Highly intensive tunnels: Sacyr and WTT

Highly intensive tunnels: Sacyr and WTT

Waste Management Review speaks with Carlos Gros Isla, Sacyr Environment, and Sean Galdermans, Waste Treatment Technologies, about Sacyr’s new high capacity in-vessel composting facility.

Composting, once considered the domain of hippies and eco- friendly farmers, has become a booming billion-dollar industry.

While public and private investment in technologically innovative equipment and facilities have a traceable history on a global level, the Australian organics market is still somewhat in its infancy.

That said, the tide is turning, with a significant number of Australian councils embarking on separate food and garden organic waste (FOGO) collections.

On behalf of eight Victorian councils, for example, the Metropolitan Waste and Resource Recovery Group (MWRRG) negotiated a contract to facilitate kerbside FOGO collection in 2016.

Increasing the recovery of organic waste is one of four key strategic objectives set down in MWRRG’s 2016 Implementation Plan. To achieve this, MWRRG developed an organics processing network through collective procurement contracts in the northwest, southeast and east.

Sacyr Environment Australia, which operates a state of the art composting facility in Melbourne’s Dandenong South, emerged as a viable option for MWRRG’s South East network.

Sacyr Environment Australia signed a contract with MWRRG in 2017. The facility, which runs on Waste Treatment Technologies (WTT) equipment and processes, opened in May this year.

With a capacity to process 120,000 tonnes of organic waste each year, the indoor composting facility is the most advanced of its type in Australia.

When asked why the Sacyr facility has been dubbed the most advanced in Australia, Carlos Gros Isla, Sacyr Environment Australian Business Manage, says while he is hesitant to make comparisons, he has a good grasp on current capacity and innovation.

“People often want to make grand statements such as, ‘this is the biggest building in the world’, and that can be embarrassing,” he says.

“It’s not rocket science. It’s still composting, so comparing our facility to other industrial facilities wouldn’t be fair. But in terms of the composting industry, we could say it is the most advanced as a whole.”

THE EUROPEAN MODEL

According to Carlos, the facility has gained recognition because it functions as a whole package.

He says however that because he and project partner Sean Galdermans, WTT Australia Bid and Project Manager, are both Europeans, the praise can feel awkward.

Carlos adds that processes that appear innovative in Australia are par for the course in Europe.

“This is a pretty standard package in Europe, and has been for the last 20 years, but it’s important to note that it’s not as through Australia is really behind. This technology just simply wasn’t needed before,” he says.

Given the availability of land, Carlos says landfill was not traditionally viewed as a problem in Australia.

“Plus, because they didn’t have to, councils had no incentive to pay additional gate fees and invest in new quality facilities,” he says.

Carlos says the market is changing however, with Sacyr identifying Australia as a market full of new opportunities.

Sean expresses similar sentiments and says that since arriving in Australia two years ago, he has seen a rise in interesting tenders and hot opportunities.

“I think legislation in Australia has been very slow. Regulators haven’t been pushing for the right developments,” he says.

“The Australian population is knocking on government’s doors and saying, what are you doing? All the countries a round us are investing in these new processes, so why aren’t we?”

Sean says the organics and wider recycling movement is now a mainstream conversation.

“Australia has been coping with the luxury problem of space, and as a result, used to landfill the majority of waste into old coal mines. An out of sight, out of mind mentality,” he says.

“That is the music of yesterday, Australians want to focus on the future.”

Sean adds that over the past five to ten years, many councils have made poor investment decisions.

“The problem is that in the waste sector you’re always talking about large sums of money, and when those projects fail, people develop distrust,” he says.

One of the reasons WTT decided to invest in Australia, Sean says, is that the market needed successful stories and high quality products.

“We felt that with over 25 years of experience and over 130 reference facilities, which have a combined throughput capacity of 7.3 million tonnes per annum, we could contribute to this transition and reduce the amount of organics going to landfill significantly.”

