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03150 Expansion mechanism of magnesia compound for oil well cement — thermodynamic principle and validation
02 Liquid fuels (derived liquid fuels)
huminite reflectance (0.26-0.30% R,) and the amount of volatiles (40-49 wt%, dry basis), they ‘belong to the category of soft brown coals (Iignites) whrch contam high a proportion of mineral components. 00103147 Degradation of polyethylene and polypropylene into fuel oil by using solid acid and non-acid catalysts Sakata, Y. r/ ul. J. Anal. Appl. Pyrolysis, 1999, 51, (l-2), 1355155. Plastic polymers, polyethylene (PE) at 430” and polypropylene (PP) at 380” were thermally and catalytically degraded into fuel oil by batch operation. The catalysts employed were acid-catalysts silica-alumina (SA-1, SA-2). zeolite ZSM-5 and non acidic mesoporous silica catalysts (silicalite, mesoporous stlica gel) and mesoporous folded silica (FSM). The yields of product gas, liquid and residues; recovery rate of liquid products, and boiling point distribution of liquid products by catalytic degradation were compared with those of non-catalytic thermal degradation. The present work is divided into three sections: (1) a study of effect of catalytic contact mode, (2) a study of effect of types of catalysts on plastic degradation, and (3) the evaluation of catalysts during the degradation of PE and PP by repeating batch operation. For PP degradation in phase contact with SA-1, the yield of liquid hydrocarbons was obtained with 69 wt%, and the boiling point of the oil ranged between 36 and 270”, equivalent to the boiling point of normal paraffins n-C,, to n-Cts. The aqueous products from catalytic degradation have a carbon number distribution very similar to commercial automobile gasoline. For vapour phase contact, the yield of liquid products was much lower (54%) and the rate of liquid recovery (or formation) was much slower. Catalysts possessing strong acid sites such as zeolite ZSM-5 accelerated the degradation of PP and PE into gases which resulted in low liquid yields. For FSM, which possesses no acid sites, the initial rates of PP and PE degradation into liquid were as fast as that over an acid catalyst (SA-1) and the liquid yields were higher. The liquid products from catalytic degradation over FSM have a carbon number distribution similar to a mixture of kerosene and diesel oil. Upon repeated use SA-1 deactivated very rapidly due to coke deposition on the catalyst, whereas FSM deactivated much more slowly. These findings concerning the FSM catalyst strongly suggest that the mesopores surrounded by the silica sheet may act as a reservoir for radical species. 00103148 Dual process for obtaining light olefins from heavy petroleum residual feedstocks Seimandi, N. M. CI crl. U.S. US 5,952,539 (Cl. 585.648; CO7C4/02), I4 Sep 1999, US Appl. 25,743, 20 Sep 1996. 9. This paper describes a process that is used in the production of gaseous olefins, such as ethylene, from two different process units that share the same downstream quench and fractionation facilities. One of the process units is a short-contact-time mechanical fluidized vaporization unit for processing petroleum residual feedstocks and the other is a conventional steam-cracking unit. The solid and vapour residue times can be controlled more accurately with this process, the other benefits include, light olefin production from less-expensive, heavier feedstocks (e.g. asphalt) compared with gas oils. A flow diagram of the process is also provided. 00103149 Ethanol production from lignocellulosic biomass by simultaneous saccharification and fermentation employing the reuse of yeast and enzyme Kim, J.-S. et al. J. Micro/Go/. Biotchol., 1999, 9, (3), 297-302. Saccharification and fermentation (SSF) experiments were carried out simultaneously with a lignocellulosic biomass. The effects of temperature on enzymic saccharification and the ethanol fermentation were also investigated. The batch SSF process gave a final ethanol concentration of 10.44 g/l and equivalent glucose yield of 0.55 gig, which was increased by 67% or higher over the saccharification at 42°C. The optimal operating condition was found to vary in several parameters, such as the transmembrane pressure, permeation rate and separation coefficient, related to the SSF combined with