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International audience; Highly porous organic aerogels have been prepared for the first time from a mixed lignin-phenol-form-aldehyde (LPF) resin. Six different P/L weight ratios and two (L + P)/F weight ratios have been tested, leading most of times to nice and reproducible hydrogels which were subsequently either supercritically of freeze-dried. A broad family of aerogels and cryogels, respectively, was thus obtained. These materials were thoroughly investigated in terms of porous structure, based on pycnometry, adsorption and electron microscopy studies. The pore-size distributions were found to depend strongly on the initial composition, but not on the method of drying. The thermal conductivity of aerogels and cryogels has been measured and found to be minimal in materials combining both high mesopore volume and ideal pore sizes.

The different methods of wood biomass thermal liquefaction at atmospheric and elevated pressures were investigated in order to select the more effective one. Wood biomass liquefaction by melted formate/alkali mixtures and with the use of metallic iron/Na2CO3 system is carried out at low pressures. But these methods give only moderate yield of bio-liquids. The highest yield of bio-liquid was obtained in the process of biomass dissolvation in methanol media in the presence of Zn–Cr–Fe catalyst at 20 MPa. Co-pyrolysis and co-hydropyrolysis of biomass/polyolefine mixtures makes it possible to obtain the rather high yield of bio-liquid at the moderate pressures (3 MPa).

The processes of brown coal autothermal carbonization and steam gasification in a fluidized bed of catalytically active materials, catalytic hydrogenation of brown coal and its mixtures with waste polyolefines and sapropelitic coal liquefaction have been studied. The application of fluidized bed of iron-containing materials, which are able to catalyse the volatives oxidation provides the autothermal conditions of coal carbonization without the formation of harmful polycyclic compounds and pyrolysis tars. Based on catalytic method of coal carbonization, the integrated process of fuel-gas and syn-gas synchronous production from brown coal was suggested. The circulation of hot char-product particles between carbonization and gasification reactors supplies by heat the steam-gasification process. Therefore it goes at the low oxygen consumption and produces more clean syn-gas as compared to conventional gasification processes. The various approaches were used in order to increase the yield and quality of liquids produced from brown coal. They including the application of inexpensive iron-ore catalysts, hydrogen-donor organic solvents, activation treatment of coal by ozone, co-processing of coal with polymer wastes. It was found that sapropelitic coal can be converted to liquids with the yield by 7 times higher as compared to brown coal.

Co-processing of polyolefinic polymers with Kansk-Achinsk (Russia) brown coal was investigated by thermogravimetry (TG) and autoclave pyrolysis under argon and hydrogen pressure in catalytic conditions (or not). Gas chromatography–mass spectrometry (GC–MS) and high performance thin layer chromatography (HPTLC) were used to analyze the distillate products. Some synergistic effects indicate chemical interaction between the products of thermal decomposition of coal and plastic. In co-pyrolysis under H 2 a significant increasing of coal conversion degree as a function of polymer amount in feedstock was found. Simultaneously the coal promoted formation of distillate products from polymers. Some alkyl aromatic and O-containing substances were detected in co-pyrolysis fraction boiling in the range 180–350 °C, indicating interactions between coal and plastic. Iron containing ore materials, modified by mechanochemical treatment, demonstrated a catalytic activity in hydropyrolysis process. In catalytic conditions, increases of the mixtures conversion degree by 9–13 wt.%, of distillate fraction yields by 1.2–1.6 times and a decrease of olefins and polycyclic components were observed.

The pyrolysis in a hydrogen atmosphere of pine wood and synthetic polymers (polyethylene and polypropylene) mixtures was studied in a rotating autoclave. The effects of reaction temperature, wood/polymers mixture composition and catalysts, on the mixtures conversion into liquids and gases were established and discussed. The used catalysts were pyrrhotite and haematite materials activated by mechanochemical treatment. In the co-liquefaction processes the interaction between fragments of wood and polymers thermal decomposition took place. This results in non-additive increase of the wood/polymers conversion degree by 10–15 wt.% and of the yield of distillate fractions by 14–19 wt.%. Iron ore materials were found catalytically active in the process of hydropyrolysis of wood/polymers mixtures. By using these catalysts a significant increase of the distillable liquids amounts (by 14–21 wt.%) and a sharp decrease of olefins and cycloparaffins content (by approximately two to three times) were observed.

