Epichlorohydrin (ECH; CAS 106-89-8, HS 2910.30) is a chlorinated propylene oxide with a molecular weight of 92.52 g/mol, a normal boiling point of 116.1 °C at 101.3 kPa, and a liquid density of 1.18 g/cm³ at 20 °C. ECH is miscible with most organic solvents and has a water solubility of approximately 6.5 g/100 g at 20 °C. The current Global Epichlorohydrin Capacity Map: China Supply Dominance and Trade Flows is defined by feedstock integration and downstream epoxy resin demand. Industrial production follows two routes. In the propylene-based allyl chloride chlorohydrin route, propylene and chlorine react in a heated radical substitution reactor at 450–500 °C to produce allyl chloride; subsequent hypochlorination with chlorine and water at 40–60 °C yields dichloropropanols, which are saponified with lime or sodium hydroxide to ECH. In the glycerin-to-ECH route, refined glycerin is hydrochlorinated with hydrogen chloride in a catalytic reactor at 110–130 °C, producing monochloropropanediols that are dehydrochlorinated to ECH. China’s coastal chlor-alkali and biodiesel glycerin availability anchors the global capacity map.

What Drives the Global Capacity Map Around China’s ECH Supply Dominance?

Published industry surveys place China’s share of global ECH nameplate capacity in the range 55–60%, with the remaining capacity distributed across Northeast Asia, Europe, North America, and the Middle East. The propylene-based route remains significant in Europe and North America because existing allyl chloride infrastructure is integrated with epichlorohydrin elastomer and epoxy resin producers. The glycerin route has expanded in China and Thailand because it decouples ECH from steam-cracker propylene and uses lower-cost glycerin from biodiesel and oleochemical processing. Process selection influences the capacity map: glycerin-based single-line capacity is often 50–100 kt/a, while propylene-based trains are typically 100–160 kt/a per line. Capacity utilisation in China fluctuates with caustic soda economics and glycerin price; published trade data indicate operating rates between 55% and 75% during periods of weak epoxy resin demand.

The global capacity map is further shaped by chlorine balance. Propylene-based ECH consumes both chlorine and caustic soda in downstream saponification, whereas glycerin-based ECH consumes hydrogen chloride and can be integrated with toluene diisocyanate or polyurethane HCl byproduct streams. China’s supply dominance therefore reflects the country’s broader chlor-alkali and polyurethane capacity expansion, not only ECH economics. Nameplate share is not equivalent to merchant supply. Chinese ECH units with captive chlorine and caustic soda can be idled when chlor-alkali margins tighten, while propylene-based units in Europe and North America may operate as swing capacity for allyl chloride monomer. The capacity map therefore requires a distinction between installed nameplate and trade-relevant merchant volume.

China’s ECH capacity is concentrated in Shandong, Jiangsu, Zhejiang, and Liaoning, where chlor-alkali complexes and glycerin refining units share steam, hydrogen chloride, and wastewater treatment. A typical glycerin-to-ECH block includes a continuous stirred-tank hydrochlorination vessel with external circulation cooling, a stripping column for HCl recovery, a packed reactive distillation column for ECH purification, and a thin-film evaporator for heavy ends. Crude ECH is separated from water and monochloropropanediols using azeotropic distillation at atmospheric pressure; the ECH-water azeotrope boils near 88 °C and requires decanting and reflux control. Vendor technical bulletins describe crude ECH yields exceeding 90% relative to glycerin when an adipic acid catalyst is maintained at 110–130 °C. Chlorohydrin-based trains in China use either calcium hydroxide or sodium hydroxide saponification; calcium chloride brine disposal remains a constraint in inland locations. Batch-to-batch variance in crude glycerin—methanol, soaps, and fatty acid residues—can poison the adipic acid catalyst and increase light ends formation, which appears as higher acrolein content in the crude ECH. The expansion of ECH capacity has been tightly linked to liquid epoxy resin units that consume ECH and bisphenol A under alkaline conditions at 60–100 °C to produce bisphenol A diglycidyl ether. Small-volume derivatives include synthetic glycerin, epichlorohydrin elastomers, paper wet-strength resins, and polyamine epichlorohydrin water-treatment polymers. The capacity map therefore does not show a uniform supply pool; it shows integrated blocks where ECH is internally consumed, and merchant volumes are released only when epoxy resin demand softens or when plants produce for caustic soda margins.

