Disposable diapers solve one problem by creating another.
They keep babies dry and make daily care more manageable, but after use they become a difficult mixture of plastic films, absorbent polymers, pulp, adhesives and human waste.
They are wet, contaminated and difficult to separate. Most are buried in landfill, burned with municipal rubbish or discarded into the wider environment.
In Indonesia, Merries and its parent company, Kao Corporation, are testing a different destination.
Through the Merries Senyumkan Lingkungan programme, Kao Indonesia partnered with Kertabumi Recycling Center to collect used baby diapers and process them through pyrolysis, a thermal-treatment system capable of converting parts of the waste into fuel oil.
The December 2025 initiative is not yet evidence that Indonesia has solved diaper waste at industrial scale.
But it represents something unusual:
A major diaper brand is helping build the collection system, community participation and processing technology needed to turn its own post-consumer waste into an energy product.
This is one signal from the Consensys Innovation Signals Engine, which continuously scans a library of more than one million products worldwide for emerging shifts in formulation, positioning and consumer demand.
Signal: Brand-Led Diaper Waste-to-Fuel Pilot
The programme began before the pyrolysis launch
Merries Senyumkan Lingkungan, which translates approximately as "Make the Environment Smile," predates the 2025 Kertabumi partnership.
In an earlier Indonesian programme, Kao worked with local government, community health centres and mothers to collect used diapers for recycling.
Campaign reports state that the initiative involved:
- Approximately 1,400 mothers
- 28 community health centres
- More than seven tonnes of collected diapers
The earlier processing system separated useful outputs from the waste. Oil was used to help power the recycling machinery, while recovered fibre was turned into products such as construction blocks and plant pots.
Brand: Merries
Manufacturer: Kao Indonesia
Programme: Merries Senyumkan Lingkungan
Original Model: Community collection plus material and energy recovery
This earlier phase demonstrated that the largest challenge was not only processing technology.
It was persuading households to separate, store and return a waste product normally thrown directly into mixed rubbish.
The 2025 programme introduced a pyrolysis machine
On December 2, 2025, Kao Indonesia and Kertabumi Recycling Center launched a pilot initiative centred on pyrolysis technology.
The programme included the symbolic handover of equipment and community education intended to establish an ecosystem for collecting and processing used diapers into fuel oil.
Kao described local communities around Pondok Kacang Barat, South Tangerang, as the initial focus of implementation.
Innovation Type: Pyrolysis-Based Waste Recovery
Waste Input: Used disposable baby diapers
Primary Output: Fuel oil
Programme Status: Community pilot
Location: South Tangerang, Indonesia
The important word is pilot.
Kao's announcement did not disclose a sustained monthly processing volume, annual fuel output or independently audited emissions result. It described the project as an initial step toward creating a wider collection and treatment system.
How pyrolysis turns diapers into fuel
Pyrolysis heats material in an environment with little or no oxygen.
Rather than burning the waste directly, the process thermally decomposes carbon-containing materials into outputs that may include:
- Liquid oil
- Gas
- Carbon-rich solid material
- Residual ash or contaminants
Disposable diapers contain petroleum-derived plastics that can contribute to liquid and gaseous fuel outputs. Their pulp and organic components can contribute to solid carbonaceous material.
Laboratory studies have shown that soiled diaper waste can be converted into pyrolysis oil and char. A 2019 study concluded that microwave pyrolysis had potential to transform used diapers into liquid oil and carbon products, while other experimental work has tested diaper-derived oil as an alternative fuel.
Technology Mechanism: Thermal Decomposition
The process can substantially reduce waste volume, but it is not automatically environmentally beneficial.
Its performance depends on:
- Energy required to dry wet diapers
- Operating temperature
- Emissions controls
- Fuel quality
- Treatment of human waste
- Handling of residual solids
- Whether the recovered fuel replaces fossil fuel
- Transportation required for collection
- Evidence Signal: Technically Feasible; Environmental Outcome Depends on System Design
- Used diapers are particularly difficult fuel inputs
Freshly used diapers contain large amounts of moisture.
Water does not provide useful energy during pyrolysis. It must first be removed or heated, which can increase energy consumption and reduce process efficiency.
The waste can also contain:
- Faecal matter
- Urine
- Pathogens
- Wipes or other foreign materials
- Superabsorbent polymer
- Fragrances and lotions
- Mixed plastics
A successful system therefore requires more than a reactor.
It needs:
- Separate household collection
- Safe storage
- Transportation
- Sterilisation or controlled thermal treatment
- Moisture management
- Emissions control
- A reliable buyer or use for the recovered fuel
This is why used-diaper recycling remains uncommon despite the enormous volume of waste available.
Innovation Barrier: Collection and Decontamination Infrastructure
The Indonesian model begins with mothers and communities
Kao's earlier campaign used community health centres as collection and education points.
That is strategically important in Indonesia, where waste infrastructure varies significantly between regions and much household rubbish is not separated by material.
