactor to react with sulfuric acid, forming sulfate and isopropanol. The ether-free crude isopropanol is transferred to the alcohol column for removal of high boiling impurities. The overheads product from alcohol column comprises an azeotropic mixture of isopropanol and water. Finally, dry isopropanol is produced after dehydration by means of azeotropic distillation using diisopropyl ether as azeotroping agent.
Cost Analysis
The economic evaluation of industrial processes is a valuable support tool for a myriad of activities and studies, such as screening and assessment of investment options, preliminary evaluation of the economic potential of emerging industrial processes, rough assessment of the economic feasibility of industrial ventures, cost estimates double-checking, preliminary budget approval, research planning, and so on.
A detailed cost analysis for the manufacturing of Isopropanol was developed by Intratec based on a plant constructed in 2022 Q1 in the United States with the capacity to produce 200,000 metric ton per year of Isopropanol. The table below presents a few economic figures related to the process “Isopropyl Alcohol Production from RG Propylene”.
Where,
“Outside battery limits (OSBL)” investment is the costs of OSBL, which is also known as outside battery units, offsite facilities, or site infrastructure. These installations are required, but do not directly participate in the manufacture of a product. They are support buildings and auxiliary units that provide and distribute utilities, and storage facilities.
“Total operating cost” is the sum of operating cash cost with depreciation. Operating cash cost is the sum of fixed operating costs (related to the plant capacity of an industrial site) and operating variable costs (related to the actual rate of operation of the industrial site). While depreciation is the decrease in the value of industrial assets over time.
Main Reference
[1] Intratec. 2022. Isopropyl Alcohol Production from RG Propylene, Advanced Edition. Available at: www.intratec.us/analysis/isopropanol-e11a
Isopropanol Production Processes
To learn more about processes related to Isopropanol production, visit: www.intratec.us/analysis/isopropanol-production-cost
About Intratec Commodity Production Costs Reports
The report Isopropyl Alcohol Production from RG Propylene is part of a series of reports prepared by Intratec approaching the production costs of commodities spanning a diverse range of industries: Oil & Energy; Fertilizers & Gases; Olefns & Derivatives; Aromatics & Derivatives; Alcohols & Organic Acids; Polymers; Inorganic Chemicals; Food & Nutrition; Metals & Mining; and Pharmaceuticals.
For information on all Intratec reports visit: www.intratec.us
