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MAKING POWER FROM RUBBISH What do you do with a city’s garbage and refuse? You send it off to landfill, of course. Well, until now that has been what most cities have done. But landfills fill up – and these days, can be politically incorrect. But (and it’s a big but!) that could all be about to change, with many cities using garbage as fuel for electricity generation. T he photo above shows the Isséane refuse station in the heart of Paris, France, just 5km from the Eiffel Tower. You can see only about 21m of the building’s height – the remaining 31m are underground. In some ways, it’s not too dissimilar to those waste transfer stations you’d find in Australian cities: somewhere that garbage trucks pull in, empty their loads of rubbish which is then transferred, well, somewhere else. But in the Isséane centre, the rubbish isn’t transferred anywhere. Instead, it’s used as the fuel for a four-pass horizontal boiler, which produces steam – some 200 tonnes per hour of it. About half of this steam is used to drive a turbine, which in turn drives a generator producing 52MW of power each year – enough power for around 5,500 homes and businesses. The remaining steam is fed into the district heating network that serves 80,000 households, saving them around 110,000 tons of heating oil each year. The waste produced by seven households can heat one family’s home. The electricity tapped from the turbogenerator is used primarily for plant power; the rest is by Ross 14 Silicon Chip exported to the French grid. The Isséane energy-from-waste plant consists of two process trains with a rated capacity of 30.5 tonnes per hour each, for a total of 460,000 tonnes per annum. The waste receiving area and the combustion system are subterranean, so the plant produces neither noise nor odor emissions. In fact, when the building was being planned, local authorities made sure that no plume would rise from the stack of the plant in Issy-les-Moulineaux, one of the most densely populated conurbation communities in Europe. The plant meets or exceeds the tough EU standards for pollution. The waste is incinerated on two five-zone Hitachi Zosen Inova grates. An integrated combustion control system with an infrared camera makes it possible at all times to quickly and reliably adjust the combustion parameters to rapidly changing waste compositions. The very hot incineration gases, (the high temperature essential to prevent dioxins and other “nasties”being produced when plastics are burned), are routed Tester through a secondary combustion chamber to Celebrating 30 Years siliconchip.com.au a four-pass boiler where they are cooled from 1100°C to 180°C. Some 460,000 tonnes of rubbish is disposed of this way each year. Apart from the electricity produced, the plant then processes the incinerated ash, washing and cleaning it for recycling into building materials after first separating any metals it contains. Another benefit of the process is the reduction (by half) of any remaining chlorine, which is then evenly dispersed throughout the ash. That’s just a brief introduction to the French process, developed by Hitachi. We’ll return to other overseas processors shortly. It’s more than a load of garbage! Around the world, the disposal of bulk rubbish has become a major headache. We could bore you with statistics but just consider how much you throw away each week. Sure, you diligently sort your “recyclables” into different coloured bins for the local council or contractor to pick up in special trucks for recycling – though that has an ever-increasing question mark over it according to recent reports (they say most “recycling” ends up as landfill anyway!). But what’s left, the rubbish we humans generate simply by consuming, is staggering. If you live in an urban area, think of the number of compacting rubbish trucks you see on collection days or nights. Our local “tip” here on Sydney’s Northern Beaches (woops – they like to be known as a Resource Recovery Centre these days!) receives almost a quarter of a million TONNES of waste annually. Around 70% of that IS recycled – mainly in the area of concrete, ashphalt, aggregate and so on. Now that’s a very worthwhile and laudable objective – no-one argues with re-purposing good stuff – but that still leaves 30% – or the best part of 100,000 tonnes to dispose of. Multiply that by an almost infinite number of areas around the world and you start to get an idea of the magnitude of the problem. And, traditionally, what hasn’t been sorted into recyclables has mostly gone straight into landfill. The latest figures suggest that around 20 million tonnes of garbage (about 40% of the 52 million tonnes of waste generated each year in Australia) makes its way into landfill sites each year. Around 75% of waste goes into just 38 landfill sites, mostly around our capital cities. Many landfill sites around major cities