Dataset for the estimation of costs for direct contact condenser

The dataset on equations and procedures for the estimation of detailed capital and annual costs for direct contact condenser are presented. Full dataset on four design cases relevant to the comparisons on the costs of air and oxy-fuel direct contact condenser is given. The data are presented in this format to allow the comparison with those from other researchers in this field. The data presented are related to the article entitled “A comparative study on the design of direct contact condenser for air and oxy-fuel combustion flue gas based on Callide Oxy-fuel Project” (Liu et al., 2018) [1].


Specifications
Two flue gas flue rates, two flue gas compositions, four L/G ratios were studied and optimized factors included normalized capital and annual costs.

Experimental features
The impacts of L/G ratio on capital and annual costs for both oxy-fuel and air-fuel combustion were identified.

Data source location
Shanghai, China Data accessibility The data are available with this article Related research article Liu et al. [1] Value of the data The data on the calculation methodology of capital and annual costs for direct contact condenser can potentially be used by researchers interested in the cost analysis of power plant.
Breakdown costs of direct contact condenser are useful for researchers to compare similar size of units.
Cost data is useful for these researches who have interest in the reduction of unit cost based on the proportions of breakdown costs with respect to total unit cost.

Data
The data in this article provides the detailed calculation formulas necessary to obtain capital and annual costs for DCC. Selection of these formulas are important for cost analysis and in turn relevant for the design of DCC. Four design cases in terms of different L/G ratios are given with two cases for both air and oxy-fuel combustion flue gases. The required parameters for the cost analysis include packing parameters, condenser height and diameter. With these, detailed breakdown costs data are then provided for four cases.
The whole Section 2 describes five steps involved for the calculation of costs. Based on the detailed formulas and parameters, Table1 provides the data on the breakdown costs for capital and annual costs for four cases with different L/G ratios.

Empirical expressions for equipment
Estimating procedure for total cost involves five steps: (1) determination of facility parameters; (2) design of control system; (3) determination of control system size; (4) estimation of individual components; and (5) estimation of costs for the entire system [2].
The parameters including condenser packing height, condenser diameter, packing characteristics and L/G ratio for estimating the total capital costs for DCC were obtained by simulation [1].
Eq. (1) is used to estimate the total tower height [3].
Here, D is the diameter of condenser, ft; H tower tower height, ft; H pack packing height, ft. The tower surface area is expressed by Eq. (2) and this equation assumes the ends of tower are flat and circular.
The pressure drop is estimated by Eq. (3) [4].  For Raschig rings Ceramic and a nominal size of 1 in, the value for α and β are 0.53 and 0.22 respectively for packed tower operating below flooding region. G is gas mass velocity (respective to tower cross section area), lb/(sec Á ft 2 ); L 1 is liquid mass velocity lb/(sec Á ft 2 ); ρ G is gas density, lb/ft 3 . ΔP is the pressure drop, in H 2 O/ft packing.

Estimation of total capital investment
Total capital investment TCI [3] includes purchased equipment cost, PEC, direct installation costs, DIC, and indirect installation cost, IC.

1) Purchased equipment costs (PEC)
The equipment cost is estimated based on the surface area of tower. Total tower cost is estimated by Eq. (4).
Here, TTC is the total cost of the tower using other materials than fiberglass reinforced plastic (FTP); S is the tower surface area; CF is the cost factor to convert the cost of an FRP tower to a tower The auxiliary equipment costs (AEC) not only includes costs for pump, fan and motor, but also includes these for ductwork, piping and others. a factor of 0.15 with respective of EC is used [3,5]. EC is calculated by Eq. (5).
The calculation of Chemical Engineering Plant Index (CEPI) [6,7] includes four sub-indexes incorporating equipment, construction labor, building and engineering and supervision and these aspects can be treated as the costs for building the plant. Eq. (6) [8] is used to correlate the equipment costs in 1991 to these in 2017 [6,8]. Here, CEPI is used escalate EC.
Here, C n is the projected cost in the year n; C m is the known cost in the year m; I n is the index in the year n; and I m is the index in the year m. The purchased equipment cost (PEC) includes the cost of the tower with packing and auxiliaries (EC), instrumentation (0.1EC), sales tax (0.03EC), and freight (0.05EC). Therefore, PEC is calculated as follows by Eq. (7) [9].
2) Direct installation costs (DIC) Direct installation costs (DIC) include foundations & supports, handling & erection, electrical, piping, insulation and painting. The direct installation costs are estimated as 0.85PEC.

3) Indirect installation costs (IC)
Indirect costs (IC) include engineering, construction and field expenses, contractor fees, start-up, performance test, and contingencies. The indirect costs are estimated as 0.35PEC.

4) Total capital investment (TCI)
The total capital investment (TCI) is obtained by multiplying the purchased equipment cost (PEC) by the total installation factor of 2.2 given by Eq. (8) [9].

