Circular and Waste Economics
By: Prof. Bambang PS Brodjonegoro, Ph.D., Professor of FEB UI
Waste is the result of a “take make dispose” linear economy, where materials are taken from nature, processed, and used in human life.
KOMPAS – (13/9/2021)
However, sometimes this use is only for a short time. And then it ends up being trash. In a circular economy, the waste generated from every economic activity will always return to the feedback loop to become raw materials or energy. The circular economy does not contradict economic growth, it actually brings opportunities for Indonesia to become a developed country before the 100th anniversary of its independence.
In order to get out of the middle-income trap before 2045, the Indonesian economy needs to grow at least 6 percent per year. Of course, this requires a lot of raw materials and energy resources. Bappenas estimates that in 2019 we will produce 117.6 million tons of waste to achieve 5.02 percent economic growth. If based on the Business as Usual (BaU) scenario, the volume of waste generated will increase 56 percent to 184.7 million tons in 2030.
Of course we don’t want a trade-off between being a developed country and piles of garbage in big cities. For the record, the Bantargebang Integrated Waste Management Site (TPST), which receives 7,500 tons of waste per day from DKI Jakarta is expected to be full by 2021.
Then, what can we do? Is it enough to implement the 3R principle (reduce, reuse, recycle)? The 5R principle emerged by adding two stages, becoming refuse, reduce, reuse, recycle, and recovery. Refuse to prevent waste from entering our economic activities, for example by refusing to use plastic bags. The 5R principle must follow a hierarchy of stages. This means that we must attempt to recycle before carrying out the recovery phase of energy and materials from waste.
Waste management in a circular economy
Urban waste in Indonesia is heterogeneous because the segregation of waste types upstream is still very limited. Therefore, before ending up in a landfill, waste should go through a mechanical biological treatment (MBT) process to sort out which waste can be recycled (recyclable), degraded (degradable), and burned (combustible). The degradable fraction in municipal waste is generally dominated by household food scraps, restaurants, supermarkets, and others. This type of waste has a high water and chlorine content, with a low calorific value. On average, urban waste that arrives at the TPA is dominated by this fraction, 40-60 percent.
If only left to build up in the landfill, the degradation process of food waste will release biogas containing methane and carbon dioxide gas during the decomposition process. The US Environmental Protection Agency study shows that per one ton of food waste will produce greenhouse gas emissions of about 595 kg CO2 equivalent. This is equivalent to the emissions of driving a petrol car for 3,000 km. Or the equivalent of household electricity consumption of 700 kWh.
This is where the recovery stage is important. For the degradable fraction, biological processes such as anaerobic digestion can accelerate the decomposition process so that the biogas produced is richer in methane, so that it can be converted into electricity, heat, CNG, or even hydrogen. Other biological processes such as composting can convert biomass into liquid or solid compost to fertilize the soil.
The recyclable fraction is usually plastic (PET, HDPE, PP, LDPE), aluminum, and iron. However, recycling technology has limitations and requires input of high quality materials with low levels of contaminants. This is why the percentage of plastic waste that is recycled, even in developed countries like the US, is still very low, only 9 percent of the total plastic waste produced. The recycling process also reduces the quality of the polymer bonds in the plastic so that plastic can only be recycled 2-3 times before ending up in the landfill.
Then what can be done for waste that does not meet the recycling criteria or has reached its maximum use so that it does not end up in the landfill?
MBT technology sorts out the combustible fraction from waste and processes it into a material that is more homogeneous and easier to burn (refuse derived fuel/RDF). RDF can then be used as an alternative fuel (co-firing) in cement kilns and coal-fired power plants, or as the main fuel for RDF power plants.
In co-firing combustion, both in the kiln and in coal-fired power plants, the fraction of waste that has been processed into RDF or solid fuel (BBJP) is burned together with coal so that it is expected to reduce greenhouse emissions. In Cilacap, 120 tons of municipal waste every day has been processed into 40-60 tons of RDF, which is used as an alternative fuel for coal in the cement kiln owned by PT Solusi Bangun Indonesia.
The trial for RDF co-firing at coal-fired power plants has been carried out by PLN in several power plants. Unfortunately, if the raw material for RDF is from municipal waste, it needs more complicated processing to meet the BBJP quality standards. This is because the organic material from the degradable fraction of municipal waste has properties far from coal.
Another option is the direct destruction of municipal waste with thermal technology. If what is destroyed is mixed waste, the thermal technology is called an incinerator, and if what is destroyed is RDF, this technology is called RDF Power Plant. Despite many concerns that thermal-based technologies produce hazardous exhausts, such as SOx, NOx, dioxins, furans, lead or mercury, with the implementation of proper air emission control systems, these exhaust gases can be controlled.
Switzerland, Denmark, Germany, Luxembourg and Singapore rely on thermal technology to recover energy from non-recyclable waste.
