Energy Efficient Waste Heat Coupled Forward Osmosis for Effluent Water Management at Coal-Fired Power Plants

Ragajopalan, Nandakishore

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https://hdl.handle.net/2142/113419 Copy

Description

Title

Energy Efficient Waste Heat Coupled Forward Osmosis for Effluent Water Management at Coal-Fired Power Plants

Author(s)

Ragajopalan, Nandakishore

Contributor(s)

• Baroi, Chinmoy
• Barta, Susan
• Chandrasekaran, Sriraam
• Cheng, Donghao
• del Cerro, Martina
• OBrien, Kevin C
• Ganguly, Rupa
• Ivansevic, Marko
• Karthik, Sanjana
• Muhsinah, Marihah
• Patel, V.A.
• Scott, John
• Zhang, Xuesong
• Dombrowski, Katherine
• Fisher, Kevin
• McKaskle, Ray
• Becker, P.J.
• Powell, Brandon
• Staley, Eric

Issue Date

2021

Keyword(s)

• Coal-fired power plants -- Wastewater treatment
• Aquapod
• Forward osmosis

Abstract

This project sought to evaluate the technical and economic viability of the Aquapod©, a transformational low energy (<200 kJ/kg water) waste heat coupled forward osmosis (FO) technology, to manage effluents, meet cooling water demands, and achieve water conservation in a coal-fired power plant environment.

The Aquapod© process is innovative because it is heat-driven, avoids the evaporation of water, and uses no toxic chemicals such as ammonia or amines. The Aquapod© process accomplishes this using an aqueous two-phase system (ATPS) coupled FO process.

The evaluation revealed that the Aquapod© process offers a pathway to exploit waste heat resources within a power plant to achieve flue-gas desulfurization (FGD) wastewater volume reduction and water recovery with minimal pretreatment. Water recovery of 80 percent from FGD wastewater was achieved with minimal pretreatment, exceeding the project target of 50 percent. The estimated electrical energy of 2.16 kWh/m3 of water produced for the Aquapod© process met the project target of < 3.6 kWh/m3. The heat required for the process operation was approximately 186 kJ/kg of produced water, which was slightly lower than the project target of 200 kJ/kg.

The estimated treatment cost for installing and operating the Aquapod© process in conjunction with a spray dryer evaporator to achieve zero-liquid discharge (ZLD) of the 100 gpm FGD wastewater was 13.24 USD/m3 over a 30-year lifetime. As a point of reference, this study’s host power plant currently incurs a cost of 3.70USD/m3 – 8.87USD/m3 on a discharged volume basis to discharge its wastewater into the publicly owned treatment works (POTW) after physical-chemical treatment. Therefore, the Illinois power plant would incur an incremental cost increase of 4.37USD/m3 – 9.54USD/m3 to achieve ZLD using the Aquapod© and spray dryer combination.

Ample opportunities exist to further lower the ZLD capital and operating costs in the next design iteration to attain pipe parity at the higher end of the site treatment costs.

Publisher

U.S. Department of Energy. National Energy Technology Laboratory

Series/Report Name or Number

Energy Efficient Waste Heat Coupled Forward Osmosis for Effluent Water Management at Coal-Fired Power Plants

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/113419

DOI

10.2172/1770804

Sponsor(s)/Grant Number(s)

U.S. Department of Energy. National Energy Technology Laboratory ; DE-FE0031551

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