Catalytic Upgrading of Bio-Oils Obtained from Different Sources

This work focusses on the investigation of catalytic quality improvement of pyrolysis products. The yield of gases can increase significantly using Ni-Al2O3 and Ni-Al2O3/MoO3/CeO2 catalysts in case of both residential sewage sludge and farm waste sewage sludge raw materials (from 10.7-26.8% to 11.0-39.3%). It was found, that in addition to the oxygen content of the raw materials, the reaction conditions also greatly influenced the yield and properties of aqueous phase. The yield of aqueous phase was 9.7-17.9% without catalyst and that of 11.2-21.8% with catalyst. The amount of oxygen-containing organic substances in products (e.g. aldehyde, ketone and carboxylic acid) decreased significantly after the quality improvement. The efficiency of the catalysts was also influenced by the raw materials and temperatures in the 1st reactor. The hydrogen content and hydrocarbon distribution of the gas products changed favourably after the catalytic treatment, because less aldehyde, ketone, alcohols, carboxylic acids, phenols and its derivate were formed. Keywords: waste, catalysts, pyrolysis, utilization, quality imp

Feasibility and Economic Issues of Biomass Pyrolysis-Gasification: the Effect of Moisture Content of Raw Material

The use of various wastes, such as biomass as a raw material, has significant benefits from both an emission and economic point of view. The products yield and composition, as well as the feasibility of the process, are influenced by several factors. However, the moisture content can also play an important role, because the presence of water greatly influences the chemical processes taking place and their economic characteristics. In this work, the pyrolysis and gasification of biomass were investigated at different temperatures using different moisture content (0%, 20% and 40%) of raw material, with and without steam and catalyst. The composition of the gas products was determined by GC-FID and GC-TCD methods, and that of the solid product by CHNS analysis. In addition, using given technological layout, the process and its economic issues on the basis of feasibility were also investigated with Aspen Plus V11 software. It was found, that the moisture content of the raw material has increased the yield of hydrogen and H2/CO ratio. Besides, with the increment of temperature the CO/CO2 yield was increased as well. Furthermore, steam added by externally has a beneficial effect on the hydrogen and syngas yield, but it requires significant additional costs. Keywords: biomass, pyrolysis, gasification, synthesis gas, feasi

Polimer hulladékok pirolízisével nyert szilárd maradékok további hasznosíthatósága

A műanyag hulladékok kémiai újrahasznosításával (pirolízissel) értékesebb termékek állíthatók elő, melyek alkalmasak energia vagy vegyipari alapanyagok előállítására. Azonban a keletkező kokszos maradék hasznosítása még nem megoldott. Kísérletünk során települési szilárd hulladékot pirolizáltunk 500 °C-on és azt vizsgáltuk, hogy az így előállított maradék kezelés nélkül, illetve aktiváló ágensekkel való kezelés után alkalmas-e egy alapolaj elegy bizonyos tulajdonságainak javítására

Catalytic pyrolysis of mixtures modeling municipal waste

In this work the temperatures of the thermal decomposition of model waste mixtures were determined with and without catalysts under slow heating conditions applying thermogravimetry-mass spectrometry (TG/MS) technique. The catalytic effect of HZSM-5 and Ni-Mo catalysts were tested on the thermal stability of model waste mixtures. Significantly decreased thermal decomposition temperature (by about 200°C) was observed in case of plastic mixture in the presence of 10 % HZSM-5 catalyst. The catalytic effect of HZSM-5 catalyst was hindered when the domestic waste model mixtures contained biomass components as well. The effect of cellulose and lignin on the catalytic activity of HZSM-5 catalyst was tested and significant poisoning effect was observed in both cases. The presence of 50% cellulose or 10% lignin in the waste mixture completely deactivates the HZSM-5 catalyst

LCO2 hűtőközegű külső kriogén hűtőrendszer tervezése Nikkel-bázisú szuperötvözetek horonymarásához

A nehezen forgácsolható fémötvözetek forgácsolhatóságának vizsgálata területén új kutatási terület jelent, a kriogén hűtéssel segített megmunkálás. A kriogenika alacsony hőmérsékleten végbemenő folyamatokkal foglalkozó tudományág. Az ipar számos területén alkalmazzák ezt az eljárást, például az élelmiszeriparban fagyasztott termékek gyorsfagyasztására, mellyel garantálni tudják az élelmiszerek minőségét. Forgácsolás területén egyáltalán nem elterjedt eljárásról beszélünk, az országban elsőként foglalkozunk ezzel a területtel, melynek első lépcsőfoka, hogy olyan hűtőrendszert alakítsunk ki, mely folyékony szén-dioxid (LCO2) és folyékony nitrogén (LN2) kijuttatására egyaránt alkalmas. Jelen publikációban ennek a rendszernek a kiépítését mutatjuk be. | A new area of research in the study of machinability of difficult- to-cut metal alloys is cryogenic cooling-assisted machining. Cryogenics is a discipline dealing with low temperature processes. It is used in many areas of industry, for example in the food industry for rapid freezing of frozen products to guarantee food quality. In the field of machining, we are talking about a process that is not widespread at all, and we are the first in the country to work in this field, the first step being to develop a cooling system capable of delivering both liquid carbon dioxide (LCO2) and liquid nitrogen (LN2). In this paper we present the implementation of this system

