B. Purevsuren

Pyrolysis and TG analysis of Shivee Ovoo coal from Mongolia

The coal sample of the Shivee Ovoo deposits has been non-isothermally pyrolysed in a thermogravimetric analyser to determine the influence of temperature, heating rate and purge gas employed on the thermal degradation of the sample. The heating rates investigated in the TG were 10–50 K min–1 to final temperature of 1000°C. N2or CO2 were employed as well as type of purge gas on the process of thermal degradation of the coal sample. The coal was also investigated in a fixed bed reactor to determine the influence of temperature and heating rate of the pyrolysis on the yield of products and composition of the gases evolved. The main gases produced were H2, CH4, C2H2, C2H4, C2H6, C3H6 and C3H8 and also minor concentrations of other gases.

A biochar from casein and its properties

A biochar was prepared by pyrolysis of casein. A helium and mercury porosimeter were used to measure the true and apparent densities of the chars respectively, elemental and IR analysis were used to characterize the chemical composition of char. A SEM was used to observe the char surfaces in order to verify the presence of porosity. The biochar has 9.02% of nitrogen, content of porosity is 20%. The experimental results show that it is possible to prepare chars with relatively high porosity from casein for the further preparation of activated carbon.

THERMAL ANALYSIS OF CASEIN

Case in was analyzed during thermal treatment and pyrolysis. The thermal degradation process of casein was interpreted and thermostability indices, rate, order and activation energy of thermode-structive reaction of casein were determined on the basis of thermogravimetric analysis. The thermodestruction of casein has the characteristics of a first order reaction with activation energy Ea=3.87 kcal mol−1 (16.2 kJ mol−1).The pyrolysis of casein was investigated and we determined optimal heating temperature — 550°C and yields of biochar, pitch, pyrolysis water and gases.

Estimation of the molecular mass range of the tar from pyrolysis of casein by gas chromatography-mass spectrometry, probe mass spectrometry and size exclusion chromatography with 1-methyl-2-pyrrolidinone as eluent

Casein has been pyrolysed to obtain a biochar (28.3% yield), with mostly meso- and macro-pore structure, and a liquid tar product of high yield (37.5%) with the balance as gas (20.9%) and water (13.3%). The elemental composition of the casein tar was: C 66.7%, H 8.3%, N 12.1% and O 12.9% (by difference). The tar sample has been characterised by mass spectrometry, gas chromatography (GC)/MS and heated-probe MS, to give molecular mass distributions for comparison with molecular mass ranges indicated by analytical-scale size-exclusion chromatography (SEC). The tar appeared to be completely soluble in 1-methyl-2-pyrrolidinone (NMP), the solvent used for SEC. It appeared to consist mostly of lower molecular mass fractions with elution times at 18–26 min. GC/MS analysis showed the presence of both aliphatic and aromatic nitrogen-containing components. Neither GC/MS nor heated-probe MS were able to detect more than about half the tar components.

INVESTIGATION ON PYROLYSIS OF CASEIN

First casein was processed by pyrolysis and investigated under optimal thermal treatment condition to obtain a good quality adsorbent with high developed porosity structure and liquid product as a complex raw material for different kind of organic compounds with interesting properties and structures. The yields of hard residue, pitch, pyrolysis water and gases were determined and compared with the yields of pyrolysis products of other investigated different kind of organic materials.The chemical composition of pitch was determined as following: free carbons - 4.52%, organic acids - 0.64%, organic bases -38.00%, phenols - 7.75%, asphaltenes - 0.97%, paraffins - 1.30%, neutral oils - 16.20% and preasphaltanes - 30.10%. The pitch was fractionated by air distillation into 3 liquid fractions with different boiling range and a bitumen like residue with a lower softening temperature.

Adsorption isotherms and kinetics of activated carbons produced from coals of different ranks.

