DME Technology: How fuel developed in India may help reduce LPG dependence
The West Asia crisis has revived attention on Dimethyl Ether (DME) — an indigenous alternative cooking fuel developed by CSIR-National Chemical Laboratory (CSIR-NCL) in Pune after two decades of research.
CSIR-NCL has scaled up its pilot plant for DME production to approximately 250 kg per day and is planning a demonstration plant of 2.5 tonnes per day within the next six to nine months in collaboration with Engineers India Limited (EIL).
DME can be blended with LPG without any modification to existing cylinders, regulators, or burners — the Bureau of Indian Standards (BIS) has issued IS 18698:2024 allowing blends of up to 20% DME with LPG for domestic, commercial, and industrial use.
Scientists estimate that substituting just 8% of India's LPG consumption with DME could generate annual foreign exchange savings of approximately ₹9,500 crore.
DME burns cleaner than LPG — with negligible sulphur and nitrogen oxide (NOx) emissions — and can be produced from domestic feedstocks including coal, biomass, natural gas, and methanol.
Dimethyl Ether (DME): Chemistry and Properties
Dimethyl Ether (CH₃OCH₃) is the simplest ether compound. At room temperature it is a colourless gas with a slight ethereal odour, liquefying under modest pressure (around 5 atmospheres at 25°C) — behaviour very similar to LPG. This physical similarity makes it a natural blending candidate for existing LPG infrastructure. DME has a calorific value slightly lower than LPG (~28.9 MJ/kg vs ~46 MJ/kg) but compensates through cleaner combustion — it contains no carbon-carbon bonds, virtually eliminating particulate and soot formation.
Key Details
- Chemical formula: CH₃OCH₃ (simplest ether)
- Boiling point: −24°C (close to propane at −42°C, enabling similar storage)
- Calorific value: ~28.9 MJ/kg (vs LPG ~46 MJ/kg)
- Burns completely without soot; negligible SOx, reduced NOx
- Can be produced from methanol (via dehydration), syngas, coal, biomass, or natural gas
DME's chemical properties make it a drop-in blend with LPG infrastructure — a critical advantage that lowers the transition cost for India's 300+ million LPG-using households.
CSIR-NCL and India's Technology Development Ecosystem
The Council of Scientific and Industrial Research (CSIR) is India's largest publicly funded R&D organisation, operating 37 constituent laboratories across the country. CSIR-NCL (National Chemical Laboratory) in Pune specialises in chemical sciences and has developed the DME production technology using a proprietary catalyst — now patent-protected — that dehydrates methanol into DME. CSIR-NCL signed an MoU with Engineers India Limited (EIL), a Navratna PSU under the Ministry of Petroleum and Natural Gas, to commercialise the technology.
Key Details
- CSIR was established in 1942 and operates under India's Ministry of Science & Technology
- CSIR-NCL Pune is a premier research institute focused on chemical science, biochemistry, and materials
- Engineers India Limited (EIL) is a Navratna CPSE providing engineering and consultancy services to the hydrocarbon sector
- The CSIR-NCL DME catalyst is patent-protected — a key IP asset for indigenous commercialisation
The CSIR-NCL / EIL collaboration represents the "lab-to-market" pathway India needs to convert laboratory-scale DME technology into industrial-scale domestic production within 2–3 years.
Bureau of Indian Standards (BIS) and the IS 18698:2024 Standard
BIS is India's national standards body under the Ministry of Consumer Affairs, Food and Public Distribution. Its role in energy transition is critical: new fuels and blends require BIS certification before commercial use. The issuance of IS 18698:2024, permitting up to 20% DME blending with LPG for domestic, commercial, and industrial use, is a regulatory green light that precedes commercialisation. Without this standard, DME blends cannot be legally sold in the Indian market.
Key Details
- BIS was established under the Bureau of Indian Standards Act, 1986 (revised 2016)
- IS 18698:2024 permits up to 20% DME-LPG blends — current safe blending (no infra change needed) is up to 8%
- The standard covers domestic cylinders, commercial LPG, and industrial applications
- Regulatory clearance is the first step; commercial supply infrastructure must follow
The BIS standard is already in place — removing one of the key bottlenecks for DME commercialisation. The CSIR-NCL scale-up and the West Asia crisis provide both the technology and the urgency for faster deployment.
- Substituting 8% of LPG with DME could save ~₹9,500 crore in annual forex
- CSIR-NCL pilot plant: 250 kg/day DME; target demonstration plant: 2.5 tonnes/day
- BIS standard IS 18698:2024 allows up to 20% DME blending with LPG
- Up to 8% DME blending requires zero infrastructure modifications
- DME can be produced from methanol, coal, biomass, natural gas — all available domestically
- India imports ~85% of its LPG requirement (~10–12 million tonnes/year)
- CSIR-NCL partnered with Engineers India Limited (EIL) for commercialisation
- CSIR operates 37 laboratories; NCL Pune is a premier chemical research institute