membrane system (semi-batch system). The efficiency of the enzymes and yeast lasted three times longer than in a semi-batch mode as compared to a batch mode. 00103150 Expansion mechanism of magnesia compound for oil well cement - thermodynamic principle and validation Yao, X. Xrnan Slrr)?orr Xue~uan Xuehao, 1999, 21, (2), 77-80. (In Chmese) Using the principle of chemical, thermodynamic and topochemical reaction models, the expansion mechanism of the hydroxide expanding phase for oil well cement slurry is discussed. It suggests that an expansion force results from crystallization pressure, which was converted from the reduction of chemical potentials in the reaction of hydroxide formation, i.e. the chemical energy of the reduction was converted into the mechanical work. Furthermore, special experiments were designed to validate the theoretical analysis by use of class G oil well cement and a novel expanding agent. The theoretical analysis and experimental findings indicate that two conditions are necessary: (1) the plastic strength of the slurry must be high enough to restrained crystal growth of the solid product (i.e. restrained crystal growth), and (2) soluble products of the pore solution for hydroxide in the slurry should be greater than that of the standard conditions. 00103151 Improvement of diesel performance with the addition of linear ethers of diesel fuels Jacques, V. H. cl 01. Adv. Alcohol hrrls World Proc. Int. Symp. Alcohol Furls, IZth, 1998, 188-199. Edited by Zhu Q.
356
Fuel and Energy Abstracts
November 2000
The effect two linear ethers, di-n-pentyl ether and di-n-hexyl ether, have on the cetane response, fuel performance, stability and material compatibility of diesel fuel was investigated. The selection of these ethers was based on their blending properties and the availability of potential feed stocks and proven chemtcal processes within the Sasol Process. Various concentrations of the ethers were blended with a high temperature Fischer-Tropsch synthetic diesel component to optimize the cetane number of the fuel blend. This optimum blend was then used to evaluate the general properties, rheology and stability (thermal and oxidation) of the diesel-ether blend and to determine its compatibility with fuel system elastomers and metals. Internationally approved test methods were used in this study. The benefits of using ethers as diesel blending components were demonstrated as they not only improved the cetane number of the diesel fuel, but also enhanced the overall diesel fuel performance. Literature has indicated that with ethers in diesel, improved combustion, a reduction in emissions and improved cold weather operability were some of the benefits that can be realized. 00103152 Improvements to direct coal liquefaction Eur. Comm., [Rep.] EUR, 1999, l-176. With a view to improving overall process economics of direct coal liquefaction processes without materially affecting core process design concepts, potential improvements in the dissolution stage have been examined. Work was concentrated in the areas of coal selection, coal preparation, coal blending and the addition of small quantities of ‘augmenting’ material to the usual coal-derived recycle solvents. In support of these, work was also carried out on hydrogen transfer mechanisms and on the development of novel analysis techniques. Certain blends of coal have been shown to exhibit marked synergistic or antagonistic effects in relation to the extent of coal dissolution. Although the causes of these effects are not understood, they appear to relate to specific coals. Their magnitude is sufficient to allow significant benefits to be obtained by the judicious selection and blending of coals. The use of density separation techniques during coal preparation has been confirmed to produce feedstocks of higher reactivity. This effect can be large, with the extent of coal dissolution being increased by up to 10% wt/wt (dmmf coal) if only the lower density fractions are processed. Higher density fractions would be used for applications such as gasification or combustion, where reactivity has less impact on costs. The addition of ‘aqgmenting’ solvents to coal liquefaction recycle streams has been shown to be feasible without seriously compromising process yields or operability. This would allow poor quality materials