A synthetic mixture of real waste packaging plastics representative of the residue from a material recovery facility(plasmix)was submitted to thermal and catalytic pyrolysis.Preliminary thermogravimetry experiments co...A synthetic mixture of real waste packaging plastics representative of the residue from a material recovery facility(plasmix)was submitted to thermal and catalytic pyrolysis.Preliminary thermogravimetry experiments coupled with Fourier transform infrared spectroscopy were performed to evaluate the effects of the catalysts on the polymers’degradation temperatures and to determine the main compounds produced during pyrolysis.The thermal and catalytic experiments were conducted at 370℃,450℃ and 650℃ using a bench scale reactor.The oil,gas,and char yields were analyzed and the compositions of the reaction products were compared.The primary aim of this study was to understand the effects of zeolitic hydrogen ultra stable zeolite Y(HUSY)and hydrogen zeolite socony mobil-5(HZSM5)catalysts with high silica content on the pyrolysis process and the products’quality.Thermogravimetry showed that HUSY significantly reduces the degradation temperature of all the polymers—particularly the polyolefines.HZSM5 had a significant effect on the degradation of polyethylene due to its smaller pore size.Mass balance showed that oil is always the main product of pyrolysis,regardless of the process conditions.However,all pyrolysis runs performed at 370℃ were incomplete.The use of either zeolites resulted in a decrease in the heavy oil fraction and the prevention of wax formation.HUSY has the best performance in terms of the total monoaromatic yield(29 wt-%at 450℃),while HZSM5 promoted the production of gases(41 wt-%at 650℃).Plasmix is a potential input material for pyrolysis that is positively affected by the presence of the two tested zeolites.A more effective separation of polyethylene terephthalate during the selection process could lead to higher quality pyrolysis products.展开更多
The global energy related challenges, mainly due to the worldwide growing energy consumption gone with a reduction ofoil and gas availability, is leading to an increasing interest on hydrogen as energy carrier. Molten...The global energy related challenges, mainly due to the worldwide growing energy consumption gone with a reduction ofoil and gas availability, is leading to an increasing interest on hydrogen as energy carrier. Molten salts at temperatures up to 550 ~C can be used as solar heat carrier and storage system, and hydrogen selective membranes can be used to drive reforming reaction at lower temperatures than conventional （〈 550 ~C）, with hydrogen purification achieved thereby. The combination of new technologies such as membranes and membrane reactors, concentrating solar power （CSP） systems and molten salt heat carriers, allows a partial decarbonation of the fossil fuel together with the possibility to carry solar energy in the current natural gas grid. The aim of this work is to present a life cycle assessment of a novel hybrid plant for the production of a mixture of methane and hydrogen, called enriched methane, from a steam reforming reactor whose heat duty is supplied by a molten salt stream heated up by an innovative concentrating solar power （CSP） plant developed by ENEA. The performance of this plant will be evaluated from an environmental point of view by the use of an LCA software （SimaPro7） and compared with the ones of traditional plants （reformer and cracker for the hydrogen production） for the production of enriched methane.展开更多
文摘A synthetic mixture of real waste packaging plastics representative of the residue from a material recovery facility(plasmix)was submitted to thermal and catalytic pyrolysis.Preliminary thermogravimetry experiments coupled with Fourier transform infrared spectroscopy were performed to evaluate the effects of the catalysts on the polymers’degradation temperatures and to determine the main compounds produced during pyrolysis.The thermal and catalytic experiments were conducted at 370℃,450℃ and 650℃ using a bench scale reactor.The oil,gas,and char yields were analyzed and the compositions of the reaction products were compared.The primary aim of this study was to understand the effects of zeolitic hydrogen ultra stable zeolite Y(HUSY)and hydrogen zeolite socony mobil-5(HZSM5)catalysts with high silica content on the pyrolysis process and the products’quality.Thermogravimetry showed that HUSY significantly reduces the degradation temperature of all the polymers—particularly the polyolefines.HZSM5 had a significant effect on the degradation of polyethylene due to its smaller pore size.Mass balance showed that oil is always the main product of pyrolysis,regardless of the process conditions.However,all pyrolysis runs performed at 370℃ were incomplete.The use of either zeolites resulted in a decrease in the heavy oil fraction and the prevention of wax formation.HUSY has the best performance in terms of the total monoaromatic yield(29 wt-%at 450℃),while HZSM5 promoted the production of gases(41 wt-%at 650℃).Plasmix is a potential input material for pyrolysis that is positively affected by the presence of the two tested zeolites.A more effective separation of polyethylene terephthalate during the selection process could lead to higher quality pyrolysis products.
文摘The global energy related challenges, mainly due to the worldwide growing energy consumption gone with a reduction ofoil and gas availability, is leading to an increasing interest on hydrogen as energy carrier. Molten salts at temperatures up to 550 ~C can be used as solar heat carrier and storage system, and hydrogen selective membranes can be used to drive reforming reaction at lower temperatures than conventional （〈 550 ~C）, with hydrogen purification achieved thereby. The combination of new technologies such as membranes and membrane reactors, concentrating solar power （CSP） systems and molten salt heat carriers, allows a partial decarbonation of the fossil fuel together with the possibility to carry solar energy in the current natural gas grid. The aim of this work is to present a life cycle assessment of a novel hybrid plant for the production of a mixture of methane and hydrogen, called enriched methane, from a steam reforming reactor whose heat duty is supplied by a molten salt stream heated up by an innovative concentrating solar power （CSP） plant developed by ENEA. The performance of this plant will be evaluated from an environmental point of view by the use of an LCA software （SimaPro7） and compared with the ones of traditional plants （reformer and cracker for the hydrogen production） for the production of enriched methane.
