Concentration in the tank vent
y = yi
Ci = y
vapor pressurei
atmosheric pressure
1
T
22.4(
)
273
or y =
partial pressure
total pressure
Mwi
Project Cash Flow and Economic Evaluation
Pay-Back Period (PBP) =
fixed capital investment (FCI)
annual cash flow (A𝑗 )
𝑡𝑜𝑡𝑎𝑙 𝑖𝑛𝑣𝑒𝑠𝑡𝑚𝑒𝑛𝑡
Pay-Back Period (PBP) = average annual cash flow
𝑟𝑎𝑡𝑖𝑜 𝑜𝑓 𝑎𝑣𝑒𝑟𝑎𝑔𝑒 𝑦𝑒𝑎𝑟𝑙𝑦 𝑖𝑛𝑐𝑜𝑚𝑒 (𝐻𝐾)
100
Return on Investment (ROI) = the productive life of the project (KD) × 𝑡ℎ𝑒 𝑡𝑜𝑡𝑎𝑙 𝑖𝑛𝑖𝑡𝑖𝑎𝑙 𝑖𝑛𝑣𝑒𝑠𝑡𝑚𝑒𝑛𝑡 (𝐿𝐷)%
ROI =
𝑟𝑛𝑒𝑡 𝑎𝑛𝑛𝑢𝑎𝑙 𝑝𝑟𝑜𝑓𝑖𝑡
total investment
× 100
Net present value (NPV)=∑ 𝐴𝑛𝑛𝑢𝑎𝑙 𝑑𝑖𝑠𝑐𝑜𝑢𝑛𝑡𝑒𝑑 𝑐𝑎𝑠ℎ 𝑓𝑙𝑜𝑤(𝐴𝐷𝐶𝐹 )
𝐴𝐷𝐶𝐹 𝑛 =
𝐴𝐶𝐹 𝑛
(1 + 𝑖)𝑛
CAPITAL COST
Total Capital Investment(TCI or CT )= Fixed capital investment(FCI or CF )+ working capital(WC or CW )
Fixed capital investment(CF ) = direct costs(CD )+ indirect costs(CI )
COST INDEXES
Estimating Equipment Cost by Scaling
Equipment Cost
The fixed-capital investment of a new process plant
GROSS PROFIT
NET PROFIT
Straight-line method
double declining balance (DDB)
2×𝑏𝑜𝑜𝑘 𝑣𝑎𝑙𝑢𝑒
DDB=(
)
𝑛
Book Value =FCI-DDB
Sum-of-the-Years-Digits Method
CASH FLOW
0
