Light-cycle gas oil

FIGURE 13.37 High-resolution flame photometric detector (FPD) chromatogram of light cycle gas oil (LCCO) demonstrating the effect of hydrotreating on condensed thiophenes. (Reproduced with permission of the author, Reference 104.)... 

The gas oil cut from catalytic cracking called Light Cycle Oil (LCO), is characterized by a very low cetane number (about 20), high contents in aromatics, sulfur and nitrogen, all of which strongly limit its addition to the diesel fuel pool to a maximum of 5 to 10%. 

A light distillate cut (light cycle oil - LCO) similar to gas oil but having high aromaticity and low cetane number. 

Figure 4.12 continued) (c) An expansion of the inset region from (b), with the normal alkanes shown as (a-e). Other unidentified components (f-i) are presented to locate specific peaks for comparison purposes, (d) A light gas oil analysed under the same conditions as for the cycle oil, showing the same expanded region. In this case, the oil has not been ti eated in the same manner as the cycle oil, so it retains the components that were absent from the cycle oil. Peaks (a-i) are the same as those seen in (c). 

Gas turbine and combined cycle (gas and light fuel oils) Thermal power plant (coal, lignite, wood and biomass)... 

In open cycle, the diesel has the higher efficiency, making it more attractive for light fuel oils. However, in combined cycle, the gas turbine often has the highest overall efficiency, but there is the penalty associated with the additional cost for boiler and turbine. Nevertheless, unless the prime fuel is of low cost, the use of combined-cycle gas turbine plant will prove to be the more economic. 

Light cycle oil (LCO)—used as a pumparound stream, sometimes as absorption oil in the gas plant, and stripped as a product for diesel blending and... 

In many units, the light cycle oil (LCO) is the only sidecut that leaves the unit as a product. LCO is withdrawn from the main column and routed to a side stripper for flash control. LCO is sometimes treated for sulfur removal prior to being blended into the heating oil pool. In some units, a slipstream of LCO, either stripped or unstripped, is sent to the sponge oil absorber in the gas plant. In other units, sponge oil is the cooled, unstripped LCO. 

The vapor from the primary absorber or the presaturator contains a small quantity of gasoline. The sponge oil absorber recovers this gasoline. Sponge oil is stripped or unstripped light cycle oil. It is used for final absorption of the dry gas stream. Instead of LCO, a... 

Products from the reactor are recovered in the main fractionator a J the gas plant. The main fractionator recovers the heaviest produc, such as light cycle and decanted oil, from the gasoline and ligh r products. The gas plant separates the main fractionator overhead vap< s into gasoline, Cj s, C4 s and fuel gas. The products contain sulfur compounds and need to be treated prior to being used. A combination of amine and caustic solutions are employed to sweeten these products... 

Standard cut points from ASTMD 2887 simulated distillation were used for liquid product yield calculation gasoline was defined as the C5-221°C fraction, light cycle oil (LCO) as the 221°C-343°C fraction and slurry oil as the 343°C fraction. Gasoline quality was determined by gas chromatography using PONA column and a variation of the methodology described by Anderson [1]. 

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