Spent Sulfuric Acid Spent Acid · Recovered H₂SO₄ · UN 1832
The acid that has already done its job — recovered from nitration, sulfonation and alkylation, and still worth real money to the right buyer.
Chelora Chemicals brokers spent sulfuric acid offtake and supply across the United States — placing parcels with acid regeneration plants, fertilizer producers and treatment operators, and sourcing usable spent acid for buyers who do not need virgin grade.
- CAS Number (H₂SO₄)
- 7664-93-9
- EC Number
- 231-639-5
- Proper shipping name
- Sulfuric acid, spent
- Molecular formula
- H₂SO₄
- Molecular weight
- 98.08 g/mol
- Typical strength
- 65–80% w/w
- Appearance
- Dark brown to black liquid
- UN Number
- UN 1832
- HS Code
- 2807 00
Note: spent acid is a process stream, not a specification product. Strength, organic load and metals vary with the source process, so every parcel is quoted against its own analysis. Confirm exact transport classification for your shipment with your regulatory affairs team.
The acid loop, closed
Spent acid is not waste until someone decides it is. The loop below is the one we broker — and both ends of it are products on this site.
Alternative outlets where regeneration is uneconomic: fertilizer manufacture, effluent neutralization and gypsum production · neutralization partner: caustic soda
What spent sulfuric acid is used for
Spent sulfuric acid is what comes back out of a process that used sulfuric acid as a catalyst, a dehydrating agent or a reaction medium. It is typically a dark brown to black viscous liquid at 65–80% H₂SO₄, carrying water, dissolved salts and the organics picked up from the process it served.
It arises in volume from aromatic nitration, where mixed acid from nitric and sulfuric acid leaves a weakened sulfuric stream behind; from sulfonation and alkylation; and from titanium dioxide manufacture. The economics turn on one question — whether the organic load is low enough to regenerate, or whether the acid is better used directly.
Spent sulfuric acid outlets we place into
- Regeneration to virgin acid. Thermal decomposition back to SO₂ and re-conversion, the preferred route when organics are low.
- Fertilizer manufacture. Acidulation of phosphate rock to single superphosphate, where color and organics matter far less.
- Effluent neutralization and pH control. Direct use against alkaline streams, paired with caustic soda on the other side.
- Gypsum and calcium sulfate production. Reaction with lime or limestone, yielding a saleable solid.
Handling character
Spent acid is corrosive, often hot on loading, and may carry dissolved organics and gases. Full hazard detail is in the Safety section below.
| Parameter | Typical value |
|---|---|
| Appearance | Dark brown to black viscous liquid |
| H₂SO₄ strength | 65–80% w/w |
| Water | 18–32% w/w |
| Total organic carbon | Source-dependent — stated per parcel |
| Color (Pt-Co) | Stated per parcel |
| Insoluble solids | Stated per parcel |
| Dissolved solids | Stated per parcel |
| Iron and heavy metals | Stated per parcel |
Important: the figures above are indicative of commercial material and are offered for planning only. The batch certificate of analysis is the governing document.
| Property | Value |
|---|---|
| Physical state | Viscous liquid, dark, pungent |
| H₂SO₄ molecular weight | 98.08 g/mol |
| Density | ≈ 1.55–1.73 g/cm³ with strength |
| Miscibility | Miscible with water, strongly exothermic |
| pH | < 1 (strongly acidic) |
| Reaction with water | Violently exothermic — always add acid to water |
| Odor | Pungent, with process-derived notes |
Spent acid is a process stream and not a specification product. The figures above describe the range we commonly see; every parcel is quoted against its own analysis, and that analysis governs.
Spent acid outlets across US industry
Four genuine outlets — and the logistics to move a corrosive bulk liquid to them.
Acid regeneration
Thermal cracking back to sulfur dioxide and re-conversion to virgin acid or oleum. The preferred route where organic load allows.
- Parcel screened on organics first
- Bulk tanker and ISO tank
- Returns as virgin acid or oleum
Fertilizer manufacture
Acidulation of phosphate rock to single superphosphate, where color and trace organics are tolerated.
- Strength band agreed up front
- Scheduled bulk call-off
- Documented parcel analysis
Effluent neutralization & pH control
Direct use against alkaline process water and effluent, displacing virgin acid at lower cost.
- Consistent strength within the parcel
- Paired with caustic soda
- Full analytical documentation
Gypsum & calcium sulfate
Reaction with lime or limestone to produce calcium sulfate for board, cement and filler use.
- Metals profile stated per parcel
- Bulk logistics arranged
- Technical desk review on request
Metal processing & leaching
Pickling liquor make-up and ore leaching duty, where a lower-grade acid is acceptable.
- Iron content stated per parcel
- Lined tanker delivery
- Second outlet held in reserve
Contract offtake & logistics
Producers with a steady spent stream are supported with contracted offtake and scheduled collection.
- Annual offtake contracts
- Scheduled collection calendar
- Single point of contact for the loop
Delivered to US plants and ports
We ship spent sulfuric acid to nominated delivery points across the United States. The regions below are destinations we serve — Chelora Chemicals is a sourcing and supply partner, not a US manufacturer, and does not hold US stock.
Gulf Coast
The largest US chemical cluster, and the usual entry point for bulk consignments.
- Houston & Galveston, TX
- New Orleans & Baton Rouge, LA
- Mobile, AL
Northeast
Container and bulk delivery into the mid-Atlantic and New England manufacturing belt.
- Newark & Elizabeth, NJ
- Philadelphia, PA
- Boston, MA
Southeast
Port-side delivery for the Carolinas, Georgia and Florida processing plants.
- Savannah, GA
- Charleston, SC
- Jacksonville, FL & Norfolk, VA
Midwest & Great Lakes
Inland rail and truck forwarding from the nearest coastal port to the industrial Midwest.
- Chicago, IL
- Detroit, MI
- Cleveland & Columbus, OH
West Coast
Pacific routing for West Coast processors and formulators.
- Los Angeles & Long Beach, CA
- Oakland, CA
- Seattle & Tacoma, WA
Southwest & Mountain
Inland delivery to interior states, forwarded from the Gulf or Pacific gateway.
- Dallas–Fort Worth, TX
- Phoenix, AZ
- Denver, CO
Importing into the United States
Spent sulfuric acid is a TSCA-regulated chemical substance. Under TSCA section 13 the importer of record, or its authorized agent, must certify to US Customs and Border Protection that each shipment either complies with TSCA or is not subject to it. We confirm the substance's TSCA Inventory status and agree in writing who files that certification before the first consignment moves.
Which party carries that duty follows the Incoterm. On FOB, CFR or CIF terms it is usually the US buyer; on DDP terms it can be the seller or its agent. Safety data sheets and labels are supplied to OSHA's updated Hazard Communication Standard, and the UN 1832 Class 8 transport documentation is prepared before booking.
| Item | How it works |
|---|---|
| Delivery points | Any nominated US plant, terminal or port of discharge |
| Incoterms quoted | FOB · CFR · CIF · DDP |
| Importer of record | Agreed in writing before the first shipment |
| TSCA certification | Section 13 positive certification filed at entry |
| Documentation | Batch COA, SDS, packing list, certificate of origin |
| Pack formats | IBCs, lined road tanker or ISO tank |
Note: regional coverage describes where we deliver, not where we hold inventory. Lead time depends on producer scheduling and ocean transit to your nominated US port — we confirm both in the quotation.
How we supply spent sulfuric acid
Chelora Chemicals is a supplier and sourcing partner, not a manufacturer. On spent acid we work both sides of the loop — finding an outlet for producers with a stream to move, and finding usable acid for buyers who do not need virgin grade.
Every parcel is different, so nothing is quoted blind. We take the analysis first — strength, organic load, metals, solids — and match it to an outlet that can actually take it.
We keep more than one qualified outlet on this line, so a regeneration plant going down for a turnaround does not leave your tank farm backing up.
- Parcel analysis before anything else. Strength, water, total organic carbon, color, insoluble and dissolved solids and metals decide which outlet is even possible.
- TSCA status and import certification settled first. We confirm Inventory status and agree who files the section 13 certification before the first shipment.
- UN 1832 documentation managed end to end. Class 8 classification, the correct spent-acid shipping name, and carrier compliance confirmed before booking.
- Equipment compatibility checked before we quote. Lined tanker, ISO tank or IBC — we confirm the pack suits both loading and discharge points.
- Waste or product, settled in writing. How a parcel is classified at origin and destination changes the paperwork, so we fix it before the first movement.
- One desk for the whole loop. Spent acid out, virgin acid or oleum back in.
Toted or moved in bulk
Spent acid is a bulk business. Tell us your loading arrangement and volume and we will quote and classify to it.
Lined / FRP road tanker
The standard movement for spent acid, collected from your tank farm on a scheduled call-off.
