{"id":{"repo_id":"plymouth","oai_identifier":"oai:pearl.plymouth.ac.uk:gees-theses-1836"},"canonical_url":"https://search.dev.ndltd.org/etd/plymouth/oai:pearl.plymouth.ac.uk:gees-theses-1836","repository":{"repo_id":"plymouth","name":"University of Plymouth","base_url":"https://pearl.plymouth.ac.uk/do/oai"},"display":{"title":"The Fate of Naphthalene and n-Alkylnaphthalenes During Combustion, and an Evaluation of the Sources of these Compounds in Diesel Exhaust Emissions","abstract":"The main objective of this research was to understand the fate of naphthalene and n-alkylnaphthalenes during diesel combustion, and an evaluation of their sources in diesel exhaust emissions. This was achieved by the use of a procedure which employed a [14C]radiolabelled PAH technique and a diesel enriched fuel technique (DEFT). The combustion of diesel fuel spiked with [14C]naphthalene has shown unequivocally that 0.5% of the naphthalene contained in diesel fuel survives combustion under the engine conditions studied (2500 rpm and 50 Nm). The survived naphthalene represented 22.8% of the total recovered naphthalene, the other 77.2% was presumably pyrosynthetic in nature. The sources of the pyrosynthesised naphthalene in the emissions was investigated at 2500 rpm and 50 Nm. The previously unreported input of n-methylnaphthalenes to the pyrosynthesised naphthalene was demonstrated by combusting fuel spiked with [14C]2-methylnaphthalene. Radiolabelled 2- methylnaphthalene (0.53% of the original [14C]2-methylnaphthalene) which had survived combustion, and radiolabelled naphthalene (0.02% of the original [14C]2-methylnaphthalene), were recovered in the exhaust extracts. This showed unequivocally that 2-methylnaphthalene was converted to naphthalene in the combustion chamber. The first enrichment experiments (DEFT), in which 1- and 2-methylnaphthalene were added separately to fuel prior to combustion confirmed that demethylation of both species produced naphthalene in small yields (1.9% and 6.1% respectively). The contribution of n-alkylnaphthalenes with the alkyl group greater than methyl in length, to pyrosynthesised naphthalene contained in exhaust emissions was investigated using fuel spiked with non-radiolabelled alkyl-PAH. The major product of combustion of these compounds was 2- vinylnaphthalene, with a 0.08% conversion for 2-butylnaphthalene and a 0.01% conversion for 2- ethylnaphthalene. No dealkylated products were detected in the exhaust emissions. A mechanism for the formation of 2-vinylnaphthalene was proposed. The effect of engine speed and load on the recovery of naphthalene and the contribution of pyrosynthesised and survived naphthalene to recovered naphthalene were established using [14C]naphthalene. At all speeds and loads investigated the pyrosynthesised fraction of recovered naphthalene was shown to be dominant.","abstract_html":"The main objective of this research was to understand the fate of naphthalene and n-alkylnaphthalenes during diesel combustion, and an evaluation of their sources in diesel exhaust emissions. This was achieved by the use of a procedure which employed a [14C]radiolabelled PAH technique and a diesel enriched fuel technique (DEFT). The combustion of diesel fuel spiked with [14C]naphthalene has shown unequivocally that 0.5% of the naphthalene contained in diesel fuel survives combustion under the engine conditions studied (2500 rpm and 50 Nm). The survived naphthalene represented 22.8% of the total recovered naphthalene, the other 77.2% was presumably pyrosynthetic in nature. The sources of the pyrosynthesised naphthalene in the emissions was investigated at 2500 rpm and 50 Nm. The previously unreported input of n-methylnaphthalenes to the pyrosynthesised naphthalene was demonstrated by combusting fuel spiked with [14C]2-methylnaphthalene. Radiolabelled 2- methylnaphthalene (0.53% of the original [14C]2-methylnaphthalene) which had survived combustion, and radiolabelled naphthalene (0.02% of the original [14C]2-methylnaphthalene), were recovered in the exhaust extracts. This showed unequivocally that 2-methylnaphthalene was converted to naphthalene in the combustion chamber. The first enrichment experiments (DEFT), in which 1- and 2-methylnaphthalene were added separately to fuel prior to combustion confirmed that demethylation of both species produced naphthalene in small yields (1.9% and 6.1% respectively). The contribution of n-alkylnaphthalenes with the alkyl group greater than methyl in length, to pyrosynthesised naphthalene contained in exhaust emissions was investigated using fuel spiked with non-radiolabelled alkyl-PAH. The major product of combustion of these compounds was 2- vinylnaphthalene, with a 0.08% conversion for 2-butylnaphthalene and a 0.01% conversion for 2- ethylnaphthalene. No dealkylated products were detected in the exhaust emissions. A mechanism for the formation of 2-vinylnaphthalene was proposed. The effect of engine speed and load on the recovery of naphthalene and the contribution of pyrosynthesised and survived naphthalene to recovered naphthalene were established using [14C]naphthalene. At all speeds and loads investigated the pyrosynthesised fraction of recovered naphthalene was shown to be dominant.","abstract_has_math":false,"creators":["Pemberton, Robin Douglas"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1996,"date_issued":"1996-01-01T08:00:00Z","date_published":"1996-01-01T08:00:00Z","updated_at":"2026-07-24T03:49:07Z","subjects":[],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://pearl.plymouth.ac.uk/gees-theses/394","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Pemberton, Robin