Brown Coal Liquefaction Research Articles

Direct primary brown coal liquefaction via non-catalytic and catalytic co-processing with model, waste and petroleum-derived hydrogen donors

Direct coal liquefaction (DCL) seems to be a suitable way to convert low rank coals into liquid fuels, especially when problematic wastes are used together with this feedstock. It is also a solution to become energy independent for many countries which have significant coal resources and limited access to crude oil. The aim of this research was to investigate DCL process by the co-processing of brown coal with model-, petroleum- and waste-derived solvents. The brown coal with and without W, Fe and Mo metals supported on its surface was tested. Thirteen DCL tests with added hydrogen pressure were carried out in the autoclave. These tests were classified in two groups. First group covered reactions using model and petroleum-derived solvents (tetralin, 1-methylnaphthalene, light cycle oil (LCO), hydrotreated LCO, C9+ fraction and decalin) with non-impregnated brown coal. Then, LCO was chosen as solvent for carrying out three tests using the metals supported on coal. Finally, waste tires pyrolysis oil was used as a waste-derived solvent for other three tests with molybdenum supported on coal. For tests using LCO, the total amount of direct liquid and n-heptane soluble products was 20 wt% higher using metal covered brown coal in comparison to unmodified one. The test with the brown coal impregnated by 1% of molybdenum resulted in the best efficiency, thus this type of coal was chosen as a catalytic feedstock for the tests with waste tires pyrolysis oil.

23.褐炭液化反応の研究(14) : 褐炭中のClの反応挙動

23.褐炭液化反応の研究(14) : 褐炭中のClの反応挙動

26.褐炭液化反応の研究(17) : 急速昇温オートクレーブを用いた液化初期過程の反応挙動の検討

26.褐炭液化反応の研究(17) : 急速昇温オートクレーブを用いた液化初期過程の反応挙動の検討

25.褐炭液化反応の研究(16) : パイロットプラント予熱器および反応器での液化挙動

25.褐炭液化反応の研究(16) : パイロットプラント予熱器および反応器での液化挙動

27.褐炭液化反応の研究(18) : パイロット一次水添溶剤の性状とその反応性能

27.褐炭液化反応の研究(18) : パイロット一次水添溶剤の性状とその反応性能

Direct liquefaction of lower-rank coals and biocoals with magnetically separable catalysts as a sustainable route to fuels

Direct coal liquefaction (DCL) encompasses the catalytic conversion of coal by hydrogen and high temperatures in presence of a solvent and can be used to produce transportation fuels on a commercial scale. DCL economy suffers from its severe reaction conditions (up to 20MPa hydrogen pressure and reaction temperatures up to 728K). Industrial catalysts are of low activity since only cheap disposable iron-based catalysts are used. We tested two groups of highly active low-rank coals, one “bitumen-rich” brown coal with a high aliphatic content and a biocoal from the hydrothermal carbonization (HTC) of biomass employing novel catalysts. The oil yield (up to 71wt.%) and the oil quality from the direct brown coal liquefaction with a small catalyst amount of nanostructured Co/SiO2 or Co/SiO2/Fe3O4 showed promising results for further upscaling. The liquefaction of the biocoal with low amounts of Ni/TiO2 (oil yields up to 42wt.%) proved to be a meaningful perspective especially for environmental concerns. Furthermore, Co/SiO2/Fe3O4 and Ni/TiO2 could be recovered and recycled by magnetic gradient, with only small decreases in their catalytic activity.

Direct liquefaction of a Chinese brown coal and CO2 gasification of the residues

Direct liquefaction of a Chinese brown coal (Yunnan) was carried out at moderate conditions in a laboratory-scale autoclave, and the effects of temperature and H2 pressure on the products distribution were investigated. In addition, the reactivities of the liquefaction residues during CO2 gasification were examined with a thermo-gravimetric analyzer (TGA). The results show that Yunnan brown coal is readily liquefied, with its conversion exceeds 80% at 425°C even without catalyst and no holding time. Temperature is more effective in enhancing oil and gas yield than H2 pressure, while liquefaction conversion changes negligibly with varying temperatures (above 375°C) and H2 pressures. The organic structures and inorganic compositions of the residues obtained under various liquefaction conditions were examined by IR and XRD analyses. The reactivities of the residues during CO2 gasification are very high (with reactivity index (R) higher than 30h−1), even higher than that of the raw coal in some cases. This is resulted from that the residues are enriched in mineral matters, especially the alkaline earth metals such as calcium sulfide (CaS), calcium oxide (CaO), and calcium carbonate (CaCO3). These results supply references to the efficient utilization of residues and improving the economy for direct coal liquefaction plants.

