Thermochemical refining of raw peat prior to liquefaction

The refining of raw peat prior to liquefaction has been studied. The fuel was treated with CO at an initial pressure of 1.3–4.0 MPa and a temperature of 290–320 °C in the presence or absence of K₂CO₃. The organic material of the peat underwent thermal degradation with evolution of low molecular weight oxygen-rich compounds, removed in the water and gas phase. The residual solid material had significantly improved properties compared with peat. The oxygen content was decreased to a value typical for bituminous coal and the calorific value correspondingly increased. Moreover, the hydrogen content of the product was higher than that of coals. The hydrogen demand in further hydrogenation of this artificially obtained ‘coal’ would be lower compared with natural coal. The techno-economical feasability of this process merits detailed study.     

The combined dewatering and liquid phase hydrogenolysis of raw peat using carbon monoxide

Raw peat, as received from the bog, was treated with carbon monoxide in batch autoclave at initial cold pressures comprising between 5.5 and 8.3 MPa and reaction temperatures ranging from 275° to 350°C. Potassium carbonate was added as a would-be catalyst for the shift reactions and its role has been found to be negligible in the presence of moderately humified peat with a relatively high ash content (8.1 wt. %).As a consequence of the above described treatment the organic matter in peat underwent significant changes losing its colloidal structure thus facilitating the separation between the resulting aqueous phase and the organic products. The latter appear as a sort of bitumen which is formed in quantities ranging from 25% to 60% (weight percentage relative to the maf peat initially present). Typical compositions (weight percentages) of the bitumen obtained are: C, 80%; H, 9%; O, 7%; N, 2% and S, 0.1%.     

Iron/sulfur-catalyzed coal liquefaction in the presence of alcohol and carbon monoxide

The activities of several iron-based catalyst precursors towards the liquefaction of various kinds of coals, ranging from brown to bituminous, were examined in alcohol–carbon monoxide systems. Pentacarbonyliron (Fe(CO)₅) with or without sulfur, or synthetic pyrite were found to be excellent catalyst precursors. Primary alcohols (ethanol and 1-propanol)–CO acted as an effective hydrogen source, whereas branched alcohols were less effective. In the Fe(CO)₅/sulfur catalyzed liquefaction of Yallourn coal at 375°C for 120 min, a high conversion (99.5%) was achieved in the presence of ethanol and CO (7.0 MPa/cold). The two-staged reaction (375°C, 60 min+425°C, 60 min) further improved the oil yield to 59.1% with a slight decrease in the coal conversion. The uptake of alcohol into asphaltene and preasphaltene fractions was distinctly observed, especially for Illinois No. 6 coal. The infrared analyses of the asphaltene fractions from each coal showed absorption at around 1705 cm⁻¹, characteristic for those obtained in the linear alcohol–CO systems. According to the characterization of the products by NMR and the preliminary study using a model compound, alkylation as well as the hydrogenolysis seem to contribute to the dissolution of coals.     

Catalytic liquefaction of various coals using a mixture of carbon monoxide and water

In a batch-autoclave, twenty coals were liquefied using a cobalt-molybdenum oxide catalyst with a mixture of CO and H₂0 at 400 °C with or without vehicle oil. Furthermore, lignite and peat were liquefied on tungsten oxide catalyst at 300 °C in the absence of CO. The reactivity of coal in this liquefaction is found to depend strongly on its rank. The vehicle oil significantly influences the extent of the water-gas shift reaction, especially when bituminous coals are liquefied, by dissolving such coals. Liquefaction of coal by this process is considered to take place via three routes: hydrogenolysis by the nascent hydrogen produced from the shift reaction; dissolution of coal into the vehicle oil which is an initial stage of hydrogenolysis; and a solvolytic reaction with H₂O, such as hydrolysis.     

Effect of pressure,temperature, pH,and carbon monoxide on oil yields from cellulose liquefaction

Pure cellulose was converted to oil by direct thermochemical aqueous-phase liquefaction. A model for yields from conversion was determined by regression of data from autoclave experiments. The conditions for optimum yield were found to be 315 °C, using 0.9 g equivalents/l of carbonate ion, and CO at 1.72 MPa (gauge pressure). Temperature had the most significant effect on yield. Analysis of the cellulose-derived product indicated a much larger fraction of aromatic carbon than had been thought possible previously. Compared to petroleum crude oil, the cellulose-derived oil had a greater fraction of high-molecular-weight components, a greater distillation residuum, greater viscosity, and greater oxygen content. Distillates of the cellulose-derived oil also contained significantly more oxygen than petroleum, but could potentially replace kerosene or related fuels.     