such as tyre pyrolysis oil or catalytic cracker decant oil to be upgraded at a much lower cost than would be possible in purpose-built equipment. It would have the additional merit of allowing hydrocracker conditions to be re-optimized to increase conversion by relaxing the constraints on solvent balance. Taken together, these improvements could have a significant beneficial impact on overall process economics. Although evaluation of these benefits was outside the scope of this programme, other studies indicate that several United States dollars per barrel could be saved crude oil price at which coal liquefaction could become commercially viable. 00103153 Investigation of efficient and economical chemical agents for optimization of current techniques for recycling of coal slurries Auquier, W. et al. Eur. Comm., [Rep.] EUR, 1999, l-130. An important quantity of slimes (fine coal washeries streams) is produced by the coal industry, which are difficult to valorize because of their characteristics (very fine sized particles and high ash content). These slimes possess however an energy potential which is not negligible. These fine products are naturally intended to be treated by processes based on the differences of surface properties between the hydrophobic coal particles and the hydrophilic mineral particles, such as flotation and selective oil agglomeration. An important characteristic of slimes stockpiled for a long period is the alteration and the oxidation of the coal particles. The oxidation increases dramatically the wettability of the coal particles and thus has a detrimental effect on the efficiency of these processes. A strong linking was established between the adsorbed amount of water vapour and the oxidation level of the slimes. The detrimental effect of oxidation was proved by agglomerability tests using heptane and gas oil. On the same slime artificially oxidized by staying in an oven at 150°C during different lengths of time, the yield decreases dramatically from 8 h of artificial oxidation. The conditioning, prior to agglomeration, of the slime in water slurry form using biodegrading and anionic surfactants, such as sodium oleate, improve the yields achieved on not or slightly oxidized slimes. Furthermore, good results are still achieved on slimes which were artificially oxidized during 8 h and more. Most often, such reagents have a detrimental effect on the selectivity, increasing the ash content of the agglomerates. However, this effect is minor and by cleaning the agglomerates again (two stage agglomeration), the selectivity can be improved. 00103154 Liquefaction of gases Pettman, M. Brit. UK Pat. Appl. GB 2,333,148 (Cl. F25Jl/OO), 14 Jul 1999, Appl. 19981250, 8 Jan 1998. 12. A production process for a hydrocarbon gas involves (a) producing a stream of nitrogen-containing liquid, preferably pure nitrogen, at least partly by the utilization of the refrigeration effect produced by the evaporation of liquefied natural gas (LNG) to form the hydrocarbon gas, (b) transporting
huminite reflectance (0.26-0.30% R,) and the amount of volatiles (40-49 wt%, dry basis), they ‘belong to the category of soft brown coals (Iignites) whrch contam high a proportion of mineral components. 00103147 Degradation of polyethylene and polypropylene into fuel oil by using solid acid and non-acid catalysts Sakata, Y. r/ ul. J. Anal. Appl. Pyrolysis, 1999, 51, (l-2), 1355155. Plastic polymers, polyethylene (PE) at 430” and polypropylene (PP) at 380” were thermally and catalytically degraded into fuel oil by batch operation. The catalysts employed were acid-catalysts silica-alumina (SA-1, SA-2). zeolite ZSM-5 and non acidic mesoporous silica catalysts (silicalite, mesoporous stlica gel) and mesoporous folded silica (FSM). The yields of product gas, liquid and residues; recovery rate of liquid products, and boiling point distribution of liquid products by catalytic degradation were compared with those of non-catalytic thermal degradation. The present work is divided into three sections: (1) a study of effect of catalytic contact mode, (2) a study of effect of types of catalysts on plastic degradation, and (3) the evaluation of catalysts during the degradation of PE and PP by repeating batch operation. For PP degradation in phase contact with SA-1, the yield of liquid hydrocarbons