Dirty water boosts prospects for clean hydrogen – Princeton Engineering

Report on Electrolytic Hydrogen Production from Wastewater Effluent

A Novel Approach to Advancing Sustainable Development Goals

Research from Princeton Engineering demonstrates a significant advancement in green hydrogen production by utilizing treated wastewater instead of purified fresh water. This innovation directly supports several United Nations Sustainable Development Goals (SDGs) by making clean energy more accessible, conserving water resources, and promoting sustainable industrial practices. The findings, published in the journal Water Research, indicate a potential reduction in water treatment costs by up to 47%.

Alignment with Key Sustainable Development Goals (SDGs)

SDG 6: Clean Water and Sanitation & SDG 7: Affordable and Clean Energy

The primary challenge addressed by this research is the substantial demand for clean water in conventional green hydrogen production, which competes with local freshwater supplies. By substituting reclaimed wastewater, this method advances multiple SDGs:

• SDG 6: It alleviates pressure on scarce freshwater resources by repurposing water from widely available municipal treatment plants, promoting efficient water use and integrated water management.
• SDG 7: It lowers a significant cost barrier for green hydrogen, a critical pathway for decarbonization, thereby contributing to the goal of affordable and clean energy for all.

SDG 9: Industry, Innovation, and Infrastructure & SDG 12: Responsible Consumption and Production

The research presents a technological innovation that fosters sustainable industrialization and a circular economy model.

1. Technological Innovation (SDG 9): The study identifies and solves the core technical problem of membrane fouling in electrolyzers when using wastewater, enabling the use of existing infrastructure (wastewater plants) for a new, clean industrial process.
2. Circular Economy Principles (SDG 12): It transforms wastewater from a disposal problem into a valuable resource for energy production, embodying the principles of responsible consumption and production by minimizing waste and maximizing resource utility.

Technical Analysis and Findings

Identifying the Core Problem

Previous attempts to use wastewater for electrolysis were hindered by rapid performance degradation. The Princeton team conducted diagnostic experiments using a proton exchange membrane (PEM) water electrolyzer and identified the primary cause of failure:

• Membrane Fouling: Ions of calcium and magnesium, present in wastewater, adhere to the electrolyzer’s membrane.
• Blocked Ion Transport: This buildup transforms the porous membrane into a solid barrier, blocking the transport of hydrogen ions and halting hydrogen production.

The Proposed Solution: Water Acidification

The researchers developed a simple and effective solution to counteract membrane fouling:

1. Acidification: A small amount of sulfuric acid is added to the wastewater before it enters the electrolyzer.
2. Competitive Ion Action: The resulting acidic buffer provides a surplus of protons that outcompete the calcium and magnesium ions, ensuring the membrane remains clear and conductive.
3. System Sustainability: The acid is continuously recirculated within the closed-loop system, preventing environmental discharge and minimizing operational costs. The system demonstrated stable performance for over 300 hours.

Economic and Climate Impact

Cost Reduction and Scalability

The economic benefits of this method are substantial, making green hydrogen a more viable energy source. The study estimates that using acidified reclaimed wastewater could:

• Reduce the cost of water production by approximately 47%.
• Lower the energy cost associated with water treatment by about 62%.

The team is now collaborating with industry partners to test the approach at a larger scale and is exploring its application with pretreated seawater. This work builds on previous research identifying optimal locations in the U.S. to collocate hydrogen and wastewater facilities, supporting strategic infrastructure development aligned with SDG 11 (Sustainable Cities and Communities).

Contribution to Climate Action (SDG 13)

By making green hydrogen production more sustainable and cost-effective, this research provides a crucial tool for climate action. Green hydrogen is essential for decarbonizing industries that are difficult to electrify, such as steel and fertilizer manufacturing. This innovation accelerates the transition away from fossil fuels, directly supporting the objectives of SDG 13 (Climate Action).

