Plant design which is an iterative procedure with a route of procession from the input or feed to the stated objectives, amidst intervening constraints, requires a careful, well- thought- out, comprehensive specifications of the defined or desired requirements.
The stated objective in this case is the design of a 60,000 tons/year capacity of a 2- Ethyl Hexanol (C8H18O) Plant. While many processes exist at producing 2-Ethyl Hexanol (2- EH), such as the Acetaldehyde Route and others developed by Shell Corporation etc., the Oxo Process route utilizing propylene and synthesis gas as feed components was the selected route for this design work. However, important modifications were implemented to the process description for effective process optimization, such as to improve the conversion of efficiencies of process equipment by aid of recycle processes.
The oxo synthesis began by reacting propylene feed and synthesis gas (CO + H2) in a Rhodium triphenylphosphine catalyzed hydroformylation reaction.
An acceptable design must present a process that is capable of operating under conditions which will yield a profit. A simple costing procedure was carried out for the 2- EH Plant to determine if the design is feasible economically or not based on certain estimates.
Estimates were prepared using data and Chemical Engineering plant cost index method in Literature, considering Port Harcourt, Rivers State, Nigeria as the location of the plant. Old cost information was obtained and extrapolated using the Index Method to the present 2016 costs. These costs were evaluated in U. S dollars. The Purchased Cost of Equipment (PCE) was valued at $3,150,153.93, while the Physical
Plant Costs (PPC) or direct costs was obtained by the factorial costing method at 3.4 times PCE, and valued at $10,62,544.69. Indirect costs were the expenses which are not directly involved with material and labor which included design and engineering, contractor’s fee etc, and were valued at $5,040,246.29. The Fixed Capital Investment (FCI) was obtained by summing up the direct and indirect costs, and valued at $16,002,790.98. The Working Capital was 12% of the FCI and both gave the Total Capital Investment of $17,923,125.90. The start- up cost of plant for production was evaluated at 10% of TCI.
With a selling price at $1.74/kg, the 60,000 tons/year of 2- Ethyl hexanol plant is expected to have a net profit of $22,125,469.76 and a payback period of 2.8 years. However, procedures for safe operation and start- up of the 60,000 tons/year 2-Ethylhexanol Plant was documented.