COMPOST IN DANDENONG

The Dandenong facility is not the first collaboration between Sacyr and WTT. One of Sacyr’s flagship facilities in Spain was developed using WTT technology, and, according to Carlos, has been operating for almost 15 years.

“There are not many companies that can make the high-quality in- vessel or tunnel composting facilities WTT can,” he says.

“Composting is a very simple idea, but there are huge difference between an average and good composting tunnel.”

Given Sacyr’s long-term contract with MWRRG, Carlos says seemingly small differences in design and process controls can make a big impact.

“Sacyr is very focused on providing for clients specific needs, so to be honest, if a council required a simple composting facility in a rural area, WTT wouldn’t be our first point of call,” he says.

“However, when a client tells us that high quality is their main focus, and that they are willing to pay associated gate fees, which was the case with MWRRG, WTT’s technology is the obvious choice.”

Once Sacyr had confirmed its contract with MWRRG, WTT was engaged to construct the facility’s in- vessel composting system and air and water management process.

Sean says the contract was of standard scope for WTT.

“While over the last seven years, WTT has started to adapt further processes, such as mechanical pre- and post-treatment systems, I would say in-vessel composting, anaerobic digestion and air/water treatment systems is where our core competence lays,” he says.

According to Carlos, Sacyr designed the facility to operate as close to the centre of collections’ gravity as possible.

“When you build a facility in regional areas, while the initial costs are lower, each link in the chain ends up incurring significant transport costs,” he says.

“Sacyr’s idea was to build a facility in close proximity to councils, ultimately constructing the facility within a pre- existing building.”

Carlos says Sacyr was engaged by MWRRG because the group wanted to explore the capabilities of a new market player.

“Sacyr had already built a desalination plant in Western Australia, so we were engaged in the Australian water business. But in terms of our waste division, this was our first Australian project,” he says.

On the otherhand, WTT had been involved in a number of Australian projects since opening its subsidiary office in 2018, including facilities in Wogamia and Kembla Grange NSW for SOILCO and a REMONDIS facility in Port Macquarie

AEROBIC DESIGN

After material enters the Sacyr facility, Carlos says it runs through a four-step process.

“The first step is pre-treatment or decontamination. At this stage we remove anything that shouldn’t be in the green bin or is not organic,” he says.

“From there we sieve, cut and mix the material to create a homogenous mixture. We ensure it is spongy and of the right size so it can be degraded to optimum levels in the in-vessel tunnels.”

The next stage, Carlos says, is the actual composting. He adds that in Australia, the EPA regulates a high level of pasteurisation.

“The actual composting happens in two different stages. The first is fermentation to achieve the required pasteurisation, which runs for 72 consecutive hours above a certain temperature threshold,” he says.

“After we’ve achieved the pasteurisation criteria, the material is taken to the compost tunnels, before it is transferred to the maturation hall for further curing.”

The Dandenong compost tunnels, Sean says, induce a highly intensive composting process to maximize organic breakdown.

“By controlling the temperature, oxygen and moisture content of each individual tunnel at all times, we’re able to tailer a recipe for each batch, and provide our client – the operator – with maximum flexibility and ease of operation,” he says.

Given the complexity of WTT’s technology, Sean says the company likes to function as a one-stop-shop.

“Instead of delivering a package, showing what it can do and leaving, we like to be involved on a long term basis to make sure clients feel comfortable with the technology,” he says.

While the facility is currently running smoothly, Carlos admits there were some teething problems.

“Both companies tried to adopt a design that has worked for us in Europe, but the reality is with waste you never know what you will receive,” he says.

After a number of trials, Carlos says the team developed a system suitable for the material it receives. He adds that because Sacyr recognises the added value of WTT’s experience, the two organisations were in constant contact throughout the process.

Sean says WTT’s knowledge centre worked to facilitate communication.

“WTT can essentially log into the facility 24 hours a day and see what the operators see, which means we can read the information, feed it back into the system and troubleshoot,” he says.

“Combined with the client’s operational team, it’s really a golden combination.”

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