High-temperature reaction of tantalum with carbon monoxide

Chernogolovka. Translated from Fizika Goreniya i Vzryva, Vol. 26, No. 6, pp. 108–113, November–December, 1990.     

Upgrading and dewatering of raw tropical peat by hydrothermal treatment

In this study, hydrothermal upgrading and dewatering of raw tropical peat derived from Pontianak, West Kalimantan-Indonesia was evaluated at temperatures ranging from 150 to 380 °C, a maximum final pressure of 25.1 MPa and a residence time of 30 min. The moisture content of the raw peat was approximately 90 wt.%. Raw peat was hydrothermally upgraded without the addition of water in the laboratory scale. The yield of the solid products was between 53.0 and 99.7 wt.% and the effective calorific value of hydrothermally dewatered peat was between 17,290 and 29,209 kJ/kg following hydrothermal upgrading. In addition, the oxygen content in the solid product was varied from 38.4 to 15.6 wt.% after upgrading, while the carbon content from 55.2 to 77.8 wt.%. The hydrothermally upgraded peat fuel product also had an equilibrium moisture content of 2.3 wt.% and a maximum equilibrium moisture content of 17.6 wt.%. Upgraded peat is characteristically resistant to moisture adsorption at high humidity, which makes it promising for fuel based combustion. The change in the carbon-functional groups and their properties, as determined by FTIR and ¹³C NMR, are discussed in terms of the hydrothermal upgrading and dewatering process.     

The effect of alkali metal carbonate catalysts on the liquefaction of Victorian brown coal using carbon monoxide and steam

A study has been made of the use of the water-gas shift reaction as a source of hydrogen for the liquefaction of Victorian brown coal. At the comparatively low temperature of 350 °C liquefaction proceeds readily in the presence of alkali carbonate catalysts. Potassium and rubidium were found to be the most effective carbonate catalysts, giving the greatest oil yields. It was found that an essential requirement for the production of liquid products was close contact between coal and catalyst.     

Use of peat as an organic raw material for chemical processing

Data on the use of peat in different areas of chemical processing, including the production of sorbents, dyes, biologically active materials, pharmaceuticals, and balneological and cosmetic preparations, are generalized. Special features, advantages, and prospects of the use of peat as a raw material for chemical processing are discussed.     

Formation of carbon nanofibers via carbon monoxide disproportionation

Experimental results suggesting that carbon nanofibers are formed from amorphous carbon released at several compact active sites are reported. It was shown that the sites in question are catalyst crystal lattice defects formed at the crystallite contact boundaries.     

Hydrogen/carbon monoxide separation with cellulose acetate membranes

Hydrogen/carbon monoxide ratio adjustment is of fundamental interest to the petrochemical and energy industries for the production of C₁ chemicals. Cellulose acetate membranes have been found to be effective for this service and can offer improvements over other gas purification techniques in several respects including reduced capital and operating costs. Membrane and cryogenic processes are compared for the specific case of manufacture of a 1/1 H₂/CO syngas for oxoalcohol production. A particular advantage of the membrane process is its flexibility. This has benefited a recently installed facility for the Central Research Institute of the Electrical Power Institute of Japan for variable adjustment of the hydrogen to carbon monoxide ratio at a test facility demonstrating coal gasification/ gas turbine power production. Design and operating details of this facility are discussed. The membrane process may also be used to produce a pure CO product. The performance of polysulphone and cellulose acetate are compared for this application.     

电化学一氧化碳传感器电解质研究进展

本文对国内外电化学CO传感器的基本情况进行了简介,重点对电化学CO传感器电解质的研究和应用情况做了概述,并对未来的发展做了展望。     

一氧化碳变换装置催化剂的保护

本文就哈尔滨气化厂一氧化碳变换装置使用的QCS-04催化剂,在装填、使用、再生等操作过程中,为防止其活性及使用寿命的降低,而采取有效的保护措施进行的详细介绍。     

Preparation of carbon microfibers from coal liquefaction residue

Carbon microfibers (CMFs) were synthesized directly from coal liquefaction residue (CLR) by arc-jet plasma method at atmospheric pressure, and were examined using scanning electron microscopy and EDX spectroscopy. It has been found that the as-synthesized CMFs are smooth in surface and quite uniform in diameter that is smaller than 1 μm and centers at 700 nm. The possible mechanism involved in the formation process of CMFs is proposed and discussed in terms of the special chemical composition of CLR and the process parameters. This work may open a new way for direct and effective utilization of the CLR.