Hydrogenation of liptobiolitic coal from the Barzas Pit (Russia) in a petroleum residue as a solvent was investigated in the presence of an iron containing ore catalyst at 400–430 °C and working pressure 7.1 MPa. Near 94–97% of the coal organic mass was converted into gaseous and liquid products. The addition of the catalyst in amount of 5% to the coal mass increases the degree of the coal conversion by 21–23 wt%. Under these conditions, the yield of hydrocarbon light liquid products (bp

The chemical composition of heavy liquids (b.p.>180 °C) obtained by co-pyrolysis of polyolefins/wood biomass mixtures in autoclave conditions under inert atmosphere was investigated by FTIR, 1H NMR, GC-MS, high performance TLC combined with densitometry techniques. The preliminary separation of heavy liquids into different fractions by open LC and TLC methods had been used. Some perspectives of polymer and biomass thermal conversion during co-pyrolysis process were discussed.

Carbon nutshells and hydrolytic lignin were used as starting materials for the preparation of microporous active carbons. Optimum parameters for cedar nutshell carbonization have been selected (temperature of carbonization 700–800 °C, rate of heating less than 3 °C/min) for the preparation of microporous carbons (average pore width 0.56 nm). The textural characteristics of microporous carbons made from nutshell are similar to those of a ‘Coconut’ carbon molecular sieve, but the latter has both a higher CO 2 adsorption capacity and a higher coefficient of N 2 /O 2 separation. The influence of carbonization and steam-activation parameters on the microtexture and molecular-sieve properties of granular carbons made from hydrolytic lignin was also investigated. A low rate of heating (less 3 °C/min) promotes the formation of micropores with average sizes around 0.56–0.58 nm at carbonization temperature 700 °C. At the same carbonization temperature the average sizes of micropores were 0.7–0.78 nm at rates of heating more than 3 °C/min. The activation of lignin-char with steam at 800 °C resulted in the formation of active carbons with more developed micropore volume (0.3–0.35 cm 3 g −1 ) and with micropores of widths around 0.6–0.66 nm which are able to separate He from a He–CH 4 mixture. The size of the micropores was varied as a function of burn off value.

The present paper describes the results of studies directed to novel catalytic processes design for the environmentally friendly production of cellulose. The new delignification catalyst which is produced by chemical interaction of elemental sulfur with hydrazine in superbase medium was used for the improvement of efficiency and ecological purity of the conventional pulping process. This catalyst reduces the concentration of polysulfides in pulping liquor and the yield of side sulfur-containing compounds (by 1.5 times). The processes of wood delignification with sulfur-free reagents based on catalytic pulping with acetic acid and hydrogen peroxide and on the delignification of steam-activated wood with NaOH or Na 2 CO 3 solutions have prospects for the environmentally benign production of cellulose. The new catalytic process of vanillin production by oxidation of lignosulfonates with molecular oxygen was described.

The thermal behaviour of wood biomass and synthetic polymer mixtures was studied in a rotating autoclave. Beech wood, pine wood, cellulose, hydrolytic lignin, medium density polyethylene, isotactic and atactic polypropylene were selected as starting materials. The effects of reaction conditions, biomass and polymers’ origins on the degree of mixture conversion as well as on the yields of liquid and gaseous products were established and discussed. A preliminary thermogravimetric investigation has shown that biomass is thermally degraded at a lower temperature than the studied polyolefins. As described in the literature, independent thermal behaviors were, in all cases, observed for each component of biomass/plastic mixtures (1:1 weight ratio). Co-pyrolysis of the different types of natural and synthetic polymer mixtures in an inert atmosphere has led to high yield of light distillate fraction and benzene soluble products. The optimum temperature for biomass/plastic mixture conversion which corresponds to the maximum yield of light liquids was 400 °C. The origins of both biomass and plastic had significant influences on the co-pyrolysis products’ distribution. In some cases non-additive effects were observed. This effect, generally, took place at biomass/plastic ratio lower then 1 (weight ratio) and resulted in high yields of distillate liquid fraction.

The influence of ozonization of Kansk-Achinsk lignite on the chemical composition, structure and modified lignite reactivity in hydrogenation processes with different solvents (tetralin, coal derived liquid) and pyrite catalysts was studied. According to chemical analysis data the incorporation of oxygen into the organic matter of lignite takes place during ozonization. Some data indicating that ozonization results in loosening of the lignite structure were obtained by X-ray diffraction and e.p.r. techniques. Lignite modified by ozone treatment is more reactive, than untreated lignite, in hydrogenation reactions at 380°C–430°C in the presence of pyrite catalyst. For ozonized lignite the conversion degree was increased by 1.4 times in tetralin and 1.4–1.8 times in coal derived liquid in comparison with lignite previously treated in helium.

Features of activation of chars, produced from Kansk-Achinsk lignite by different pyrolysis technologies, were studied in installation with a fluidized bed reactor. The influence of lignite carbonization parameters of the char reaction ability towards its activation by water steam and oxygen and char sorption properties was established and discussed. Some relations between the degree of lignite carbonization, the time of treatment and chars surface area, and their sorption ability were found. The empirical equation was obtained describing the dynamics at char gasification at 400–700°C and oxygen concentration 1%–4%.

