Page 228 - Plant design and economics for chemical engineers

COST ESTIMATION 199
must be given to such items as the type and arrangement of equipment,
multiplicity of units, amount of instrumentation and control for the process, and
company policy in establishing labor requirements. Table 21 indicates some
typical labor requirements for various types of process equipment.
Another method of estimating labor requirements as a function of plant
capacity is based on adding up the various principal processing steps on the flow

TABLE 22
Operating labor, fuel, steam, power, and water requirements for
various processest

Operating Maintenance Power and utilities, per ton/yr or
labor and labor and bbl/day capacity
Capacity supervision supervision
thousand workhours/ workhours/ Fuel Steam Power Water
ton/yr ton ton M M Btu/h lb/h kWh gph

Chemical plants
Acetone 100 0.518 0.315 . . . . 1.73 310 5.18
Acetic acid 10 1.483 0.984 . . . . . . . . . 1813 0.58
Butadiene 100 0.345 0.285 . . . 0.012 130 0.73
Ethylene oxide 100 0.232 0.104 . . . 4.88 140 0.148
Formaldehyde 100 0.259 0.328 . . . . 34.6 200 0.029
Hydrogen peroxide 100 0.288 0.352 . . . . 2.62 160 0.186
Isoprene 100 0.230 0.325 . . . . . 0.81 710 0.001
Phosphoric acid 10 1.85 0.442 . 0.18 40 0.03
Polyethylene 100 0.259 0.295 . . . 0.23 450 0.0004
Urea 100 0.238 0.215 . . . . 0.33 135 0.0002
Vinyl acetate 100 0.432 0.528 . . . . 1.34 275 0.27

Refinery units
Thousand Workhours/ Workhours/
bbl/day bbl bbl
Alkylation 10 0.007 0.0895 . . . . . 10.83 0.07 1.48
Coking (delayed) 10 O.Oll$ 0.0996 0.007 1.85 0.07 ...,
Coking (fluid) 10 0.0096 0.0058 0.012 2.55 0.06 0.64
Cracking (fluid) 10 0.0122 0.0115 . . . (4.7315 0.02 0.33
j Cracking (thermal) 10 0.0096 0.0025 0.012 (2.55)s 0.06 0.64
1 Distillation (atm) 10 0.0048 0.0042 0.004 0.25 0.03 0.16
c Distillation (MC) 10 0.0024 0.0154 0.003 0.95 0.04 0.18
Hydrotreating 10 0.0048 0.0028 0.006 0.92 0.01 0.14
Reforming, catalyt. 10 0.0048 0.0078 0.002 1.38 0.23 0.28
Polymeiization 10 0.0024 0.0158 . . . 4.85 0.07 0.43

t Based on information from K. M. Guthrie, Capital and Operating Costs for 54 Chemical
Processes, Chem. Eng., 77(13): 140 (June 15, 1970).
$ Includes two coke cutters (1 shift/day).
4 Net steam generated.