Building incinerators key to a sustainable waste management

An incinerator works 24 hours a day, seven days a week and 365 days a year, come rain, shine, lightning, thunderstorm or flood which means wastes are drastically...

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Published in Astro Awani, Business Today, Asia News Today, New Straits Times & Focus Malaysia, image by Astro Awani.

In August 2005, the Malaysia’s National Strategic Plan (NSP) for Solid Waste Management envisaged a target of diverting 40% of municipal waste from landfill and increasing recycling rates to 22%.

Fast-forward to 2020 – these targets remain a pipe dream for 15 consecutive years, as they were sorely missed year after year, and based on the latest figures, almost 90% of waste was disposed to landfills, while only 10.5% recycled.

The only accurate estimate then was on the municipal waste generated on a daily basis – 19,000 tonnes per day in 2005 to more than 30,000 tonnes daily by 2020 or to be more precise 38,142 tonnes of waste per day in 2018, according to the Solid Waste Management and Public Cleansing Corporation (SWCorp).

Based on these figures, there is nearly a doubling of waste produced since 2005, when the per capita generation was around 0.8kg per person per day compared to an average of 1.17kg per person each day in 2018.

Back in 2005, 75% of this waste was being collected while the remainder was disposed by others, including via illegal dumping. Almost 95% of the collected wastes were then taken to about 120 treatment disposal facilities that were distributed throughout the Peninsula.

According to the Ministry of Housing and Local Government, around RM430m (US$104m) has been spent on closing just 17 out of 165 existing dumpsites, and promoting the disposal of solid waste to sanitary landfill.

At present, landfill seems to be the preferred solid waste management option for Malaysia, as waste infrastructure is not well-developed. Local authorities responsible for the management of solid waste are outsourcing the collection and disposal of solid waste to private companies.

But it has become more untenable to rely on landfill because lands are more needed for other purposes due to the robust economic development in the last two decades and a sanitary landfill is one source of pollution in which both biodegradable and non-biodegradable wastes emit toxic gases such as methane into the air in the process of decomposition which may take years to complete – from 100 to 500 years.

To enhance solid waste management, Malaysia has taken the approach of privatisation and centralisation. The standard hierarchy of waste management involves five crucial steps: reuse, reduce, recycling, treatment and disposal.

Recycling is a big part of these crucial steps but has happened in many other countries it is very difficult to get the whole population to support it and that’s why for 15 years the target of recycling rates of 22% remains a pipe dream.

The other element of waste management is to resort to a concept of a circular economy – first propounded by Walter Stahel and Genevieve Reday in their 1976 research report to the European Commission in which they sketched the vision of an economy in loops (or circular economy) and its impact on job creation, economic competitiveness, resource savings and waste prevention. The report was published in 1982 as the book Jobs for Tomorrow: The Potential for Substituting Manpower for Energy.

Promoting a circular economy was identified as national policy in China’s 11th five-year plan starting in 2006. The Ellen MacArthur Foundation has more recently outlined the economic opportunity of a circular economy, bringing together complementary schools of thought in an attempt to create a coherent framework, thus giving the concept a wide exposure and appeal.

In its essence, the circular economy is based on the principles of designing out waste and pollution, keeping products and materials in use, and regenerating natural systems. Singapore’s adoption of the circular economy is legendary based on a three-pronged strategy. The first and key strategy is waste reduction. Second, is to recycle what the city-state can’t reduce.

The third strategy is waste-to-energy – the use of incinerator to reduce the volume of waste, and the toxic ash is sent to the Semakau Landfill – the only landfill in Singapore built on a man-made island away from the mainland.

It is called waste-to-energy because the heat from burning the wastes can be harnessed to generate electricity for domestic use. Singapore incinerates more than 2.8 million tonnes of waste a year, up from 2.4 million tonnes in 2000.

The next thing that the Republic is focusing on now is how to re-use the incineration ash, and to turn it into sand – called NEWSand – for construction purposes, thereby closing the waste loop and is akin to recycling.

