Start-up aims to turn brewery wastewater into fuel

NSW start-up SwitcH2 has launched technology which it claims will allow breweries to turn their wastewater into fuel.

The system uses an electrolysis technique in which an electric current is passed through a substance, in this case brewery wastewater, to separate out the hydrogen while oxidising the organics in the wastewater. The hydrogen can then be used as a fuel to power the brewery or for transport.

Founders Bijil Subhash, Khushal Polepalle and Constantine Tsounis met in the early days of a chemical engineering degree at UNSW.

“We were training to solve problems while enjoying a few cold ones” explained Subhash.

“We had the idea in mind for quite some time, especially during the late years of undergrad, as it combined our passion for beer and renewable energy. It was in our heads, but we didn’t pursue it as a business until late 2019.”

Reusing wastewater on a large scale has previously been the arena of big brewers like Lion, which has invested in a reverse osmosis plant to reuse its water and reduce its ratios to 2.8 litres of water for every litre of beer produced. Craft brewers like Alice Springs Brewing Co have found smaller-scale solutions, such as treating it to water crops.

While conventional electrolysis techniques to produce hydrogen use pure water, the SwitcH2 chemical engineers have developed a system which allows wastewater with organics like that produced by a brewery to be electrolysed, removing the need to purify water first.

“Basically, SwitcH2 is a tech hardware start-up, producing a clean-burning fuel to use in things like heating or transport – we want to help breweries achieve their sustainability goals in a profitable manner,” Subhash explained.

“This approach isn’t new but because of global realisation of hydrogen as an important fuel, it’s being actively pursued [in lots of industries].”

The technology is in its early days, but the SwitcH2 team are in discussions with a number of breweries to implement their system.

SwitcH2 systems
While the process on the surface seems relatively straightforward, there will be a number of considerations for brewers, including electricity costs, integration with existing brewing equipment as well as renewable and other energy systems, in addition to the question of what to do with the hydrogen output.

“Currently, the plan we’re fiddling around with is retrofitting [the system] to existing processes, unless you’re starting a new brewery and can implement it from the get-go,” said Subhash.

“It’s an easily-implemented turnkey solution, you basically just need to plug it into a wastewater outlet on one side and the hydrogen is produced on the other side.”

The team focused on an industry which has sustainability in mind but can also be resource-intensive, and produces a waste product which could be put to good use.

“Conventionally electrolysis has had a bad reputation, mainly due to its high energy consumption, and the fact that it uses pure water,” explained Subhash.

“In our case, we’re using wastewater which would normally be a cost to the brewery as they would have to pay to get it processed or removed.

“And by oxidising the organics in the wastewater, we are essentially producing hydrogen at a reduced energy demand than a conventional electrolysis would.

‘Ultimately, by using our solution, breweries can convert a cost-centre into a profit centre.”

Energy use
Energy usage is always a major issue in a brewery, so adding another power-hungry system to the mix could be a barrier to entry for brewers, which Subhash acknowledged.

“A lot of breweries we’re looking at and speaking to are already powered by renewables in some sense, and they have very ambitious near-term sustainability goals.

“By operating our device during renewable hours, breweries are able to increase their uptake of renewables in the form of hydrogen, analogous to how a battery would function,” he explained.

SwitcH2 is working to mediate concerns about power. It has partnered with renewable energy companies to help develop a solution if breweries do not already have renewable energy systems such as solar powers in place.

The system is also a scalable one, so breweries of any size can implement it.

“Electrolysis technology in general does not change engineering efficiency with scale, so you can scale it up to whatever size you need,” he said.

Costs
“The cost of renewable electricity as well as the cost of electrolysers are estimated to decrease with time, which works in our favour in the long-term,” said Subhash.

In the event that renewable energy is used to power the electrolyser and the hydrogen is reused in the brewery, it could have good returns.

“Our current estimates are around four to six years of payback, but that depends on the size of the brewery,” he said.

“Renewable technologies beyond solar panels will be a key component for breweries that are looking to tackle ambitious sustainability goals, an angle that we are striving to achieve.”

Not only will brewers have to consider the acquisition and installation of the system itself, but also how it will use the hydrogen, and how it will power the system.

Uses of hydrogen
Once the wastewater has been processed through the electrolysis unit, it produces a useful by-product.

However, the production of hydrogen leads to another problem to be solved, which is how to use it.

“Hydrogen is an incredibly versatile fuel, with enormous potential to disrupt the fossil fuel market,” explained Subhash.

“The energy market is only now starting to see potential of it as a clean burning fuel.”

“You can blend it with natural gas, you can use it in transport as an alternative to diesel, or by feeding it into a fuel cell, it can also be used as a source of electricity.”

A fuel cell will mean that the hydrogen can be used to power and provide heat to the brewery itself, with the potential for an entirely closed-loop system.

While it is still early days and there are numerous issues to iron out, the SwitcH2 team are confident that they will have a proof-of-concept, commercially viable model in a working brewery by the end of the year.

“We’re in talks with a lot of breweries at the moment, “We also have a few interested partners, and hopefully we will have a pilot plant in the near future,” said Subhash.

“We’re really focusing on building relationship with breweries that can form the foundation to our pathway to the market.”