The fine01
₹4,43,355
Per month · Automatic
- Formula
- EC = PI × N × R × S × LF
- Issued by
- CPCB environmental compensation
- Statute
- Section 31A, Air Act 1981
- Outcome
- Consent revoked · gates closed
IThe Atmosphere
Mining the sky·Fueling the earth
Jaipur · Site 01
Stack reading 1,849 mg/Nm³
Status Exceedance
IIQuestion the Assumption
The atmosphere is the largest untapped mine on Earth.
A coal or biomass boiler does not emit waste. It emits sulfur, at concentration, on a schedule, for free. India already imports the same sulfur back as fertilizer. The stack is not a problem to be sealed. It is a seam to be worked.
IIIThe Regulatory Pincer
Between them
A boiler under pressure
Fined if it runs · Broke if it complies
The fix that isn’t02
₹1.5 Cr
Limestone scrubber · Upfront
- Water
- 3,27,000 L consumed every day
- Sludge
- 240 MT of gypsum to landfill daily
- Return
- Nil. A cost centre, permanently
- Verdict
- Pays to move the problem
IVThe Chemistry
SO2+2KOHK2SO3+SK2S2O3
Poison enters. Value leaves.
Potassium thiosulfate · A sulfur and potassium fertilizer
IN
SO2
Sulfur dioxide, straight from the flue. The pollutant every consent order is written about.
ADD
KOH + S
Potassium hydroxide to capture it. Elemental sulfur to finish it.
OUT
K2S2O3
Potassium thiosulfate: a liquid fertilizer that carries sulfur and potassium to the crop.
By stoichiometry, every kilogram of SO2 captured becomes roughly 2.97 kg of potassium thiosulfate.
VThe Unit
Retrofit · between boiler and stack
It bolts to the duct, not the balance sheet.
Airthra is a modular capture-and-conversion unit for the small and mid-scale boilers that a crore-and-a-half scrubber was never sized for. Flue gas goes in carrying sulfur. It leaves the stack within consent, and the sulfur leaves the gate as product.
In
Boiler flue
SO2 at 1,840 mg/Nm³, arriving on the boiler’s own schedule.
01 · Condition
Cool & clean
The gas is quenched and de-dusted, so the chemistry only ever sees gas.
02 · Capture
Alkaline wash
A potassium hydroxide scrub pulls SO2 out of the gas and into solution.
SO2 + 2KOHK2SO3 + H2O
03 · Convert
Sulfur dosing
Elemental sulfur turns the sulfite liquor into thiosulfate.
K2SO3 + SK2S2O3
04 · Recover
Concentrate
The liquor is brought up to fertilizer grade and pumped to storage.
Out
Stack42 mg/Nm³ · within consent
TankK2S2O3 · sold, not landfilled
- Form
- Modular, skid-mounted
- Fit
- Retrofits between boiler and stack
- Water
- Closed loop · no daily make-up
- Solid waste
- None · no gypsum, no sludge
- Output
- Liquid potassium thiosulfate
- Telemetry
- Stack SO2 and yield, logged live
VIWho Pays
The ledger
Who pays for the unit? The sulfur does.
A scrubber turns a compliance problem into a capital problem and a landfill problem. Airthra turns it into an offtake. The plant gets a stack that stays within consent; the sulfur that would have been fined in the air, or buried as gypsum, leaves the gate as fertilizer and pays for the unit that caught it.
Limestone scrubberAirthra
Upfront₹1.5 Cr₹0Capital expenditure
Water3,27,000 L consumed every dayClosed loop · no daily make-up
Solid waste240 MT of gypsum to landfill dailyNone produced
Leaves the gateSludge, on the plant’s accountPotassium thiosulfate, sold
ReturnNil. A cost centre, permanentlyRevenue on every tonne of sulfur
VerdictPays to move the problemThe problem pays for itself
VIIStack to Soil
From stack to soil.
Sulfur leaves a boiler as a pollutant and reaches a farm as an import. Airthra closes the distance between the two: the same element, caught at the chimney and returned to the field.
01
Stack
SO2 leaves the boiler at concentration, on a schedule.
02
Unit
Captured and converted on site, at the duct.
03
Tank
Potassium thiosulfate, held at fertilizer grade.
04
Offtake
Dispatched from the gate into the fertilizer channel.
05
Field
Sulfur and potassium, back where the crop needs them.
Built for the boilers nobody builds for.
Coal- and biomass-fired · small and mid-scale · under consent pressure
- Textile processing
- Food & agro-processing
- Paper & board
- Chemicals
- Pharmaceuticals
- Rice mills
- Dairy
- Captive steam
VIIIThe Discovery
Compliance, without capital expenditure
Airthra was not invented. It was discovered.
The way a seam is discovered rather than designed. The sulfur was always there, at grade, arriving free, on a schedule no mine could match. What was missing was someone willing to treat a stack as a deposit.
Stack SO242mg/Nm³within consent
KTS yield38.0kg/hon spec
Water make-up0Lclosed loop
Gypsum to landfill0MTnone produced
Consent statuscompliantday 214
Offtake dispatched1.9 MTKTS 40%
IXThe Founder
The builder behind the seam
Founder · Airthra
Abhik Choudhary.
“Make sustainability convenient — practical enough, affordable enough, and accessible enough that industries adopt it not out of obligation, but because it simply makes sense.”The long-term mission
Abhik is a founder and researcher. Airthra is his first step toward that mission: a modular flue-gas capture and conversion system that turns SOx and NOx emissions into usable industrial chemicals, giving small and mid-scale operators an alternative to expensive scrubbing systems. Instead of treating emissions as waste, Airthra turns them into resources.
Beyond clean-tech engineering, he works across AI, systems design and computational creativity, with trading algorithms, ML-powered creative tools, hackathon-winning prototypes and full-stack projects behind him.
In climate governance, he contributes to the UNFCCC and has volunteered alongside UNDP on SDG outreach and youth inclusion. In Jaipur he is a guest speaker, mentoring students on innovation, sustainability and international relations, bridging STEM with global policy.
On record05
- Airthra
- Builder & founderSep 2025 — present · “I make stuff.”
- UNFCCC
- Contributing expert, SB64 Policy PositionTechnology & Innovation · 2026
- UN Climate Change
- Contributing EditorPart-time
- UNDP
- VolunteerSDG outreach & youth inclusion
- Jaipur
- Guest speaker & mentorInnovation · sustainability · international relations
Technology becomes transformative only when it’s usable.
— What drives the work
- Clean-tech engineering
- Artificial intelligence
- Systems design
- Computational creativity
- Climate policy
Building in clean-tech, AI, policy innovation or youth-led impact? Let’s connect.
abhik.airthra.com