The brand is using existing maternal and child-health relationships to build a reverse supply chain:
Parent → Community Collection Point → Recycling Partner → Processing Facility
This makes the programme as much a behaviour-change innovation as a recycling technology.
Parents must be told:
- Which diapers are accepted
- How they should be cleaned or prepared, if required
- How they should be packaged
- Where they should be delivered
- Why separation is worthwhile
- Innovation Type: Community Reverse Logistics
The product leaves the factory through retail distribution.
The sustainability programme attempts to create a second system that brings it back after use.
Indonesia is not the only country turning diapers into fuel
The original the original finding describes Indonesia as the only place on Earth with a real diaper-to-fuel programme.
That claim is incorrect.
Japan has tested and operated several diaper energy-recovery systems.
Kao's Japanese carbonisation system
Kao has been developing equipment that converts used diapers into a sterile, deodorised, semi-carbonised material.
A unit installed at a childcare facility in Saijo, Ehime Prefecture, reduced diaper-waste volume by approximately 95%. Kao reported that the resulting material had sufficient calorific value to be used as an alternative to fossil fuel.
A later system in Kamikatsu was designed to process 50 kilograms per batch and support broader community testing.
Zuiko's diaper-to-fuel pellets
Japanese machinery company Zuiko developed a system that shreds, dries and sterilises used diapers before converting them into refuse-paper-and-plastic fuel pellets.
Japan's circular-economy platform presents the system explicitly as a method for using discarded diapers as fuel.
Other recycling routes
Japanese companies have also developed systems that wash and separate used diapers into recovered plastic and pulp rather than fuel. Kurita Water Industries, for example, operates a separation and treatment technology for sterilising, washing and sorting diaper materials.
The defensible the original finding is therefore:
Indonesia is an unusually visible example of a diaper brand sponsoring a community diaper-to-fuel pilot—not the only country processing diapers into energy.
What makes Indonesia's programme distinctive
Japan's projects are frequently driven by municipal waste concerns, care facilities, ageing populations and specialist machinery companies.
The Indonesian programme has a different structure.
It connects:
- A consumer diaper brand
- Mothers and families
- Community health centres
- Local government
- Waste banks
- A specialist recycling organisation
- Brand-led environmental education
The programme therefore treats post-use disposal as part of the consumer relationship.
Merries is not only selling diapers and leaving municipalities to manage the waste.
It is placing the brand inside the recovery process.
Innovation Type: Extended Brand Responsibility
This is not the same as legally mandated extended producer responsibility, but it moves in that direction commercially.
The scale remains small relative to the waste problem
The earlier collection of more than seven tonnes is meaningful for a community programme.
It is tiny compared with the amount of disposable diaper waste generated across Indonesia.
Kao's December 2025 announcement did not disclose:
- Daily machine capacity
- Total diaper volume processed
- Litres of fuel produced
- Net energy output
- Cost per tonne
- Greenhouse-gas savings
- Percentage of Merries products recovered
- Plans for additional processing sites
Without these figures, the programme cannot yet be described as a commercially proven circular system.
Evidence Gap: Throughput and Life-Cycle Data
The next phase needs to show whether the process can move from symbolic collection events to reliable continuous operation.
Converting plastic into fuel is not the same as recycling it
The word recycling can obscure an important distinction.
If used diaper plastics are converted into fuel and later burned, the material does not return to another diaper or plastic product.
It becomes energy and ultimately releases much of its carbon.
This is better classified as:
- Chemical conversion
- Waste-to-fuel
- Energy recovery
- Feedstock recovery
It is not closed-loop material recycling.
A genuinely circular diaper system would recover pulp, plastics or absorbent materials and use them to manufacture new products—ideally new hygiene products.
Risk Signal: Circularity Overstatement
Waste-to-fuel may still be preferable to uncontrolled dumping or inefficient disposal, particularly if it reduces landfill volume and displaces some fossil fuel.
But brands should not describe every waste-to-energy process as full circularity.
A new European project is pursuing diaper-to-plastic recycling
The technology landscape continues to evolve.
In May 2026, Borouge International, BlueAlp and reusable-diaper service company Woosh announced work to convert used disposable baby diapers into pyrolysis oil that could serve as feedstock for new plastics.
That model differs from producing fuel for combustion. Its ambition is to return diaper-derived carbon to plastic manufacturing.
Innovation Type: Chemical Feedstock Recycling
This could offer a more circular route if the system proves that the recovered oil can reliably replace virgin fossil feedstock and if the collection process is economically viable.
The economics are likely to decide the outcome
Used diapers have little inherent market value.
They are expensive to collect because they are bulky, wet and distributed across millions of households.
For the Indonesian model to scale, someone must pay for:
- Collection containers
- Community education
- Transportation
- Labour
- Processing energy
- Equipment maintenance
- Emissions control
- Residual-waste disposal
Potential revenue can come from:
- Fuel sales
- Material recovery
- Municipal waste-management fees
- Producer funding
- Carbon savings
- Brand marketing value
At pilot scale, Kao can support the programme as part of its sustainability strategy.
