Chemistry and Technology of Fuels and Oils, Vol. 47, No. 4, September, 2011 (Russian Original No. 4, July-August, 2011)
PULPING BLACK LIQUOR USED DIRECTLY AS A GREEN AND EFFECTIVE
SOURCE FOR NEAT OIL AND AS AN EMULSIFIER OF CATALYTIC
CRACKING HEAVY OIL
Xu Ge, Yang Ji-he, Mao Hui-hui, and Yun Zhi
1,2221
The objective of this study is to evaluate the u of emulsified heavy oils to conduct the FCC reaction.
The emulsified heavy oil was prepared by homogenizing. Properties of emulsified heavy oil, including interfacial tension, dynamic viscosity, droplet distribution, and stability, were determined. Emulsified heavy oils were made using two types of pulping black liquor, namely untreated and partially recycled alkali black liquor. Stabilized emulsified heavy oil was ud in the FCC reaction to investigate the product distribution, and pure heavy oil was ud as the control. If the black liquor infiltration capacity i
s 5 wt. %, the catalytic cracking conversion and lectivity of the emulsified heavy oil and pure heavy oil were appraid at a temperature of 450°C using a fluid fixed bed.Compared with the pure heavy oil, the emulsified heavy oil had higher conversion and better lectivity towards the liquid products, and the liquid products yield of l-E-5 emulsion increas from 66.73 wt. % to 71.30 wt. %. Furthermore, the lectivity towards coke of emulsified heavy oil conversion is lower than that of the pure heavy oil, and the coke yield of l-E-5 emulsion decreas from 10.74 wt. % to 6.26 wt. %. The No.l black liquor is more suitable as a catalytic cracking black liquor fuel oil emulsifier than that of No.2 black liquor.
Additionally, the negative effect of the emulsified heavy oil on the catalysis is limited, and the uful life of the catalysis was extended.
Keywords: black liquor; heavy oils; emulsion; catalytic cracking reaction
1. Introduction
Kraft (or sulfate) and soda are the two major alkaline process to produce chemical pulps. However, in both process, cellulo fibers are disassociated from lignin by chemical reactions. The reactions occur in a pressurized digester, where wood chips or fibers are heated and cooked
with the cooking liquor, compod basically
S is added to the digester for improving the disassociation of of NaOH. Specifically in the Kraft process, Na
2
lignin from cellulo fibers, accelerating the wood cooking operation and increasing the mechanical resistance of the pulp (Marcelo Cardoso et al., 2009). Note that the products resulting from the digester reactions are the cellulo pulp and the black liquor. In chemical pulp mills, about half of the original raw wood material is dissolved
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1 – College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009, China.
2 –Faculty of Petrochemical Engineering, Changzhou University, Jiangsu, Changzhou 213164, China. Published in revid form in Khimiya i Tekhnologiya Topliv i Mal, No. 4, pp. 27 – 30, 2011.
0009-3092/11/4704–0283 © 2011 Springer Science+Business Media, Inc.
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in the spent pulping liquor. Most modern pulp mills burn the liquor in order to recover the cooking chemicals and utilize the heat value of the organic material, whereas in a forest biorefinery, wood components such as lignin and hemicellulos are extracted from the pulping liquor and ud in high-value-added chemicals (Fargues et al., 1996; van Heiningen, 2006; Wising and Stuart, 2006). In addition to being ud as a biofuel (Axelsson et al., 2006; Olsson et al., 2006), lignin can be ud as binder, dispersant, or emulsifier (Gargulak and Lebo, 2000) in phenolic resins (Danielson and Simonsson, 1998; Nada et al., 1999; Sarkar and Adhikari, 2000; Sellers et al., 2004; Villar et al., 2001), as precursor for carbon fibers (Compere et al., 2004; Kadla et al., 2002; Kubo and Kadla, 2005), and as a wet strength additive to kraft liner (Antonsson et al., 2008; Elegir et al., 2007). Hemicellulos can be ud as hydro gels (Gabrielii et al., 2000; Soderqvist Lindblad et al., 2001, 2004, and 2005), barrier films (Hartman et al., 2006; Grondahl et al., 2004), and paper additives (Lima et al., 2003; Hannukla et al., 2004; Westbye et al, 2006).