Bulk ISO tank container
Containerised bulk for port-to-plant movement and longer hauls.
1000 L IBC totes
Where volumes are small or a tanker cannot reach the loading point.
250 kg HDPE drums
Sealed drums for sampling parcels and small residual quantities.
Incoterms to suit you
Quoted on the Incoterm your purchasing team works to, with documentation filed before booking.
Representative sample first
A representative sample and its analysis are exchanged before any parcel is committed.
Corrosive and variable — handle accordingly
Spent sulfuric acid burns on contact and can carry dissolved organics and gases from the process it served. Because composition varies with source, the parcel analysis matters as much as the generic hazard profile. The summary below is orientation only — the safety data sheet supplied with your specific parcel is the authoritative document.
Classified hazards
H290May be corrosive to metals.H314Causes severe skin burns and eye damage.
Unknowns are the real risk. A spent stream can carry residual nitro compounds, dissolved sulfur dioxide or organics that off-gas in the tank. Never blend parcels from different sources without a compatibility check, and never assume the profile of the last load applies to this one.
Storage
Store in lined or acid-resistant tanks in a bunded, well-ventilated area away from alkalis, oxidizers, organics and active metals. Vent safely — dissolved gases can evolve on standing. Keep parcels from different sources segregated until compatibility is confirmed.
Handling
Handle in closed transfer systems with local exhaust ventilation. Wear chemical goggles, a face shield, acid-resistant gloves and apron. Always add acid to water, never the reverse. Have an eyewash and safety shower within immediate reach of the loading point, and treat every new parcel as an unknown until its analysis is in hand.
Transport
Shipped as UN 1832, Sulfuric acid, spent, Class 8, Packing Group II. The spent shipping name is distinct from virgin acid and must be used. We confirm and document the exact classification, approved tanker lining and routing for your specific shipment and destination.
Every batch, documented
We verify documentation before dispatch so there are no surprises at your incoming-goods bench.
Parcel analyzed
Strength, water, total organic carbon, color, solids and metals established on a representative sample before anything is committed.
Outlet matched
The analysis is matched to a regeneration plant, fertilizer producer or treatment operator that can actually take it.
Documentation review
SDS, parcel analysis, TSCA certification data and UN 1832 transport paperwork checked by our desk before the movement is booked.
Traceable movement
Each parcel is traceable to its originating process, with full chain-of-custody records on request.
Where spent acid comes from
Spent sulfuric acid is not manufactured — it is generated. The largest source is aromatic nitration, where mixed acid from nitric and sulfuric acid nitrates a ring and the sulfuric component, diluted by the water of reaction, is drawn off weakened and colored. Every tonne of nitrobenzene or nitrochlorobenzene made carries a spent-acid stream behind it.
Sulfonation is the second source, where oleum or concentrated acid introduces a sulfonic group and the excess is spent. Alkylation units in refineries and titanium dioxide plants on the sulfate route generate the other large volumes.
Because the organic load is inherited from whatever process made it, two parcels at the same strength can behave very differently in a regeneration furnace. That is why the analysis, not the strength figure, decides where a parcel can go.
We do not publish operating process parameters here; this is background only. Full technical documentation accompanies every shipment, and any process-specific detail you need is best confirmed directly with our technical desk.
| Material type | Process stream, not a specification product |
|---|---|
| Principal component | Sulfuric acid at 65–80% w/w |
| Typical sources | Nitration, sulfonation, alkylation, TiO₂ sulfate route |
| Upstream | Sulfuric acid, oleum, nitric acid |
| Outlets | Regeneration, fertilizer, neutralization, gypsum |
| Shipping name | Sulfuric acid, spent — UN 1832 |
The rest of the sulfur and acid range
Virgin acid, oleum, the sulfonating agents and the neutralization partners around the loop — all supplied from the same desk.
Spent sulfuric acid, answered
What is spent sulfuric acid?
Where does spent sulfuric acid come from?
What is spent sulfuric acid used for?
Is spent sulfuric acid a waste or a product?
What analysis do you need before quoting?
Is spent sulfuric acid hazardous?
How is it shipped?
Can parcels from different sources be blended?
Do you supply or collect spent sulfuric acid in the United States?
Do you manufacture or regenerate this yourself?
Get a quote on spent sulfuric acid
Send us the parcel analysis — strength, organic load, metals and volume — along with your loading point and preferred Incoterm. We will come back with an outlet, a firm price and the transport documentation.