Coal Liquefaction Yield Research Articles

Karakteristik Batubara Peringkat Rendah Formasi Bobong dan Implikasinya Terhadap Coal Liquefaction

This research was conducted on the Bobong Formation coal in the form of geochemical analysis. The Bobong Formation is geologically located in the Banggai Sula Basin, Pulau Taliabu Regency, North Maluku Province. The study focused on low rank coal on the liquefaction process. Sampling locations are carried out in each coal outcrop near the river channel north of Taliabu Island. Sampling is done by the ply by ply method. Sampling is done at several points of observation in the form of a station. Coal sample analysis is carried out in the form of proximate and ultimate. The coal liquefaction experiment through the pyrolysis method with assisted microwave was carried out with raw material in the form of 300 g of 20 mesh coal, 3 g active carbon catalyst, temperature of 600 C, vacuum pressure (-3 mmHg) and 600 watt microwave power. These problems are focused on the influence of low rank coal geochemistry of the Bobong Formation in the Banggai Sula Basin on coal liquefaction and the behavior of coal liquefaction on changes in time variables. The physical and chemical characteristics of coal in coal content are ash (16.36%) adb, inherent humidity (8.19%) adb, volatile substances (22.21)%) adb and fixed carbon (48.60% ) adb, hydrogen (4.55% adb), oxygen (25.94% adb), carbon (65.33% adb), sulfur (2.54% adb) and nitrogen (1.64% adb). The optimal coal liquefaction yield with a reaction time of 60 minutes is 49%. The results of coal liquefaction did not change at the reaction time of 70 minutes and 80 minutes, respectively 49.01% and 49.02%. Coal with more lignite is more easily liquefied than sub-bituminous because coal has a higher hydroxyl group.

Characteristic of low rank coal from Warukin Formation, South Kalimantan and their implication for coal liquefaction

The research was conducted on petrology and geochemistry of coal at Warukin Formation, Barito Basin, in South Kalimantan. Research is focused on composition and behavior of low rank coal toward its liquefaction. The sampling location is in the coal mining of PT. Adaro Indonesia which involves some mining location such as Wara, Tutupan and Paringin area. The sampling was conducted in seam Wara 110, Wara 120, Wara 200, Tutupan 210 and Paringin 712 with ply by ply method. Sample analysis consists of proximate and ultimate properties, composition of maseral, reflectance vitrinite, as well as composition of mineral, major element and organic geochemistry. Experiment of coal liquefaction was conducted on the autoclave with temperature and pressure of 120° C and 14.17 psi. The problems are focusing on influence of maceral, mineralogy and geochemistry low rank coal of Warukin formation in Barito Basin on coal liquefaction, behavior of coal liquefaction to the change in variable of time to result of coal liquefaction yield. The physical and chemical characteristics of coal in Wara seam content are ash (< 7 %) adb, inherent moisture (< 31%) adb, volatile matter (< 5)%) adb and fixed carbon (< 33%) adb. Then in Tutupan and Paringin are ash < 3% adb, inherent moisture < 21% adb, volatile matter < 48% adb and fixed carbon < 40 % adb. Composition element in Wara coal are carbon < 64 % adb, hydrogen < 7 % adb, oxygen < 34% adb and nitrogen < 1% adb, then in Tutupan and Paringin seam consist of carbon (< 65 % adb), hydrogen (< 6 % adb), oxygen (< 32% adb) and nitrogen < 2% adb. The content of maseral in Wara seam coal consist of vitrinite, liptinite, inertinite maseral group which are 81%, 51% and 27% respectively. Result of coal liquefaction on Wara seam with time reaction of 30 minutes is 48.60 % and for 60 minutes is 51.27%. The result of liquefaction is decreasing on reaction time of 90 minutes and 120 minutes, which are 46.72%, 35.51% respectively. The liquefaction conversion obtained from Tutupan and Paringin seam within reaction time 30 minutes and 60 minutes are 8.22% and 15.46% respectively. The conversion is decreasing on reaction time 90 minutes and 120 minutes which of 6.23% and 5.54% respectively. The coal with more lignite is easier to be liquefied than sub-bituminous because the coal has higher hydroxyl group.

Combination of electron beam irradiation and electro-reduction — A novel method for direct coal liquefaction

A novel method was developed to combine electron beam irradiation with electrochemical reduction to increase coal liquefaction yield. Coal samples were irradiated by a stream of high energy electron beam. The samples were treated with tetrahydrofuran to extract the possible products from electron beam irradiation. The products were analyzed to calculate the yield. It was observed that the extract yield increased as the absorbed doses increased. The increase was more significant when the absorbed dose was 25 kGy in O2 atmosphere. The irradiated samples were further electrochemically reduced in sodium hydroxide electrolyte solution for liquefaction. Corresponding elemental analyses, Fourier Transform Infrared spectroscopy, linear sweep voltammetry, nuclear magnetic resonance and chronoamperometry were employed to investigate the effect of the electron beam irradiation on the electrochemical reduction of coal.

