Stage 01
Collect
Residue is aggregated from farms across the Khandesh belt under long-term procurement arrangements with farmers and farmer producer organisations. Material that is burned in the open today becomes a contracted purchase.
Same wing. Same engine. Different carbon.
Sustainable Aviation Fuel is jet fuel made from non-fossil feedstock. Chemically it belongs to the same class of hydrocarbons as conventional jet fuel, which is the entire point: it is a drop-in fuel. Same tanks, same pipelines, same wing. No aircraft is modified and no airport is rebuilt.
Because the feedstock absorbed carbon while it grew, the lifecycle emissions of a certified pathway can be far lower than fossil jet fuel — figures of up to roughly 80% are commonly cited for the neat fuel, depending on feedstock, process and supply chain.1
Two things make a fuel SAF rather than merely bio-derived. The production pathway must be certified under ASTM D7566, the specification for aviation turbine fuel containing synthesised hydrocarbons. And the feedstock's sustainability and lifecycle emissions must be independently verified — under ICAO's CORSIA framework and schemes such as ISCC CORSIA or RSB.
Under current specification, certified blending components are blended with conventional jet fuel up to defined limits — 50% for most major pathways — and the blend is re-certified to conventional jet fuel specification for use. The near-term industry is a blending industry, which is precisely why supply volume is the constraint.
Residue in. Certified jet fuel out.
The same five stages apply whichever certified pathway is selected. What changes is the intermediate made in stage three.
Stage 02
Prepare
The feed is dried, sized and densified to a fixed specification. This is the unglamorous half of the plant, and the half that decides whether the other half runs.
Stage 03
Convert
Prepared biomass is converted into an energy-dense intermediate — syngas or alcohol — through an internationally certified licensed process.
Stage 04
Synthesise
Catalysis builds the intermediate into liquid hydrocarbon chains, which are then hydroprocessed and fractionated into the jet range.
Stage 05
Certify & lift
The fuel is tested to aviation specification, blended with conventional jet fuel within certified limits, and delivered into the airport supply chain.
Pathways
The certified routes, and where residue fits.
ASTM D7566 certifies pathways individually, each as an annex to the standard. Only some can use lignocellulosic agricultural residue — which narrows the field considerably for a plant built on cane, cotton, soy and pulse waste.
| Pathway | Annex | Typical feedstock | Blend limit | Fit for this project |
|---|---|---|---|---|
| FT-SPKGasification and Fischer-Tropsch synthesis | A1 | Lignocellulosic biomass, agricultural and forestry residue, municipal waste | 50% | Strong — designed for solid residue |
| ATJ-SPKAlcohol-to-jet | A5 | Ethanol or isobutanol, including cellulosic ethanol from residue | 50% | Strong — leverages India's ethanol base |
| FT-SPK/AFischer-Tropsch with aromatics | A4 | As FT-SPK, with aromatic content | 50% | Possible variant of the FT route |
| HEFA-SPKHydroprocessed esters and fatty acids | A2 | Used cooking oil, tallow, vegetable oils | 50% | Not applicable — different feedstock class |
| CHJCatalytic hydrothermolysis | A6 | Fats, oils and greases | 50% | Not applicable |
| HFS-SIPSynthesised iso-paraffins from sugars | A3 | Fermentable sugars | 10% | Blend limit too restrictive |
Annexes and blend limits reflect ASTM D7566 as published at the time of writing; the standard is revised periodically and the current revision governs. Pathway selection for this project will be made with the technology licensor ahead of the final investment decision.2
Feedstock
Residue, not crops.
Everything the plant runs on is already a by-product of food production. No land is converted and no edible crop is diverted, so the indirect land use change debate around first-generation biofuels does not apply in the same way.
Sugarcane bagasse
The fibrous residue left after cane is crushed. Already aggregated at mill gates, which makes it the easiest tonne to buy.
Sugar mill catchment
Cotton stalks
Woody stems left standing after picking, today mostly uprooted and burned to clear the field for the next sowing.
Khandesh cotton belt
Soybean husk
Processing residue from one of Maharashtra's largest oilseed crops, available in volume through the year rather than in one window.
Oilseed processing
Pigeon pea residue
Stalk and pod waste from tur cultivation, collected after the harvest window and stored ahead of the lean season.
Pulse crop residue
The real engineering problem
Aggregation, not conversion
Converting biomass to fuel is well understood. Getting several hundred thousand tonnes of loose, seasonal, low-density material to a plant gate at a stable price and specification is the part that decides whether the asset works. The supply chain is therefore being built alongside the plant, not after it: defined collection catchments, satellite densification and storage yards, contracted transport, and moisture and ash specifications agreed at the point of purchase.
Chain of custody
Sustainability has to be provable
Under CORSIA an airline can only claim emissions reductions for fuel whose sustainability has been verified by an approved scheme, and that verification runs backwards to the field. Procurement is being designed to carry the evidence: origin records for every consignment, mass-balance accounting through storage and processing, and third-party audit. The commercial value of the fuel depends on it.
Questions
Frequently asked.
Is SAF safe in existing aircraft?
Yes. Certified SAF blends meet the same aviation turbine fuel specification as conventional jet fuel and are handled identically. Certification under ASTM D7566 exists to establish that the finished blend is indistinguishable in service.
How much does SAF reduce emissions?
It depends on feedstock, conversion pathway, process energy and transport. Residue-based pathways certified under CORSIA are generally assessed at large lifecycle reductions against fossil jet fuel, with figures of up to roughly 80% commonly cited for the neat fuel. The reduction applies to the SAF portion of the blend, not the whole tank.
Which technology will the Chalisgaon plant use?
Pathway and licensor selection is under evaluation. The project is scoped around routes that process lignocellulosic agricultural residue — principally gasification with Fischer-Tropsch synthesis, and alcohol-to-jet. Selection will be confirmed with the licensor before the final investment decision.
Does using crop residue harm soil health?
Only if too much is removed. Sustainable removal rates leave sufficient organic matter in the field, and procurement volumes are planned against agronomic guidance for each crop and soil type. Certification schemes audit this.
Who buys the fuel?
Airlines and fuel suppliers, under long-term offtake agreements. Demand is underpinned by national blending targets, corporate travel commitments and the CORSIA framework, which lets airlines claim verified emissions reductions against their obligations.
What stage is the project at?
Memorandum of understanding stage with the Government of Maharashtra. Land, approvals, technology selection, feedstock contracting, offtake and financing are in development. Commissioning is planned in phases through 2029.
Licensors and EPC contractors, get in touch.
If you license a certified residue-to-jet pathway, build process plants at this scale, or supply critical equipment, we would like you in the evaluation.
- 1.Lifecycle emissions reduction figures are industry-wide indicative ranges published by bodies such as ICAO and IATA for certified SAF pathways generally. They are not project-specific claims. Project lifecycle emissions will be assessed and independently verified as engineering progresses.
- 2.ASTM D7566 pathway certification, CORSIA eligibility and sustainability certification are design objectives for this project. No certification is held at present.