Activated carbons (ACs) from six coals, ranging from low-rank lignite brown coal to high-rank stone coal, were utilized as adsorbents to remove basic methylene blue (MB) from an aqueous solution. The surface properties of the obtained ACs were characterized via thermal analysis, N2 isothermal sorption, scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and Boehm titration. As coal rank decreased, an increase in the heterogeneity of the pore structures and abundance of oxygen-containing functional groups increased MB coverage on its surface. The equilibrium data fitted well with the Langmuir model, and adsorption capacity of MB ranged from 51.8 to 344.8 mg g⁻¹. Good correlation coefficients were obtained using the intra-particle diffusion model, indicating that the adsorption of MB onto ACs is diffusion controlled. The values of the effective diffusion coefficient ranged from 0.61 × 10⁻¹⁰ to 7.1 × 10⁻¹⁰ m² s⁻¹, indicating that ACs from lower-rank coals have higher effective diffusivities. Among all the ACs obtained from selected coals, the AC from low-rank lignite brown coal was the most effective in removing MB from an aqueous solution.

Investigation of adsorption of methylene blue from aqueous phase onto coal-based activated carbons

Abstract We prepared activated carbons (ACs) from coal samples ranking from lignite to anthracite. The pore structures and surface functional groups of the obtained ACs were examined by nitrogen adsorption isotherm, field-emission scanning electron microscopy, Fourier transform infrared spectroscopy, and Boehm’s titration method. Isothermal adsorption experiments using methylene blue (MB) solution were conducted to evaluate the adsorption capacities of the ACs. The obtained ACs had different sorption properties due to their differences in structural characteristics and surface chemical groups. The maximum adsorption was achieved using the ACs made from low-ranked lignite coals. The MB adsorption process could be described well by the intra-particle diffusion model with a wide range of effective diffusion coefficients. The results indicated that both the proportion of mesopores and the number of basic sites within the ACs mainly governed the MB adsorption capacities.

Pyrolysis of waste polypropylene and characterisation of tar

Waste polypropylene (PP) has been pyrolysed to obtain mainly a liquid tar product of high yield (83.5%) with the balance as gas (15.5%) and a little residue (1.0%). The elemental composition of the PP tar was: C: 87.1%, H: 12.6% and O+others: 0.4% (by difference). The tar samples have been characterised by gas chromatography/mass spectrometry, heated-probe mass spectrometry and laser desorption mass spectrometry (LD-MS), to give molecular mass distributions for comparison with molecular mass ranges indicated by size-exclusion chromatography (SEC). About 50% of the tar was soluble in 1-methyl-2-pyrrolidinone, the solvent used for SEC. It appeared to consist mostly of low molecular mass materials with elution time at 20–27 min. Mass ranges from SEC and LD-MS agreed approximately in showing the upper mass limit of the tar to be about 1200 u, consisting of aromatics, alkenes, dialkenes and only minor quantities of alkanes.

Washability of Coal from Seams IV and VIII of the Tavantolgoi Deposit

Samples from the Tavantolgoi coal deposit were analyzed by petrographic, elemental, FT-IR, XRD, and float-and-sink tests. The deposit is Permian age and characterized by lithotypes that are bright, semi-bright, semi-dull, and dull. Microscopically identified macerals in the deposit are fusinite and vitrinite components and minerals. The inorganic elements in the deposit are Si and Al, indicating an abundance of aluminum silicates, followed by Fe, Cu, and Ca in decreasing order. Ash in the deposit is silica type, in which the point of fusibility is usually higher than the other types. Float-and-sink tests show that the ash in seam IV can be separated easily from coal, whereas the ash in seam VIII has medium degree of difficulty of separation.

AN ATTEMPT FOR ENVIRONMENTALLY FRIENDLY UTILIZATION OF OIL-SHALE IN MONGOLIA

Abstract Oil-shales from 8 deposits in the central economic region of Mongolia were characterized and carried out pyrolysis experiments on the basis of oil-shale samples. The oil-shale of Kh-46-th ditch deposit was chosen as a best quality oil-shale with maxim yield of pitch (15 %) and determined a optimum condition of its pyrolysis (heating temperature-550°C and rate of heating −137,0 C/min.). The yield of liquid fractions with different boiling temperature interval and hard residue of pitch were obtained by using an air-distillation. These liquid products can be used as a gasoline, diesel, oil materials and binding materials (bitumen like hard residue), after isolation of organic bases, acids and phenolic compounds from each fraction.