**2.1 Supply chain of fuel ethanol**

As soon as fuel ethanol is produced at a manufacturer's facility, it is held in storage tanks pending its release for distribution. Generally, manufacturers add the denaturant before or in the course of onsite storage. In addition, an inhibitor is added during storage or just preceding discharge of the shipment for supply. This may be one reason for SCC experience at some downstream facilities and no reported failures at manufacturer facilities. On entering the distribution system, fuel ethanol can be transported by numerous means, which include pipeline, barge, tanker truck and railroad tanker car [16].

The duration that fuel ethanol spends in the sequence can fluctuate significantly from days to months, subject to several factors: the obtainability of intermediate distribution storage, the site of the manufacturing facility, the transportation mode used, and the location of gasoline blending terminals. Fuel ethanol is held in storage tanks as soon as it comes into a gasoline blending facility. Contingent on usage and traffic requirements, the residence period in these tanks also differs. In certain cases, it can be held for months in the course of a period of dormancy [16].

However, in certain instances, at gasoline blending facilities, the residence period in the storage tank is relatively short as incoming ethanol supplies and outgoing shipments of blended gasoline are a proximate frequent process. Nevertheless, observations of SCC have been restricted to the lot of the supply chain encompassing the intermediate liquids storage through the gasoline blending facility and possibly will be linked to circumstances that develop in the distribution system or variations that transpire in the fuel ethanol [16].
