Influence of metal addition to Ni-based catalysts for the co-production of carbon nanotubes and hydrogen from the thermal processing of waste polypropylene

Abstract

ABSTRACT:This paper investigates the co-production of hydrogen and carbon nanotubes from the pyrolysis-catalytic gasification of waste plastics (polypropylene). We report on the influence of a range of metal additions to a nickel based catalyst based on ternary mixed oxides types catalyst support plays a significant role in the gasification process; weak metal support interaction (for the Ni-Mn-Al catalyst calcined at 300 °C) resulted in a lower hydrogen production and much higher yield of carbon products. In addition, the influence of steam injection rate on hydrogen and carbon nanotube production was investigated for the Ni-MnAl catalyst. Increasing the steam injection rate significantly increased hydrogen production and decreased carbon deposition. However, at lower steam injection rates, the quality of the product carbon nanotubes was improved.

Present Advancement in Production of Carbon Nanotubes and Their Derivatives from Industrial Waste with Promising Applications

“…Even though recycling rates for waste plastics have recently increased there is still a large remaining amount which ends up by being unsustainably disposed in landfill sites (Zhang et al, 2008;Mishra et al, 2012;Bajad et al, 2015;Nahil et al, 2015). In almost every country, the governmental sector has enforced more serious criteria for such industrial waste handling, such as limitation or avoidance of landfilling while encouraging promotion of waste management techniques are provided.…”

“…In addition, it has been recognized that the industrial CNT manufacturing processes become sustainable and inherently safe though it would be sensible to use readily-available alternative fuels, such as existing waste streams. At the moment, since the production of CNTs has been successfully transferred from laboratory-scale to industrial-scale, their worldwide market is expected to grow from $215 million in 2009 to over $9 billion by 2020 (Iijima, 2012;Li et al, 2012;Nahil et al, 2015).…”

“…Converting such plastic wastes into valuable products, such as carbon nanotubes (CNTs) could be an important and profitable option for industry and for environmental protection. Recently many research works focusing on synthesis of CNTs and other nanostructure derivatives through thermal decomposition of plastic wastes, such as polypropylene (PP), low density polyethylene (LDPE), high density polyethylene (HDPE), polyacrylate (PC), polyvinyl chloride (PVC), polystyrene (PS) and polyethyleneterephthalate (PET) with the presence of specific catalysts have been reported (Zhang et al, 2008;Quan et al, 2010;Zhuo et al, 2010;Mishra et al, 2012;Yang et al, 2012;Savant et al, 2013;Acomb et al, 2014;Bajad et al, 2015: Nahil et al, 2015. Within those previous works, usage of low-cost alternative feedstocks which are post-consumer plastic wastes for CNT production has been demonstrated.…”

“…Among various materials, carbon is recognized as an excellent candidate due to its stability and compatibility (Bazargan and McKay, 2012;Nahil et al, 2015). For example, Yang et al (2005) prepared spherical carbon particles or carbon spherules for accommodating Pt nanoparticles which was employed as electrocatalyst in direct methanol fuel cells (DMFCs).…”

“…Many technical reports have indicated that the thermal pyrolysis of organometallic compounds, such as ferrocene, iron phthalocyanine, and nickel phthalocyanine can be employed as either reactants or catalysts for production of carbon nanotubes and nanocapsules (Afre et al, 2006;Liu et al, 2006;Vijayaraghavan and Stevenson, 2007;Charinpanitkul et al, 2009a;Zhuo et al, 2010;Sano et al, 2012;Li et al, 2012;Yang et al, 2012). With the thermal pyrolysis, some metal species, such as Fe, Ni or Co, in those compounds are well recognized to play an important role as catalyst for CNP growth (Auer et al, 1998;Li et al, 2003;Zeng, et al, 2006;Yuan et al, 2007;Morales et al, 2013;Nahil et al, 2015). Many novel methods to incorporate necessary catalyst with carbon sources are also the on-going research issues which have been reported by various research teams around the world.…”