was obtained with 69 wt%, and the boiling point of the oil ranged between 36 and 270”, equivalent to the boiling point of normal paraffins n-C,, to n-Cts. The aqueous products from catalytic degradation have a carbon number distribution very similar to commercial automobile gasoline. For vapour phase contact, the yield of liquid products was much lower (54%) and the rate of liquid recovery (or formation) was much slower. Catalysts possessing strong acid sites such as zeolite ZSM-5 accelerated the degradation of PP and PE into gases which resulted in low liquid yields. For FSM, which possesses no acid sites, the initial rates of PP and PE degradation into liquid were as fast as that over an acid catalyst (SA-1) and the liquid yields were higher. The liquid products from catalytic degradation over FSM have a carbon number distribution similar to a mixture of kerosene and diesel oil. Upon repeated use SA-1 deactivated very rapidly due to coke deposition on the catalyst, whereas FSM deactivated much more slowly. These findings concerning the FSM catalyst strongly suggest that the mesopores surrounded by the silica sheet may act as a reservoir for radical species. 00103148 Dual process for obtaining light olefins from heavy petroleum residual feedstocks Seimandi, N. M. CI crl. U.S. US 5,952,539 (Cl. 585.648; CO7C4/02), I4 Sep 1999, US Appl. 25,743, 20 Sep 1996. 9. This paper describes a process that is used in the production of gaseous olefins, such as ethylene, from two different process units that share the same downstream quench and fractionation facilities. One of the process units is a short-contact-time mechanical fluidized vaporization unit for processing petroleum residual feedstocks and the other is a conventional steam-cracking unit. The solid and vapour residue times can be controlled more accurately with this process, the other benefits include, light olefin production from less-expensive, heavier feedstocks (e.g. asphalt) compared with gas oils. A flow diagram of the process is also provided. 00103149 Ethanol production from lignocellulosic biomass by simultaneous saccharification and fermentation employing the reuse of yeast and enzyme Kim, J.-S. et al. J. Micro/Go/. Biotchol., 1999, 9, (3), 297-302. Saccharification and fermentation (SSF) experiments were carried out simultaneously with a lignocellulosic biomass. The effects of temperature on enzymic saccharification and the ethanol fermentation were also investigated. The batch SSF process gave a final ethanol concentration of 10.44 g/l and equivalent glucose yield of 0.55 gig, which was increased by 67% or higher over the saccharification at 42°C. The optimal operating condition was found to vary in several parameters, such as the transmembrane pressure, permeation rate and separation coefficient, related to the SSF combined with membrane system (semi-batch system). The efficiency of the enzymes and yeast lasted three times longer than in a semi-batch mode as compared to a batch mode. 00103150 Expansion mechanism of magnesia compound for oil well cement - thermodynamic principle and validation Yao, X. Xrnan Slrr)?orr Xue~uan Xuehao, 1999, 21, (2), 77-80. (In Chmese) Using the principle of chemical, thermodynamic and topochemical reaction models, the expansion mechanism of the hydroxide expanding phase for oil well cement slurry is discussed. It suggests that an expansion force results from crystallization pressure, which was converted from the reduction of chemical potentials in the reaction of hydroxide formation, i.e. the chemical energy of the reduction was converted into the mechanical work. Furthermore, special experiments were designed to validate the theoretical analysis by use of class G oil well cement and a novel expanding agent. The theoretical analysis and experimental findings indicate that two conditions are necessary: (1) the plastic strength of the slurry must be high enough to restrained crystal growth of the solid product (i.e. restrained crystal growth), and (2) soluble products of the pore solution for hydroxide in the slurry should be greater than that of the standard conditions. 00103151 Improvement of diesel performance with the addition of linear ethers of diesel fuels Jacques, V. H. cl 01. Adv. Alcohol hrrls World Proc. Int. Symp. Alcohol Furls, IZth, 1998, 188-199. Edited by Zhu Q.
