{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/29520"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/29520","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Characterization of carbonaceous aerosols from biofuel combustion: emissions and climate relevant properties","abstract":"Aerosol direct radiative forcing on climate is significant but highly uncertain. Carbonaceous aerosols, composed of black carbon (BC) and organic carbon (OC), are important to understand aerosol radiative forcing due to their prevalence in the atmosphere. Biofuel combustion is responsible for nearly 20% of primary BC and OC emissions, but this source is relatively unstudied. Both emissions and optical properties (especially absorption) of carbonaceous aerosols from biofuel combustion need to be better characterized to estimate climate impact of biofuel combustion in models. An experimental method was developed to examine light absorption by primary OC emitted from wood combustion and to provide realistic imaginary refractive indices to radiative-transfer models. Water-soluble OC contributed to light absorption at both ultraviolet and visible wavelengths. However, a larger portion of the absorption came from OC that is not extractable by water but by methanol. Higher wood temperature is the main factor creating OC with higher absorption when compared to wood size and type. Mass absorption cross-section (MAC) of BC is an essential variable in climate models. MAC for ambient BC from literature is 10.3±4.2 m2/g. Filter-based absorption methods provide more variant and higher MAC than in-situ absorption measurement. Semi-continuous mass analyzers measure higher MAC than sample-integrated mass measurements. Thermal transmittance method measures higher MAC than the methods which remove OC prior to mass analysis. BC MAC reduces by 13-40 percent when OC is removed by a thermal denuder upstream of the BC measurement. Biofuel combustion is a highly variable source. Emission fingerprint approach was developed and used to compare emissions from different combustion activities. Improved cookstoves reduce emissions by eliminating formation of OC with high SSA, which occurs at low combustion efficiency. In the laboratory a large part of emission is missing for particles with greater SSA which generally produces under low combustion efficiency and we should seek for a way to add this part in the future cookstove testing. I also established the groundwork of data processing for the newly developed cookstove sampling system and interpreted the emission data obtained from in-field cookstove tests in Africa and South Asia. Results show that improved cookstoves may be more fuel efficient, but combustion still needs to be cleaner. Gasifier stoves in India have the lowest PM emission factors of 1 g/kg fuel.","abstract_html":"Aerosol direct radiative forcing on climate is significant but highly uncertain. Carbonaceous aerosols, composed of black carbon (BC) and organic carbon (OC), are important to understand aerosol radiative forcing due to their prevalence in the atmosphere. Biofuel combustion is responsible for nearly 20% of primary BC and OC emissions, but this source is relatively unstudied. Both emissions and optical properties (especially absorption) of carbonaceous aerosols from biofuel combustion need to be better characterized to estimate climate impact of biofuel combustion in models. An experimental method was developed to examine light absorption by primary OC emitted from wood combustion and to provide realistic imaginary refractive indices to radiative-transfer models. Water-soluble OC contributed to light absorption at both ultraviolet and visible wavelengths. However, a larger portion of the absorption came from OC that is not extractable by water but by methanol. Higher wood temperature is the main factor creating OC with higher absorption when compared to wood size and type. Mass absorption cross-section (MAC) of BC is an essential variable in climate models. MAC for ambient BC from literature is 10.3±4.2 m2/g. Filter-based absorption methods provide more variant and higher MAC than in-situ absorption measurement. Semi-continuous mass analyzers measure higher MAC than sample-integrated mass measurements. Thermal transmittance method measures higher MAC than the methods which remove OC prior to mass analysis. BC MAC reduces by 13-40 percent when OC is removed by a thermal denuder upstream of the BC measurement. Biofuel combustion is a highly variable source. Emission fingerprint approach was developed and used to compare emissions from different combustion activities. Improved cookstoves reduce