The effect of non-isobaric short-time pre-hydrolysis of Siberian type wood and wood bark (Populus tremula wood, Larix sibirica bark, Abies sibirica bark) on the isolation of different organic substances was studied. From Populus tremula wood, activated at 187–240°C and 1.2–3.4 MPa, cellulose and sugar solution were isolated with yields up to 50 wt%, and 11 wt%, respectively. The composition of water-soluble compounds was studied by chemical and chromatographic methods. The main compounds were represented by mono- and oligo-saccharides, low molecular mass lignin, acetic acid, furfural and other products of sugar destruction. Methanol, isopropanol, propionic acid and hydroxymethylfurfural were formed in small amounts. The non-isobaric pre-hydrolysis of coniferous bark promoted the extraction process and increased the yield of extracted compounds. Some information on functional composition of extracts was obtained by NMR and IR spectroscopy. An integrated technology for wasteless processing of coniferous wood bark was suggested based on the combination of non-isobaric steam activation of bark, extractive isolation of some groups of organic substances, and oxidative pyrolysis of solid residue in a fluidized bed of catalyst.

Genesis of silica-supported [Fe 5 RhC(CO) 16 ] − and [Fe 4 RhC(CO) 14 ] − clusters with interstitial carbon atoms have been investigated in CO, syn-gas and Ar media. Complete conversion of the former cluster to the latter was obtained at 50°C in any medium, with [Fe 4 RhC(CO) 14 ] − cluster yielding Fe 4 Rh 2 C(CO) 16 and [Fe 3 Rh 3 C(CO) 15 ] − mixtures at 100–150°C. Simultaneously, Fe 2+ ions emerged on the SiO 2 surface. Mossbauer and electron microscopic studies on the silica-deposited clusters showed that at treatment in any medium in the range of 250–350°C highly dispersed FeRh particles are located on the silica surface, where Fe atoms exist mainly in the oxidized state even after H 2 reduction. Silica-supported catalysts derived from a family of FeRh carbidocarbonyl clusters were found to exhibit increased activity and selectivity toward oxygenates in CO hydrogenation and C 3 H 6 hydroformylation compared to those of monometallic cluster-derived catalysts. Possible explanations are discussed.

Steam cracking in the presence of haematite catalyst was used for the upgrading of coal hydrogenation liquids with b.p.

Physical and chemical studies of Kansk-Achinsk lignite bioconversion were carried out. The main stages of lignite biotransformation process under the action of biocoenosis of microorganisms consisting of Acinetobacter sp 10, Pseudomonas sp 2 and Pseudomonas sp 57 strains have been defined. At first the accumulation of microorganisms in the reaction mixture takes place with the growth of H, O, N, S contents in the organic products and with increasing oxygen-containing functional groups and paramagnetic centres concentration. At this stage of bioconversion the oxidation of aliphatic fragments of coal matter takes place over a period of about 20 h. At the second stage of lignite biotransformation, the resources of easily assimilated aliphatic carbon are exhausted and less digestible molecular fragments come into use. The lignite conversion rate and concentrations of oxygen-containing groups and paramagnetic centres fall and the growth of carbon content relative to other elements concentration is observed. At the final stage of lignite bioconversion the chemical composition of products remains practically unchanged and an increase of suspension viscosity takes place.

The activity of haematite, magnetite, pyrite and pyrrhotite containing ore catalysts, modified by treatment in a tensile-energy planetary activator mill and by elemental sulphur additions, has been studied in lignite hydrogenation and coal-derived liquid hydrocracking processes. The application of modified ore catalysts resulted in a significant (by two to four times) increasing of lignite conversion degree and in higher yields of distillate fractions, obtained by hydrocracking of heavy coal-liquids. Mechanical activation of iron ore catalysts in the presence of elemental sulphur increased their surface area and promoted the formation during hydrogenation process at dispersed pyrrhotite particles with high catalytic activity.

Catalytic and adsorption properties of (Pt + Fe)SiO2 catalysts prepared by coimpregnation of SiO2 with FeCl3 and H2PtCl6 aqueous solutions have been studied. According to the X-ray diffraction data, FePt particles of the size 5–36 nm and bcc or fcc crystal lattice are formed during the reduction of catalysts by flowing hydrogen. Bimetallic catalysts exhibit higher specific activity for the reaction of CO hydrogenation than do monometallic samples. The enhanced activity of FePt particles manifests itself mainly through increased formation of C4+ olefins. These observations suggest that the effect of Pt addition on the catalytic properties of silica-supported iron in CO hydrogenation is similar to the effect of potassium addition.