have already closed – they’re full – and many more measure their life expectancy in just a few years. It’s amazing how quickly a large landfill site can fill. When I started working in 1970, there was a huge brick pit just down the road from where I lived. It had just closed – they’d exhausted all the clay – so the several-acre and rather deep hole was then converted into a rubbish tip (and it stank!). But it only took a couple of decades to be filled to the brim. These days, there are beautiful playing fields and parks covering the area . . . so where does the rubbish go now? Other landfill sites have of course been opened – but as they fill, as they will, the authorities will find it more and more difficult to find new sites. That’s due not only to much tighter laws restricting how, where and who but just as importantly (perhaps more importantly) the modern city trait of “NIMBY”ism. In times past, many coastal cities disposed of their garbage by taking it way offshore in barges – they called them garbage scows – and dumping it in the sea (some didn’t even worry about the offshore bit!). Today, that’s almost a hanging offence. . . Lately, we’ve seen large-scale transportation of waste from states with very high waste disposal charges (eg, NSW) to states with lower (or minimal/even no) charges (eg, Queensland). Officially they moved 670,000 tonnes last financial year; the industry believes it’s closer to one Waste receiving and storage Combustion and boiler           Flue gas treatment Energy recovery 1: Tipping hall 5: Feed hopper 13: Primary air distribution 6: Ram feeder 14: Secondary air fan 7: Hitachi Zosen Inova grate 15: Secondary air/recirculated 8: Infrared camera    flue gas injection 9: Start-up and support burners 16: Recirculation fan  10: Burner fan 17: Bottom ash transport 11: Primary air fan 18: Ash conveyor 12: Primary air preheater 19: Four-pass boiler 28: Turbine and generator 2: Waste pit 3: Waste crane 4: Loader control cabin 20: Electrostatic preciptator 21: Sodium bicarbonate silo 22: Flue gas entrainment duct 23: Fabric filter 24: SCR Catalyst 25: Induced-draft fan 26: Silencer 27: Stack The basic operation of a waste-to-energy plant. Long before any rubbish reaches the combustion furnace it is sorted to remove any non-combustibles which, where possible, are reused or recycled. siliconchip.com.au Celebrating 30 Years February 2018  15 The giant Woodlawn open-cut mine near Tarago, between Canberra and Sydney, is now Australia’s largest tip and is also producing electricity from landfill methane. The long-term goal is 200,000MWh each year. Notice the wind turbines on the horizon? million tonnes. It’s mainly moved by semi-trailers. That has a three-fold effect: (a) it puts a lot of trucks on the road with attendant accidents and slowing of traffic; (b) that creates an incredible amount of diesel pollution and (c) it simply moves the problem from one place to another. Incidentally, despite what some media (and some politicians) may tell you, it’s not illegal – section 92 of the Australian Constitution allows free “trade” between states (even if the trade is in rubbish!). But legislators are said to be looking for some means of stopping it. So landfill is frowned upon – up to a point! Dumping at sea is out. Interstate transport is not the answer. Even recycling is questionable (see panel). What to do? Methane power generation As an aside, even in a landfill tip, it is possible to generate power. The average domestic rubbish bin contains about 60% organic material, which breaks down over time. And as the material breaks down, it generates methane. The now-closed Belrose tip in northern Sydney has 93 gas wells collecting this methane, providing up to 680 cu- Fancy a bite to eat . . . in an incinerator? The Willoughby incinerator in Sydney is one of several designed by Walter Burley Griffin – this one is now an art gallery and restaurant. 16 Silicon Chip bic metres per hour. Onsite generators fueled by this gas produces around 4MW of electricity – part of the 160MW being produced by landfill methane around Australia. The generation, commenced in 1994, is ongoing despite no more garbage being dropped at the site. A secondary benefit is the reduction of odours from the tip – again, caused by the breaking down of the buried garbage. The Woodlawn tip, about 200km southwest of Sydney, collects more waste than any other in the country. An old open cut mine, it’s reckoned to be about one quarter full and receives waste, mainly from Sydney, by the trainload. It too is generating methane-powered electricity – a network of pipes built layer on layer as the tip fills, so far collecting between 400 and 700 cubic metres of methane power hour, with a goal of generating up to 200GWh each year. Up to 24 generators will be built, depending on the project’s success. Incineration Again back in history (the best part of a century ago), many councils built