褐炭液化前処理としての水熱処理および油添造粒による高濃度改質褐炭・溶剤スラリーの調製

褐炭液化前処理としての水熱処理および油添造粒による高濃度改質褐炭・溶剤スラリーの調製

Efficient Direct Brown Coal Liquefaction with Sulfided Co/SiO2 Catalysts

Efficient Direct Brown Coal Liquefaction with Sulfided Co/SiO₂ Catalysts

Direct Liquefaction of Brown Coal Using a 0.1 Ton/Day Process Development Unit: Effect of Hydrothermal Treatment on Scale Deposition and Liquefaction Yield

Scale deposition is a very troublesome problem for a long-term stable operation of a direct coal liquefaction plant. The scale reduction effect of hydrothermal treatment (HTT) for a brown coal liqu...

Hydrothermal Treatment of Brown Coal To Improve the Space Time Yield of a Direct Liquefaction Reactor

The possibility of hydrothermal treatment (HTT) of brown coal at 200–350 °C was examined as a pretreatment method for improving the space time yield of a Victorian brown coal liquefaction reactor. Main reactions occurring during HTT below 350 °C were decarboxylation and dehydration, by which most of carboxylic groups were decomposed. Sodium and chlorine in the brown coal were almost completely removed below 250 and 300 °C, respectively, during HTT. Around 20–30% of Ca and Mg in the brown coal was also removed by HTT below 350 °C. The viscosity of the coal–solvent slurry prepared from a HTT coal was less than ¹/₁₀ of the viscosity of the coal–solvent slurry prepared from a just dewatered coal. This enabled the increase of the coal concentration of the coal–solvent slurry from 28 to 40 wt %. The significant increase of the coal concentration of the coal–solvent slurry prepared from the HTT coal was found to be realized mainly by the decrease of the pore volume of the coal particles through HTT. These results suggest that HTT will be a pretreatment method effective not only to increase the space time yield but to suppress the scale formation of the brown coal liquefaction process.

64 褐炭および木質バイオマスの溶剤抽出液化(液化・共処理)

64 褐炭および木質バイオマスの溶剤抽出液化(液化・共処理)

Liquefaction of brown coal by rubber-degrading micro-organisms

Liquefaction of brown coal by rubber-degrading micro-organisms

Absorption characteristics of methane and carbon dioxide on fluorinated LaNl 4.7Al 0.3 alloy hydride surface

The Brown Coal Liquefaction (BCL) process is a two-stage liquefaction (hydrogenation) process developed for Victorian brown coal in Australia. In the BCL process, the heavy product (vacuum residue) derived from the coal in the primary hydrogenation, which is named CLB (coal liquid bottom, boiling point > 420°C), is treated in a solvent (CLB/solvent ratio, 18–14, wt./wt.) under high temperature (200–290°C) and high pressure (4–5 MPa) to remove the ash and heavy preasphaltenes. This solvent de-ashing process uses toluene or coal-derived naphtha as a de-ashing solvent. After dissolving the CLB into the solvent, insoluble solid particles which consist of the ash and heavy preasphaltenes are settled in a settler by gravity and separated from the solution as an ash-concentrated slurry. The ash-concentrated slurry and the de-ashed solution are withdrawn from the settler as an underflow and overflow, respectively. The de-ashing solvent is recovered from both the overflow and underflow by distillation, and reused in the de-ashing process. The de-ashed heavy product recovered from the solution by eliminating the solvent is further hydrogenated in the secondary hydrogenation.This paper discusses the solubility of the CLB into toluene and settling velocity of the ash under the de-ashing conditions. The extraction experiments made clear that toluene dissolved ∼ 60 wt.% of preasphaltenes (benzene insoluble-pyridine solubles) in the CLB under the following conditions, temperature 100–300°C and CLB/toluene ratio (wt./wt.) of 13 or less. This solubility of CLB (ϵCLB) under the de-ashing conditions is expressed as ϵCLB = CBS + 0.6CBIorg, where CBS and CBIorg are the contents of benzene solubles and organic benzene insolubles, respectively, and organic CLB (ash-free CLB) = CBS + CBIorg. The de-ashing experiments confirmed that the insolubles including ash formed a boundary of concentration during the settling period, and the de-ashing efficiency was represented by the settling velocity of the boundary (V), V is expressed as V = ACLB(CSA/2.5)−0.91(T/573)9.5. Where, ACLB, CSAand T are parameters expressing the properties of organic CLB, ash content in the feed slurry (wt.%) and temperature (K), respectively. The ACLB is also expressed by using the analytical results of the organic insolubles in the CLB under the de-ashing conditions. The ash content of the de-ashed heavy product recovered from the upper zone of the boundary is less than 3000 ppm, which is low enough to feed as a mixture with two times of the middle distillate to the secondary hydrogenation over NiMo catalyst with fixed bed reactors.

