Cashew Nut Shell Liquid (CNSL)

About This Product

Cashew nut shell liquid, CNSL, is extracted from the honeycomb layer inside the shell of the cashew nut, Anacardium occidentale. It carries CAS number 8007-24-7 and is a dark brown viscous liquid. Because it comes from the shell rather than the kernel, it is a by-product of nut processing and is classified as a residue rather than a crop-derived oil. It is important to be clear about what it is not. Vegetable oil feedstocks are triglycerides, and the whole biodiesel process depends on that structure, since transesterification works by swapping the glycerol backbone for methanol. CNSL contains no glycerides at all: it is a mixture of alkyl phenols, principally anacardic acid, cardol and cardanol, each carrying a fifteen-carbon unsaturated side chain. There is no backbone to displace, so it cannot be converted to FAME by the standard route. What it offers instead is a renewable liquid of good calorific value used directly as an industrial fuel oil and as a blend component in heavy fuel and boiler applications, and a phenolic feedstock that can be routed to resins, friction materials and specialty chemicals. Its acidity and viscosity are the handling constraints. It is used as industrial and boiler fuel, as a fuel blend component, and as feedstock for cardanol, resins and specialty chemicals. Bio Green Fuels supplies CNSL to specification on cardanol and anacardic acid content, calorific value, viscosity, moisture, ash and iodine value.