Richgro Bioenergy Plant gas management set-up including gas train, first generator, transformer and distribution infrastructure

Richgro Bioenergy Plant, Jandakot, Western Australia

Biogass Renewables recently commissioned its first Australian bioenergy plan for Richgro Garden Products, which offset its client’s power costs while offering the potential for revenue from the outputs of biofertiliser, electricity, CO2 and heat.

Biogass Renewables is an Australian-owned technology company, established in 2011, specialising in providing viable anaerobic digestion (AD) plants to the energy and waste industry. It officially commenced operations from Richgro’s Jandakot-based bioenergy plant in September 2015 – a project more than four years in the planning.

Situated about 20km south of Perth’s central business district, the
$8 million facility was commissioned for Richgro and is located next to its principle metropolitan composting and manufacturing operations.

It is the first of plant of its kind in Australia.

The facility can process more than 35,000 tonnes of commercial and industrial organic waste a year, with the scope to handle 50,000 tonnes, therefore diverting this from landfill. Using this feedstock, it has the capacity to produce up to 2 megawatts of electricity and 2.2 megawatts in heat.

That energy is now being harnessed by Richgro’s operations to power equipment, with the surplus exported into the Western Australian electricity grid. Excess heat is channelled into the site’s hothouses, where blueberries are grown, leading to a new revenue stream for the business. The digestate by-product from the plant can be used as a raw material in Richgro’s garden products.

Over a 20-year lifespan, it’s also expected to save 142,722 tonnes of carbon dioxide emissions.

Background to the build

Richgro Managing Director Geoff Richards originally approached Hamish Jolly, Managing Director of Biogass Renewables, in 2011, as they had known each other for some time through environmental interests.

As a company that specialises in natural solutions to tackle garden problems, such as weeds, aphids and ants, Geoff saw there was room for renewable energy and potential for a revenue stream from taking organic waste to create energy along with a biofertiliser that would boost food sustainability in Australia.

Hamish set up Biogass in 2011 to deliver an AD plant for Richgro, as the latter had limited expertise to implement such a project.

In 2011, Richgro looked at options in European technology, which was well proven there, but was expensive, often over-engineered and not geared specifically to Australian conditions. So Biogass set out to deliver a low capital-expenditure plant for Richgro, using European suppliers, but designed for Australian conditions using Australian know-how.

Joe Oliver, General Manager at Biogass, was project manager for the plant delivery. Having built up considerable experience in the UK with this kind of facility, he oversaw all stages from design, construction, procurement and completion.

“The sticking points were applying the technology in an Australian context and the considerable cost with a payback period of 10 years,” he says. “Hamish visited Europe and North America to investigate technology and potential supply chains for equipment.”

Meanwhile, in 2012 Biogass helped Richgro develop and submit the proposal for the AD plant to WA’s Department of Environment Regulation. It approved the facility, with no concerns over issues such as odour, noise and emissions, which the plant is designed to manage.

Funding

To find financial support to help Richgro pay for the project, Biogass coordinated applications and liaised with government agencies for grants and funding.

“In 2013, we received $2.2 million from the Clean Energy Finance Corporation under a debt funding arrangement, where we would pay it back in a set timeframe,” explains Joe.

The project received grants totalling $1.6 million from the Australian Government’s Clean Technology Investment Program due to its green credentials and the WA State Government, who was backing innovative waste-to-energy projects.

Biogass then went ahead and constructed a plant package, pulling together a full facility in Jandakot. They secured tanks from the UK and generators from Europe, all providing clean outputs and energy, with proven equipment for gas management and waste depackaging. Construction started in September 2013.

One of the main challenges to overcome was the connection to the power grid on the Richgro site.

“It had a low voltage grid connection, which needed to be upgraded to high voltage to enable Richgro to import enough and export up to two megawatts of power in the future,” says Joe.

Western Power runs the local distribution network, so Biogass had to apply for permission to export power, as it has the potential when running at full capacity to provide electricity for 3,000 homes. CleanTech Energy buys all the green power the plant generates to retail within WA.

Connection to the grid was achieved in September 2014, and the facility was completed in November 2014.

The site became operational in March 2015, with trials of taking waste and generating the power. This also allowed Richgro to start generating income from the gate fee for diverting the waste from landfill and the biofertiliser by-product.

“This is better than incineration, where hazardous ash is a by-product of the process,” says Joe. “It’s a clean input process, with a clean output and a full closed loop.”

The food stream waste is turned back into energy and the digestate into a compost to grow new fruit and vegetables for the food supply chain. The commissioning phase involved testing and ramping up the operation.

“While waiting for a decision on exporting the power, we had to flare the gas to use up the heat,” adds Joe. Western Power eventually approved connection to the grid for exporting electricity in October 2015.

The bioenergy plant process

The Anaerobic Digestion and Bioresources Association describes anaerobic digestion (AD) as “the natural breakdown of organic matter into carbon dioxide, methane and water, by two groups of microorganisms, bacteria and archaea. The process is known as anaerobic because many of these are intolerant to oxygen”.

The Richgro bioenergy plant comprises three key stages: reception, digestion and energy. Each stage breaks the organic matter into smaller and smaller parts, until the only remaining substances are methane, carbon dioxide, water and the biofertiliser by-product.