Analysis of Sustainable Development Goals in the Article

1. Which SDGs are addressed or connected to the issues highlighted in the article?

1. SDG 6: Clean Water and Sanitation
   • The article’s central theme is the use of treated wastewater for hydrogen production, which directly addresses the sustainable management of water resources. It proposes a solution to reduce the strain on local freshwater supplies caused by current hydrogen production methods, which require large amounts of clean water.
2. SDG 7: Affordable and Clean Energy
   • The research focuses on making “green hydrogen” a more practical and affordable clean energy source. By reducing the costs associated with water purification, the technology helps make this form of renewable energy more accessible for industrial use, contributing to the global energy transition.
3. SDG 9: Industry, Innovation, and Infrastructure
   • The article describes a significant technological innovation from Princeton Engineering. This innovation is aimed at upgrading industrial processes by providing a pathway to “decarbonize industries that are difficult to electrify, such as steel and fertilizer production.” It also suggests new infrastructure development by collocating hydrogen facilities with wastewater treatment plants.
4. SDG 12: Responsible Consumption and Production
   • The research promotes a circular economy approach by finding a valuable new use for a waste product (treated wastewater). This method represents a more sustainable production pattern for hydrogen, ensuring the efficient use of natural resources (water) and reducing waste.
5. SDG 13: Climate Action
   • The primary motivation for developing green hydrogen is to combat climate change. The article explicitly states the goal is to “decarbonize industries,” which is a critical climate action strategy to reduce greenhouse gas emissions from high-emitting sectors.

2. What specific targets under those SDGs can be identified based on the article’s content?

1. Under SDG 6: Clean Water and Sanitation
   • Target 6.3: “By 2030, improve water quality by … substantially increasing recycling and safe reuse globally.” The article directly supports this target by demonstrating a viable method for reusing treated wastewater for an industrial purpose (hydrogen production), thereby increasing its recycling rate.
   • Target 6.4: “By 2030, substantially increase water-use efficiency across all sectors and ensure sustainable withdrawals and supply of freshwater to address water scarcity.” The technology eliminates the need for ultrapure freshwater in hydrogen electrolysis, directly increasing water-use efficiency in the energy sector and reducing competition for local freshwater resources.
2. Under SDG 7: Affordable and Clean Energy
   • Target 7.2: “By 2030, increase substantially the share of renewable energy in the global energy mix.” The research makes green hydrogen, which is produced using renewable electricity, more economically feasible. This helps accelerate its adoption and increases the overall share of renewable energy.
   • Target 7.a: “By 2030, enhance international cooperation to facilitate access to clean energy research and technology… and promote investment in energy infrastructure and clean energy technology.” The Princeton research is a prime example of advancing clean energy technology, and the article mentions collaboration with industry partners to scale up the approach.
3. Under SDG 9: Industry, Innovation, and Infrastructure
   • Target 9.4: “By 2030, upgrade infrastructure and retrofit industries to make them sustainable, with increased resource-use efficiency and greater adoption of clean and environmentally sound technologies…” The article’s focus on decarbonizing steel and fertilizer production through a cleaner hydrogen production method directly aligns with this target of making industries more sustainable.
   • Target 9.5: “Enhance scientific research, upgrade the technological capabilities of industrial sectors…” The entire article is about a scientific breakthrough (“new research from Princeton Engineering”) that upgrades the technological capability for producing clean energy for industrial use.
4. Under SDG 12: Responsible Consumption and Production
   • Target 12.2: “By 2030, achieve the sustainable management and efficient use of natural resources.” By replacing purified freshwater with reclaimed wastewater, the technology promotes the efficient use of water, a critical natural resource.

3. Are there any indicators mentioned or implied in the article that can be used to measure progress towards the identified targets?

1. Explicit Indicators:
   • Cost Reduction in Water Treatment: The article explicitly states that the method could “reduce the cost of water production by about 47% and the energy cost of water treatment by about 62%.” This directly measures increased efficiency (relevant to Targets 6.4 and 9.4).
   • Operational Longevity: The system was shown to last “for more than 300 hours without apparent issues,” which serves as a performance indicator for the technology’s viability (relevant to Target 9.5).
2. Implied Indicators:
   • Volume of Freshwater Saved: Progress towards Target 6.4 can be measured by the volume of freshwater that is no longer required for hydrogen production as this new technology is adopted.
   • Volume of Wastewater Reused: The amount of treated wastewater utilized for hydrogen production would be a direct indicator for measuring progress on Target 6.3.
   • Amount of Green Hydrogen Produced: The quantity of green hydrogen produced using this method would be an indicator for Target 7.2, as it reflects the increase in the supply of clean energy.
   • Reduction in Carbon Emissions: The ultimate success of this technology in contributing to Target 13.2 can be measured by the reduction in CO2 emissions from industries (like steel and fertilizer) that switch to using this green hydrogen.

4. Summary Table of SDGs, Targets, and Indicators

Source: engineering.princeton.edu