Biomass volatiles reforming by integrated pyrolysis and plasma-catalysis system for H2 production: Understanding roles of temperature and catalyst

Biomass utilization is considered a carbon–neutral way to simultaneously tackle the energy crisis and environmental contamination. Challenges still exist to hinder its application, such as low products yield, tar blockage, harsh condition and inferior stability. This paper aims to study whether the newly developed integrated pyrolysis and plasma-catalysis system can be applied into practice of H2 production from real biomass volatiles, and to understand roles of temperature and catalyst. The experiments were performed in a two-stage reactor embedded with a coaxial dielectric barrier discharge plasma zone. Impacts of operating conditions (i.e. discharge power, steam input, heat supply and catalyst packing) on H2 production were investigated. The results show that proper input of discharge power and steam can promote H2 production. Heating supply is recognized as two different effects on plasma-only and plasma-catalysis systems, since reaction temperature elevation acts as inhibitor to plasma characters and cut down the contribution of plasma reforming. After packing bimetallic Ni-Fe/γ-Al2O3 catalyst into plasma, optimal 47.65 mmol/g of H2 can be attained at reforming temperature of 500 ℃, with synergy effects observed. Plasma-catalysis system also outperformed in tar cracking, tar elimination and stability test, attributed to plasma assistance. This work provides an alternative to construct a new plasma-catalysis process for H2 production from biomass volatiles or to couple plasma technology with existing biomass conversion industries for preferable energy and fuel production, highlighting its promising commercialization prospects

Processing real-world waste plastics by pyrolysis-reforming for hydrogen and high-value carbon nanotubes

Producing both hydrogen and high-value carbon nanotubes (CNTs) derived from waste plastics is reported here using a pyrolysis-reforming technology comprising a two-stage reaction system, in the presence of steam and a Ni-Mn-Al catalyst. The waste plastics consisted of plastics from a motor oil container (MOC), commercial waste high density polyethylene (HDPE) and regranulated HDPE waste containing polyvinyl chloride (PVC). The results show that hydrogen can be produced from the pyrolysis-reforming process, but also carbon nanotubes are formed on the catalyst. However, the content of 0.3 wt.% polyvinyl chloride in the waste HDPE (HDPE/PVC) has been shown to poison the catalyst and significantly reduce the quantity and purity of CNTs. The presence of sulfur has shown less influence on the production of CNTs in terms of quantity and CNT morphologies. Around 94.4 mmol H g plastic was obtained for the pyrolysis-reforming of HDPE waste in the presence of the Ni-Mn-Al catalyst and steam at a reforming temperature of 800 C. The addition of steam in the process results in an increase of hydrogen production and reduction of carbon yield; in addition, the defects of CNTs, for example, edge dislocations were found to be increased with the introduction of steam (from Raman analysis)

Thermo-Catalytic Pyrolysis of Waste Plastics from End of Life Vehicle

Pyrolysis of waste plastics is widely used recycling method. Owing to the end-of-life vehicles regulations, 95% of passenger cars and vehicles must reused/recovered after the dismantling. Pyrolysis of waste polyethylene and polypropylene obtained from end-of-life vehicles was investigated in a continuously stirred batch reactor using 500 and 600°C temperatures. To ensure the pyrolysis reactions the tested catalysts (5% of ZSM-5, HZSM-5, Ni-ZSM-5 and Fe-ZSM-5) were added directly to the mixtures of raw materials. Products of pyrolysis were separated into gases, pyrolysis oil and heavy oil, which was further analyzed by gas-chromatography, Fourier transformed infrared spectroscopy and other standardized methods. Based on the results it was concluded, that the catalysts significantly increase the yields of volatile products, and modify their composition. Especially the alkane/alkene ratio, the methane concentration and the concentration of branched hydrocarbon could be affected by the applied catalysts. Ni-ZSM-5 catalyst had the highest activity in methane production, while HZSM-5 catalyst proved effective in isomerization reactions. Using H-ZSM-5, Ni-ZSM-5, and Fe-ZSM-5 catalyst notably decreased average molecular weight of pyrolysis oils and significantly higher aromatic content was observed