Every day, trucks bring in about 100 tonnes of solid food and liquid waste to the reception building from commercial and industrial sectors, such as fruit and vegetables from markets, and food and drink waste from supermarkets, abattoirs, agricultural companies, and food manufacturing facilities.

“When tankers bring liquids to the site, the facility has liquid handling equipment, so that the wet waste can be pumped directly into the facility and processed automatically,” explains Joe.

With the solid organic waste streams, between 30 and 40 per cent are dry solids. These arrive at the reception building and are tipped into the solid in-feed hopper. The businesses sending the waste pay a gate free for diverting the material from landfill.

The facility has further capability – a pre-processing de-packager feeding system – as many of the products sent to the site are in packets, bottles, cans or cartons.

“This de-packages the products
and removes all contamination to 
leave a clean, pumpable feedstock for forwarding on to the digestion process,” says Joe. “The leftover packaging is in many cases recyclable, so we collect and send that for recycling.”

After being de-packaged and decontaminated, the organic matter 
is fed into the AD tanks. These have
 a 5,000-cubic-metre capacity, with a feed-in and outlet tanks made from glass-fused steel panels, which helps with low on-site civil works and are a cost effective solution. This is where the AD process starts.

The slurry is then passed into the primary digester. Each primary digester has its own external heating and
mixing system, using the co-generated surplus heat to maintain a “mesophilic” temperature with the digester.

AD operates at a mesophilic temperature
– of around 36 degrees Celcius – and
is a continuous flow digestion process, drip-feeding a small volume into each of the two primary digesters. Maintaining an external heating and mixing system ensures that in the event of a machinery breakdown, the digester does not require emptying.

Meanwhile, everything is managed from a control room, which has the Biogass control panel. This allows full automation of the facility, control of all the motors, pumps, valves and instrumentation. The software house here collects all data for analysis, and there is full access for remote connection, as the plant can be remotely operated by iPad!

The final stage of energy production requires a gas management plant.
The biogas is drafted off from the digester, chilled down to its dew point to remove moisture, before boosting to a containerised co-generator, which produces heat and power through a reciprocating high-efficiency engine.

“The first unit installed will provide 1.2 megawatts of power and 1.26 megawatts of heat, which will service Richgro’s entire energy draw on a behind-the-meter basis and has the potential to export up to one megawatt back into the power grid,” adds Joe.

If the biogas produced on-site is not being used, it outputs through the emergency high temperature enclosed flare.

The leftover digestate by-product is taken to Richgro’s factory, as it can easily and safely be used as a commercial organic biofertiliser or in compost products.

Community & industry reaction

After receiving favourable general and industry media coverage, Joe says there has been a lot of interest in the plant from the local community and waste collectors, particularly due to its green credentials and cost savings.

“We deal with waste services contractors, such as SUEZ, Veolia and Cleanaway, who are looking for cheaper ways to dispose of waste streams,” says Joe. “We’re not subject to landfill levies, and it’s a cleaner way of dealing with the materials.”

The Australian Organics Recycling Association (AORA) has recognised
 AD as “a very positive contributor” 
to the organics recycling sector.

AORA Executive Oficer Peter McLean emphasises its scope as an effective process to ensure organic resources
can be used to produce energy before becoming a compost input or organic fertiliser. He endorses the Biogass plant.

“The Biogass facility at Jandakot is capable of processing almost every type of commercial and industrial organic waste, which makes it a very valuable addition to Perth’s organic waste management infrastructure and ensures diversion from landfill,” says Peter.

“This technology has been adopted in various forms throughout Europe for two decades, so it’s very pleasing to see some Australian cities take advantage of this practical technology.”

Potential and next steps

Having its first plant operational allows Biogass to highlight the commercial viability of the project. It is now looking for other companies to invest in the next facilities, and has a long list of opportunities are showing great potential.

“The Richgro plant is our visitable reference site, so we can showcase this type of system in Australia now for interested parties to see how it works and its viability,” says Joe. “This will allow us to go out into the market with a view to installing and rolling out further plants in Australia.”

For Biogass, bioenergy plants a good return on investment for low capital expenditure considering the volume
 of waste they can process.

As innovative waste-to-energy projects, bioenergy plants qualify for 
a range of state government grants and Australian Government renewable energy finance through the Clean Energy Finance Corporation (CEFC).

Biogass now has first-hand experience of securing such funding. In terms of financial viability, Biogass estimates that investing in building such a plant has a three-year payback period.

“In addition to the very significant annual gate fees from accepting organic waste, taking Richgro off the grid saves it between $600,000 and $800,000 year in energy bills,” states Joe. “There’s the potential to generate a revenue of $500,000 a year when it can sell on the power, and that’s not including income from sales of the biofertiliser.”

“It has green credentials, it isn’t dirty – 99 per cent of the incoming product is recycled and processed,” he adds.

Peter McLean also sees the potential wider opportunity and value of more bioenergy plants around the country.

“To maximise beneficial reuse of organic resources, AORA wants to see anaerobic digestion as a common waste-to-energy solution covering
all regions of Australia,” he states. “Localised energy production plays an important role in Australia’s energy future.”

The next steps for the Richgro plant is to ramp up input of material further to an average of 35,000 tonnes a year, and then to bring the second generator into operation by December 2016.

Additional information about Biogass is available on the company website.