Coal Macerals Response to Coal Liquefying Activity Based on SPSS - Take No.11 Coalbed in Antaibao Mine for Example

Coal liquefaction is the available, adoptable method of relieving the energy crisis from crude oil supply in large scale. The coal type and react activity are hot research. In this paper, From the SPSS (Statistical Product and Service Solutions) data correlation analysis and hierarchical clustering graph about the macerals respond to coal liquefaction yield, all the correlation coefficients determine the liquefying activity of submacerals. It shows that every liquefaction intendancy is agreed with the maceral inherent petrology property, and these views have been found in previous study. The results indicated that by means of SPSS method, we can take investigation when there is not proper experiment condition. Compared with painstaking seperating-maceral experiment and the impossible separation to submacerals, it may be a simple, accurate, comprehensively, completely and practically method in a sense.

First-stage direct liquefaction of a subbituminous coal with oil-soluble metal naphthenates as dispersed catalyst precursors

The activities of catalysts produced from Mo, Co and Fe naphthenate oil-soluble precursors were investigated and the particle size and crystalline phase of each metal sulfide from each metal precursor were determined by SEM-EDX, TEM and XRD. Also, the synergistic effect between Fe and Co or between Fe and Mo in the hydroliquefaction of Usibelli (Alaska) subbituminous coal was investigated. In catalytic liquefaction experiments, excess elemental sulfur (three times the stoichiometrically required amount to convert the metal to the respective sulfide form: FeS 2, Co 9S 8 and MoS 2) was added to produce highly dispersed metal sulfide catalysts in situ. Parametric continuous unit tests were carried out to verify the reproducibility of the batch microautoclave results and to gather enough sample for further quantitative analyses of the coal liquid products (distillate yields and H/C atomic ratio). The hydrogen pressure drop or relative hydrogen consumption followed the order Mo > Co > Fe. This trend gave good linear correlations with coal liquefaction yields (coal conversion and oil yield). It was confirmed that the addition of Co or Mo as a promoter to Fe as a primary component gave a synergistic effect on both coal liquefaction yields (coal conversion, oil yield and distillate) and H/C ratio of the liquid products.

96/01391 A study of chemical dehydration of coals and its effect on coal liquefaction yields

Although great strides have been made in developing the technology of coal liquefaction processes in recent years, many unsolved problems still remain before a viable and economical process can be achieved. The technological problems that still exist can be solved through a more fundamental understanding of the chemistry associated with each stage of the coal liquefaction process, starting with any pretreatment steps that may be carried out on the coal itself. One pretreatment process which can improve the economics of coal liquefaction is coal drying, particularly for the lower rank coals. However, there is also considerable evidence to show that drying has a detrimental effect on the liquefaction behavior of coals. The problem that needs to be solved is that of economically drying coal without adversely affecting its liquefaction reactivity. Only recently have there been any systematic studies of the methods of coal drying on coal structure and the role water plays in enhancing or lessening coal reactivity toward liquefaction. Thermal methods of drying can alter the physical structure of coal as well as promote undesirable chemical reactions. Low-temperature drying of coal, on the other hand, should preserve the structural integrity, reduce retrograde reactions, reduce thermal degradation, and provide informationmore » on nonbonded, chemisorbed, and physisorbed water. Chemical drying of coals is a relatively unexplored technique for removing water at low temperature.« less

95/00232 Mechanism of surfactant-assisted increase in coal liquefaction yields

95/00232 Mechanism of surfactant-assisted increase in coal liquefaction yields

The effects of solvent quality on the liquefaction of two different types of coal

Thermal and catalytic liquefaction runs were performed at 400 and 430 °C for 30 min in hydrogen with different hydroaromatic:aromatic, hydroaromatic:naphthenic or naphthenic:aromatic solvent blend ratios for Australian bituminous and Indonesian subbituminous coals. The results indicate that the subbituminous coal needs more efficient external hydrogen transfer to maintain high conversion than does the bituminous coal, implying that both hydrogen transfer from donor solvent and catalytic transfer from molecular hydrogen are important in improving subbituminous coal liquefaction yields. In bituminous coal liquefaction, it appears that the form of hydrogen, whether molecular or donatable from hydroaromatic solvent, is not critical as long as the internal hydrogen is present in sufficient amount and in a form usable by the coal and a minimum hydroaromaticity of the solvent system (tetralin:naphthalene ratio 1:3) is maintained. A temperature increase from 400 to 430 °C significantly affects the bituminous coal liquefaction yield, but little improvement is observed for the subbituminous coal. To optimize liquefaction, the solvent quality, temperature and catalyst must be properly chosen, depending on coal rank.

