Cashew Nut Shell Liquid (CNSL)

About This Product

Cashew nut shell liquid (CNSL) is the dark, viscous liquid held in the honeycomb structure of the cashew nut shell. It is released when shells are roasted or heated during nut processing, or recovered from shells by solvent extraction or expellers. Unlike the other feedstocks in this catalogue, CNSL is not a triglyceride oil. It is a mixture of phenolic lipids with a long unsaturated C15 side chain: anacardic acid, cardanol, cardol and 2-methylcardol. Heat-extracted technical CNSL is largely decarboxylated during processing, so cardanol predominates, together with cardol and a polymeric fraction; solvent-extracted CNSL is rich in anacardic acid. Because it contains no glycerides, CNSL cannot be transesterified into FAME, and it is not a conventional HVO or HEFA feedstock. Its fuel uses are more modest. It is burned as an industrial fuel oil in suitable burners and boilers, including at cashew processing sites, and it has been studied for pyrolysis, hydrotreating and blending into heating and marine fuels. Its main value lies in chemicals: friction dust for brake linings, phenolic and epoxy resins, coatings and, after distillation, cardanol for curing agents and surfactants. Buyers considering CNSL as a fuel should run trials on their own equipment, because its viscosity, tendency to polymerise and phenolic nature differ from those of fatty oils. The usual lipid parameters apply only in part. FFA and iodine value are not used in the same way; instead buyers specify cardanol and cardol content, polymerised material, viscosity, specific gravity, moisture, ash, matter insoluble in toluene and loss on heating. For fuel uses, sulphur, metals and calorific value are added. Technical CNSL typically has a specific gravity of around 0.95–0.97, with moisture and ash each around 1 % or less. Annex IX Part A of the Renewable Energy Directive lists nut shells among agricultural residues. Whether a liquid extracted from cashew shells falls under that entry, and how any fuel made from it is treated under RED III, depends on the national authority and the certification scheme. Buyers should not assume Annex IX status. They should confirm the classification and certificate scope with their certification body, and ask for traceability to the processing site that fits their mass-balance records. CNSL irritates and can sensitise the skin, so handle it to the safety data sheet with gloves and eye protection. It thickens in cold weather and slowly polymerises under prolonged heat, so it is stored closed, away from strong oxidising agents, and warmed only as much as pumping requires. It moves in drums, IBCs, ISO tanks and flexitanks, with liner compatibility confirmed for a phenolic cargo. In an enquiry, say whether you need technical (heat-extracted) or solvent-extracted CNSL, the intended use, your cardanol, polymer, viscosity, moisture and ash limits, and the volume, packaging, delivery terms and documentation you need.