László Bartha

Two stages catalytic pyrolysis of refuse derived fuel: production of biofuel via syncrude.

Thermo-catalytic pyrolysis of refuse derived fuels with different catalysts had been conducted in a two stages process due to its important potential value as fuel. The first stage was a pure thermal pyrolysis in a horizontal tubular reactor with feed rate of 0.5kg hourly. The second stage was a semi-batch process in the presence of catalysts. Results showed that the tested catalysts significantly have affected the quantity of products. E.g. gas yield could be increased with 350% related to the catalyst free case using ZSM-5, while that of pyrolytic oil was 115% over Y-zeolite. Gases consisted of mainly CO and CO(2) obtained from the tubular reactor, while dominantly hydrocarbons from the second stage. Ni-Mo-catalyst and Co-Mo-catalyst had shown activity in pyrolytic oil upgrading via in-situ hydrogenation-dehydrogenation reactions. Sulphur, nitrogen and chlorine level in pyrolytic oils could be significantly declined by using of catalysts.

Utilization of α-olefins obtained by pyrolysis of waste high density polyethylene to synthesize α-olefin-succinic-anhydride based cold flow improvers

Abstract A new route of utilization of α-olefin rich hydrocarbon fractions obtained by waste polymer pyrolysis was investigated. α-olefin-succinic-anhydride intermediate-based pour point depressant additives for diesel fuel were synthesized, in which reactions needed α-olefins were obtained by pyrolysis of waste high-density polyethylene (HDPE). Fraction of α-olefins was produced by the de-polymerization of plastic waste in a tube reactor at 500°C in the absence of catalysts and air. C 17 – 22 range of mixtures of olefins and paraffins were separated for synthesis and then, these hydrocarbons were reacted with maleic-anhydride (MA) for formation of α-olefin-succinic-anhydride intermediates. The olefin-rich hydrocarbon fraction contained approximately 60% of olefins, including 90-95% α-olefins. Other intermediates were produced in the same way by using commercial C 20 α-olefin instead of C 17 – 22 olefin mixture. The two different experimental intermediates with number average molecular weights of 1850 and 1760 g/mol were reacted with different alcohols: 1-butanol, 1-hexanol, 1-octanol, i -butanol, and c -hexanol to produce their ester derivatives. The synthesized ten experimental pour point depressants were added in different concentrations to conventional diesel fuel, which had no other additive content before. The structure and efficiency of experimental additives were followed by different standardized and non-standardized methods. Results showed that the experimental additives on the basis of the product of waste pyrolysis were able to decrease not only the pour but also the cloud point and cold filter plugging point (CFPP) of diesel fuel, whose effects could be observed even if the concentration of additives was low. Furthermore, all additives had anti-wear and anti-friction effects in diesel fuel.

Olefin-maleic-anhydride copolymer based additives: A novel approach for compatibilizing blends of waste polyethylene and crumb rubber

In our work processing conditions and mechanical properties of waste polyethylene (PE)/crumb rubber (CR) blends have been improved by new types of compatibilizing additives synthesized from experimental olefin-maleic-anhydride copolymers at our laboratory. Compatibilizing additives have been introduced into the PE/CR blends in 0.2 wt% while CR concentration has been varied between 10 and 50 wt%. For comparison of the effects commercially available MA-g-PO type compatibilizing additives have also been applied. Tensile and Charpy impact tests of the compression moulded samples have been carried out. Several experimental additives have enhanced properties of the PE/CR blends either from the point of view of tensile or Charpy impact strength while commercial additives have had improving effects only on one of the abovementioned mechanical properties but not for both of them simultaneously. Since good mechanical properties could be achieved by our experimental compatibilizers good adhesion in the waste PE/CR samples have been considered and was proven by SEM graphs either.

Study on Characteristics of Micelles Formed by Surfactants and Polymer Mixtures for Enhanced Oil Recovery

The bio-degradable vegetable oil based nonionic surfactants are generally used in the oil and petrochemical industry. This publication considers two combinations of various surfactants applied in enhanced oil recovery (EOR). The polymer-surfactants solutions prepared by mixtures of two types of nonionic surfactant and an anionic surfactant and a flow modifier type polymer used in various concentrations were studied. The physical properties of micelles formed in aqueous solution in terms of viscosity are measured by dynamic shear rate rheometer (DSR). The study was extended to measure the size of micelles formed in aqueous solution of various surfactants mixtures. The results obtained by dynamic light scattering (DLS) technique at different temperatures have been also presented. The influence of the surfactant composition on micelle size and the surface properties of the synthesized surfactants were also considered. As a results of the rheological measurement were demonstrated that higher viscosity of the surfactant solution was caused by the increased micelle size. The hydrodynamic radius was also calculated based on current measurements, and fitted well with the results. The size distribution of micelles formed in aqueous solution by different surfactant mixtures were examined as a function of temperature, and surfactant concentration.

Synthesis and Evaluation of Modified Polyethylene Wax Applied as Dispersant in Rubber Bitumen Composites

Grain rubber obtained from waste tyre has become one of the most important bitumen modifiers nowadays, but rubber precipitation from bitumen can cause problems during utilization. In our experimental work additives were synthesised as dispersant for rubber bitumen composites. Raw material was polyethylene wax (PEW) obtained from mild thermal cracking of polyethylene waste. The synthesis was a copolymerisation of olefins and maleic-anhydride. During the products evaluation the main analytical method was Fourier transform infra-red (FT-IR) spectroscopy. There were significant differences between the characteristic of raw material and synthesised products. The dispersant effect of the additives was studied in rubber-bitumen composites. All additives increased the stability of rubber-bitumen composites. From the results of the experiments it was stated that the modified polyethylene wax obtained from polyethylene waste can solve the instability problem of rubber-bitumen composites.