Electrolytic pretreatment of coal for enhanced liquefaction

Mild oxidation of coal can result in enhanced coal liquefaction yields, presumably due to the formation and decomposition of carbonyl or hyperoxide groups from the benzylic groups of alkyl bridges in the coal structure. Due to the ability to closely control the oxidizing or reducing conditions at the electrode, electrochemical routes for coal pretreatment have attracted considerable interest. Electrolysis of an Illinois coal in NaOH and H 2SO 4 electrolytes at potentials of between 1.0 and 1.3 V vs. saturated calomel electrode (SCE) resulted in hydrogen production at current efficiencies of about 100% while a significant amount of sulfur was removed from the coal. Liquefaction of the coal was carried out in tetralin at 375°C with an initial hydrogen pressure of 140 psig (10.5 bar). The data obtained clearly indicate that electrochemical oxidation of coal slurries results in significant enhancement (up to 27%) in coal liquefication yields. The products (liquid) obtained from the liquefication of the electrolyzed coal contained substantially larger amounts of the more desirable pentane soluble fraction, while the undesirable benzene insoluble fraction content diminished. The data also show that the molecular weight of the liquid products obtained from pre-electrolyzed coal samples is very much lower than the corresponding molecular weight of the liquid products obtained from an untreated coal under the same liquefaction conditions.

VARIATION OF TEMPERATURE EFFECT WITH HYDROGEN SUPPLY IN NON-CATALYTIC COAL LIQUEFACTION

ABSTRACT A Spanish subbituminous coal was subjected to non-catalytic liquefaction with tetralin in a 250 ml stirred autoclave. The operating conditions used were: one hour reaction time, 17 MPa operating pressure and 400 r.p.m, stirring speed. The liquefaction products were fractionated into oils, asphaltenes, preasphaltenes and solid residue by a solvent extraction technique using pentane, toluene and THF as extractive solvents. It was found that the influence of temperature on coal liquefaction yields and product distributions varies with the amount of donatable hydrogen. Total coal conversion increases with temperature, when very high tetralin/coal ratios are used On the contrary, when 1/1 ratio is used, conversion does not seem to depend on temperature, and appears to be limited by the amount of liquid medium available as physical solvent. At intermediate tetralin/coal ratios,conversion generally increases with both factors: temperature and amount of solvent. However, retrogressive reactions are observed at 475°C which indicates that these reactions are produced at high temperatures when there is not enough hydrogen in the system As far as product distribution are concerned, it is observed that asphaltenes and preasphaltenes decrease, while oils + gases increase with temperature.

Temperature programmed aqueous liquefaction extended to supercritical conditions

Temperature programming of liquefaction reactors is further refined for increasing coal liquefaction yields by matching radical production rates with the slurring medium's ability to donate hydrogen atoms. E.s.r., DTA and TGA data are utilized in the design of two different 60 min temperature programming profiles. For Indian Head lignite, using an aqueous/H 2S slurry medium, the improvement in yield essentially followed the order: isothermal < rapid < slow increasing temperature programming profiles of the reactor. The optimum conversion yields of Indian Head lignite for the 300–400 °C temperature range were 95% THF-soluble products, 83% toluene-soluble products and 57% cyclohexane-soluble product yields. These are +14%, +11% and +20% respective yield improvements over those obtained with the corresponding 60 min, 400 °C isothermal reaction. Residence times at 300 °C improved the THF-soluble product yield; in the 300–350 °C range further improved all three product yields; in the 350–400 °C range primarily improved the yields of toluene- and cyclohexane-soluble products; in the 400–450 °C range further improved the toluene-soluble product yield; and in the 450–480 °C range reduced the THF-soluble product yield.

石炭水添液化反応における循環溶剤の水素供与性の評価

Hydroaromatic components in solvents for coal liquefaction reaction, by donating their naphthenic hydrogen, play an important role in stabilization of radical fragments caused by thermal repture of coal.The starting solvents AO and HAO and the recycling solvent S-1-S-6 were analysed with the HPLC-MS method to elucidate their chemical components . From the results of mass analyses for various compounds of different aromatic ring number classes, the amounts of donatable hydrogen bonded to naphthenic rings in hydroaromatic structure were estimated. These were called PDQI values (proton donor quality index), indicating the measure of hydrogen donatability. Also new procedure by 1H-NMR were devised for estimation of PDQI. The amounts of hydrogen in the β and further positions in naphthenic rings (HPLC-1H-NMR (β)) and in the α position as well as further positio ns in aromatic rings (HPLC-1 NMR (α)) were measured. These measurements were performed on compound class fractions in which the ranges of chemical shifts for various bonding hydrogens especially α hydrogens, can be precisely calculated owing to their uniform aromatic ring structure separated by HPLC. The estimates of the PDQI from the three different methods were compared, and showed fairly good agreement.Benzene soluble conversion yields of coal liquefaction were correlated with the PDQI values of each recycling solvent used for liquefaction reaction . The solvent HAO had the highest value of PDQI: from 7.7 to 10.2mg-H/g-solvent, according to the different methods described above. HAO also provided the highest yields in coal liquefaction . As solvents were recycled, their PDQI gradually decreased, and coal liquefaction yields also decreased. This phenomena indicates that hydrogen donatability of solvent gradually decreases owing to the loss of hydroaromatic naphthene hydrogen to donate to coal fragments, with repetition of recycle runs.