Transcontinental combustion: Hitachi Zosen Inova

Transcontinental combustion: Hitachi Zosen Inova

Carsten Kaiser and Marc Stammbach of Hitachi Zosen Inova speak to Waste Management Review about technology installed on Europe’s largest waste-to-energy facility in Istanbul. 

Straddling Europe and Asia, Turkey’s capital is a transcontinental centre known for colourful labyrinth-like bazaars and the iconic Blue Mosque. 

While perhaps not as recognisable outside of Turkey, within the country, Istanbul is also identified by the tragic Umraniye-Hekimbasi open dump explosion. 

The explosion, which took place in April 1993, was the result of unsustainable and unregulated solid waste dumping, with the site receiving more than 2000 tonnes of uncompacted solid waste each day. 

The event engulfed 11 houses, causing the death of 39 people.

In a recent op-ed for the Daily-Sabah, Mehmet Emin Birpınar, Turkey’s Deputy Environment Minister, argued that the event spurred major environmental reform. Specifically, Mr Birpınar highlighted that in the preceding 25 years, Turkey’s recycling rate rose from one to 12 per cent. 

While the country is now working towards “zero waste” legislation, much of that initial environmental reform focused on sanitary and well-regulated landfills. 

Despite this representing an initial step in the right direction after widespread open dumping, the solution is now no longer sustainable. 

Istanbul’s population is growing, according to Carsten Kaiser, Hitachi Zosen Inova (HZI) Senior Sales Manager, and putting pressure on the city’s existing landfills. He adds that throughout the region, landfills are close to capacity. 

To address the problem, the Istanbul Metropolitan Municipality engaged HZI and Turkish construction partner Makyo to construct and operate a waste-to-energy (WtE) facility for municipal solid waste. 

Once complete, the plant will be the first to operate in Turkey and the largest of its kind in Europe. 

“The facility will process up to one million tonnes of waste per annum and will be located close to Istanbul’s new airport in the northwest of the city,” Carsten says. 

“HZI’s three combustion lines will process roughly 15 per cent of the city’s municipal solid waste every year and generate around 70 megawatts of net electricity.”  

He adds that the plant will process roughly 25 per cent of the European side of Istanbul’s daily waste.

TECHNO-ECONOMICAL PARAMETERS 

As a Switzerland-based globally operating engineering, procurement and construction contractor, HZI has delivered more than 600 WtE plants worldwide. 

“Our solutions are based on efficient and environmentally sound technology, are thoroughly tested, can be flexibly adapted to user requirements and cover the entire plant lifecycle,” Carsten says. 

“To enable us to work even closer to our clients, we actively foster good working relations with our branch and regional offices, which is how we first came into contact with the Istanbul Metropolitan Municipality.” 

 HZI’s first conversations with the Istanbul Metropolitan Municipality started in early 2013, Carsten says, before a competitive tender process began for the project in 2016. He adds that diversion from landfill, which still accounts for 84 per cent of the city’s waste disposal, was a key priority for the city. 

As the fifth largest city in the world, it should come as no surprise that Istanbul has to deal with large volumes of waste, Carsten says, producing upwards of six million tonnes of solid municipal waste each year. 

“Six international consortia participated in the tender, before HZI and Makyol were awarded the contact including operations and maintenance of the facility for a minimum of one year in September 2017,” Carsten says. 

“The tender evaluation was based on techno-economical parameters, for example, considering the investment and operations costs, but also the overall efficiency of the facility.” 

The planning process for a facility of this scale is similar to a standard WtE plant, Carsten says, with differences more apparent during execution. 

“We approached our design for this facility like we would any other WtE plant – we just scaled it up. Once construction is complete, however, everything will become bigger and faster,” he says. 

The facility’s core technology components include a moving combustion gate, boiler design and efficient flue gas treatment systems. This combination of components is an example of HZI’s thermal WtE process, which Carsten says represents an efficient, environmentally sound solution for modern cities. 

