# Cost and Performance Baseline for Fossil Energy Plants Volume 1: Bituminous Coal and Natural Gas to Electricity
Revision 2a, September 2013
Revision 2

, November 20 10

DOE/NETL

- 20 10 / 1397Cost and Performance Baseline for Fossil Energy Plants

Water Use Three water values are presented for each technology in Exhib it ES

- 4 : raw water withdrawal

, process discharge

, and raw water consumption . Each value is normalized by net output. Raw water withdrawal is the difference between demand and internal recycle. Demand is the amount of water required to satisfy a particular process (slurry, quench, f lue gas desulfurization [ FGD ] makeup, etc.) and internal recycle is water available within the process (boiler feedwater [BFW] blowdown, condensate, etc.). Raw water withdrawal is the water removed from the ground or diverted from a surface

- water source for use in the plant. Raw water consumption is the portion of the raw water withdrawn that is evaporated, transpired, incorporated into products or otherwise not returned to the water source it was withdrawn from. Raw water consumption is the difference between withdrawal and process discharge , and it represents the overall impact of the proce ss on the water source, which in this study is considered to be 50 percent from groundwater (wells) and 50 percent from a municipal source. All plants are equipped with evaporative cooling towers, and all process blowdown streams are assumed to be treated and recycled to the cooling tower. The primary conclusions that can be drawn are:

• In all cases the primary water consumer is cooling tower makeup, which ranges from 73 to 99 percent of the total raw water consumption

.

• Among non

- capture cases, NGCC requ ires the least amount of raw water withdrawal

, followed by IGCC and PC. If an average raw water consumption for the three IGCC cases and two PC cases is used, the relative normalized raw water consumption for the technologies is 2. 5 :1. 7 :1.0 (PC:IGCC:NGCC) . The relative results are as expected given the much higher steam turbine output in the PC cases

, which results in higher condenser duties, higher cooling water flows

, and ultimately higher cooling
water makeup . The IGCC cases and the NGCC case have com parable steam turbine outputs, but IGCC requires additional water for coal slurry (GEE and CoP), syngas quench (GEE), humidification (CoP and Shell), gasifier steam (Shell), and slag handling (all cases), which increases the IGCC water withdrawal over NGCC

.

• Among capture cases, raw water withdrawal requirement s increase ( relative to non

capture cases) more dramatically for the PC and NGCC cases than for IGCC cases because of the large cooling water demand of the Econamine process

, which results in greater c ooling water makeup requirements. If average water consumption values are used for IGCC and PC cases, the relative normalized raw water consumption for the technologies in CO 2 capture cases is 2. 4 :1. 4 :1.0 (PC: I GCC: N GCC). T he NGCC CO 2 capture case still has the lowest water consumption.

• CO 2 capture increases the average raw water consumption for all three technologies evaluated, but the increase is lowest for the IGCC cases . The average normalized raw
water consumption for the three IGCC cases incr eases by about 58 percent due primarily to the need for additional water in the syngas to accomplish the WGS reaction. With the addition of CO 2 capture, PC normalized raw water consumption increases by 83 percent and NGCC by 9 1 percent. The large cooling water demand of the Econamine process drives this substantial increase for PC and NGCC

.

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