At national scale, the economics must work without depending entirely on promotional funding.
Commercial Risk: High Reverse-Logistics Cost
The technology also creates a trust question
Parents are being asked to store and return a contaminated hygiene product.
The programme must demonstrate that collection does not create:
- Odour
- Leakage
- Insect attraction
- Pathogen exposure
- Unsafe handling for workers
- Contamination of other recyclable waste
The most successful system may require purpose-designed disposal bags or sealed community bins.
This creates a new innovation territory beyond the diaper itself:
Post-Use Hygiene Packaging
A diaper brand could eventually sell or provide an integrated system containing:
- The diaper
- A sealed disposal sleeve
- A collection subscription
- A return point
- Verified processing data
The product would become a service rather than a disposable object.
The real breakthrough would be measurable continuity
The Merries programme is easy to photograph:
Mothers return diapers. A machine is handed over. Fuel is produced.
The harder achievement is building a system that works every day.
the original should track:
- Tonnes processed per month
- Participation rates
- Fuel yield per tonne
- Machine downtime
- Collection costs
- Energy consumed
- Emissions produced
- End use of the recovered fuel
- Expansion into other Indonesian cities
- Inclusion of competing diaper brands
If the system accepts only Merries diapers, its waste impact may remain limited.
If it becomes brand-neutral and municipal, its environmental value could become much larger.
Indonesia is building an important pilot—not claiming the global first
The most compelling part of the story does not need an inaccurate world-first claim.
Indonesia is demonstrating that diaper-waste innovation does not have to begin in a wealthy European market.
A Japanese consumer-goods company, an Indonesian recycling organisation and local communities are attempting to build a recovery system around a product that usually has no route back.
The programme is still early.
Its scale and environmental performance remain unproven publicly.
But its strategic importance is real.
Merries is treating the used diaper not as the end of the consumer relationship, but as the beginning of another product system.
The fuel is only one output.
The more important innovation behind Kao's Merries pilot is the infrastructure required to get the diaper there.
Brand Radar Signal Tags
Brands and Organisations
MerriesKao CorporationPT Kao IndonesiaKertabumi Recycling CenterZuiko CorporationKurita Water IndustriesBorouge InternationalBlueAlpWoosh
Programmes and Technologies
Merries Senyumkan LingkunganUsed-Diaper PyrolysisDiaper Carbonisation SystemRefuse-Paper-and-Plastic Fuel PelletsPyrolysis OilSemi-Carbonised Diaper MaterialUsed-Diaper Separation and Treatment System
Innovation Types
Brand-Led Diaper Waste RecoveryWaste-to-FuelPyrolysisCommunity Reverse LogisticsExtended Brand ResponsibilityWaste-Bank PartnershipPost-Use Product SystemChemical Feedstock RecyclingMaterial and Energy RecoveryBehaviour-Change Innovation
Outputs and Benefits
Fuel OilAlternative Fossil FuelWaste-Volume ReductionRecovered FibreConstruction BlocksPlant PotsCarbon-Rich PelletsRecovered Plastic Feedstock
Community and Channel Signals
Mothers as Collection PartnersCommunity Health CentresWaste BanksLocal Government PartnershipHousehold Waste SeparationCommunity EducationBrand-Funded Collection
Sustainability Signals
Used-Diaper DiversionLandfill ReductionEnergy RecoveryWaste-to-ValueReverse Supply ChainCircularity AmbitionAlternative Fuel ProductionLocal Processing
Evidence and Risk Signals
Pilot-Scale ProgrammeThroughput Not Publicly DisclosedFuel Yield Not Publicly DisclosedLife-Cycle Assessment GapHigh Moisture ContentCollection Hygiene RiskReverse-Logistics CostCircularity OverstatementEnergy-Intensive DryingEmissions-Control RequirementNot a Verified Global First
Geography
IndonesiaSouth TangerangWest JakartaJapanSaijoKamikatsuEurope
Sources
Comparative international sources
Kao Japan — Carbonisation-system verification: Reports 95% volume reduction in Saijo and development of 30-kilogram and 50-kilogram batch systems. https://www.kao.com/global/en/newsroom/news/release/2025/20251023-001/
Japan Platform for a Circular Economy — Used Diaper Recycling Project: Documents a Japanese system producing fuel pellets from used diapers.
Zuiko — Used diapers as an energy source: Describes sterilised RPF pellets produced for boiler fuel.
Kurita Water Industries — Used-diaper separation: Describes sterilisation and recovery of diaper plastics and pulp.
Packaging Europe — Borouge, BlueAlp and Woosh: Reports a 2026 project converting used diapers into pyrolysis oil for new plastic production.
Technical research
Bioresource Technology — Microwave pyrolysis of used baby diapers: Found potential to convert diaper waste into liquid oil and char products.
Experimental diaper-to-liquid-fuel research: A small-scale study pyrolysed soiled diapers at 500°C and assessed the resulting oil as an alternative fuel.