large-scale incinerators to dispose of (particularly) household garbage, which had previously been dumped into waterways. Several notable incinerators were designed and built by Walter Burley Griffin, the same architect who designed Canberra (wags have claimed the purpose of both was similar). But there are very few left these days, as councils face mounting public opposition and much stricter anti-pollution laws than were in existence in decades previous. The Moonee Ponds (Melbourne) incinerator which opened in 1930 closed in 1942, while the Willoughby (Sydney) incinerator opened in 1934 and burnt its last garbage in 1967. Both have since been converted to art galleries and even (Willoughby) into an upmarket restaurant! In the 21st century, however, incinerators are starting Celebrating 30 Years siliconchip.com.au Recycling? Or perhaps not? Many people – most, even – refuse to believe this account when I tell it, as I have done several times. But I swear this is true because it is first hand! Some years ago, I was involved in a bottle clean-up around a local club and we had almost filled a box trailer near the end of the day. Realising that the closest tip would close in half an hour, I called “enough” and drove the trailer to the tip and into the bottle recycling area. This had an area for white bottles, an area for brown bottles and an area for green bottles. I said to the attendant “I suppose you want me to sort the bottles into their colours”. It was about ten minutes before closing. “No mate, just dump them anywhere you like” “But don't they have to be sorted for recycling?” He guffawed and said “Recycling? This is all for show for the public and to appease the greenies. As soon as we close the gates, we pick up all the bottles with the front-end loader and take them down to bury them. We can't even give them away to the glass recyclers and even if we did, they won't come and pick them up because it costs them more in fuel than they’re worth.” We can tell you that this has not changed one iota! to make a comeback, due to the fact that the pollution restrictions, even tighter today than when the old incinerators closed, have been largely overcome with modern technology. There is also the fact that authorities are now starting to treat rubbish, garbage, refuse, waste . . . whatever you like to call it, as a resource, not a problem. That’s where the plant we opened this story with – and many more like it around the world – come into their own. Mitsubishi’s SMASH in Japan Japan has a gargantuan waste disposal problem – in the twenty years between 1960 and 1980, it increased by five times, to more than 44 million tonnes per annum – with precious little land available for landfill. Faced with mountains of trash, the Japanese Government revised and enforced its Waste Management Act. As a result, standards in waste management at both corporate and local government level had to improve – with the result that some of their procedures are now the most advanced in the world. The refuse centre in Iwate-Chubu, in north-eastern Hon- The Iwate-Chubu plant in north-east Japan which burns 56.000 tonnes each year and as well as producing electricity, its SMASH technology recycles most of its ash. siliconchip.com.au shu, Japan, is typical; a showcase of modern waste management – and the technology is now used in many similar installations in operation, or being built, around the world (except, regrettably, in Australia!). It utilises both advanced resource recycling systems and the SMASH system to re-purpose as much of the incoming waste as possible, even using the ash produced by the incineration process as one of the raw materials for cement. To achieve a high level of heat recovery during incineration, an advanced technology called Internal Gas Recirculation (IGR) is employed as a secondary combustion air supply. It combines recycled combustion gas from the furnace with a rich supply of oxygen to feed the furnace during combustion. This enables the furnace to operate with a lower ratio of air, not only improving efficiency but reducing the amount of exhaust gas. In addition, the higher level of heat recovery increases the amount of electricity generated from each tonne of waste by two or three percent compared to conventional furnaces. And Hamm in Germany The waste plant in the city of Hamm, Germany, was designed for the incineration of municipal waste. It mainly handles domestic waste but also commercial waste and bulky refuse. Originally commissioned in 1985, the Hamm plant has had several extensions, which have increased the incineration capacity to 295,000 tonnes/year. Each of the four identical combustion lines has a throughput of 10 tonnes per hour. Normally, combustion is completely self-sufficient, without the need for supplementary fuels such as paper, etc. The heat of the flue gas produced during combustion is used to generate steam, which is fed to the