Waste water re-mediation and power generation using an electrochemical device

Thanks to an innovative electrochemical device, this project will add value to organic materials dissolved in waste-water streams by generating electricity upon their electrochemical oxidation. Large amounts of waste water contaminated with
sugars and other high energy organic molecules are currently generated as a result of the industrial activity in sectors including food manufacturers, beverage production, breweries, wineries or biofuel generators. These water streams represent an increasing problem for those industries as expensive and slow water cleaning procedures are mandatory prior to municipal disposal. Toxic chemicals and/or and sensitive biological cleaning processes deliver cost ranging 40 USD per ton of water. The system here proposed enables significant carbon dioxide savings and a dramatic drop the energy
requirements for water remediation and related costs.

The current industrial trend is the generation of electricity from biomass utilizing and multi-step process. The fermentation of biomass to biogas and subsequent combustion to generate electricity is an indirect conversion method that leads to an electricity yield below 10%. Nonetheless, this strategy represents a high capital cost and need of delicate operation conditions that require long time periods. Microbial fuel cells can and directly produce electricity from waste-water. However, the use bacteria to oxidise the fuel is linked to similar time-requirements issues and very low production of power
(<2 mW/cm2). Larger power is achieved using expensive catalysts (such as Pt) but, such materials quickly undergo deactivation due to fuel contaminants present in the industrial water streams.

This project will develop the first large power density (15 mW/cm2) fuel cell demonstrator utilizing fuels dissolved in industrial waste-waters. A 10W prototype will be designed along the lines of reducing power consumption required for
waste water treatment while creating clean electricity. As a result of the unique chemistry proposed in this project, this prototype will not only provide with a low-energy water-remediation system, the utilization of organic fuels in waste-water
permits the generation electricity at a cost of about USD0.01/kWh (below existing electricity generation technologies). Unlike other renewable energy sources such as wind or solar suffer which suffer from generation intermittency, this fuel cell
represents a continuous and clean electricity generation that can provide power in applications including grid balancing or peak shaving which enables a higher proportion of green energy technologies.

The range of envisioned applications here described cannot be found in any other device. The tasks to be carried during the present project will be: i) design and manufacture 10W prototype; ii) field testing as a function of the water stream
composition paying exceptional emphasis in ensuring long term durability.

Environmental: The project will also support the Government's strategy to reduce the CO2 emissions by 2050 by 80%. It is expected that the introduction of this new technology can have the potential to support this target by reducing the emissions due to water treatment and also providing a new source of CO2 free electrical energy. The deployment of clean energy generators will help the UK meet the challenge of handling projected energy needs-including addressing climate change by integrating more energy from renewable sources. The outcome of this project will be large scale economic, social and environmental benefits for the UK. In general, the development of a more economical and fast system for water remediation that generates electricity from biosourced fuels serves to the wellness improvement of all the society by providing clean water and protecting the environment.

From the social point of view, the development of electrochemical water remediation systems based on abundant, low-cost and non-geographically restricted materials, can be considered a powerful source of wealth. Due to their modular character, this new fuel cell system could inject power enabling applications including grid-support. Additionally, compared with the current utilization toxic chemicals in water cleaning, our system increases the safety of the plants. Similarly, compared to biological water treatments, fuel cell modular design will allow for a lower environmental footprint, lower
installation cost and shorter treatment times prior water disposal.

Economic: This project could be disruptive to the waste water treatment sector, and particularly to those businesses producing waste water streams with high CODs (Chemical Oxygen Demand). For instance the glycerol market (by-product from biodiesel industry) is expected to grow to 2.5 billion USD by 2020. Waste water from the beer brewing industry poses another vast market creating 2 billion hectolitres p.a. waste water. Using the waste water from the brewery industry would allow generation of up to 1000 GWh of electricity with a net worth of 100 million USD per year, thus substantially reducing energy consumption from other sources and significantly reducing the pressure on municipal waste water treating facilities. This project will develop a durable, efficient, cost-effective, versatile and compact energy generation technology with a high potential for utilization of green energy sources of any kind and not restricted to specific waste-water compositions. Moreover, due to its chemistry, the fuel cell system here proposed will be based on abundant elements which can be
readily manufactured in bulk chemical plants reducing manufacturing costs. These combinations of low cost and customization is not available in other technologies and could form the basis of a strong UK based water remediation and clean electricity generation industry

Finally, unlike solar or wind energy, the device here proposed produces electricity continuously as long as fuel is fed into the system. This characteristic allows for fast response and grid integration without requiring expensive energy storage
(currently above USD500/kWh). This not only results in zero net emission electricity but also saves greenhouse gases associated with the production of water cleaning chemicals.