Part 1, Cetane Improver
There exists only one industry wide accepted Cetane Response Curve for cetane improver chemical added to diesel fuels. This graphed data depicting three different anticipated response levels for 2-ethyl hexyl nitrate was developed more than two decades ago using cetane engine laboratory test data generated predominantly by the cetane additive manufacturers. The Cetane Response Curve is the only general test data available for predicting the expected engine cetane number change when 2-ethyl hexyl nitrate is added to any diesel fuel.
Following world-wide publication of the Cetane Response Curve, the petroleum, diesel equipment, and fuel consuming industries all universally accepted the data and subsequently adopted its use for predicting increases in distillate (diesel) engine cetane number with dosages of 2-ethyl hexyl nitrate (cetane improver).
This same Cetane Response Curve data is also used by diesel fuel additive suppliers when formulating their products for sale into the petroleum industry. Unfortunately, not all diesel fuel additive suppliers are using the data shown on the chart in the same manner. Many diesel fuel additive suppliers are intentionally using the curve data to substantially ?over predict? the average and typically expected cetane engine number response of cetane improver additives.
The deliberate misuse of the data displayed on the Cetane Response Curve has resulted in significant frustration for the diesel fuel additive purchaser and continual disappointment for the diesel fuel user because the quoted cetane response is not achieved in the actual engine. This has been and continues to be a major problem for the ?premium diesel fuel additive buyer?.
The associated costs for conducting cetane engine tests to determine the cetane number of only one diesel fuel can easily exceed $250.00. As a result, the premium diesel fuel additive buyer often is forced to rely solely on the integrity of the premium diesel fuel additive supplier when discussing the expected cetane number increase to be achieved from a specific multifunctional additive product (formulation).
The misuse and confusion perpetrated by unscrupulous additive suppliers is done entirely as a means to keep the price for their particular additive product lower than other competitor products being offered to the premium diesel fuel additive purchaser. This exploitation is accomplished by using only the cetane improver dosage rates shown on the Cetane Response Curve for high response fuels to predict the ?average and typical? cetane number increase in all fuels. When using only the high response fuel data for additive formulation purposes, the required cetane improver component volume will be dramatically reduced. Since cetane improver typically is the single largest percentage volume in all premium diesel fuel additive formulations, the over prediction of cetane improver response level will drastically reduce the price of the fuel additive products, but provide less than desired results.
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