摘要:

AbstractIn this study, a nonhydrogenative process for partial upgrading of heavy oil was evaluated in a semi‐continuous laboratory scale unit for producing a low viscosity oil which could be pipelined easily. The process was conducted at atmospheric pressure and over a temperature range of 400 to 470°C. Gas production was negligibly small (1‐2 wt. % of the feed) and there was virtually no coking of reactor except at high coal concentrations (>9.1 wt. %) and high reactor temperatures (470°C). The particulate content of the liquid product which contained unreacted coal, ash and coke (defined as toluene‐insolubles) was less than 5 wt.% in the majority of the cases. In the presence of coal, iron oxide mixed with coal. and iron oxide alone, maximum reductions in viscosity were: from 1540 to 248 mPa.s, from 1540 to 192 mPa.s, and from 1540 to 80 mPa.s, respectively. A moderate improvement in API gravity (from 13.0 to 18.2) was obtained using 1 wt. % iron oxide additive at 470°C. However, apparent pitch (resid) conversion were of the order of only 20

ISSN:0008-4034    

DOI:10.1002/cjce.5450710512

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractBenzene isopropylation over medium port ferrisilicate to obtain cumene has been studied. Effects of reaction conditions on cumene selectivity are discussed. Based on the reaction network, various models were derived and fitted to kinetic data. A simple stoichiometric model represented the kinetic data significantly better than other models. Estimated activation energy values indicated that benzene alkylation is faster than cumene isomerisation to n‐propylbenzen

ISSN:0008-4034    

DOI:10.1002/cjce.5450710513

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe volatility of iodine above dilute CsI solutions has been investigated experimentally. The partitioning of iodine between air and solutions prepared with iodide was found to increase with decreasingpH and iodide concentration. Aqueous to gaseous partition coefficients ranging from 3 X 103to 107were observed indicating that only a very small fraction of the iodide was oxidized to volatile forms. It was concluded that under these very dilute conditions, the rate of iodide oxidation was proportional to the square root of the iodide concentration; the rate also depended onpH under acidic conditions but not under basic conditions.

ISSN:0008-4034    

DOI:10.1002/cjce.5450710514

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe performance of a continuous bioreactor under periodic inlet substrate concentration is theoretically analyzed for productivity improvement which under conventional steady‐state operation shows input multiplicities in the feed substrate concentration. Two values of feed substrate concentration give identical productivity under conventional steady‐state operation. A periodic rectangular pulse is assumed for the feed substrate concentration. It is shown by simulation that under concentration forcing the average productivity is significantly different for these two substrate concentrations. The larger value of feed substrate concentration gives improved average productivity and shows a resonance with the period of oscillation. The effect of periodic operation on the average productivity under the input multiplicities in dilution rate is also analy

ISSN:0008-4034    

DOI:10.1002/cjce.5450710515

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractAn impinging‐stream reactor, developed and tested for calcination of phosphate with low organic matter content, has proven to be an efficient device for conducting this process.Modeling of the calcination process has been done along two lines. Considering a single particle and assuming that calcination rate is controlled by the heat transfer in the particle, resulted in a criterion for testing the effect of temperature on the enrichment of P205 and other phenomena. Performing a heat balance on the reactor and on the particle, and incorporating physical concepts, led to correlations with only one adjustable parameter for the conversion of carbonates as a function of the operating parameters.The major conclusion drawn from implementation of the model was that phosphate calcination is governed by the internal resistance of the particle to the heat transfer. The calcination efficiency results, as well as the practical experience gained in this study, indicated that the impinging‐stream calciner may provide a promising tool for phosphate enrichment, and more generally, for processes involving gas‐solid contact at high tempera

ISSN:0008-4034    

DOI:10.1002/cjce.5450710516

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractCalcination of a high organic matter phosphate and a phosphate containing pulverized coal up to 10 wt % was performed successfully in an impinging stream calciner. The results re‐established previous conclusions that the present calciner is a useful device.A simplified model has been developed for exploring the effect of various operating parameters on the concentration of phosphate particles at the impingement plane of the streams. It also assisted us in explaining the effect of the phosphate flow rate on the efficiency of calcination.It was established that the calcination rate of phosphate is governed by the internal resistance of the particle to the heat transfer, which was consistent with previous result

ISSN:0008-4034    

DOI:10.1002/cjce.5450710517

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractDifferent magnetic fractions of narrow‐sized industrial residues of zinc ferrite [(Zn1‐x, Fe x2+)Fe 23+O4, x ≤ 0.4] have been leached with 1 mol/L H2SO4at temperatures ranging from 348 to 368 K. Fractions with excess iron, which exhibit higher magnetic susceptibility, are found to dissolve faster. It is believed that the lattice substitution of Zn by Fe2+in the more magnetic ferrite fractions creates crystal defects and renders the ferrite more chemically reactive. An interfacial electrochemical reaction mechanism has been advanced to account for the effects of solid state composi tion and solution composition on the variation of the dissolution kinetics of zinc ferrite. Finally, the practical implications of these findings on the industrial leaching of zinc ferrite are briefly

ISSN:0008-4034    

DOI:10.1002/cjce.5450710518

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe effect on the interfacial tension of the water toluene system has been studied at 25 °C in the presence of four phase‐transfer catalysts i.e. tricaprylmethyl ammonium chloride, hexadecyltrimethyl ammonium chloride, hex‐adecytrimethyl ammonium bromide and hexadecyltributyl phosphonium bromide. The interfacial tension of aqueous phenol/resorcinol‐toluene in the presence and absence of tricaprylmethyl ammonium chloride has also been reported. Attempt has been made to elucidate the change in volumetric rate of extraction with different catalysts for two phase reactions, on the basis of interfacial t

ISSN:0008-4034    

DOI:10.1002/cjce.5450710519

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractA study was made of the abilities of the Soave and Peng‐Robinson equations to represent the phase behavior of ethane + n‐paraffin and CO2+ n‐paraffin systems. These equations are capable of describing the phase behavior of such systems; however, the level of precision obtained varies with the degree of complexity used in representing the interaction parameters in the mixing rules employed. For ethane/C02with n‐paraffins extending from C3to n‐C44, an uncertainty of about 1 % is obtained for bubble point pressures (or about 0.005 mole fraction for solubilities) when two system‐specific interaction parameters per isotherm are used. Simple generalized correlations are presented for the equation‐of‐state interaction parameters which allow prediction of the bubble point pressures with an expected uncertainty of about 5.7% (0.014 in

ISSN:0008-4034    

DOI:10.1002/cjce.5450710520

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe presence of solid particles at lower contents (up to 6% by volume) caused an increase in the gas holdup in the three‐phase reciprocating plate column, compared to that in the two phase (gas‐liquid) column of the same type, under the same other operating conditions. The decrease in the gas holdup, which was normally observed in the two‐phase column, was not found in the three‐phase column as the vibration speed was increased at lower

ISSN:0008-4034    

DOI:10.1002/cjce.5450710521

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY