Looks good on paper: Creating energy from waste

Australian Paper
Australian Paper's Maryvale Mill

By Nichola Davies

Like many local manufacturing businesses, Australian Paper is facing viability challenges. But, in what could be the difference between sinking or swimming in the long run, the company is determined to face these challenges efficiently and responsibly with innovative, proven technologies, and it’s looking to Europe for the precedent: creating energy from waste (EfW).

Australian Paper is in fact Victoria’s largest generator of baseload renewable energy, producing 600,000 tonnes of biofuel from its pulping process each year. But, it’s also Victoria’s largest industrial user of natural gas and uses significant quantities of coal-fired electricity. Australian Paper is therefore exposed to surges in energy prices and uncertainty of supply, which has led to Australia’s last office paper manufacturer taking its energy supply into its own hands.

In 2017, Australian Paper announced it would undertake a feasibility study on a proposed $600 million, 225 MW thermal combustion EfW plant adjacent to its Maryvale Paper Mill, which would process up to 650,000 tonnes of municipal solid waste as well as commercial and industrial waste per year, with the help of partner Suez.

This would provide energy security for the Maryvale Mill, divert non-hazardous residual waste away from landfill, reduce greenhouse gases by 540,000 tonnes per annum and support an estimated 1600 jobs during construction.

The $7.5 million feasibility study – of which the federal and state governments contributed $2.5 million each – has just been completed. In short, the report found that an EfW facility at the Maryvale Mill would be economically, environmentally and commercially viable.  

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Australian Paper’s Maryvale Mill requires both steam and electricity to function, and the design of the EfW plant means it will be able to produce both via an energy efficient heat and power mode.

Currently steam is produced by on-site natural gas boilers and is used by four on-site generators to produce 45 MW of electricity each hour. Additional high-voltage electricity demand comes from the grid. On top of this, it purchases six million gigajoules of natural gas annually and 30 MW per hour of electricity.

Australian Paper
A 3D rendering shows the proposed EfW plant in situ at Australian Paper’s Maryvale Mill

The key technical characteristics of Australian Paper’s EfW plant will include two 112 MW thermal boiler lines, with each line being at the upper end of the main manufacturer’s size range. A condensing/extraction steam turbine generator (70 MW electric) converts the steam energy that isn’t sent to the mill into electricity, which is then used for the mill’s electricity needs.

Moving grate incinerator technology has been selected for the project as well, being an environmentally and commercially proven low emissions technology. It’s ideal for municipal solid waste as it doesn’t need prior sorting or shredding, and can incorporate large quantities and variations of waste.

Flue gases will achieve a minimum of 850ºC for at least two seconds to completely combust organic waste and destroy dioxins and furans. The flue gas cooling via the economiser section is designed to reduce potential for dioxins to re-form and flue gas recirculation will be in place to minimise nitrogen oxide generation in the furnace and assist with complete combustion.

Taking a technology-first approach, flue gas oxygen measurement to ensure sufficient oxygen for complete combustion, including a carbon monoxide analyser for further combustion tuning, can all be monitored online.

To manage the by-products of combustion, the facility will incorporate lime injection systems to neutralise acid gases, activated carbon injection to absorb trace heavy metals and hydrocarbons and single stage bag filters to collect fly ash particulates, lime and activated carbon solid residues.

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Planet Ark CEO Paul Klymenko said during a study tour, which informed Australian Paper’s feasibility study and the design of the facility, he asked an engineer working in the Swiss waste industry where their landfills were located. He was surprised to learn there weren’t any.

Many European countries, which are considered to be at the forefront of EfW technology, have achieved sending less than three per cent of their waste to landfill, including Germany, Sweden and the Netherlands. In contrast, Australia sends 40 per cent of its waste to landfill.

Australian Paper’s chief operating officer Peter Williams said the project would alleviate issues Victoria is facing with landfill, and gas supply pressures as well.

“… with Melbourne’s looming landfill challenge, Australian Paper’s EfW project is the missing link in waste management infrastructure for the South East, creating efficient energy from residual household and commercial waste, achieving a more sustainable outcome than disposal to landfills,” Mr Williams said.

“By diverting 650,000 tonnes per annum of residential and commercial waste from Victorian landfill, the facility could provide Melbourne with essential waste management and resource recovery infrastructure.”

When Australian Paper’s EfW facility is up and running, the Hampton Park landfill site 40 minutes from Melbourne is set to close. 

Mr Williams noted that by replacing natural gas at the Maryvale site, Australian Paper would return enough gas to the market to meet the annual needs of up to 70,000 Victorian households annually.

“Australian Paper is now focused on taking this important regional investment for the Latrobe Valley to the Development Stage where, with our partner Suez, we will work to finalise approvals and seek to secure long-term waste supply contracts as well as appoint suitable partners to undertake the engineering, procurement and construction phases,” he said.

The company expects to finalise contracts and financing in 2020 with construction commencing in 2021 and completing in 2024. Commissioning and start up is set for 2025.