Estimation of annual cost
Total annual costs (AC) [3] include direct annual costs (DC) and indirect annual costs (IC). In the direct annual costs part, operating labor (operator and supervisor), operating materials (solvent and chemicals), wastewater disposal, maintenance (labor and material) and electricity (fan and pump) are included. In the indirect annual costs part, overhead, administrative charges, property tax, insurance and capital recovery are included.

1) Direct annual cost (DC)
Direct annual cost (DC) is defined as expenses related to operating the equipment such as labor and materials.
Operating labor is estimated at ½-h per 8-h shift. The supervisory labor cost is estimated at 15% of the operating labor cost. Maintenance labor is estimated at ½ -hour per 8-h shift. The operating labor was paid $28.84/hr based on the latest mean hourly wage for plant and system operators; while the maintenance labor was paid $24.48/h based on the latest mean hourly wage for industrial machinery installation, repair, and maintenance workers [10].
For cost of solvent (water), it should be corresponding to the delivery cost. Here, the value of $0.13/ m 3 ($0.6/1000 gal) is used [11]. The cost of solvent (Cs) is calculated based on Eq. (9). Typically, the fraction of solvent wasted varies from 0.1% to 10% of the total solvent throughput.
Where WF is the waste fraction; SUC is the solvent unit cost $/gal; AOH is annual operating hours, hr; SUC is solvent unit cost, $/ft; L i is the water flow rate, gpm; The waste water needs to be treated by caustic soda for neutralization before disposal [12]. An intermediate value for the cost of caustic soda of $500/dmt is adopted here [13]. The cost of chemical replacement (Cc) is based on the annual consumption of the chemical and can be calculated by Eq. (10).
Where CUC is the chemical unit cost is in terms of $/lb; AOH is the annual operating hours; CUPH is chemical used per hour, lbs/hr; Caustic soda is used and assumed to be NaOH and the molar ratio between SO 2 and NaOH is 1:2 [14]. Molar rate of caustic (MRC) is calculated by Eq. (11).
Here, G 0 is molar rate of flue gas, kmol/s; P SO2 is the inlet partial pressure of SO 2 ; η SO 2 is SO 2 removal efficiency; In terms of the cost for waste water disposal, a value of $2/100 gal is adopted [15,16]. Mass flow rate (MFR) of salt in the form of Na 2 SO 4 , is calculated as Eq. (12).
MFR Na 2 SO 4 is the mass flow rate of Na 2 SO 4 , g/s; M Na 2 SO 4 is the molecular weight of Na 2 SO 4 , g/mole; If the maximum concentration of Na 2 SO 4 in the wastewater is assumed to be 10% [3], the wastewater volume flow rate (WVFR) is calculated as Eq. (13).
WVFR is wastewater volume flow rate, L/min; DSS is the density of Na 2 SO 4 solution, g/L; Here the density of 10% w/w Na 2 SO 4 solution at 20°C is 1090.5 g/L. Solvent disposal costs (C ww ) are calculated by Eq. (14).
Where SDC is the unit solvent disposal costs, $/gal; L i WF ¼ WVFR=3:7854; 3.7854 is the conversion factor from L to gallon. Maintenance materials costs are assumed to equal maintenance labor costs. Electricity costs include fan to drive the flue gas flow and pump requirements to recirculate the solvent. The electricity cost in industry was $0.675/kWh [17]. The energy required for the fan (Energy f an ) can by calculated by Eq. (15).
Here, G i is the gas flow rate, actual cubic feet per minute (ft 3 /min); P is the total pressure drop through the system, inches of water; ε is the fan motor efficiency chosen as 70%; The energy required for the pump (Energy pump ) is calculated by Eq. (16).
Here, 0.746 is the factor used to convert horsepower to kW; pressure is expressed in feet of water; ε is the combined pump motor efficiency chosen as 70%; for the value of pressure, the pump is assumed to work at a pressure of 60 feet of water. The cost of electricity (C e ) is then given by Eq. (17).
Where COE is the unit cost of electricity, $/kWh. 2) Indirect annual costs [3] Indirect annual cost include overhead, taxes, insurance, general and administrative (G&A), and capital recovery costs.
Overhead is assumed to be equal to 60% of the sum of operating, supervisory, and maintenance labor, and maintenance materials. G&A costs, property tax, and insurance are factored from total capital investment, typically at 2 percent, 1 percent, and 1 percent, respectively. Capital recovery cost, CRC, is based on an estimated 15 year equipment life. For a 15-year life and an interest rate of 10%, the capital recovery factor is 0.1315. The capital recovery cost is then estimated by Eq. (18).
3) Total annual cost [3] Total annual cost (TAC) is calculated by adding the direct annual cost and the indirect annual costs through Eq. (19).