Recently, emulsification technology has been ud to improve the fogging effects (Lasheras, J. C, et al., 1980; Yap, L. T., et al., 1984). Under the action of the emulsifier, the water and oil would form a stable W/O emulsion system. The feedstock nozzle would atomize the emulsion droplets form 40-60
μm to 5-10 μm through microexplosion (Toshikazu Kadota, et al., 2007; MASATO MIKAMI, et al., 2002; Suk H. Chung, et al., 1991). The atomized emulsion droplets can increa the contact surface of the oil and catalysts. Accordingly, the coke formed in the surface of catalysts decrea and the lectivity towards light oil increa. This heavy oil emulsion in the catalytic cracking reaction achieves higher conversion and lectivity towards liquid products.
In this study, the black liquor has been ud directly as neat and emulsifier for heavy oil emulsification. Two kinds of pulping liquors were investigated, that is, untreated (No.2) and partially recycled alkali (No.l)
Table 1 Specifications of FCC crude oil
Table 2 Specifications of pulping black liquor
Table 3 Effect of incorporating proportion of No.1 black liquor on emulsion oil properties
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花的诗句大全pulping black liquors. Although lignosulfonates (LS) have been ud as surfactants for a long time, such
as O/W emulsion stabilizer (S.A. Gundern et al., 1999; B. Kosikova, et al., 2000), stable W/O emulsions were
obtained by adding black liquor to FCC heavy oil in this work. Black liquor is a lignin residue with water and
other chemicals ud during pulping production. Pulping black liquor, ud directly as a green and effective
source of neat oil and as an emulsifier of FCC heavy oil, has not only the advantage of low cost but is also a
feasible method to deal with waste water pollution problems, and thus gives good environmental and economic
benefits. This heavy oil emulsion in fluid catalytic cracking (FCC) reaction achieves higher conversion and
lectivity towards liquid products. The negative effect of the emulsified heavy oil on the catalysis is limited; the
uful life of the catalysis is extended. It is a promising process for energy production and chemical recovery in
the pulp and paper industry.
2. Experimental process
2.1.Materials
The heavy oil was obtained from Yangzi Petro-chem. Co. Ltd, Taizhou Refinery factory, PRC. The industrial
pulping black liquor was obtained from Weifang Paper Mill, Shandong Province, PRC. The properties of the
heavy oil ud are shown in Table 1. The properties of the black liquor are shown in Table 2.
2.2.Procedure
为爱奉献The heavy oil was heated under 80°C for 10 min to get a stable and flowable liquid. The pulping black
liquor with partial recycling alkali was dropped into the heavy oil slowly under stirring. The mixture was stirred
弹珠超人
for 15 min to form the stable W/O emulsion. The emulsion was denoted 1-E-X (X is the added black liquor
朝露昙花in wt. %). The heavy oil emulsified with pulping black liquor was prepared by the same process above. The
emulsion was denoted 2-E-X.
2.3. Catalytic cracking test
The catalytic cracking test was conducted at atmospheric pressure and a reaction temperature
of 450°C using a fixed fluid-bed microreactor (manufactured by Beijing Torch Petrochemical Corp.,
Beijing, PRC). The microreactor was loaded with 100.0 g of catalyst (LOB-16 was obtained from Lanzhou) and
瑜伽坐姿the emulsion/catalyst ratio was 5.
如何祛斑美白2.4. Characterization
The N 2 adsorption isotherms were obtained using a Micromeritics ASAP 2000 instrument manufactured
by Micromeritics Instrument Corp., USA. The catalyst samples were degasd at 115°C for 8 h before the
Fig. I Effect of reaction temperature on FCC product distribution with heavy oil feed:
1- liquid; 2 - liquid gas; 3 - dry gas; 4 - coke
老舍的作者简介
Reaction temperature,°C
Y i e l d , w t .
%
measurement. The specific surface area (S
) was estimated by the BET equation, and the pore radius distribution
BET
and mesopore analysis were obtained from the desorption branch of the isotherm using the Barrett-Joyner-Halenda (BJH) method. Droplet size distribution was obtained by a biological microscope (xl000) (made by Chongqing Photoelectric Co. Ltd., Chongqing, PRC). The apparent dynamic viscosity of the emulsions was obtained in a rotary viscometer (manufactured by Tongji University Electromechanical Factory, Shanghai, PRC). The interfacial tension was obtained by an interface tension apparatus (made by Chengde Testing Machine Factory, Heibei Province, PRC).