The residual ash at the bottom of the incinerator after the wastes have been burnt is toxic but it can be potentially used for non-structural purposes, once it has been treated to ensure that it is suitable for construction purposes.

This is done by extracting more than 200 tonnes of metal a day from the incinerated bottom ash. Singapore is currently exploring treatment process to render the ash for compliance with the environmental standards for construction application.

By reusing the incinerated bottom ash, the demand for landfill space will be reduced and the lifespan of Semakau Landfill extended.

In Malaysia, the narrative on using incinerator is still on the toxic gases that the incinerator is emitting to the air through its chimney, and building an incinerator plant involved heavy and hefty capital outlay. This is an outdated argument.

There are very stringent pollution control measures at the waste-to-energy (WTE) plants – one third of the incineration process is devoted to flue gas treatment systems for pollution control.
The flue gas goes through the electrostatic precipitators to remove 99.7 per cent of the dust. The flue gas then passes through the catalytic bag filters where the dioxin – a highly toxic pollutant and powerful carcinogen produced from burning plastic – is converted into carbon dioxide and water.

The final emissions from the plant are hence clean and this is the standard adopted by incineration plants in Singapore and advanced countries such as Switzerland and Germany.
And in the case of Singapore, it is soon to launch a fifth integrated waste-to-energy plant, which will integrate water management with waste to energy. Building this new plant will enable older, less efficient plants to be replaced and help to reduce the carbon footprint as well i.e., the same amount of waste can produce double the amount of energy.

The reason why the republic co-located the new plant at Tuas with the used water reclamation facility is the synergy obtained when these are combined for better efficiency and resource recovery.

The food waste collected can also be co-digested with used water sludge from wastewater. That will help increase the amount of biogas produced, and in turn the amount of electricity generated.
With all these advantages and pay-offs in the form of power generation, re-using the incinerator ash for making construction materials, and integrating water management with waste to energy, the cost factor becomes less compelling.

What’s more, an incinerator works 24 hours a day, seven days a week and 365 days a year regardless of rain, shine, lightning, thunderstorm or flood which means on a daily basis much of the waste is drastically reduced – 90% with a 10% ash residual.

Already a Malaysian inventor is reported to have devised a smaller incinerator suitable for the management of municipal waste in which it features a solar-powered incinerator that is able to treat the flue gas and at the same time is able to convert the incinerator ash into organic fertilisers by merely adding sawdust. These fertilisers will come in handy for those involved in urban farming.

The incinerator dubbed as “The Asher” is being exported to countries such as China, Indonesia, Philippines, Dubai and Singapore.
Perhaps what is needed is for private-public partnership to build one incinerator in every state in Malaysia which was actually in the pipeline but being opposed by environmentalists for the sake of opposing.

If the cost is so hefty such that we can’t build a big plant to get the economies of scale like what Singapore did, then Malaysia can follow the Japanese model in its adoption of waste to energy when it built a few hundred smaller incineration plants, where each prefecture and municipality has responsibility for its own waste.

But before we follow any one country on this, we have to assess our own unique scenario by looking at our own waste landscape and adapt the model we borrowed to suite our own unique circumstances.

Jamari Mohtar is Director of Media & Communications at EMIR Research, an independent think-tank focused on strategic policy recommendations based upon rigorous research.

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Diterbitkan di Malaysia Now & Astro Awani & Bernama.

Pada 2005, 75% sisa pepejal dikumpulkan sementara bakinya dibuang oleh pihak lain, termasuk melalui pembuangan sampah secara haram. Hampir 95% sampah yang terkumpul kemudian dibawa ke sekitar 120 kemudahan pelupusan sisa pepejal di seluruh Semenanjung.

Menurut kementerian perumahan dan kerajaan tempatan, sekitar RM430 juta (AS$104 juta) telah dibelanjakan untuk menutup hanya 17 dari 165 tempat pembuangan sampah yang ada, dan mempromosikan pembuangan sisa pepejal ke tempat pembuangan sampah.