Improvement of the Selection Method of Surfactants and Their Mixtures for Chemical Enhanced Oil Recovery

Our research focuses on the evaluation of various surfactants by several test methods in order to develop the effective surfactants or their mixtures for Chemical Enhanced Oil Recovery (CEOR) and to characterize the most important surfactant properties. Previously no correlation was found between the specific characteristics. Therefore, a complex evaluation (CE) method was developed to select the surfactants (Nagy et al., 2015). A weak correlation was observed using the CE method. Thus, developments were needed to contribute significantly to the selection of nonionic surfactants and their mixtures for EOR applications. A new solubility property was incorporated to the screening method; therefore the correlation improved. A relationship was found between the additional oil yield and the solubility properties of anionic and nonionic surfactants. Therefore, the new evaluation method (CRE-complex rigorous evaluation) has a more accurate relationship with additional oil yield. This developed method can reduce the cost and time required for the applied screening method.

Analysis of the interaction between polymer and surfactant in aqueous solutions for chemical-enhanced oil recovery

ABSTRACT Most petroleum reservoirs are subjected to Improved and Enhanced Oil Recovery (IOR and EOR) processes following secondary recovery. EOR involves the application of external forces and substances to improve the chemical and physical interactions in hydrocarbon reservoirs in order to improve preferable recovery conditions. The process of chemical flooding with solutions of polymers and surfactants can be used for developing oil exploitation. Studying the interaction between surfactants and polymers is indispensable for successful oil recovery. The interaction between non-ionic and anionic surfactants and polymers in ternary mixtures was examined at different concentrations and temperatures by dynamic light scattering and gel permeation chromatography. The hydrodynamic size of surfactant-polymer composites was higher than the particle size of individual components indicating a formation of associates. The size of associates was increased by increasing the concentration of the surfactants and the temperature. It could be supposed that the polymer formed a mixed micelle with the surfactants. Gel permeation chromatography has confirmed the increase in molecular weight of the associate formed by surfactants and polymers.

Environmental saving disposal of contaminated plastic wastes by their pyrolysis

The pyrolysis of different contaminated plastic wastes has been investigated in a 2.0 dm autoclave at 450 and 500°C under nitrogen. Results show considerable differences in yields and quality of products applying different pre-treatings and parameters. The properties of the products were determined by standardized methods, gas chromatography and FTIR. The gaseous products of the pyrolysis were distributed in the range of C1-C5 and consisted of different inorganic compounds. Liquids can be characterized as hydrocarbons in the carbon atom range of 5-34, with mainly aliphatic compounds. In the liquid products were different heteroatom containing organic compounds, too. The contaminant level of products considerably can be decreased by washing of the raw materials while the parameters of pyrolysis have only negligible effect on this.

Investigation of Modified PIB-Succinimides in Low SAPS Engine Oils

Along with the ever stricter economical, technical and mainly environmental regulations new types of low phosphorus, sulphur and metal containing multifunctional lubricant additives are required for formulating so-called low SAPS (Sulphated Ash, Phosphorus and Sulphur) engine oils. In the greatest volume dispersant additives, mainly polyisobuthylene-succinimide types are used in the formulation of engine oils. By structural modification of the dispersants with molybdenum and sulphur containing compounds advantageous complementary effects could be achieved along dispersant efficiency. Various modified PIB-polysuccinimides with complementary antifriction and antiwear (AF/AW), viscosity-index improver and enhanced detergent-dispersant properties were synthesized and investigated both in base oil and engine oil compositions. The detergent-dispersant and the high temperature deposit preventing effects, thermal- and oxidation stability, AF/AW properties and seal compatibility were studied in fully formulated, low SAPS engine oils with reduced zinc-dialkyl-dithiophosphate (ZnDDP) content. Based on the results it was found that by using suitable additive concentrations the conventional dispersant can be advantageously combined or replaced with these new additives to enhance the properties and to reduce the ZnDDP concentration level of the experimental engine oils.

Hydrocarbon mixtures from waste polymer degradation

The degradation of waste polymers is one of the possible routes of utilization. Various cracking processes are suggested for different waste polymers, when long alkyl chains are degraded and transformed into lighter hydrocarbons. Yields of the liquid and gas reaction products can be increased and composition thereof can be modified by catalysts. Catalytic cracking of polyolefin waste polymers was studied in a batch reactor without and with Y, FAU (FCC), H-ZSM5 and natural clinoptilolite zeolite catalysts. The additives of the feed polymers did not significantly affect the yields and properties of the products but the type of the catalysts did. Both the gas and liquid yields increased with the catalyst concentration. The activity of the catalysts influenced the yields and the molecular weight of the volatile compounds. In the presence of catalysts both double bond and carbon chain isomerization were observed, but the latter was less significant than the former. The minimum temperature of cracking is lower with catalyst than without catalyst. The grain size of catalyst affects the yields, but less significantly the composition of products.