Plastic is versatile, lightweight, resistant, and inexpensive materials and an increase of its demand in the world has been observed in the last years (299 million tonnes in the 2013 and 311 in 2014) [1]. About 25 million tonnes of the plastic produced become waste upstream and about 39% comes in the landfill [1] causing environmental pollution problems. Pyrolysis process for the recovering of product and energy can represent a useful strategy to achieve and sustainable plastic waste management [1]. A large amount of studies has been developed to assess the possibility to convert waste plastic to bio-oil by pyrolysis process [1] either catalytic or not catalytic. Nevertheless, only limited numbers of papers refer to the use of real plastic waste more than simulated mixture [2] even if the performances obtained are strongly influenced by the feedstock characteristics. In this work, a real SRF (Solid Recovered Fuel) made by the plastic resulting from the process of the plastics recycling has been used to perform pyrolysis experiments. The effect of temperature on the yield of gas, condensable and solid has been evaluated in addition to the use of high surface g-alumina as a catalyst to upgrade the pyrolysis products. The SRF used for this work has been gently supplied by P.R.T. Srl. The feedstock has been characterized by means of proximate and ultimate analysis carried out by LECO TGA 701, LECO CHN 628, LECO SC 144 DR, Metrohm 883 Basic IC plus ionic chromatography, and by PARR 6200 calorimetric bomb for the determination of HHV. Pyrolysis experiments were carried out at different temperatures in the range 500-800 °C under nitrogen flow (60Nl/h), using a fixed bed quartz micro-reactor having an ID of 26mm. For each test, a mass of about 3g of the sample has been loaded in the reactor and heated up to the required temperature by means of a heating rate of 30°C/min and maintaining the chosen final temperature until no further gas production was detected. For the catalytic tests, a weight ratio of about 6 has been adopted between the ?-alumina and the SRF batch. The produced gas was vented from the end of the reactor into a set of different condenser cooled at -12°C were the condensed compounds (oil and wax) were collected and weighted in order to evaluate their yield. The oil and wax have been characterized by means of GC-MS Agilent 7890A, a simultaneous TGA-DSC Perkin Helmer STA 6000 thermogravimetric analyser and LECO CHN 628. The permanent gas leaving the condensation block was sent to a set of online analyzers to measure in continuous the concentration of CH4, CO, CO2 and H2. Further analysis of gas has been performed collecting a batch the gas, at the exit of condenser, in a Tedlar bags, at different reaction time, and analyzed by means of a micro-GC Agilent 3000, for the determination of light hydrocarbon (up to c5). At the end of the test, the reactor was cooled at room temperature under nitrogen flow and the solid residue was weighted to calculate the solid yield and subsequently analysed by a LECO CHN 628. The results show that, as expected, the gas yield is strongly enhanced by both the increases of temperature and the presence of catalyst; the quality of the condensed compounds is affected by the presence of the catalysts. In particular, a higher fraction of gasoline (C5-C11) and diesel fraction (C11-C20) and the formation of cyclic and aromatic hydrocarbons is obtained in presence of alumina. Finally, fast coke deposition is also observed.
PRELIMINARY ACTIVITY ON PYROLYSIS OF SRF CONTAINING PLASTIC
Massimo Urciuolo;Renata Migliaccio;Giovanna Ruoppolo
2019
Abstract
Plastic is versatile, lightweight, resistant, and inexpensive materials and an increase of its demand in the world has been observed in the last years (299 million tonnes in the 2013 and 311 in 2014) [1]. About 25 million tonnes of the plastic produced become waste upstream and about 39% comes in the landfill [1] causing environmental pollution problems. Pyrolysis process for the recovering of product and energy can represent a useful strategy to achieve and sustainable plastic waste management [1]. A large amount of studies has been developed to assess the possibility to convert waste plastic to bio-oil by pyrolysis process [1] either catalytic or not catalytic. Nevertheless, only limited numbers of papers refer to the use of real plastic waste more than simulated mixture [2] even if the performances obtained are strongly influenced by the feedstock characteristics. In this work, a real SRF (Solid Recovered Fuel) made by the plastic resulting from the process of the plastics recycling has been used to perform pyrolysis experiments. The effect of temperature on the yield of gas, condensable and solid has been evaluated in addition to the use of high surface g-alumina as a catalyst to upgrade the pyrolysis products. The SRF used for this work has been gently supplied by P.R.T. Srl. The feedstock has been characterized by means of proximate and ultimate analysis carried out by LECO TGA 701, LECO CHN 628, LECO SC 144 DR, Metrohm 883 Basic IC plus ionic chromatography, and by PARR 6200 calorimetric bomb for the determination of HHV. Pyrolysis experiments were carried out at different temperatures in the range 500-800 °C under nitrogen flow (60Nl/h), using a fixed bed quartz micro-reactor having an ID of 26mm. For each test, a mass of about 3g of the sample has been loaded in the reactor and heated up to the required temperature by means of a heating rate of 30°C/min and maintaining the chosen final temperature until no further gas production was detected. For the catalytic tests, a weight ratio of about 6 has been adopted between the ?-alumina and the SRF batch. The produced gas was vented from the end of the reactor into a set of different condenser cooled at -12°C were the condensed compounds (oil and wax) were collected and weighted in order to evaluate their yield. The oil and wax have been characterized by means of GC-MS Agilent 7890A, a simultaneous TGA-DSC Perkin Helmer STA 6000 thermogravimetric analyser and LECO CHN 628. The permanent gas leaving the condensation block was sent to a set of online analyzers to measure in continuous the concentration of CH4, CO, CO2 and H2. Further analysis of gas has been performed collecting a batch the gas, at the exit of condenser, in a Tedlar bags, at different reaction time, and analyzed by means of a micro-GC Agilent 3000, for the determination of light hydrocarbon (up to c5). At the end of the test, the reactor was cooled at room temperature under nitrogen flow and the solid residue was weighted to calculate the solid yield and subsequently analysed by a LECO CHN 628. The results show that, as expected, the gas yield is strongly enhanced by both the increases of temperature and the presence of catalyst; the quality of the condensed compounds is affected by the presence of the catalysts. In particular, a higher fraction of gasoline (C5-C11) and diesel fraction (C11-C20) and the formation of cyclic and aromatic hydrocarbons is obtained in presence of alumina. Finally, fast coke deposition is also observed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