Sampah perbandaran yang dihasilkan setiap hari telah meningkat dua kali ganda – dari 19,000 tan sehari pada 2005 kepada 38,142 tan sampah sehari pada 2018, menurut Perbadanan Pengurusan Sisa Pepejal dan Pembersihan Awam (SWCorp). Ini bermakna penjanaan sisa pepejal per kapita sekitar 0.8kg seorang sehari pada 2005 berbanding purata 1.17kg seorang sehari pada 2018.

Pada masa ini, tapak pembuangan dan pelupusan sampah merupakan pilihan utama pengurusan sisa pepejal untuk Malaysia, kerana infrastruktur sampah tidak dibangunkan dengan baik. Pihak berkuasa tempatan yang bertanggungjawab untuk pengurusan sisa pepejal mengalihkan pengumpulan dan pelupusan sisa pepejal kepada syarikat swasta.

Namun, kebergantungan pada tapak pembuangan sampah merupakan kaedah kurang mampan kerana tanah lebih diperlukan untuk tujuan lain kerana pembangunan ekonomi yang pesat dalam dua dekad terakhir ini dan tapak pembuangan serta pelupusan sisa pepejal adalah satu sumber pencemaran di mana sisa buangan biodegradasi dan bukan biodegradasi mengeluarkan gas beracun seperti metana ke udara dalam proses penguraian yang memakan masa bertahun-tahun – dari 100 hingga 500 tahun.

Satu lagi unsur pengurusan sisa pepejal yang mampan ialah melalui pelaksanaan konsep ekonomi pekeliling (circular economy) – diguna pakai China sebagai dasar nasional dalam rancangan lima tahun ke-11 bermula pada 2006.

Intipati konsep ekonomi pekeliling didasarkan pada prinsip merancang penghapusan sisa dan pencemaran, memastikan produk dan bahan digunakan seberapa lama mungkin, dan menjana semula sistem semula jadi.

Usaha Singapura menerapkan ekonomi pekeliling berdasarkan strategi serampang tiga mata boleh dicontohi banyak negara – pengurangan sisa; mengitar semula apa yang tidak dapat dikurangkan; dan menjana tenaga melalui pelupusan sisa pepejal dengan menggunakan insinerator untuk mengurangkan jumlah sampah.

Ia disebut penjanaan tenaga dari sisa pepejal (waste-to-energy) kerana haba akibat pembakaran sisa dapat dimanfaatkan untuk menjana tenaga elektrik untuk kegunaan domestik. Singapura membakar lebih dari 2.8 juta tan sampah setahun, meningkat daripada 2.4 juta tan pada tahun 2000.

Perkara berikutnya yang difokuskan oleh Republik itu adalah bagaimana menggunakan kembali abu pembakaran, dan mengubahnya menjadi pasir – yang diungkapkan dengan nama NEWSand – untuk tujuan pembinaan, sehingga menutup gelung sampah yang dianjurkan oleh ekonomi pekeliling.

Sisa abu di bahagian bawah insinerator setelah sisa pepejal dibakar sememangnya toksik tetapi ia berpotensi digunakan setelah dirawat untuk memastikannya sesuai untuk tujuan pembinaan.

Ini dilakukan dengan mengeluarkan lebih 200 tan logam sehari dari abu bawah insinerator. Singapura kini sedang melakukan proses rawatan untuk menjadikan abu itu sesuai dengan piawaian persekitaran untuk aplikasi pembinaan.

Dengan menggunakan kembali abu dasar insinerator itu, permintaan untuk ruang pembuangan sampah dapat dikurangkan dan jangka hayat tapak pembuangan diperpanjang.

Di Malaysia, naratif penggunaan insinerator masih berkisar pada gas toksik yang dikeluarkan ke udara melalui cerobong asap, dan membina insinerator melibatkan pengeluaran modal yang besar. Ini adalah hujah yang ketinggalan zaman.