Processing of waste into electrical energy (PSEL)
Germany, as the world’s recycling champion, recycles 65 percent of its waste. Does the rest end up in landfill? Apparently not. Landfill avoidances rate in Germany reaches 99.12 percent or only 0.88 percent of waste ends up in landfill. The key is to destroy waste massively through thermal technology so that the remaining ash is minimal.
The development of thermal technology has also made the emissions produced more environmentally friendly. Dioxin formation can be prevented by designing the combustion chamber to obtain complete combustion conditions at high temperatures and turbulence. As a final step, to minimize the risk of dioxin release that may be regenerated due to the cooling process, exhaust gases are neutralized by injection of activated carbon and other substances before being filtered through other gas cleaning processes such as catalytic converters and wet/dry scrubbers. This lengthy process of cleaning the exhaust gases ensures that the emissions from the incinerators do not exceed the required quality standards, making them acceptable in countries with high environmental demands, such as Switzerland, Denmark and Luxembourg.
Another thermal technology is gasification. During the gasification process, the waste is heated with a minimal amount of air so that its chemical structure is degraded. This chemical degradation process produces synthetic gas (syngas), which has low temperature and pressure. This syngas contains energy-rich hydrogen and hydrocarbons and can be used to generate electricity via steam turbines, ICE (internal combustion engines), or gas turbines.
Gasification power plants have higher electricity conversion efficiency and lower emissions than incineration. Syngas can also be further processed into biofuels, such as methanol, ethanol, fuel, and hydrogen.
In waste applications, gasification technology is an emerging waste processing technology, promising in the future, and requires final refinement. Currently, gasification has been implemented in PSEL Surabaya and PSEL in Solo.
PSEL’s main challenge is that investment costs are still expensive. Through Presidential Decree No. 35/2018, the government is trying to provide incentives for PSEL projects to be able to sell their electricity more expensively than other power plants. However, incentives in terms of electricity generation alone are uncertain and inadequate for PSEL. This is because the quality of waste is far from the quality of coal, so the electricity produced will also follow that quality.
The main function of PSEL is the destruction of waste as part of the local government’s obligation to carry out waste management (Law No. 23/2014 on Local Government, Law No. 18/2008 on Waste Processing, and Presidential Regulation No.97/2017 on National Strategic Policy in the Waste Sector).
In 2019, the DKI Provincial Government issued a budget of around IDR 1.2 trillion for the management of the Bantar Gebang TPST and various compensations given to the Bekasi City Government or IDR 440,000 per ton of waste. This figure excludes the cost of mobilizing waste from Jakarta to the Bantar Gebang TPST as well as the rehabilitation and maintenance costs that the DKI Provincial Government must pay for 30 years after the TPA is no longer used.
This figure also does not include all the external costs of negative impacts due to piles of waste, such as the economic impact due to groundwater pollution, greenhouse gas emissions, health damage due to dioxins if the landfill is burned (as happened in 2015 for days), and the decline in the economic value of land around the landfill.
Unfortunately, of the 12 cities mentioned in the Presidential Regulation for the acceleration of PSEL, only PSEL Benowo in Surabaya has successfully started operations. This PSEL processes 1,000 tons of municipal waste every day with the gasification method to generate 9 MW of electricity. The return on investment is obtained from the sale of electricity to PLN at a price of 13.5 US cents/kWh and a waste management service fee (BLPS) from the Surabaya City Government of Rp. 170,000/ton.
From these figures, it can be calculated that the cost to destroy waste in PSEL Benowo is equivalent to Rp. 520,000/ton of waste.
This is not much different from the cost of the DKI Provincial Government to organize its waste at the Bantargebang TPST. However, the waste that ends up in PSEL Benowo does not add to the pile of garbage, thereby reducing the long-term liabilities faced by the Surabaya City Government due to external factors.
Whose responsibility is Garbage
The problem of waste is not only the responsibility of the government. Collaboration of all parties is needed so that waste is not treated outside the circular economy concept. Efforts to accelerate it can be done through, first, intensifying waste sorting from upstream to increase the efficiency of the amount of waste that is recycled and reduce the chance of contamination.
Second, the application of the polluter pays principle. If you look at the data on waste management costs in Jakarta and Surabaya, a minimum processing fee of Rp 440-Rp 520/kg of waste is required.
Third, the government needs to encourage the integration of funding for PSEL projects. Assistance by the central government is currently through the BLPS non-physical special allocation fund. Private sector involvement is encouraged through a government-business partnership (PPP) scheme. With a PPP, the central government can provide support for project preparation through the project development facility. Fiscal support can also be provided through a viability gap fund so that the project can be financially viable so as to attract the involvement of investor business entities.
Source: Kompas Daily. Edition: Monday, August 13, 2021. Rubrik Opini. Page 6.
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