Calcium Sulfonate Detergent —
Overbased TBN 300, 400 & 500
Overbased calcium sulfonate is the most-used detergent chemistry in modern PCMO and HDD engine oil — it neutralises acidic combustion products, suspends sludge precursors and provides reserve alkalinity (TBN). This guide covers synthetic alkylbenzene sulphonic acid (SABS) feedstock, the CO2 carbonation manufacturing process, TBN selection (300 / 400 / 500) by service category, branded lubricant additive suppliers (Lubrizol / Afton / Infineum / Chevron Oronite / IPAC), and the custom locally-blended route at 35-42% cost saving versus premium imports, with formula IP transferred to the client.
Six Detergent Chemistries
For Engine Oil & Marine
Six-Step Carbonation
From SABS to TBN 400 Product
Detergent TBN & Treat
Across Seven Service Categories
| Component group | Typical role | Typical share |
|---|---|---|
| Active components | Detergents / dispersants / anti-wear / antioxidants / inhibitors (as applicable) | ~40–60% |
| Carrier / diluent oil | Handling & blend compatibility | ~40–60% |
Indicative high-level composition only. The exact components, treat rates, performance additives and approved suppliers are shared under NDA as part of a Lubechem formulation engagement.
Eight QC Tests
For Overbased Sulfonate Release
| Component group | Typical role | Typical share |
|---|---|---|
| Active components | Detergents / dispersants / anti-wear / antioxidants / inhibitors (as applicable) | ~40–60% |
| Carrier / diluent oil | Handling & blend compatibility | ~40–60% |
Six Overbased Ca Sulfonate
Suppliers Active Worldwide
Frequently Asked About
Calcium Sulfonate Detergent
Match overbased Ca sulfonate TBN to the service: PCMO API SP needs finished TBN 7-9, use TBN 300-400 detergent at 2-3% treat; HDD CK-4 needs finished TBN 10-13, use TBN 400-500 at 3-4% treat; marine system oil needs finished TBN 9-12, use TBN 300 salicylate at 3-5% treat; marine cylinder oil needs finished TBN 70-100, use TBN 500 sulfonate + booster at 15-25% treat.
Industrial R&O turbine uses no detergent (residual TBN <2); gear oil uses small TBN 300 for CI role at 0.5-1.5%.
Neutral Ca sulfonate (TBN 20-50) is the direct stoichiometric salt of sulphonic acid and lime — only modest base reserve. Overbased Ca sulfonate (TBN 300-500) carries 6-10× more calcium per molecule as colloidal CaCO3 micelle stabilised by the sulfonate surfactant.
Overbasing is achieved by adding excess lime + methanol promoter and sparging CO2 to convert Ca(OH)2 to CaCO3 inside the micelle. Overbased gives the high reserve alkalinity needed for engine and marine — neutral is largely a corrosion-inhibitor / co-emulsifier role today. The same overbased Ca sulfonate chemistry is also the thickener backbone in Calcium Sulfonate Complex Grease (CaSX).
Three coupled reactions. (1) Sulphonic acid + Ca(OH)2 → Ca sulfonate (neutral) + H2O — primary salt-formation. (2) Excess Ca(OH)2 dispersed by methanol as fine particles inside the sulfonate micelle. (3) CO2 sparge: Ca(OH)2 + CO2 → CaCO3 + H2O — the colloidal CaCO3 stays trapped inside the micelle.
After dehydration and methanol stripping, the product is a stable single-phase overbased detergent with TBN 300-500 depending on the Ca:sulfonate stoichiometry. Methanol is recovered and recycled.
SABS = Synthetic Alkylbenzene Sulphonic Acid, made by sulphonating C20-C32 linear or branched alkylbenzene with SO3 (oleum or gas). The alkyl chain length controls oil solubility — shorter chain (C16-C20) gives high water solubility (cleaning detergents); longer chain (C20-C32) gives oil solubility (lubricant detergents).
Global SABS feedstock from BRB International (Belgium, with India distribution), IPAC India (Mumbai), Stepan (US import) and select sulfonation houses in India (Mumbai / Gujarat) and other regions.
Marine cylinder oil for two-stroke crosshead diesel (MAN B&W, Wärtsilä) requires 70-100 TBN finished oil to neutralise the high sulfur content of marine residual fuel. Built from TBN 500 overbased Ca sulfonate at 15-25% treat plus calcium phenate booster + dispersant + AW + AO.
The high active TBN matter precipitates the sulphuric acid from combustion before it attacks the cast-iron cylinder liner. CIMAC TGL E-class cylinder oil tests measure neutralisation rate and TBN retention through 250 hr run.
Sulfonate has the best global availability and lowest cost per TBN unit. Calcium phenate (overbased calcium alkylphenate) has higher thermal stability and contributes secondary antioxidant function — used in marine cylinder oil and high-temperature industrial.
Calcium salicylate (overbased calcium alkylsalicylate) is the low-SAPS detergent of choice for ACEA C-class — better Mg compatibility, lower sulfated ash per TBN unit. Modern PCMO API SP often uses a sulfonate + salicylate hybrid for balanced performance. Calcium chemistry also extends into greases — see Calcium Soap Grease Manufacturing for the anhydrous and hydrated calcium soap route.
Branded overbased Ca sulfonate TBN 400 from Lubrizol / Oronite / Infineum lands in India at ₹320-450 / kg (~US$4-5) depending on volume; comparable landed pricing applies across other markets. Locally-blended from Lubechem / IPAC custom equivalents land at ₹190-260 / kg (~US$2-3) — 35-42% saving versus premium imports.
The manufacturing process is well-established public-domain chemistry; the saving comes from regional feedstock sourcing (BRB Belgium via Mumbai, IPAC India) and absence of brand premium.
Yes — Lubechem custom detergent is built to client's spec with target TBN (300 / 400 / 500), Ca content, filterability, base oil compatibility (Group I vs II vs III), and storage stability hold.
Engagement: 4-6 weeks from SABS receipt to finished detergent in drum. MOQ 100-500 kg for custom; lab-scale samples 1 kg available for evaluation. Formula IP transferred at closeout — client owns the BOM and process method.
From Detergent Brief
to Custom Solution
Need Custom Overbased
Ca Sulfonate Built?
Share your target TBN (300 / 400 / 500), Ca content target, service category and volume requirement. We respond within one business day with a process plan, BOM and indicative cost.