Читать книгу Process Intensification and Integration for Sustainable Design - Группа авторов - Страница 32

Process simulation was performed to meet the required specifications (sales gas gross heating value of 950–1150 Btu/SCF [British thermal unit/standard cubic feet], 1000 psig, and CO₂ content of 2–3 mol% maximum, 0.3 g H₂S/100 SCF gas) [22,23], and process designs were developed for each feed. ProMax simulation software [24] was used to simulate this process.

The simulation results were then used to size process equipment, develop mass and energy balances, and determine operating conditions and utility consumption of process equipment. Aspen process economic analyzer [25] was used to estimate the equipment purchase costs. The Hand factor was utilized to account for installation and other costs. The fixed capital investment (FCI) for each processing unit was then estimated [26].

(2.1)

where FCI_i, fixed capital investment for a given processing unit; , Hand factor for equipment q; and , the purchased cost of equipment q.

Table 2.4 shows the values and assumptions used to estimate the variable costs (raw material costs were considered separately):

Table 2.4 Parameters used for the techno‐economic analysis.

Parameter	Values	Units	References
Variable cost parameters
TEG price	0.93	$/lb	[27]
Refrigerant price	13.11	$/GJ	[28]
Electricity price	0.049	$/kWh	[29]
Fuel price	2.98	$/MSCF	[30]
Plant operator rate	32.74	$/h	[31]
Plant supervisor rate	68.13	$/h	[32]
Maintenance	5	% of FCI	[25]
Operating charges	25	% of operating labor cost	[25]
Plant overhead	50	% of operating labor + maintenance cost	[25]
General administrative	8	% of all other operating costs	[25]
Stream factor	0.96	—	—

The only additional equations used were those to estimate the number of workers based on the number of processing steps [28]:

(2.2)

where N_np, the number of non‐particulate processing steps, which is related with the number of operators per shift (N_OL), given as in Eq. (2.3):

(2.3)

where P, the number of processing steps where particulate solids are handled.