three turbogenerators for power generation (approximately 26MW installed capacity). With the aim of maintaining the waste disposal operations at a high technical level and to meet tighter environmental regulations, the plant was retrofitted and upgraded in several stages. In the USA In 2015, the last year for which data is available, there were 71 waste-to-energy power plants and four other power plants in the United States which burned what they term MSW: Muncipal Solid Waste. There are obviously many more now. These plants burned about 29 million tons of MSW in The Hamm, Germany waste-to-power plant with an installed capacity of 26MW. It burns almost 300,000 tonnes of waste each year. Celebrating 30 Years February 2018  17 An energy-from-waste plant for Sydney? Architect’s impression of the Eastern Creek plant In 2015, then again in 2017, the CEO of Dial-a-Dump industries, Ian Malouf, proposed the world’s largest power-generating incinerator to be built on land (actually an existing landfill site) the company owned at Eastern Creek, in Sydney’s western suburbs. The facility would be co-sited with its existing “Genesis” recycling facility and would, in fact, take all of its input from that facility. He has formed a company called TNG: The Next Generation, to develop and operate the plant, the first in Australia. Their aim is to dramatically reduce the generation of greenhouse gases and to help solve the energy needs of Western Sydney over the next fifty years. The $700 million plant would take mainly building and construction waste, separate it into fully recyclable materials (eg, road base, aggregate, etc) and then incinerate the remainder, using stateof-the-art furnaces which almost eliminate any smoke exhaust. This plant would initially treat about 530,000 tonnes of waste each year, rising to more than 1.1 million tonnes after proving itself. Along the way, it would produced the steam for turbines which would generate enough energy to power 100,000 homes (rising to 200,000). However, despite growing concerns about power prices, power station closure and the possibility of blackouts, it has had a very loud “anti” backlash from the community. Much of the opposition appears to have been fed by deliberate misinformation campaigns. Project stalled against local opposition The local Blacktown and Penrith councils, Western Sydney’s Local Health District, Labor, the Greens and even the Government’s Environmental Protection Authority have all come out in opposition to the proposal. It must be said that the EPA’s arguments were more along the “insufficient evidence” line than the sometimes spurious reasons other groups gave. NSW Health’s main objection was that it was twice the size of any similar plant anywhere in the world, while the Greens claimed 18 Silicon Chip that it would “reduce recycling rates, spew out air pollution and impact on the health of residents.” The attitude of the Greens is puzzling, given their party’s antilandfill policy. The TNG proposal would reduce landfill by between eighty and ninety percent. . . yet they oppose it! Some community groups, as might be expected, have even displayed placards reading NIMBY – Not In My Back Yard. However, Mr Malouf told Fairfax Media that despite the objections, he remained confident “that the project represents a positive environmental outcome”. “The facility will process only residue building, commercial and demolition waste that is currently being landfilled,” he said. “It will provide a secure, long-term supplement to western Sydney’s energy demands.” He said that more than 2200 facilities in urban areas, alongside homes, schools, shops and businesses across 35 countries are already using the same safe and efficient thermal technology, to generate power. These facilities have all passed rigorous approval processes and for many years have been producing clean, cheap energy, with less harm to the environment, compared with coal fired stations or by dumping waste into landfill. Dial-a-Dump has commissioned independent research into the proposal, which found that 69% of respondents supported the concept of energy from waste. The future The proposal is currently back before the State Government, probably for a decision early this year. Even with a “sweetener” by TNG of free solar power panels for 1000 homes closest to the site (bear in mind that the closest house is more than 800m away), there is no guarantee that the locals’ NIMBY attitude or the “object to anything” philosophy of the Greens will change. Time will tell! Celebrating 30 Years siliconchip.com.au And another one for Mt Piper? As we went to press (late December 2017) a proposal was released for another energy-from-waste scheme, this time for the 1400MW Mt Piper power station, located about 100km west of Sydney near the town of Lithgow. The proposal, named Refuse Derived Fuel (or RDF) called for the conversion of part of the Mt Piper plant to