Ethylbenzene
A single-purpose intermediate. Almost all ethylbenzene made in the world is dehydrogenated straight to styrene, usually without leaving the site.
Molecular Structure
What is Ethylbenzene?
Ethylbenzene is a benzene ring carrying a two-carbon ethyl side chain. It is a clear liquid boiling at 136.2 °C, and it shares the C₈H₁₀ formula and 106.17 g/mol molecular weight with the three xylene isomers.
Almost all of it is made by alkylating benzene with ethylene, now generally over a zeolite catalyst that has replaced the older aluminium chloride and phosphoric acid routes. Recovering ethylbenzene from mixed xylenes by superfractionation is technically possible but takes an extremely tall column, and it is rarely economic.
Its purpose is almost singular: catalytic dehydrogenation over an iron oxide catalyst in the presence of steam removes two hydrogens from the ethyl chain and gives styrene. Well over 99% of world ethylbenzene follows that route, and most of it is consumed in an integrated plant rather than traded.
Chelora supplies merchant-grade ethylbenzene at ≥99.5 wt% with xylenes, cumene and non-aromatics controlled for dehydrogenation service. Available in ISO tanks, road tankers and drums for non-integrated styrene and solvent users.
Quick Reference
Key Physical & Chemical Properties
Structure & Bonding
The whole of ethylbenzene's industrial value sits in the ethyl side chain. Dehydrogenating it to a vinyl group turns an unremarkable solvent into styrene — a monomer that will polymerise.
Skeletal structure — ethyl side chain at C-1
Structural Identity
- IUPAC NameEthylbenzene
- Molecular FormulaC₈H₁₀
- Molecular Weight106.17 g/mol
- Hybridisationsp² ring, sp³ side-chain carbons
- Bond typeAromatic ring + ethyl substituent
- Bond lengths1.39 Å ring C–C; 1.51 Å C–CH₂
- GeometryPlanar ring, rotatable side chain
- Key reactionDehydrogenation to styrene
- CAS Number100-41-4
- InChI KeyYNQLUTRBYVCPMQ-UHFFFAOYSA-N
Product Specifications
Chelora supplies Ethylbenzene in standard and custom grades. Contact us for specification sheets tailored to your process.
| Chemical name | Ethylbenzene |
|---|---|
| CAS Number | 100-41-4 |
| Molecular formula | C₈H₁₀ |
| Molecular weight | 106.17 g/mol |
| Purity (standard grade) | ≥ 99.50 wt% |
| Purity (high-purity grade) | ≥ 99.80 wt% |
| Total xylenes (max) | ≤ 0.30 wt% |
| Cumene (max) | ≤ 0.10 wt% |
| Benzene (max) | ≤ 0.05 wt% |
| Toluene (max) | ≤ 0.05 wt% |
| Non-aromatics (max) | ≤ 0.10 wt% |
| Total sulfur (max) | ≤ 1.0 ppm wt |
| Chlorides (max) | ≤ 1.0 ppm wt |
| Water (max) | ≤ 100 ppm wt |
| Colour | ≤ 10 Pt-Co (Hazen) |
| Distillation range | 135.5 – 137.0 °C |
| Density | 0.865 – 0.869 g/cm³ at 20 °C |
| Flash point | 15 °C (closed cup) |
| Autoignition temperature | 432 °C |
| Flammable limits | 0.8 – 6.7% v/v in air |
| UN Number | UN 1175 |
| IMDG / ADR Class | Class 3 (Flammable Liquid), PG II |
Downstream Applications & Derivatives
Key derivative chains and industrial uses of Ethylbenzene.
Styrene Monomer
Catalytic dehydrogenation over promoted iron oxide with superheated steam at 600–650 °C removes hydrogen from the ethyl group to give styrene. This takes well over 99% of world ethylbenzene.
Propylene Oxide Co-Production
In the PO/SM route, ethylbenzene is oxidised to its hydroperoxide, which epoxidises propylene to propylene oxide and yields styrene as the co-product.
Downstream Polystyrene Chain
Through styrene, ethylbenzene underpins polystyrene, EPS insulation, ABS and SAN engineering plastics, SBR latex and unsaturated polyester resins.
Acetophenone & Derivatives
Controlled oxidation of the benzylic position gives acetophenone, used in fragrance, as a photoinitiator precursor and as a pharmaceutical intermediate.
Diethylbenzene & Divinylbenzene
Further alkylation gives diethylbenzene, dehydrogenated to divinylbenzene — the cross-linking monomer used in ion-exchange resins and specialty polymers.
Solvent & Blend Component
A minor but real outlet as a solvent in coatings and inks, and as a constituent of mixed xylenes solvent blends and high-octane gasoline.
Why source Ethylbenzene through Chelora Petrochem?
Verified Origin
Full origin certification and asset-backed supply chain documentation — no grey-market supply.
Grade Flexibility
Standard and high-purity grades available. Xylenes, cumene, chlorides and sulfur can be tightened to protect dehydrogenation catalyst life.
Full Documentation
CoA, SDS, UN transport docs, REACH compliance, and destination-market certificates with every shipment.
Logistics Support
Experienced in bulk aromatic liquid logistics — ISO tanks, road tankers, and drums with nitrogen blanketing where required, for Indian and international delivery.
Storage & Handling Guidelines
Always refer to the full SDS before handling. The following is a summary of key requirements.
- Store in a bunded, well-ventilated, dedicated area away from ignition sources, heat and direct sunlight.
- All electrical equipment in storage and transfer areas must be ATEX/IECEx rated for the applicable zone.
- Bond and earth tanks, tankers, drums and hoses before every transfer — aromatic liquids accumulate static readily.
- Keep away from strong oxidisers, acids and halogens; use PTFE or Viton seals, as many elastomers swell in aromatics.
- Maintain a nitrogen blanket on bulk storage where the tank headspace can sit inside the flammable range.
- Fit fixed flammable-vapour detection with audible and visual alarms set below the LEL in enclosed storage and pump areas.
- Provide local exhaust ventilation at sampling, drumming and loading points, and monitor personal exposure against the OEL.
- Keep foam, dry chemical or CO₂ media available for firefighting — water jets spread the burning liquid.
Hazard Summary
Classification: Flam. Liq. 2 (H225) · Carc. 2 (H351) · Acute Tox. 4 inhalation (H332) · STOT RE 2 (H373, hearing organs) · Asp. Tox. 1 (H304) · Skin and Eye Irrit. 2.
Carcinogenicity: Ethylbenzene is classified Carc. 2 under CLP and sits in IARC Group 2B, possibly carcinogenic to humans. This is a weaker classification than benzene's, but it still calls for closed handling and exposure control rather than general ventilation alone.
Health: Repeated exposure is associated with hearing damage, and aspiration into the lungs can cause chemical pneumonitis — never induce vomiting.
Exposure limits: ACGIH TLV 20 ppm 8-h TWA; EU IOELV 100 ppm TWA / 200 ppm STEL with a skin notation; OSHA PEL 100 ppm TWA. Confirm the limit in force in your jurisdiction.
Flammability: Flash point 15 °C — flammable vapour forms below normal room temperature. Vapour is heavier than air and can travel to a distant ignition source.
PPE minimum: Chemical splash goggles, nitrile or Viton gloves, flame-retardant antistatic clothing, and organic-vapour respiratory protection where ventilation cannot hold exposure below the limit.
Consult the full SDS for exposure limits, spill containment, emergency response, and disposal before any use.
Frequently Asked Questions
Technical and commercial questions about Ethylbenzene sourcing and specifications.
What is ethylbenzene used for?
Overwhelmingly one thing: making styrene. More than 99% of global ethylbenzene is dehydrogenated to styrene monomer, either in a conventional steam dehydrogenation unit or as the co-product of the propylene oxide/styrene monomer process. Small volumes go to acetophenone, diethylbenzene and divinylbenzene, and to solvent and gasoline blending.
How is ethylbenzene produced?
By alkylating benzene with ethylene. Modern plants use zeolite catalysts in liquid or vapour phase, which have displaced the older aluminium chloride and supported phosphoric acid processes because they avoid corrosive waste streams and give better selectivity. Polyethylbenzenes formed as by-products are transalkylated back with benzene to improve overall yield.
Why isn't ethylbenzene separated from mixed xylenes instead?
It can be, but rarely economically. Ethylbenzene boils at 136.2 °C and para-xylene at 138.4 °C — a gap of about 2 °C, which demands a superfractionation column of several hundred trays and a very high reflux ratio. Alkylating benzene with ethylene is cheaper, so ethylbenzene recovery from mixed xylenes is only practised where a complex has a specific reason to remove it.
Why is ethylbenzene rarely traded on the merchant market?
Because styrene plants are almost always built with an ethylbenzene unit alongside them. The intermediate is produced and consumed within the same site, which avoids storing and shipping a Class 3 flammable liquid with a 15 °C flash point. Merchant volumes exist for non-integrated producers and for solvent and specialty users, but they are a small fraction of total production.
What impurities matter to a styrene plant?
Xylenes carry through the dehydrogenation reactor and end up as impurities in the styrene product, where they are difficult to remove because the boiling points are close. Chlorides and sulfur poison the iron oxide dehydrogenation catalyst. Cumene and other alkylbenzenes reduce yield. That is why merchant ethylbenzene specifications are tight on all four.
What documentation does Chelora provide?
Every shipment includes a Certificate of Analysis covering purity, total xylenes, cumene, benzene, toluene, non-aromatics, sulfur, chlorides, water, colour and distillation range; a Safety Data Sheet (GHS/REACH); UN 1175 Class 3 PG II transport documentation; an origin certificate; and any destination-market certificates required.
Request a quote or specification sheet
Talk to Chelora's sourcing team about Ethylbenzene grade, volume, logistics, documentation, and lead times. We respond within one business day.