emissions by eliminating formation of OC with high SSA, which occurs at low combustion efficiency. In the laboratory a large part of emission is missing for particles with greater SSA which generally produces under low combustion efficiency and we should seek for a way to add this part in the future cookstove testing. I also established the groundwork of data processing for the newly developed cookstove sampling system and interpreted the emission data obtained from in-field cookstove tests in Africa and South Asia. Results show that improved cookstoves may be more fuel efficient, but combustion still needs to be cleaner. Gasifier stoves in India have the lowest PM emission factors of 1 g/kg fuel.","abstract_has_math":false,"creators":["Chen, Yanju"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Environ Engr in Civil Engr","degree_department":null,"school":null,"contributors":["Bond, Tami C.","Rood, Mark J.","Strathmann, Timothy J.","Kirchstetter, Thomas W."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2012,"date_issued":"2012-02-01T00:53:47Z","date_published":"2012-02-01T00:53:47Z","updated_at":"2026-07-22T22:25:27Z","subjects":["Carbonaceous aerosols","optical properties","absorption","organic carbon","black carbon","biofuel combustion","cookstove","emission"],"languages":["en"],"rights":["Copyright 2010 Yanju Chen & Tami C. Bond"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/29520","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Bond, Tami C.","Rood, Mark J.","Strathmann, Timothy J.","Kirchstetter, Thomas W."]},{"key":"dc:creator","label":"Author","values":["Chen, Yanju"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2012-02-01T00:53:47Z","2014-02-01T11:00:33Z","2011-12"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation / Thesis","text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Environ Engr in Civil Engr"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Carbonaceous aerosols","optical properties","absorption","organic carbon","black carbon","biofuel combustion","cookstove","emission"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2010 Yanju Chen & Tami C. Bond"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/29520"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Aerosol direct radiative forcing on climate is significant but highly uncertain. Carbonaceous aerosols, composed of black carbon (BC) and organic carbon (OC), are important to understand aerosol radiative forcing due to their prevalence in the atmosphere. Biofuel combustion is responsible for nearly 20% of primary BC and OC emissions, but this source is relatively unstudied. Both emissions and optical properties (especially absorption) of carbonaceous aerosols from biofuel combustion need to be better characterized to estimate climate impact of biofuel combustion in models. An experimental method was developed to examine light absorption by primary OC emitted from wood combustion and to provide realistic imaginary refractive indices to radiative-transfer models. Water-soluble OC contributed to light absorption at both ultraviolet and visible wavelengths. However, a larger portion of the absorption came from OC that is not extractable by water but by methanol. Higher wood temperature is the main factor creating OC with higher absorption when compared to wood size and type. Mass absorption cross-section (MAC) of BC is an essential variable in climate models. MAC for ambient BC from literature is 10.3±4.2 m2/g. Filter-based absorption methods provide more variant and higher MAC than in-situ absorption measurement. Semi-continuous mass analyzers measure higher MAC than sample-integrated mass measurements. Thermal transmittance method measures higher MAC than the methods which remove OC prior to mass analysis. BC MAC reduces by 13-40 percent when OC is removed by a thermal denuder upstream of the BC measurement. Biofuel combustion is a highly variable source. Emission fingerprint approach was developed and used to compare emissions from different combustion activities. Improved cookstoves reduce emissions by eliminating formation of OC with high SSA, which occurs at low combustion efficiency. In the laboratory a large part of emission is missing for particles with greater SSA which generally produces under low combustion efficiency and we should seek for a way to add this part in the future cookstove testing. I also established the groundwork of data processing for the newly developed cookstove sampling system and interpreted the emission data obtained from in-field cookstove tests in Africa and South Asia. Results show that improved cookstoves may be more fuel