Douglas"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.issued","label":"Date","values":["1996-01-01T08:00:00Z"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://pearl.plymouth.ac.uk/gees-theses/394"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The main objective of this research was to understand the fate of naphthalene and n-alkylnaphthalenes during diesel combustion, and an evaluation of their sources in diesel exhaust emissions. This was achieved by the use of a procedure which employed a [14C]radiolabelled PAH technique and a diesel enriched fuel technique (DEFT). The combustion of diesel fuel spiked with [14C]naphthalene has shown unequivocally that 0.5% of the naphthalene contained in diesel fuel survives combustion under the engine conditions studied (2500 rpm and 50 Nm). The survived naphthalene represented 22.8% of the total recovered naphthalene, the other 77.2% was presumably pyrosynthetic in nature. The sources of the pyrosynthesised naphthalene in the emissions was investigated at 2500 rpm and 50 Nm. The previously unreported input of n-methylnaphthalenes to the pyrosynthesised naphthalene was demonstrated by combusting fuel spiked with [14C]2-methylnaphthalene. Radiolabelled 2- methylnaphthalene (0.53% of the original [14C]2-methylnaphthalene) which had survived combustion, and radiolabelled naphthalene (0.02% of the original [14C]2-methylnaphthalene), were recovered in the exhaust extracts. This showed unequivocally that 2-methylnaphthalene was converted to naphthalene in the combustion chamber. The first enrichment experiments (DEFT), in which 1- and 2-methylnaphthalene were added separately to fuel prior to combustion confirmed that demethylation of both species produced naphthalene in small yields (1.9% and 6.1% respectively). The contribution of n-alkylnaphthalenes with the alkyl group greater than methyl in length, to pyrosynthesised naphthalene contained in exhaust emissions was investigated using fuel spiked with non-radiolabelled alkyl-PAH. The major product of combustion of these compounds was 2- vinylnaphthalene, with a 0.08% conversion for 2-butylnaphthalene and a 0.01% conversion for 2- ethylnaphthalene. No dealkylated products were detected in the exhaust emissions. A mechanism for the formation of 2-vinylnaphthalene was proposed. The effect of engine speed and load on the recovery of naphthalene and the contribution of pyrosynthesised and survived naphthalene to recovered naphthalene were established using [14C]naphthalene. At all speeds and loads investigated the pyrosynthesised fraction of recovered naphthalene was shown to be dominant."]},{"key":"dc:title","label":"Title","values":["The Fate of Naphthalene and n-Alkylnaphthalenes During Combustion, and an Evaluation of the Sources of these Compounds in Diesel Exhaust Emissions"]}]}],"canonical_facts":{"dc:creator":["Pemberton, Robin Douglas"],"dc:date.issued":["1996-01-01T08:00:00Z"],"dc:description.abstract":["The main objective of this research was to understand the fate of naphthalene and n-alkylnaphthalenes during diesel combustion, and an evaluation of their sources in diesel exhaust emissions. This was achieved by the use of a procedure which employed a [14C]radiolabelled PAH technique and a diesel enriched fuel technique (DEFT). The combustion of diesel fuel spiked with [14C]naphthalene has shown unequivocally that 0.5% of the naphthalene contained in diesel fuel survives combustion under the engine conditions studied (2500 rpm and 50 Nm). The survived naphthalene represented 22.8% of the total recovered naphthalene, the other 77.2% was presumably pyrosynthetic in nature. The sources of the pyrosynthesised naphthalene in the emissions was investigated at 2500 rpm and 50 Nm. The previously unreported input of n-methylnaphthalenes to the pyrosynthesised naphthalene was demonstrated by combusting fuel spiked with [14C]2-methylnaphthalene. Radiolabelled 2- methylnaphthalene (0.53% of the original [14C]2-methylnaphthalene) which had survived combustion, and radiolabelled naphthalene (0.02% of the original [14C]2-methylnaphthalene), were recovered in the exhaust extracts. This showed unequivocally that 2-methylnaphthalene was converted to naphthalene in the combustion chamber. The first enrichment experiments (DEFT), in which 1- and 2-methylnaphthalene were added separately to fuel prior to combustion confirmed that demethylation of both species produced naphthalene in small yields (1.9% and 6.1% respectively). The contribution of n-alkylnaphthalenes with the alkyl group greater than methyl in length, to pyrosynthesised naphthalene contained in exhaust emissions was investigated using fuel spiked with non-radiolabelled alkyl-PAH. The major product of combustion of these compounds was 2- vinylnaphthalene, with a 0.08% conversion for 2-butylnaphthalene and a 0.01% conversion for 2- ethylnaphthalene. No dealkylated products were detected in the exhaust emissions. A mechanism for the formation of 2-vinylnaphthalene was proposed. The effect of engine speed and load on the recovery of naphthalene and the contribution of pyrosynthesised and survived naphthalene to recovered naphthalene were established using [14C]naphthalene. At all speeds and loads investigated the pyrosynthesised fraction of recovered naphthalene was shown to be dominant."],"dc:identifier":["https://pearl.plymouth.ac.uk/gees-theses/394"],"dc:language":["eng"],"dc:title":["The Fate of Naphthalene and n-Alkylnaphthalenes During Combustion, and an Evaluation of the Sources of these Compounds in Diesel Exhaust Emissions"],"dc:type":["Thesis"]},"updated_at":"2026-07-24T03:49:07Z"}