3. Results and discussion
3.1. Properties of heavy oil emulsion with different addition percentages of No. 1 pulping black liquor
The properties of 1-E-0, l-E-3, l-E-5, and 1-E-10 are shown in Table 3. It is obvious that with increa
in the amount of black liquor added from 3 wt. % to 5 wt. %, the emulsified oil surface tension and the dynamic viscosity incread, while the stability of the emulsified oil clearly decread. This is becau the black liquor contains lignin. The lignin is a complex compound with multifunctional groups, including both polar groups such as phenyl, hydroxyl, aldehyde, etc. and nonpolar aryl groups. Such a complex molecular structure contributes to the surface properties similarly to nonionic surfactants. Thus, the black liquor can reduce the surface tension of emulsified oil and improve the stability of emulsified oil. However, with increa in the amount of black liquor from 5 wt. % to 10 wt. %, emulsion stability decread. This is probably due to the fact that the lignin content of the emulsifier is fixed (solid content of 2.15 wt. %), so the increa of black liquor cannot bring enough lignin but excessive water. The excessive water increas the risk of droplet collision and condensation and caus the poor stability of the emulsion.
3.2.Properties of heavy oil emulsion with different addition percentages of No. 2 pulping black liquor
A similar effect has been obrved in 2-E-O, 2-E-3, 2-E-5 and 2-E-10. The properties are shown in Table
4. The best black liquor incorporating amount is 3-5 wt. %.
3.3.FCC for heavy oil stuff
For l-E-5 emulsion and 2-E-5 emulsion FCC stuff, the product distributions were studied at various temperatures and compared with pure heavy oil stuff.
Table 4 Effect of incorporating proportion of No.2 black liquor on emulsion oil properties
快乐春节Table 5 Comparison of FCC product distribution for emulsion oil
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2873.3.1. FCC for pure heavy oil stuff
For a pure heavy oil FCC reaction temperature from 430°C to 470°C, the difference in the lectivity towards the product can be en in Fig. 1. The lectivity towards liquid products firstly increas with increa in reaction temperature and then decreas after 450°C. Liquid products lectivity has a high peak at 450°C. The lectivity towards liquefied gas and dry gas changes little with increa in reaction temperature, while a downward trend in lectivity towards coke is obrved. The results are due to the endothermic reaction of FCG. The increa in temperature is beneficial to the FCC reaction, but the condary reaction increas with temperature ri.Above all, considering the liquid products, liquefied petroleum gas, dry gas, and coke product distribution, when the reaction temperature reaches 450°C, the FCC gives the best product distribution with the highest lectivity towards liquid products and the lowest coke yield.
3.3.2. FCC for l-E-5 emulsifying oil stuff
As shown in Fig. 2, when the l-E-5 catalytic cracking reaction temperature increas from 420 to 460°C,the liquid product lectivity changes gently but has a higher peak at 440°C. The lectivity towards liquefied gas yield and dry gas yield changes little with rising temperature. The lectivity towards coke decread with increasing temperature. Considering the conversion and the lectivity towards all the products, the best reaction temperature is 440°C; at such temperatures the lectivity
towards liquid products is highest, and that towards coke, lowest.
3.3.3. FCC for 2-E-5 emulsifying oil stuff
As shown in Fig. 3, the 2-E-5 catalytic cracking reaction temperature increas from 420 to 460°C, and the
lectivity towards liquid products increas from 420 to 440°C and then decreas from 450 to 460°C. The liquefied
Fig. 2 Effect of reaction temperature on FCC product distribution with No.1 emulsion
oil feed: 1- liquid; 2 - liquid gas; 3 - dry gas; 4 - coke
Fig. 3 Effect of reaction temperature on FCC product distribution with No.2 emulsion
oil feed: 1- liquid; 2 - liquid gas; 3 - dry gas; 4 - coke
Reaction temperature,°C
Reaction temperature,°C
Y i e l d , w t . %
Y i e l d , w t . %