Export Logistics, Antidumping Duty Exposure, and HS 2910.30 Trade Corridors

China’s merchant ECH exports move through bulk liquid terminals in East China and are classified under HS 2910.30. The main trade corridors include China to South Korea, China to India, China to Southeast Asia, and China to European buyers; smaller flows from Japan and South Korea to China persist when specialty propylene-based ECH is required for low-chloride epoxy resin formulations. Export volumes fluctuate with domestic epoxy resin operating rates. Public customs data for this specific configuration are fragmented; China does not publish detailed ECH export destination data at the same granularity as polyolefins. The following matrix summarises the dominant flow directions reported in trade statistics.

Trade flows are also shaped by antidumping and countervailing duty investigations. Existing measures in India, the United States, and the European Union have at different periods targeted ECH from China, Japan, South Korea, Russia, Thailand, and the United States; duty margins are product-specific and are revised through sunset reviews. A producer shipping under HS 2910.30 must track the importer of record’s declared country of origin and any ongoing review. Logistics constraints include lined or stainless-steel cargo tanks, nitrogen padding, and inhibitor addition during long-haul marine transport. Chemical parcel tanker freight rates for UN 2023 from Shanghai to Rotterdam and Nhava Sheva are published weekly; these rates alter the effective delivered cost when Chinese ECH prices are quoted FOB Shanghai versus CFR India. ECH is subject to the International Maritime Dangerous Goods Code as a flammable, toxic liquid; typical rail and road shipments use UN 2023 (Class 3, 6.1, Packing Group II). Blending ECH with toluene or methanol for certain resin syntheses is exothermic and requires cooled addition.

Liquid epoxy resin production consumes the largest single share of ECH demand. Typical BPA epoxy resin formulations use an ECH to bisphenol A molar ratio close to 2:1, with excess ECH recovered by vacuum distillation. The reaction is carried out in stainless-steel or glass-lined stirred reactors; liquid epoxy resin specifications include epoxide equivalent weight by ASTM D1652-11, viscosity by ASTM D2196-20, and hydrolyzable chloride limits below 300 ppm for many electronics applications. Because ECH oligomerisation can occur during resin advancement, vacuum stripping at temperatures below 140 °C is used to avoid colour body formation. For epichlorohydrin elastomers, copolymerisation with ethylene oxide or propylene oxide is performed in stainless-steel autoclaves at 40–80 °C with organoaluminium or phosphorus-based catalyst systems. Polyamine epichlorohydrin water-treatment resins require controlled addition of ECH to aqueous polyamine solutions; the reaction is cooled to 40–60 °C and pH is held between 8.5 and 9.5 to control crosslink density. The operational boundary for these downstream processes is strict: free water above 0.1% in the ECH feed can hydrolyse ECH to monochloropropanediol, altering stoichiometry and reducing cured-resin crosslink density.

When Epichlorohydrin Is Handled Outside Controlled Nitrogen-Blanketed Storage, What Operational Boundaries Apply?

ECH is a flammable liquid and a direct-acting alkylating agent. Under the EU CLP Regulation (EC) No 1272/2008, the harmonised classification includes Carc. 1B H350, Flam. Liq. 3 H226, Acute Tox. 3 H331, Skin Corr. 1B H314, Eye Dam. 1 H318, and Aquatic Chronic 3 H412. The ACGIH TLV-TWA is 0.5 ppm (1.9 mg/m³) with a skin notation; the OSHA PEL is 5 ppm (19 mg/m³) as an 8-hour time-weighted average. Atmospheric storage requires closed-loop vapour recovery, nitrogen blanketing below 30 kPa positive pressure, and temperature maintenance below 30 °C to minimise peroxide formation and ring-opening hydrolysis. Carbon steel is acceptable only when moisture is excluded; stainless-steel or phenolic-lined vessels are preferred for long-term storage because iron chlorides can initiate cationic polymerisation. Contact with strong bases, aqueous ammonia, amines, aluminium chloride, boron trifluoride, or zinc chloride must be avoided because these substances initiate rapid, exothermic ring-opening polymerisation and can generate pressure. Water content in bulk ECH should be kept below 0.05% by Karl Fischer titration using ASTM D6304 or equivalent. The storage area must provide emergency showers and eyewash stations per ANSI Z358.1-2014 and continuous area monitoring using photoionisation detectors calibrated for ECH response. Thermal destruction of ECH-containing waste requires incineration above 1100 °C with alkaline scrubbing of hydrogen chloride off-gas. Published data for this specific configuration is limited for small-scale blending in non-chemical facilities; the safest operating practice is to use sealed transfer loops with single mechanical seals and nitrogen-purged lines.