Effect of feedstock

In the FCC, HjS is formed principally by the catalytic decomposition of non-thiophenic (non-ring) sulfur compounds. Table 2-3 shows the effects of feedstock sulfur compounds on H2S production. 

Complete data collection should be carried out weekly. Since changes in the unit are continuous, regular surveys permit distinction among the effects of feedstock, catalyst, and operating conditions. An accurate assessment of a cat cracker operation requires reliable plant data. A reasonable weight balance should have a 98% to 102% closure. 

In the unit, the heat of reaction is a useful tool. It is an indirect indication of heat balance accuracy. Trending the heat of reaction on a regular basis provides insight into reactions occurring in the riser and the effects of feedstock and catalyst changes. 

As with troubleshooting, a proper debottlenecking exercise must consider the effects of feedstock, catalyst, operating conditions, mechanical hardware, environmental issues, and the ability of the rest of the refinery to handle the additional feed/product rates and quality. 

The effects of feedstock cellulose content on cellulase enzyme activities in the digester system were examined in multiple laboratory-scale CSTR digesters operated under similar conditions with identical levels of feedstock organic loading (g VS/reactor d) but different levels of cellulose (Solka Floe). In general, all celli se enzyme... 

Figure 1. Comparison of the effects of feedstock cellulose content on specific ceUulase enzyme activities in sludge from 4 CSTR reactors operated under similar conditions. Although the cellulose content of the feedstock was varied, the total volatile solids content for all reactors was equivalent.

Fisher, I. P. Effect of Feedstock Variability on Catalytic Cracking Yields. Applied Catalysis 65 (1990) 189-210. 

Figure 3. Effect of feedstock price on European ethylene production costs (1000 MM Ibs/yr ethylene production premium value by-products)...

Figure 6. Effect of feedstock price on U.S. ethylene production costs (1000 MM Ibs/yr ethylene production premium value by-products). Note by-proauct prices as given in Table V. However, for n-butane feed9 the butanes contained in the Ch by-product are valued the same as n-butane feed.

Figure 4-6 Effect of feedstock molecular weight on hydroconversion processes.

Figure 5. Effect of feedstock hydrogen content on response to fluid catalytic...

The effect of feedstock quality and oil partial pressure on coking is given by ... 

Fig. 33.19. Effect of feedstock composition on minimum ethanol selling price (MESP).

Ibs/ft hr (0.10 kg/m s) in minimum as liquid mass velocity utilized in a pilot plant test and a correction method involving mainly effects of feedstock properties on desulfurization activity are proposed to get better agreement in evaluating aging performance and cycle length of a catalyst system with multiple catalysts between pilot and commercial units. 

Proposal was made on a correction method which involves mainly the effects of feedstock properties on desulfurization activity. It shows much better agreement in catalyst aging performance between the pilot and commercial operations. 

It is also believed that nozzle life is affected by feedstock characteristics. Although the dry-feed system may be more difficult to operate at high pressures, nozzle life may be longer in the absence of large amounts of evaporating water. Deeper understanding is needed to identify the effect of feedstock preparation. 

Feedstock impurities, or chemicals left over in the system from a previous operation, are often the cause of undesirable reactions in columns. Should an undesirable reaction be suspected, it may pay to look into the nature and effects of feedstock impurities, and to attempt deriving plant feedstock from an alternative source for a trial period. If the impurity is chemically unstable, or reacts with the column chemicals explosively, a detonation may result some examples were reported (96, 275). In absorber-regenerator systems, contamination of the solvent charge can lead to imdesirable reactions or poor stripping one example has been reported (14a). 

Effects of feedstock particle size and pretreatment techniques. 

Variations in Product Due to Feedstock. While process-related differences in product composition have been evident, extensive study of the effect of feedstock on product composition has never been undertaken. Some limited comparative tests can be gleaned from the literature however, most process research in direct liquefaction of biomass has been performed with woods of various species. Table I provides some of the results available in the literature for non-woody feedstocks. Significant differences in heteroatom content are evident, but only limited chemical analysis is available in most cases. 

The comparison of the peat and wood flash pyrolysis products by Elliott ( ) is a good example of the effect of feedstock on product oil composition. The poplar oil typically was composed of phenolic, ketone and furan compounds with a substantial fraction of low molecular weight organic acids. The main components of the peat oil were hydrocarbons, mostly straight chain olefins. Minor quantities of ketones were noted but no acids, aldehydes or furans were identified by mass spectrometry. Phenols were also present in significant quantities. 

Effects of Feedstock and Process Technology on the Production Cost of Chemicals... 

Figure 5.5 Effect of feedstock cost on production cost of chemicals characteristic parameters, see Table 5.5 definitions and assumptions, see Table 5.4 examples, see text.

The amormt of polymer synthesised by the effect of feedstock heating from Tq to " boil can be estimated by the following equation [88] ... 

Leuenberger, E.L., Moorehead, E.L. and Newell, D.F., "Effects of Feedstock Type on FCC Overcracking", Paper Presented at the NPRA Annual Meeting, San Antonio, Texas, March 20-22 (1988). 

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