Reactions of brown coals with CO/H2O in the presence of sodium aluminate

In this paper, the influence of Na 2 CO 3 (NC) on the hydroliquefaction performances of Hongliulin (HLL) coal with an Fe-based catalyst, γ-FeOOH (FC), under mild conditions was investigated, and the properties of the resulting preasphaltene and asphaltene were examined. Results show that the addition of NC to FC-catalyzed liquefaction significantly promoted coal conversion and oil production and reduced water production under mild conditions, especially at high initial H 2 pressure. The H 2 consumption of mild liquefaction (0.53−1.93%) is much smaller than that of the traditional liquefaction processes, and the addition of NC to FC can enhance H 2 consumption, especially the runs with weak hydrogen donor solvents. The addition order of NC and FC is an important factor which can affect the activity of FC and NC binary catalysts. There exists a prominent synergistic effect between NC and FC in HLL coal hydroliquefaction, and the synergistic effect could be ascribed to the combined promotion actions of NC for the hydrolyzation of abundant oxygen-containing moieties (such as ether bonds and carbonyl groups) in HLL coal and the depolymerization of macromolecular structures of HLL coal.

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Effects of Sodium Carbonate Additive on the Hydroliquefaction of a Sub-bituminous Coal with Fe-Based Catalyst under Mild Conditions

Huang

et al. 2017

“…Reactions of low-ranking coals with CO and water have been shown to be promoted by addition of alkalis such as sodium aluminate. 30 Similar evidence for CO promotion comes from reactions of a Jordanian oil shale in the presence of water. 31 Reactions of Green River oil shale in CO−H 2 O 32−35 gave yields at least equal to those obtained by Fischer assay at low temperatures and oil differing in its characteristics from conventional retorted oil.…”

Section: Introductionmentioning

confidence: 81%

“…The water itself might increase conversion and improve the quality of the oil so that CO–H 2 O reactions should be compared to N 2 –H 2 O rather than to dry N 2 reactions. Reactions of low-ranking coals with CO and water have been shown to be promoted by addition of alkalis such as sodium aluminate . Similar evidence for CO promotion comes from reactions of a Jordanian oil shale in the presence of water .…”

Section: Introductionmentioning

confidence: 88%

Long-Time-Period, Low-Temperature Reactions of Green River Oil Shale

Marshall

Jackson

et al. 2018

Reactions of water-washed chunks of a deeply buried Green River oil shale (2880–2920 ft, well below the water table) have been carried out in N2–H2O and CO–H2O for up to 28 days at temperatures in the range of 280–370 °C. Large variations in yields of liquid products were observed for reactions below 330–340 °C. These were attributed to varying mineralogy in the chunks because the variations disappeared for reactions of ground samples or reactions above 330–340 °C, at which point the chunks disintegrated. Liquid-product yields of up to 70 wt % dry mineral matter free could be obtained from the chunks at temperatures as low as 320 °C, provided that long reaction times of 14 or 28 days were used. In particular, at lower temperatures, yields were higher under N2 than under CO, but the quality of the CO–H2O petroleum or oil/gas products tended to be better than that of N2–H2O products. The liquid products contained 1–2 wt % nitrogen, were high in aliphatic material, and contained significant amounts of heavily substituted aromatic rings.

“…Many of the studies in this area have been carried out under an inert atmosphere. However, a method of increasing the liquid yield, particularly for low-rank coals, is to substitute CO/H 2 O for an inert atmosphere. − Other potential advantages of the CO/H 2 O system are that hydrogen, which can be used for upgrading reactions, is produced by the water-gas shift reaction and that drying of the feedstock is not required.…”

Section: Introductionmentioning

confidence: 99%

Thermochemical Reactions of Blue Gum and Fossil Wood with CO/H₂O: Some Mechanistic Comments

Subagyono¹,

Marshall²,

Jackson³

et al. 2016

Our previous work suggested that liquid product yields from wood, unlike those from other biomass types, were not increased by CO/H2O reaction. Reactions of blue gum (BG) and fossil wood (FW) using high-temperature, high-pressure reactions have been investigated to define more precisely the biomass types for which CO/H2O is beneficial in liquefaction and to help understand the mechanism of the reaction. BG contains 25% lignin and 45% cellulose, whereas FW consists almost entirely of lignin derivatives with negligible cellulose derivatives. The effects of gas, water, and alkali have been investigated separately. Reactions of BG gave similar results under N2, H2, or CO with or without added alkali, and improved yields were obtained with an increase in the water-to-biomass ratio. These results are in agreement with the reactivity of BG being mainly associated with its carbohydrate content. In contrast, the product yield from FW was enhanced by the use of CO and further enhanced by the addition of a strong base, sodium aluminate. Some of the effect of alkali addition is associated with the extraction of humic materials from the much greater amount of lignin present in FW. The beneficial effects of CO and alkali are both consistent with the greater phenolic content of FW. Surprisingly, increasing the water-to-biomass ratio for FW led to a dramatic decrease in conversion to liquid products. The highest-quality products in terms of lower oxygen content were obtained from reactions of both BG and FW with CO/H2O/alkali.