Bronisław Buczek

Oxygen distribution within oxidised active carbon granules

The differences in chemical structure within activated carbon granules were estimated for oxidised and unmodified carbon substrates. Samples from various parts of the carbon granules were obtained using the spouted-bed attrition method. A commercial granulated active carbon (Norit R3ex) demineralised with concentrated HF and HCl acids was used. Suitable powdered and core samples were obtained by stripping off successive layers of granules from carbon oxidised with concentrated HNO3 and from unmodified carbon for comparison. The following techniques were employed to characterise the surface properties of these samples: selective neutralisation and pH-metric titration of functional groups, and transmission FTIR spectroscopy. The distribution of oxygen chemically bound to the internal surface of the granules is discussed on the basis of the results.

Kinetic models assessment for swelling of coal induced by methane and carbon dioxide sorption

The ability of five kinetic equations to describe the sorption kinetics and expansion rate of solid coal samples was investigated. The conducted experiment included the measurements of sorption of methane and carbon dioxide on cuboidal hard coal samples at high pressure using volumetric method. Simultaneously the kinetics of coal sorption induced swelling was monitored. All of the approaches used to fit the experimental sorption and dilatometric data were literature-based equations. Two equations represent the traditional approach for sorption on powder and grain fractions based on the bidisperse gas transport model, and have been used to interpret and quantify the observed gas uptake rates in coal. The other three kinetic equations are the pseudo-second-order kinetic equation, Elovich equation, and stretched exponential (SE) equation. Four of the five equations are suitable to describe the kinetics of methane and carbon dioxide sorption in the porous structure of solid coal samples and the kinetics of coal expansion that accompany the sorption processes. The SE equation gave the best fit to the experimental data.

Preparation of Active Carbon by Additional Activation with Potassium Hydroxide and Characterization of Their Properties

A commercially available activated carbon was used to prepare active carbon via reactivation with KOH at 750°C. Active carbon was obtained with 60.5% yield. The resulting active carbon showed a well-developed porous structure with specific surface area 2939 m2/g, total pore volume 1.488 cm3/g, and micropore volume 1.001 cm3/g. Process reactivation of carbon changes its particle size as well as density properties and increases by nearly twice the amounts of methane and carbon dioxide adsorbed under high pressure conditions. Such active carbon may be used to enrich methane or carbon dioxide by pressure swing adsorption technique. Other possible applications of reactivated carbon are storage of hydrogen and methane and sequestration of carbon dioxide.

Nanostructural Materials for Energy Storage Systems

The aim of this study was to assess of carbonaceous monoliths used for adsorption cooling systems. The carbonaceous monoliths prepared from coal precursors are obtained. The porous structure of monoliths was evaluated on the basis of nitrogen adsorption-desorption data. The investigated monoliths have significantly developed microporous structure. The large specific area of carbonaceous monoliths (about 2000 m2/g) and volume of micropores are observed. Methanol adsorption isotherms and heat of wetting using methanol was determined. Results show that monoliths materials are high adsorption capacity of methanol and heat of wetting, which can improve of heat exchange and efficiency in processes of refrigeration and air conditioning.

Improvement of Methane Storage Capacity for Active Carbons

A method for increasing storage capacity by working of the commercial active carbons in a spouted bed is proposed. By abrasion of external layers of grain active carbons with better adsorptive properties, smaller voids of bed and improved attrition strength was obtained. Investigations of methane storage capacity for active carbon NORIT R2 with different degrees of external layers removed, were carried out. Experiments indicate that methane storage capacity can be increased up to 15–20% over commercial carbon.

Diesel Fuel from Used Frying Oil

New conversion technologies of used edible oils and waste animal fats into a biofuel appropriate for use in standard diesel engines have been developed, taking into consideration environmental requirements and improvement in the economics of current trans-esterification technologies. The variation in the properties of substrates made from used rape oil after treatment with mixed adsorbents (active carbon, magnesium silicate) was studied in this work. The obtained results are compared with the quality requirements for the substrates used in Vogel & Noot GmbH technology for transesterification of oils and fats.

Purification of the used palm oil by adsorption

Purification of the used palm oil by adsorption The components of fresh vegetable oils are mainly non-polar. During frying of food, complex and multistage reactions occur in the oil, which produce various polar compounds. Active carbons are characterized by small contents of polar functional groups, which are responsible for adsorbing such polar compounds. Effective purification of the used frying oils must involve the removal of the polar substances. To improve the quality of the used palm oil, an active carbon oxidized by a hydrogen peroxide treatment was used. Such a carbonaceous adsorbent improves the quality of the oil used for frying food by purifying it from colour substances, lipid hydrolysis products, oxidation products and total polar compounds.

Biodegradable lubricating greases containing used frying oil as additives

Purpose – The aim of this paper was to investigate the possibility of reusing frying oil, obtained during thermal treatment of food in fast-food restaurants for production of plastic greases. Design/methodology/approach – In accordance with the proposed research concept, the used frying oil was to be the base oil of biodegradable plastic greases thickened with calcium 12-hydroxystearate and lithium 12-hydroxystearate. These studies included the determination of the effect of variable amounts of used oil component in the base oil on the properties of the resultant plastic greases. Findings – It was found that the optimum amount of the component in the base oil is 10-15 per cent. Calcium and lithium greases prepared in such a way possess a quality to that of greases prepared with fresh rapeseed oil. Research limitations/implications – Higher concentrations of used frying oil in the base oil adversely affect the degree of thickening, thixotropic properties and dropping point of the grease, as well as, creati...

Properties of spent active coke particles analysed via comminution in spouted bed.

Samples of active coke, fresh and spent after cleaning flue gases from communal waste incinerators, were investigated. The outer layers of both coke particles were separately removed by comminution in a spouted bed. The samples of both active cokes were analysed by means of densities, mercury porosimetry, and adsorption technique. Remaining cores were examined to determine the degree of consumption of coke by the sorption of hazardous emissions (SO2, HCl, and heavy metals) through its bed. Differences in contamination levels within the porous structure of the particles were estimated. The study demonstrated the effectiveness of commercial active coke in the cleaning of flue gases.

Effect of Carbonisate Particles on the Properties of Active Carbons

In this article, the effect of particle geometry on the properties of active carbons, which are obtained by treating steam with hard coal-tar carbonisate, is reported. Different shapes of carbonisates were activated by superheated steam at 1123 K in a monolayer reactor with burn-off rates between 45.3% and 72.0%. Steam activation leads to a faster development of ring-shaped particles, and the kinetics of the process influence surface area Brunauer–Emmet–Teller, surface mesoporosity and the micropore volume. The micropore and mesopore structures of active carbons are evaluated using nitrogen adsorption/desorption isotherms and the corresponding parameters of the Dubinin–Radushkevich equation are presented. Micropore-size distribution is calculated using the Horvath–Kawazoe method. The results of these textural investigations showed that a more uniform micropore structure and better mechanical properties are present in ring-shaped active carbon particles than that were reported earlier.