MAB catalyst

FIGURE 2.2 2-D chromatogram from a MAB catalyst product showing higher concentra-... 

In an exploratory experiment, 13 different powder materials were tested in a FFB ACE unit. Most of the results were unremarkable except for three catalysts a low Z/M commercial maximum distillate catalyst (the same LZM catalyst used in the pilot riser experiment), a spray dried low surface area silica (inert) and the minimum aromatics breakthrough (MAB) catalyst. The inert material was included in the study to represent thermal cracking. The catalysts were steam deactivated in the fixed bed steamer prior to testing. Catalysts and the VGO-B feed properties are displayed in Tables 2.3 and 2.1, respectively. LCO aromatics were measured with 2D GC. Figures 2.7 through 2.9 illustrate the main results. 

In a follow-up study, the MAB catalyst was submitted to a metals resistance test using Mitchell impregnation [8]. Two levels of metal contamination, 500 ppm and... 

FIGURE 2.10 Comparing MAB catalyst with a standard residual catalyst at extreme metal contaminant levels with atmospheric residue in the ACE unit. (O) LZM resid catalyst, ( ) MAB. 

The results from the ACE FEB unit showed clearly that the low activity of the MAB catalyst would produce high slurry oil yields in present day FCC configurations, optimized for Y-zeolite based catalysts. Some adjustments of the FCC hardware would certainly be necessary to fully exploit the new catalyst selectivity potential. 

To evaluate the new process conditions that would allow the MAB catalyst to produce lower slurry oil yields than those obtained in the FEB unit, a series of experiments were carried out using a Riser Simulator—built and perfected at the Institute of Petrochemistry and Catalysis Research (INCAPE/FIQ-UNL) in Santa Fe, Argentina (Figure 2.11). 

In the Riser Simulator it was possible for the MAB catalyst to reach slurry oil yield levels compatible with the conventional LZM catalyst operating at typical conditions for maximum mid-distillate. However, the yields of heavy naphtha range aromatics were half of those obtained with the LZM catalyst compared at the same slurry oil yield (Figure 2.12). The MAB ClO-Cll aromatics trend as a function of slurry oil yield was a continuation of the inert catalyst trend, an indication that a similar reaction mechanism could be taking place. The minimum slurry oil yield for the inert catalyst, even at maximum severity, was still above 40 wt% ... 

FIGURE 2.12 Riser simulator results Heavy naphtha aromatics (ClO-Cll) as a function of slurry oil yield (343°C+) (X) Inert, ( ) LZM catalyst, (a) MAB catalyst. 

Looking at the selectivity differences in greater detail (Table 2.5), the MAB catalyst will prodnce more gas, coke, and LCO and less gasoline and LPG. Gasoline quality is also affected because of the significant decrease in aromatics resulting in a much lower octane number. 

By avoiding the acid catalysis mechanism of the conventional FCC zeolite catalyst (optimized over the years for high octane gasoline), the novel MAB catalyst will produce substantially lower aromatics in the liquid products than is possible by less extreme FCC catalyst adaptations. By changing the FCC reaction system, it is possible to overcome the MAB catalyst low activity drawback and achieve slurry yields compatible with those observed in maximum distillate operation in today s FCC units. 

FIGURE 2.8 ACE unit coke yield versus conversion (<221°C). Catalysts within the ellipse region produced roughly twice as much coke as the LZM catalyst at the same conversion. (X) New materials—high to moderate acidity, (O) new materials—low acidity, (O) inert, ( ) LZM catalyst, (A) MAB. 

In this particular unit, the reforming reaction was carried out at an absolute pressure of approximately 2 bar, since the plant was conceived as a fuel processor for a PEM fuel cell that would operate at slightly above atmospheric pressure. The reformer catalyst was a proprietary monolith-supported, noble metal catalyst (Engelhard). The combustion side operated at atmospheric pressure and employed a proprietary palladium-based, monolith-supported catalyst (Engelhard). Heatric states that the MAB PCR offers improved selectivity or productivity on a broader basis through ... 

MAC), methyl 2-acetamidoacrylate (MAA), and methyl 2-acetamidobutenoate (MAB) (Figure 15.7) as well as two itaconic acid derivatives, namely dimethyl ita-conate (DMI) and ( )-dimethyl-2-phenyl itaconate (DMPI). In general, good to excellent enantioselectivities (of up to >99% ee) were observed. Ligand backbone modification by coordination of bulky Au-X substituents to the free phospholane unit of the tripodal DPP Hgand led to a remarkable enhancement of the catalyst... 

WenF, Yang J, ZongX, MaB, Wang D, Li C (2011) Photocatalytic H-2 production on hybrid catalyst system composed of inorganic semiconductor and cobaioximes catalysts. J Catai 281 318-324... 

---