The process of oxidative pyrolysis of Kansk-Achinsk lignite was studied in a pilot installation with capacity 60 kg h−1. Powdered lignite with a particle size

The process of powdered lignin pyrolysis was studied in a pilot installation with a fluidized bed of AlCuCr oxide catalyst under different operating conditions. The advantages of the studied thermocatalytic process are the high productivity, the increased yield of char and the low level of harmful compounds in the gaseous products of lignin pyrolysis. The porosity of the chars varied from 1.58 to 2.15 cm 3 /g with an increase of gas flow-rate from 100 to 154 m 3 /h. Increasing the O 2 /lignin ratio in the reaction mixture resulted in formation of char products with higher sorption ability. Char samples obtained under different operating conditions of lignin pyrolysis showed different reactions to water-steam activation. The application of a manufacturing scheme, including the stages of catalytic pyrolysis, steam activation and ash removal by water treatment, would allow production of good-quality carbon sorbents (porosity up to 2.9 cm 3 /g, surface area 750–800 m 2 /g) in a yield of 15–19% relative to dry lignin.

Low-rank bituminous coal and its blends with 2.5 wt% of coke dust and with a mixture of 2.5 wt% of coke dust and 0.25 wt% of pyrite were pyrolysed in a quartz reactor taking 20–25 g samples. In the presence of the additives some changes were observed in the yields of solid, liquid and gaseous products of pyrolysis in the 350–450 °C range. The additives also influenced the mesophase composition. The formation of substances soluble in dimethylformamide but insoluble in hexane and chloroform (α-fraction) was shifted to higher temperatures of pyrolysis by the additives. This effect resulted in increases in coke strength and anisotropy.

The chemical composition and secondary structure of the surface layer of PA-6 were studied with the aim to elucidate tribochemical processes proceeding in this polymer. The high and fluctuating values of the friction coefficient of PA6 were attributed to tribochemical reactions promoted in the presence of oxygen. Two simultaneous processes are involved in tribochemical reactions of PA-6 in air; mechanical degradation of amidic bonds and tribochemical oxidation of the carbon atom in position, α, leading to the formation of branched and/or crosslinked structures.

The hydrogenolysis of ethane on (Mo + Pt) SiO 2 catalysts exhibits the following features as compared to hydrogenolysis on a Pt SiO 2 catalyst: (1) a much higher activity in the temperature range 200–300 °C; (2) constant activity in a series of successive runs; and (3) a lower activation energy and a decrease of inhibiting effect of hydrogen. The change in the electronic properties of platinum due to its interaction with molybdenum on the support surface is considered a major reason for these specific features of (Mo + Pt) SiO 2 catalysts.

New approaches to the preparation of supported metallic catalysts by decomposition of surface organometallic complexes have made it possible to prepare: (a) highly dispersed particles of Group VIII metals which may be used in the study of the dependence of catalytic properties on the size of metallic particles; (b) surface species which contain a Group VIII metal and a modifying element. With these particles it is possible to study the change in the catalytic properties of active species with variation in their composition. The results of the study of Ni, Pd, and Pt supported catalysts and of catalysts containing Group VIII metals and modifying elements (Sn, Mo, W, Re) are presented.

The relation between the composition and catalytic activity of surface metal complexes prepared by anchoring of allyl and ethoxy compounds Mo, W and Re to silica was studied. It was concluded that the precursors of metathesis active centers in these catalysts are coordinatively unsaturated metal ions with oxidation number + 4. The activity of surface species in olefin metathesis also depends to a great extent on the ligand environment of the metal ion.

Anchored organometallic complexes of tungsten were prepared by supporting tetramethallyltungsten on SiO2. The composition of the surface compounds obtained by treatment of the anchored complexes with H2S was studied. The activities of sulphided catalysts containing different surface species of tungsten in the hydrogenolysis of thiophen were measured. An increase in turn-over number (per surface atom of tungsten) was observed for catalysts containing small sulphide aggregates. The electron-deficient state of W and S in these aggregates by comparison with WS2 was shown by the x.p.s. technique.

The conversion of neopentane has been studied on Pt/SiO 2 , Pt + W/SiO 2 and Pt + Mo/SiO 2 catalysts. The bimetallic samples exhibit a decreased selectivity towards isomerization but increased activity toward hydrogenolysis when compared with the sample containing platinum only. Everything happens as if combining Pt with W or Mo had moved Pt toward the left in the Periodic Table, although it must be noted that W/SiO 2 and Mo/SiO 2 samples prepared in the same way as the bimetallic catalysts were totally devoid of any catalytic activity.

The results are presented of a physico-chemical investigation of thermal conversion of lignite in a fluidized bed of oxidation catalyst. Use of the catalyst allows an autothermal process at temperatures associated with low temperature pyrolysis processes. Quantitative aspects of the autothermal lignite pyrolysis process, and the compositions of the solid and gaseous products, have been studied. A model of lignite particle decomposition under conditions of flash pyrolysis is proposed.