“Waste is delivered to the site and stored in a bunker, before a crane both thoroughly mixes and feeds the waste into a feed hooper. From there, material is pushed onto the grate by a ram feeder,” Carsten says. 

“A fully integrated control system ensures stable and efficient operation and optimised fire position on the grate. Upon combustion completion, the remaining inert ashes fall into the bottom ash extractor. From there, they’re taken to a bunker or storage area for metals recovery.” 

Gases released from the waste are mixed with secondary air and recirculated flue gases above the grate, Carsten says. 

He adds that this process assures complete combustion and lowers carbon monoxide, nitrous oxides, and volatile organics emissions. 

“The recirculation of flue gases also increases the plant’s energy efficiency,” he says. 

Released energy is then used to produce superheated steam, Carsten explains, which is expanded in a turbine generator to produce electricity. Following this, flue gases are cleaned to strictest standards, and constantly monitored before being released at the stack. 

All electricity produced at the site will be exported to the national electricity grid via 154-kilo volt substations at Tasoluk and Habibler, villages northwest of Istanbul. Carsten says technical controls will be installed to meet all EU Industrial Emissions Directives. 

According to Carsten, over 20 per cent of the facilities components will be sourced in Turkey from local businesses. 

He adds that construction is, and will continue to be, carried out exclusively by local workers. 

This, he says, highlights HZI’s commitment to engaging and supporting the communities in which they operate. 

“HZI strived to maximise the local scope of the supply chain in Turkey,” he says. 

“While Turkey provides great opportunities in various aspects of the supply chain for a WtE plant, special equipment parts, for example the pressure parts of the boiler for such a large size of thermal output, are limited, and had to be procured from other European suppliers.” 

The majority of construction is estimated to be complete by the end of 2020, with the facility fully operational by 2021. 

“With the realisation of this prestigious project, another region devotes itself to an ecological and sustainable waste management system, and contributes to worldwide decarbonisation and a reduction of other harmful emissions,” Carsten says.

LEARNING FROM ISTANBUL

As a global supplier of WtE technologies, HZI has a range of other projects under construction throughout the world, including Australia’s East Rockingham facility near Perth, Western Australia. 

The state-of-the-art facility, which will process 300,000 tonnes of municipal and industrial waste each year, will be part-owned and co-operated by HZI. 

The facility reached financial close earlier this year, and as the country’s largest WtE facility, is set to serve as the missing link in Australia’s waste hierarchy. The Western Australian facility is set to be fully operational by 2022. 

Marc Stammbach, HZI Australia Managing Director, says the plant’s key technology components, such as a moving combustion grate, boiler design and flue gas treatment system, are similar to those employed in Istanbul. 

He adds however that while the Istanbul plant features three combustions lines, the East Rockingham facility will operate just one. 

Marc explains that this comes down to the scale of the facility, Western Australia’s population and associated throughput. 

East Rockingham will generate 29 megawatts of renewable energy and is the first facility of its kind to use ‘waste-arising’ contracts. 

The contracts provide flexibility to councils to maximise recycling and meet waste reduction targets.   

Marc says he hopes the Australian facility will be the first of many developed by HZI across the country. 

“Even though there is no official ban on landfill in Australia, people have been rethinking sustainability and efficient waste management for some time. 

“As one of the first of its kind in the country, East Rockingham will play a pioneering role and point the way forward for future WtE installations in Oceania,” Marc says. 

“For HZI, this project marks our entry into the Australian market and introduces our world renowned and leading technology to Australia – something we’ve been working on for a long time. 

“For the Perth area, this project marks a major step towards sustainability and renewable WtE,” Marc says.

In addition to East Rockingham, Marc says HZI is preparing for Australia’s renewable future via other avenues. 

“Considering the large Australian footprint available for wind and solar, we can see a future where Australia becomes fully sustainable and a net exporter of renewable energy,” he says. 

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