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: Degree of polymerization of inulin GFC Jerusalem artichoke Prebiotic effect a b s t r a c tThe tubers of Jerusalem artichoke are rich of inulin, which makes the plant one of primary inulin resources in China. The aim of this study was to extract inulin from tubers and test the degree of polymerization (DP) 10 days before flowering to 80 days after flowering. The DP of inulin reaches a maximum of 19 at 50 days after flowering. The variation tendencies of inulin content and DP were almost the same, which increase rapidly at the beginning and then decrease gradually at a lower speed. Meanwhile, the effects of inulin on probiotics in yogurt have been evaluated. It indicated that inulin with low DP has higher activities. Experimental data improve the understanding of status change of inulin in whole growth of Jerusalem artichoke tubers in Northeastern China and are instructive to get inulin with different properties.

Catalytic cracking experiments in which various blend levels of coker gas oil (CGO) in fluidized catalytic cracking (FCC) feedstock were reacted over two kinds of commercial equilibrium catalysts (RGD-1 and LBO-16) demonstrate that the blending ratio affects the potential ability of a FCC unit treating CGO obviously. The limits of the blending ratio for Daqing CGO and Dagang CGO are 30 and 20 wt %, respectively, to obtain a desirable product distribution at a relatively high feed conversion. The operating condition of a high catalyst/ oil ratio in combination with a short residence time (or high weight hourly space velocity) and moderate reaction temperature is the optimal operating condition for catalytic cracking of CGO and its mixture. A FCC catalyst, such as RGD-1, which has proper acidities and high accessibility, is suitable for dealing with CGO effectively, which leads to an obvious improvement over conversion and product distribution. The analysis and contrast catalytic cracking experiments of narrow cuts of Daqing CGO show that the fraction of Daqing CGO is accumulated largely in the range of 300-450 °C and there exists high content of basic nitrogen and polycyclic aromatics. The lowest crackability of the cut from 400 to 450 °C constrains total CGO cracking performance, which is caused by a preferential chemisorption of the polycyclic aromatic molecules, and basic nitrogen compounds take place prior to the desirable adsorption of the other hydrocarbons, which is necessary for the cracking reaction to occur.

Reactive adsorption desulfurization of FCC gasoline over a Ni/ZnO-SiO 2 -Al 2 O 3 adsorbent was carried out in a fixed-fluidized bed reactor at low pressures in the presence of hydrogen. The results show that high temperature, high pressure, high molar ratios of hydrogen-to-oil, and low weight hourly space velocity are favorable to improve the desulfurization ability of adsorbent but not conducive to maintaining the octane number of FCC gasoline throughout the condition range examined. Under optimal operating conditions, ultralow sulfur gasoline can be produced, and the RON loss is only 1 unit. Furthermore, the effect of prereduction and adsorbent characterization data (SEM/EDX, N 2 adsorption) reveal that reduction increases the interaction between Ni and S compounds and improves the pore structure of adsorbent, leading to a significant improvement in the desulfurization capability of adsorbent. Take 3-methylthiophene for example, after adsorbing on an active Ni atom via the S-Ni bond, the sulfur of 3-methylthiophene is removed by direct hydrogenolysis of the C-S bond, resulting in the formation of NiS x and 2-methyl-1,3-butadiene in hydrogen atmosphere. The latter is mainly hydrogenated to 2-methyl-2-butene and 2-methylbutane. ZnO acts as a sulfur-acceptor, which can regenerate the active Ni in situ in hydrogen atmosphere. The complete sulfidation of adsorbent particles takes place by ion diffusion.

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Contrastive fluid catalytic cracking (FCC) performances of coker gas oil (CGO) narrow-boiling fractions before and after HCl aqueous solution and furfural further treatment were investigated. Nonbasic nitrogen compounds and condensed aromatics in test oil samples were identified by negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) and gas chromatography and mass spectrometry (GCÀMS), respectively. The results show that basic nitrogen compounds mainly retard the feed conversion and liquid products due to their interaction with Brønsted acid sites or Lewis acid sites during catalytic cracking reactions, while the nonbasic nitrogen compounds and condensed aromatics are hard to convert into smaller molecules, just resulting in obvious effects on yields of gasoline and diesel. Moreover, nonbasic nitrogen compounds with single N species are dominant in CGO, identified as carbazoles, cycloalkyl-carbazoles, benzocarbazoles, and cycloalkyl-benzocarbazoles. Condensed aromatics include three to four rings of large dynamic size, usually presented as chrysene, pyrene, and phenanthrene. These compounds deposit on the surface of catalysts and thus redundant coke is formed; consequently, entrances for other hydrocarbons into acid centers are jammed.

The effect of residence time, catalyst-to-oil (CTO), and temperature of regenerated catalyst (T RC) on the product distribution of residue fluid catalytic cracking (RFCC) are investigated in a technical pilot scale riser apparatus. Under simulated realistic conditions, thermal cracking predominantly occurs at two different parts of the riser reactor: one is at the bottom of riser for hot catalyst contacting with relatively cool feedstock droplets and another is at the second half of the riser for deactivation of the catalyst. Therefore, the optimal reaction conditions and a modified RFCC process are proposed for lowering thermal cracking and maximizing liquid products. The simulation experiments of the modified process show that product distribution at lower T RC and higher CTO of the optimal conditions is superior to that of the routine RFCC at a nearly similar conversion level, more than 0.4−2.7 wt % liquid products could be obtained. The balance of hydrogen for the products indicates that the decrease of dry gas and coke at the optimal reaction conditions leads to more H of the feed is distributed into the liquid products.

Hierarchical SAPO-34 crystals were synthesized by a facile TEAOH etching post-treatment for the first time.