By Udbhav Bhargava
Winter diesel may soon be used by the Indians armed forces for operations in high altitude areas such as Ladakh. The Indian Oil Corporation (IOCL) has sought the permission of the armed forces’ Directorate-General for Quality Assurance (DGQA) to allow winter diesel use for military vehicles.
What happens to fuel in Low temperatures?
Standard diesel fuel contains paraffin wax which is used to improve viscosity and lubrication. The paraffin wax gets thicker or “gels” at low temperatures, which impedes the fuel flow in the car engine. Gel point is the temperature at which solid diesel fuel melts and cannot flow by gravity or be pumped into fuel lines any more. This phenomenon happens when a fuel reaches a temperature that is low enough that ample wax crystals have formed to prevent any movement in the oil.
For diesel this is usually around −8 °C and for petrol this is at -68 °C. Use of kerosene to dilute diesel to make it functional can seem like an improvisation that can help but it will cause more air pollution and harm to modern diesel engines, contrary to common opinion. If improvised, then fuel tank preheating can be fatally risky. A rational alternative may be to apply anti-gel additives to diesel or biodiesel where the temperature is supposed to cool. They serve to reduce the formation of wax crystals in the fuel, thereby reducing the fuel’s pour point and gel point.
The armed forces in these areas are fuelled by winter-grade diesel in cold deserts, like Ladakh. IOCL and other oil marketing firms are supplying armed forces with Diesel High Sulphur Pour Point (DHPP -W) for operations in those areas which also have a -30 ° C pour point.
What is Winter Diesel?
The winter-grade diesel produced by IOC has a low pouring point (the temperature below which the liquid loses its flow characteristics) of -33 ° Celsius, enabling it to withstand the harsh winter weather conditions in Ladakh. It also follows the Bureau of Indian Standards (BIS) BS-VI Grade specification. The winter-grade diesel is provided by the Indian Oil Corporation Limited Panipat Refinery. The special winter-grade diesel would help the the challenges for transport and mobility faced by local citizens during the harsh winter months.