石炭液化用高活性リモナイト触媒の開発 ２ インドネシア産Ｎｉ含有リモナイトの性状と液化活性

Properties and liquefaction activities of Ni containing Soroako limonite ores, deposited in the upper layers of nickel mine, Sulawesi Island in Indonesia, were examined by comparing with those of Yandi Yellow limonite in Australia. It was found that Soroako limonite consisted of mainly a -FeOOH and Al (OH) 3, containing 1.0-2.0wt‰ of Ni, Cr, Si and a small amount of Mg and Co on the dry basis. Results of the wet pulverization test with a process solvent by using an agitated mill showed that Soroako limonite could be easily pulverized to sub-micron particle size as well as Yandi Yellow. The finely pulverized Soroako limonite catalyst exhibited a high liquefaction activity in the liquefaction of Indonesian Banko coal, compared to Yandi Yellow catalyst. It appeared that Soroako limonite could be transformed into smaller crystallite size of pyrrhotites (Fe1-XS) by the addition of elemental sulfur, leading to high catalytic activity. The agglomeration or crystal growth of pyrrotites may be suppressed by Al-O-Fe strong interaction between FeOOH and Al (OH) 3. Results of TEM-EDX analysis indicated that Ni could be coexisted with Fe and S in the used catalyst. It suggested that Ni could be located near the Fel_xS structure, leading to the promotion effect on the liquefaction activity. Soroako limonite can be used advantageously in a commercial plant as a cata-lyst raw material for the liquefaction of brown coal in Indonesia.

Solvent deashing from heavy product of brown coal liquefaction using coal-derived naphtha

Solvent deashing from heavy product of brown coal liquefaction using coal-derived naphtha

00/02515 Scales and sediments formed during liquefaction of Victorian brown coal with a 50 ton (dry coal)/day pilot plant

00/02515 Scales and sediments formed during liquefaction of Victorian brown coal with a 50 ton (dry coal)/day pilot plant

00/01250 Hydrotreatment of liquefied oil derived from brown coal

The synthetic liquids derived from the liquefaction of brown coal may be used as alternative feed stocks for producing organic chemicals and various carbon materials, in addition to their use for producing transportation fuels. However, the liquefied crude oils from coal have higher amount of hetero atoms such as nitrogen, sulfur and oxygen than petroleum feed stocks, resulting in the formation of gum or sludge during their storage or their transportation to the oil refinery. In this paper, effects of hydrotreatment conditions for the crude liquefied oil were examined by using a fixed bed reactor with a conventional Ni-Mo-P/Al{sub 2}O{sub 3} catalyst, in relation to the storage stability and the chemical compositions of product oil. It was found that denitrogenation, desulfurization and deoxygenation reactions resulted in the improvement of storage stability by the two stages hydrotreatments. Analysis indicated that aromatics were finally decreased to about half of crude liquefied oil by the hydrotreatments. It was considered that coal liquefied oil could be utilized as a part of feed stocks for conventional oil industries not only to produce transportation fuels but also to produce chemicals.

99/03514 Solvent de-ashing from heavy product of brown coal liquefaction using coal-derived naphtha: Okuma O. et al. Fuel Processing Technoloy, 1999, 60, (2) 119–134

99/03514 Solvent de-ashing from heavy product of brown coal liquefaction using coal-derived naphtha: Okuma O. et al. Fuel Processing Technoloy, 1999, 60, (2) 119–134

Solvent de-ashing from heavy product of brown coal liquefaction using coal-derived naphtha

The brown coal liquefaction (BCL) process is a two-stage liquefaction (hydrogenation) process developed for Victorian brown coal in Australia. In this process, the heavy liquefaction product (vacuum residue) derived from the coal in primary hydrogenation, which is named CLB (coal liquid bottom), is treated in a solvent at high temperature (200–290°C) and high pressure (5 MPa) to remove the ash and heavy preasphaltenes (solvent de-ashing). This solvent de-ashing step uses toluene or coal-derived naphtha as a de-ashing solvent. After dissolving the CLB into the solvent, insoluble solid particles which consist of the ash and heavy preasphaltenes are settled by gravity and separated from the solution as an ash-concentrated slurry. The de-ashing efficiency (recovery of the heavy product and rate of ash removal) depends on the operating conditions and the properties of CLB and solvent, because they affect the extract yield from CLB, the settling velocity and concentration of the ash in the settler. This paper describes the stable operating conditions of the de-ashing plant using a coal-derived naphtha produced in the primary hydrogenation by discussing the effects of such parameters on the de-ashing efficiency. The de-ashing experiments with batch and continuous systems using the naphtha were carried out to determine the extract yield from CLB ( ε CLB), the settling velocity of the ash boundary ( V NP) and the maximum ash content ( Z NP) in underflow of the settler under the de-ashing conditions. According to the results of these experiments, the equations expressing ε CLB, V NP and Z NP are introduced by using the de-ashing conditions, the naphtha density and the properties of CLB expressed by analytical results of ash content and solvent extraction. The stable operating conditions of a continuous de-ashing system using coal-derived naphtha can be fixed by determining the upward velocity of solution in the settler, and the flow rates of ash in underflow and feed slurry based on the predictions of these equations.