LPG yields

The hydrocracking process is characterized by a very low gas production and a low LPG yield especially when operated for maximum distillates. Byproducts in this operating mode are ... 

When using ZSM-5, there is almost an even trade-off between FCC gasoline volume and LPG yield. For a one-number increase in the research octane of FCC gasoline, there is a 1 vol% to 1.5 vol% decrease in the gasoline and almost a corresponding increase in the LPG. This again depends on feed quality, operating parameters, and base octane. 

Increasing feed/catalyst mix zone temperature. Conversion and LPG yield can be increased by injecting a portion of the feed, or naphtha, at an intermediate point in the riser (see Figure 6-1). Splitting or segregation of the feed results in a high-mix zone temperature, producing more LPG and more olefins. This practice... 

The catalyst activity increased when the RE level increased as expected [16]. Product yields compared at the same conversion (76.2 wt%) are shown in Table 3.9. When the RE level increased, the decreased LPG yield was as expected, as well as the increased naphtha yield and the decreased ECO yield. The decreased coke yield was also expected becanse of the behavior of the catalysts with low RE content in the pilot unit. 

The LPG yield was lowest for the reference catalyst and highest for Catalyst B, see Figure 3.16. 

Both the dry gas yield and the LPG yield showed very little difference between the two feeds and therefore only the total gas yields are shown in Figure 3.22. 

The LPG yield decreased when the ZSA/MSA ratio and the zeolite surface area increased for both types of catalysts, see Figure 4.4a and b. The reason for this might be that the LPG yield nsnally decreases when the naphtha selectivity increases. This might also explain the fact that the LPG yield increased for type A catalysts when the matrix snrface area increased. However, the LPG yield was almost unaffected of any changes in the matrix surface area for Type B catalysts, see Figure 4.4c. 

Figure 5. Effect of sulfur level and catalyst treatment on LPG yields from hydrocracking. 371°C (700°F), 7000 kPa (1000 psig), 2 LHSV, 5 hydrogen-to-hydrocarbon mole ratio. Q, reduced 0.7 wt % Pd — 15 wt % Ni-SMM , sulfided 0.7 wt % Pd — 15 wt % Ni-SMM.

Modified silico-aluminate materials were investigated as candidates for inclusion in mat-ricies of FCC catalysts for cracking heavy hydrocarbons. Through thermal and chemical treatments of kaolinite is possible to gain at least 40 conversion units with respect to the base material, as well as a reduction of 75 wt.% of heavy cycle oil and a 500 % increase in high-olefinic LPG yield. 

Figure 4. Comparison of the performance of mix28 (o) to that of c56 ( ) and reg (curve), a) conversion b) gasoline yield c) LPG yield and d) coke yield as function of catalyst-to-oil ratio (CTO), c56 coke data has been corrected for initial amounts of coke. Error bars are included to illustrate the accuracy of the experimental data.

The conversion of HCO (Figure 4a) obtained with the mixture, mix28, is much closer to the conversion obtained with the regenerated catalyst than to that of the coked catalyst. The same trends are observed for the gasoline- and the LPG yields in Figure 4b and 4c, respectively. 

Liquefaction of LNG yields a 500-620 fold reduction in volume at 1 bar for bulk transport and storage, as well as for industrial and domestic energy usage. (Liquefaction of LPG yields a 240-310 fold reduction in volume at 1 bar.)... 

Table 4.19 shows the DELTA-BASE vectors we generated using the procedure in Figure 4.36. The new BASE vector accurately reflects the current base gasoline and LPG yields of the FCC unit In addihon, as a consistency check, we note that SUL coefficient for the sour gas (row 1) has a negative coefficient This indicates that the sour gas increases as the sulfur in the feed increases. A similar consistency test with CON coefficient and coke (row 5) shows the same result We can use the LP model optimally, knowing that LP model does not underestimate key product yields. 

---