Crop residue leaves the field to fuel a bio-power boiler. The potassium and the silicon that the crop pulled out of that soil leave with it, and end up concentrated in the fly ash. We collect that ash, measure what is in it, recover the potassium and the silicon, and formulate them back into fertilizer. That is the loop. The potassium half of it is closed: recovered potassium now covers about 20% of the potash VAN puts into its own products, in place of imported material. We have processed 3,000 tonnes of fly ash on the pilot line to get there, and we are building the production line to 500 tonnes of recovered potash from 5,000 tonnes of ash by 2027. The silicon half is finishing R&D.
This route started in 2014, with a question from a bio-fuel producer about
the ash their boilers left behind. The first commercial batch came out in late 2023 —
the ten-year route is set out on the process
page.
The two nutrients are at two different stages, and we print both.
Recovered potassium is already a working raw material inside VAN's own manufacturing, and we are building that
capacity up. Silicon recovery is in its final stage of R&D — proven in our laboratory, not yet running
alongside the potassium line.
Each step below is something VAN does, not something VAN believes. Where the technical detail is not yet cleared for publication it is tagged, not padded.
We take the captured fly ash from boilers fired on agricultural residue. 3,000 tonnes processed to date; 5,000 tonnes a year is the 2027 line. One plant supplies under a long-term contract and four more are at contracting and commercial-terms stage.
We assay K₂O under our PNAC-accredited scope (ISO/IEC 17025:2017, LAB 336). Silicon we measure by an in-house method that sits outside that accredited scope — we say so rather than borrow the accreditation.
We separate the plant-available fraction from the inert ash body — roughly one tonne of potash per ten tonnes of ash. Potassium recovery is in production and scaling; the silicon route is in final-stage R&D. Process route and reagents stay proprietary.
We charge recovered potassium into VAN's own manufacturing as a raw material, in place of imported potash — about 20% of our potash intake today. It goes into the shared potash stream rather than a ring-fenced grade, so it reaches every potash-containing product we make.
It leaves as part of a registered VAN product, applied at a published rate and growth stage — back onto the land the residue was cut from.
Recovered potassium enters VAN products as a raw material, the same way bought-in potash does — it is not sold as a separate registered product, and we make no separate performance claim for it. Silicon recovery is still finishing R&D and is not in any product. Because recovered potassium joins the shared potash stream, we publish the intake share and not a per-grade split — attributing it to one bag rather than another would be an accounting choice, not a measurement.
Pakistan does not mine potash. It arrives by ship, in foreign currency, and its price is set somewhere else. Recovering potassium from ash that is already inside the country changes where our raw material comes from — that is the part of this we can point at, and it is already happening.
We charge recovered potassium into our own formulations in place of bought-in potash. It covers about 20% of VAN's potash intake today, and has replaced more than 1,000 tonnes of imported potash between 2023 and 2026, across several forms and grades.
We are setting up to recover 500 tonnes of potash from 5,000 tonnes of fly ash by 2027 — beyond what our own plant currently consumes.
The ash is generated in Pakistan and the nutrient goes back onto Pakistani fields, without a shipping leg in between.
Burning residue for energy releases the carbon and the nitrogen. It does not destroy potassium or silicon — those are mineral, and they stay behind in the ash. That is the fraction we go after.
We do not claim to close the carbon loop. Combustion takes the carbon; we recover the minerals. Saying otherwise would be a claim we cannot test.
We hold ourselves to one editorial rule across every page: a sentence about soil or sustainability must name an action we take, the mechanism it works through, and the evidence behind it. If we cannot supply all three, we do not write the sentence.
The process itself, step by step — what enters, what we do to it, what leaves, and which numbers are still pending.
Read the process →Every soil intervention VAN makes, listed with its mechanism and its evidence status. No entry without both.
Open the register →The formulation capability that turns a recovered nutrient into a granule that survives a bag, a truck and an alkaline soil.
See the capability →Send us a sample. We will assay it in our own accredited laboratory and tell you what is recoverable from it and what is not — including when the answer is nothing. We are scaling the potassium line and taking on feedstock.