356
Fuel and Energy Abstracts
November 2000
The effect two linear ethers, di-n-pentyl ether and di-n-hexyl ether, have on the cetane response, fuel performance, stability and material compatibility of diesel fuel was investigated. The selection of these ethers was based on their blending properties and the availability of potential feed stocks and proven chemtcal processes within the Sasol Process. Various concentrations of the ethers were blended with a high temperature Fischer-Tropsch synthetic diesel component to optimize the cetane number of the fuel blend. This optimum blend was then used to evaluate the general properties, rheology and stability (thermal and oxidation) of the diesel-ether blend and to determine its compatibility with fuel system elastomers and metals. Internationally approved test methods were used in this study. The benefits of using ethers as diesel blending components were demonstrated as they not only improved the cetane number of the diesel fuel, but also enhanced the overall diesel fuel performance. Literature has indicated that with ethers in diesel, improved combustion, a reduction in emissions and improved cold weather operability were some of the benefits that can be realized. 00103152 Improvements to direct coal liquefaction Eur. Comm., [Rep.] EUR, 1999, l-176. With a view to improving overall process economics of direct coal liquefaction processes without materially affecting core process design concepts, potential improvements in the dissolution stage have been examined. Work was concentrated in the areas of coal selection, coal preparation, coal blending and the addition of small quantities of ‘augmenting’ material to the usual coal-derived recycle solvents. In support of these, work was also carried out on hydrogen transfer mechanisms and on the development of novel analysis techniques. Certain blends of coal have been shown to exhibit marked synergistic or antagonistic effects in relation to the extent of coal dissolution. Although the causes of these effects are not understood, they appear to relate to specific coals. Their magnitude is sufficient to allow significant benefits to be obtained by the judicious selection and blending of coals. The use of density separation techniques during coal preparation has been confirmed to produce feedstocks of higher reactivity. This effect can be large, with the extent of coal dissolution being increased by up to 10% wt/wt (dmmf coal) if only the lower density fractions are processed. Higher density fractions would be used for applications such as gasification or combustion, where reactivity has less impact on costs. The addition of ‘aqgmenting’ solvents to coal liquefaction recycle streams has been shown to be feasible without seriously compromising process yields or operability. This would allow poor quality materials such as tyre pyrolysis oil or catalytic cracker decant oil to be upgraded at a much lower cost than would be possible in purpose-built equipment. It would have the additional merit of allowing hydrocracker conditions to be re-optimized to increase conversion by relaxing the constraints on solvent balance. Taken together, these improvements could have a significant beneficial impact on overall process economics. Although evaluation of these benefits was outside the scope of this programme, other studies indicate that several United States dollars per barrel could be saved crude oil price at which coal liquefaction could become commercially viable. 00103153 Investigation of efficient and economical chemical agents for optimization of current techniques for recycling of coal slurries Auquier, W. et al. Eur. Comm., [Rep.] EUR, 1999, l-130. An important quantity of slimes (fine coal washeries streams) is produced by the coal industry, which are difficult to valorize because of their characteristics (very fine sized particles and high ash content). These slimes possess however an energy potential which is not negligible. These fine products are naturally intended to be treated by processes based on the differences of surface properties between the hydrophobic coal particles and the hydrophilic mineral particles, such as flotation and selective oil agglomeration. An important characteristic of slimes stockpiled for a long period is the alteration and the oxidation of the coal particles. The oxidation increases dramatically the wettability of the coal particles and thus has a detrimental effect on the efficiency of these processes. A strong linking was established between the adsorbed amount of water vapour and the oxidation level of the slimes. The detrimental effect of oxidation was proved by agglomerability tests using heptane and gas oil. On the same slime artificially oxidized by staying in an oven at 150°C during different lengths of time, the yield decreases dramatically from 8 h of artificial oxidation. The conditioning, prior to agglomeration, of the slime in water slurry form using biodegrading and anionic surfactants, such as sodium oleate, improve the yields achieved on not or slightly oxidized slimes. Furthermore, good results are still achieved on slimes which were artificially oxidized during 8 h and more. Most often, such reagents have a detrimental effect on the selectivity, increasing the ash content of the agglomerates. However, this effect is minor and by cleaning the agglomerates again (two stage agglomeration), the selectivity can be improved. 00103154 Liquefaction of gases Pettman, M. Brit. UK Pat. Appl. GB 2,333,148 (Cl. F25Jl/OO), 14 Jul 1999, Appl. 19981250, 8 Jan 1998. 12. A production process for a hydrocarbon gas involves (a) producing a stream of nitrogen-containing liquid, preferably pure nitrogen, at least partly by the utilization of the refrigeration effect produced by the evaporation of liquefied natural gas (LNG) to form the hydrocarbon gas, (b) transporting