burn selected materials, including paper, plastics, disused linen, etc which would otherwise go into landfill. It would have the capacity to generate about 27MW and use an estimated 200,000 tonnes of refuse annually. Energy Australia, owners of Mt Piper, were conducting the study in conjunction with the recycling management company Re.Group. The project would cost around $60 million, take 12-18 months to build and originally claimed could be generating its first power as early as 2019, although this appears to have blown out to 2021. Energy Australia claimed there were significant environmental benefits in the project, as materials that would be used in the energy recovery project would otherwise go to landfill. While having a nominal life until the middle of the century, the future of Mt Piper has been under somewhat of a cloud since the green activist group “4nature” successfully launched action in the NSW Land and Environment Court against the NSW Government’s 2015 planning consent for the extension of the Springvale Colliery (one of Mt Piper’s main coal sources) on the basis that it could contaminate water catchments in the Blue Mountains area. Without an assured supply of coal, Mt Piper faced cutback or even closure, which would take a further 15% of supply out of the east coast electricity market. This came not long after the news that AGL’s 2000MW Liddell power station will close in 2022. The Energy Australia/Re.Group study, due to be completed about now, would be looking at the project from the economic viability and benefits side (eg, the extra power produced) but also the negative side (environmental impact in particular). Even before the study was complete, environmental groups were condemning the proposal, with bodies such as the Colong Foundation saying it was the “wrong step for diversifying sources of power”. The Colong Foundation has a “zero waste” policy so burning refuse to produce power goes counter to their code. They also claimed the plant would give off “highly toxic pollutants” and the ash produced would pose a risk to waterways, including the Coxs River, part of the Sydney water supply catchment. 2015 and generated nearly 14 terrawatt-hours of electricity (1012 Watts!). The biomass materials in the MSW that were burned in these power plants accounted for about 64% of the weight of the MSW and contributed about 51% of the energy. The remainder of the MSW was non-biomass combustible material, mainly plastics. As we mentioned earlier, many large landfills are also generating electricity by using the methane gas that is produced from decomposing biomass. Where to from here? The rest of the world is forging ahead with garbage-topower plants, alleviating three problems: avoiding landfill, generating power and using up resources for building materials. In Australia, the future is not so rosy, with obstacles being placed at every turn for the proponents of garbage-topower plants. Many of the arguments put forward are spurious in the extreme. Many appear to represent the current view of “if it moves, object to it”. Of course, in amongst the garbage (no pun intended) there may be some elements of truth, which from our reading the company has tried to answer. But for the rest, the old adage applies: “why let the facts get in the way of a good story.” Only time will tell. Further media There is a considerable amount of information on the internet regarding energy from waste. Some of these are obviously “puff pieces” written by PR companies and/or newspaper journalists with very little knowledge of the subject they are writing about. But they at least give some interesting facts, which you might like to peruse. All of the URLs are shown here in the form of SILICON CHIP ShortLinks, which will take you direct to the URL in question. If you’re looking at SILICON CHIP OnLine, simply clicking on any of them will do the same thing. For a start, the Isséane (Paris) transfer station shown at the start of this report is featured in some TV commercials by NextGen – you may have seen them on late-night TV: siliconchip.com.au/link/aahy The Japanese plant mentioned here is featured in a report by Mitsubishi: siliconchip.com.au/link/aahz If you really have plenty of time on your hands (!), read through Nextgen’s almost 400-page environmental impact statement answering many of the questions raised by the authorities and by objectors: siliconchip.com.au/link/aai0 And there are various media and newsletter reports which also give interesting background: The 1400MW coal-fuelled Mt Piper power station near Lithgow, NSW faces a somewhat uncertain future. siliconchip.com.au http://siliconchip.com.au/link/aai1 http://siliconchip.com.au/link/aai3 http://siliconchip.com.au/link/aai4 http://siliconchip.com.au/link/aai5 http://siliconchip.com.au/link/aai6 http://siliconchip.com.au/link/aai7 http://siliconchip.com.au/link/aai8 Celebrating 30 Years SC February 2018  19