## Process Economics – Global Homework Experts

Process Economics

You oversee a chemical plant producing 1,000 tonnes per year of biodiesel. The overall biodiesel yield is 70wt% of the raw material used. Raw material costs £500/tonne, and the biodiesel obtained sells for £900/tonne. A process modification has been devised that will increase the biodiesel yield to 80wt% of the raw material used, and requires an additional investment of £525,000. If the process is not modified, maintenance will be needed which costs £380,000. In either case, the plan is to scrap the plant after four more years of operation. No taxes are to be considered.

According to the data provided would you recommend proceeding with the modification? Justify your answer using simple return on investment, and simple payback.

Draw the discounted cash flow diagrams for both scenarios (with and without process modification), in the same chart. Use an interest rate of 10%. Clearly indicate the key stages of the cash flow diagram, i.e. the break-even point, payback time, expenditure and income.

Based on the economic indicators you obtained, critically discuss the profitability of the plant in an industrial context. What would you do if new competitors were emerging?

Explain your understanding of the discounted cash flow rate of return (DCFRR) and how this analysis complements the economic indicators previously obtained

Process Optimisation

Objective: Given the reaction scheme,

Assuming the following rate law,

If the inlet concentration is pure  with an inlet concentration,  and the volumetric flowrate is  and the isothermal rate constant is,

Suppose that the target conversion is 90%, using MATLAB,

Find the optimal volume of a single CSTR

Find the optimal volume of two CSTRs in series.

The required work and marking criteria are as follows,

Define the steady-state design equations for the CSTR(s)

Briefly, define the objective function, giving reasons for the choice and identify all the constraints associated with the optimisation problem(s).

Re-write the CSTR design equations in the structure that is required for solution using MATLAB’s optimisation algorithm, fmincon, clearly defining all the equality and inequality constraints. Provide details of your final code.