Terdapat langkah-langkah pengawalan pencemaran yang sangat ketat di loji penjanaan tenaga dari sisa pepejal (WTE) – sepertiga proses pembakaran ditujukan untuk sistem rawatan gas serombong untuk kawalan pencemaran.

Gas serombong itu melalui pemendap elektrostatik untuk menghilangkan 99.7% habuk. Ia kemudian melalui penapis beg katalitik di mana dioksin – bahan pencemar yang sangat toksik yang merupakan karsinogen kuat hasil dari pembakaran bahan plastik – diubah menjadi karbon dioksida dan air.

Oleh itu, pelepasan akhir dari cerobong asap insinerator bersih dan ini adalah piawaian yang digunakan oleh insinerator di Singapura dan negara maju seperti Switzerland dan Jerman.

Singapura juga akan melancarkan loji sisa-ke-tenaga bersepadu yang kelima, yang akan menyepadukan pengurusan air dengan sisa ke tenaga. Membina loji baru ini akan membolehkan loji yang lebih usang dan kurang cekap diganti, lantas mengurangkan jejak karbon yang bermakna jumlah sisa yang sama dapat menghasilkan dua kali ganda jumlah tenaga.

Sisa makanan yang dikumpulkan juga dapat dicerna bersama lumpur air bekas dari air buangan yang dapat membantu meningkatkan jumlah biogas yang dihasilkan, dan seterusnya jumlah penjanaan tenaga elektrik.

Dengan semua kelebihan ini dalam bentuk penjanaan tenaga, menggunakan semula abu insinerator untuk membuat bahan binaan, dan menyepadukan pengurusan air dengan sisa ke tenaga, faktor kos menjadi kurang ketara.

Lebih-lebih lagi, insinerator berfungsi 24 jam sehari, tujuh hari seminggu dan 365 hari setahun tanpa mengira cuaca – panas, hujan, kilat, ribut petir atau banjir – yang bermakna setiap hari banyak sisa sampah dikurangkan secara drastik – 90% dengan 10% baki abu.

Malah, seorang pencipta Malaysia dilaporkan telah mereka cipta insinerator lebih kecil untuk pengurusan sampah perbandaran yang menggunakan tenaga solar serta dapat merawat gas serombong dan pada masa sama, dapat mengubah abu menjadi baja organik dengan hanya menambahkan habuk papan. Baja ini sangat berguna bagi mereka yang terlibat dalam pertanian bandar.

Insinerator yang dikenali dengan nama “The Asher” sedang dieksport ke negara-negara seperti China, Indonesia, Filipina, Dubai dan Singapura.

Mungkin apa yang diperlukan adalah untuk perkongsian swasta-awam membina satu insinerator di setiap negeri di Malaysia yang sebenarnya sedang dalam perancangan tetapi ditentang oleh pencinta alam semata-mata untuk menentang.

Jika harganya sangat besar sehingga kita tidak dapat membina insinerator besar untuk mendapatkan skala ekonomi seperti yang dilakukan Singapura, maka Malaysia dapat mengikuti model Jepun dalam penggunaan sampah menjadi tenaga dengan membina ratusan insinerator yang lebih kecil, di mana setiap wilayah dan perbandaran mempunyai tanggungjawab untuk melupuskan pembazirannya sendiri.

Tetapi sebelum kita mengikuti mana-mana negara, kita harus menilai senario unik kita sendiri dengan melihat landskap sampah kita dan menyesuaikan model yang kita pinjam dengan keadaan khusus di Malaysia.

Jamari Mohtar adalah pengarah, media & komunikasi di EMIR Research, sebuah organisasi pemikir bebas yang berfokuskan kepada pencernaan saranan-saranan dasar strategik berteraskan penyelidikan yang terperinci, konsisten dan menyeluruh.    

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