Title: Cost optimization of high recovery single stage gap membrane distillation

Abstract

Estimating the cost of membrane distillation (MD) processes at scale is confounded by the vast array of possible process configurations, module configurations, and operating conditions and the extreme sensitivity of MD costs to these parameters. This work develops a comprehensive MD cost optimization framework for minimizing the levelized cost of water (LCOW) as a function of feed salinity and temperature. Our single stage gap MD model fully captures solution properties, heat transfer, and mass transfer relationships in the modules to determine the cost optimal design as a function of multiple decision variables, including process configuration (feed location and connectivity between the hot and cold-side), the gap type (air, permeate, conductive), equipment sizes (membrane, heater, chiller, and heat exchanger units), and operating conditions (flow rates, hot and cold side temperatures, and heating and cooling duties). We estimate that the minimum LCOW of conductive gap MD ranges between $$\$$$$10 and $$\$$$$16 per m³ for feed salinities of 25 g/L to 200 g/L and water recoveries of 30%–75%. Further, we update several heuristic assumptions for cost optimal system operation, including: increased thermal conductivity of the gap decreases system costs; cost optimal MD operates at the highest allowable temperature; and the LCOW is a strong function of brine salinity. Finally, we find that improving membrane properties and lowering heating and cooling costs will provide only modest reductions in costs (<25%).

Authors:

Bartholomew, Timothy V.  ^[1];

• Search DOE PAGES for author "Bartholomew, Timothy V."
• Search DOE PAGES for ORCID "0000-0001-5091-7923"

Dudchenko, Alexander V.  ^[2];

• Search DOE PAGES for author "Dudchenko, Alexander V."
• Search DOE PAGES for ORCID "0000-0002-4808-6195"

Siefert, Nicholas S. ^[3]; Mauter, Meagan S. ^[4]

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+ Show Author Affiliations

1. Carnegie Mellon Univ., Pittsburgh, PA (United States); National Energy Technology Lab. (NETL), Pittsburgh, PA (United States)
2. Stanford Univ., CA (United States)
3. National Energy Technology Lab. (NETL), Pittsburgh, PA (United States)
4. National Energy Technology Lab. (NETL), Pittsburgh, PA (United States); Stanford Univ., CA (United States)

Publication Date:

Fri Jun 12 00:00:00 EDT 2020

Research Org.:

National Energy Technology Laboratory (NETL), Pittsburgh, PA, Morgantown, WV, and Albany, OR (United States); Oak Ridge Inst. for Science and Education (ORISE), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE Office of Fossil Energy (FE); National Science Foundation (NSF)

OSTI Identifier:

1891112

Alternate Identifier(s):

OSTI ID: 1635556

Grant/Contract Number:  

CBET-1554117

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Membrane Science

Additional Journal Information:

Journal Volume: 611; Journal ID: ISSN 0376-7388

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Membrane distillation; Techno-economic analysis; Cost optimization; Process design and operation