Contaminated Absorbent & Oily Waste Incinerators

Contaminated absorbent waste is the material used to capture a spill and everything that gets soaked in the process: granular absorbent, pads and booms, rag, disposable PPE, oil filters, drip trays and the packaging around them. On a defence site it comes from vehicle lines, generator installations, fuel points and aviation maintenance, and it arrives unpredictably — a large spill produces in an afternoon what routine maintenance produces in a quarter. It is classified hazardous once it holds fuel or oil, which is what makes it awkward. Storage has a fire-loading limit and a duration limit, movement needs a consignment note and a licensed carrier, and the interval between the spill and the collection is exactly the period the site is holding a hazard it did not plan for. Thermal destruction resolves the organic fraction rather than transferring it. At 850–1,200°C with a two-second secondary-chamber retention, hydrocarbons on the absorbent are destroyed along with the substrate carrying them. Where the stream includes halogenated content above 1% — some solvents and cutting fluids do — the secondary chamber holds 1,100°C instead. One constraint governs the whole stream: absorbed, not free. Liquid fuel or oil in bulk does not go into a batch chamber under any circumstances. What goes in is the absorbent with the liquid held in it, charged in reasonable proportion rather than saturated, and declared in the permit as the hazardous stream it is.

450 kg of used absorbent ÷ 250 kg per charge = 2 AMBI-250 charges, each mixed with the drier fraction. Ash is 14–23 kg at 3–5%, leaving on an ordinary transfer note rather than a hazardous consignment. Charge saturated absorbent mixed with the drier fraction; a chamber loaded entirely with soaked granular runs hotter than the operating band intends.

Not as free liquid, no. These are batch chambers, not liquid injection plant: oil and fuel go in absorbed onto granular absorbent, pads or rag, never poured. Recoverable waste oil should go for recovery anyway — it has a value and a route, and burning it is worse on both counts.

It does when it leaves the site. Destroying it on site removes the movement, so the consignment is replaced by a cycle and the residue leaves as ordinary ash under a transfer note. The stream still has to be named as hazardous in the environmental permit.

Mixed rather than loaded alone. Saturated absorbent burns hot enough to push the primary chamber above its operating band if it makes up the whole charge, so it is charged with the drier fraction of the stream — packaging, rag and filters — in proportion.

Drained filters, yes. The metal shell survives the burn and is recovered from the ash as inert scrap; the media and the residual oil in it are destroyed. Do not charge undrained filters, and never charge a filter housing still holding free oil.

The standard 850°C two-second secondary-chamber condition covers hydrocarbon-contaminated absorbent. Where the stream includes halogenated solvents or cutting fluids above 1%, the requirement rises to 1,100°C — the units hold it, but the permit application has to declare the products in use.

One charge per working day is the planning unit, so 450 kg of bagged absorbent is two cycles on an AMBI-250 — days rather than the weeks a carrier collection typically takes. The practical benefit is that the holding area stops being a standing fire load between the spill and the collection.