efficient, but combustion still needs to be cleaner. Gasifier stoves in India have the lowest PM emission factors of 1 g/kg fuel.","Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2011-11-02T17:38:27Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 1 Chen_Yanju.pdf: 5234882 bytes, checksum: 2fbb386f13528f480e3dcaa2f264c27b (MD5)","Made available in DSpace on 2012-02-01T00:53:47Z (GMT). No. of bitstreams: 2 Chen_Yanju.pdf: 5240257 bytes, checksum: ecf93f2c8fb19224cb0b3be1bdb23f23 (MD5) license.txt: 4058 bytes, checksum: e49ade371f7b72399e80afc6636e0ff0 (MD5)","Item marked as restricted to the 'Administrator' Group (id=1) by William Ingram (wingram2@illinois.edu) on 2012-02-01T00:57:02Z Item is restricted until 2014-02-01T00:56:58Z","Item reinstated by Sarah Shreeves (sshreeve@illinois.edu) on 2014-02-01T11:00:33Z Item was in collections: Dissertations and Theses - Civil and Environmental Engineering (ID: 672) Graduate Theses and Dissertations at Illinois (ID: 204) No. of bitstreams: 3 Chen_Yanju.pdf.txt: 418754 bytes, checksum: 856b98eb004bb186bceaf48d5deffb90 (MD5) Chen_Yanju.pdf: 5240257 bytes, checksum: ecf93f2c8fb19224cb0b3be1bdb23f23 (MD5) license.txt: 4058 bytes, checksum: e49ade371f7b72399e80afc6636e0ff0 (MD5)","Item released from any restrictions by Sarah Shreeves (sshreeve@illinois.edu) on 2014-02-01T11:00:33Z"]},{"key":"dc:title","label":"Title","values":["Characterization of carbonaceous aerosols from biofuel combustion: emissions and climate relevant properties"]}]}],"canonical_facts":{"dc:contributor":["Bond, Tami C.","Rood, Mark J.","Strathmann, Timothy J.","Kirchstetter, Thomas W."],"dc:creator":["Chen, Yanju"],"dc:date":["2012-02-01T00:53:47Z","2014-02-01T11:00:33Z","2011-12"],"dc:description":["Aerosol direct radiative forcing on climate is significant but highly uncertain. Carbonaceous aerosols, composed of black carbon (BC) and organic carbon (OC), are important to understand aerosol radiative forcing due to their prevalence in the atmosphere. Biofuel combustion is responsible for nearly 20% of primary BC and OC emissions, but this source is relatively unstudied. Both emissions and optical properties (especially absorption) of carbonaceous aerosols from biofuel combustion need to be better characterized to estimate climate impact of biofuel combustion in models. An experimental method was developed to examine light absorption by primary OC emitted from wood combustion and to provide realistic imaginary refractive indices to radiative-transfer models. Water-soluble OC contributed to light absorption at both ultraviolet and visible wavelengths. However, a larger portion of the absorption came from OC that is not extractable by water but by methanol. Higher wood temperature is the main factor creating OC with higher absorption when compared to wood size and type. Mass absorption cross-section (MAC) of BC is an essential variable in climate models. MAC for ambient BC from literature is 10.3±4.2 m2/g. Filter-based absorption methods provide more variant and higher MAC than in-situ absorption measurement. Semi-continuous mass analyzers measure higher MAC than sample-integrated mass measurements. Thermal transmittance method measures higher MAC than the methods which remove OC prior to mass analysis. BC MAC reduces by 13-40 percent when OC is removed by a thermal denuder upstream of the BC measurement. Biofuel combustion is a highly variable source. Emission fingerprint approach was developed and used to compare emissions from different combustion activities. Improved cookstoves reduce emissions by eliminating formation of OC with high SSA, which occurs at low combustion efficiency. In the laboratory a large part of emission is missing for particles with greater SSA which generally produces under low combustion efficiency and we should seek for a way to add this part in the future cookstove testing. I also established the groundwork of data processing for the newly developed cookstove sampling system and interpreted the emission data obtained from in-field cookstove tests in Africa and South Asia. Results show that improved cookstoves may be more fuel efficient, but combustion still needs to be cleaner. Gasifier stoves in India have the lowest PM emission factors of 1 g/kg fuel.","Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2011-11-02T17:38:27Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 1 Chen_Yanju.pdf: 5234882 bytes, checksum: 2fbb386f13528f480e3dcaa2f264c27b (MD5)","Made available in DSpace on 2012-02-01T00:53:47Z (GMT). No. of bitstreams: 2 Chen_Yanju.pdf: 5240257 bytes, checksum: ecf93f2c8fb19224cb0b3be1bdb23f23 (MD5) license.txt: 4058 bytes, checksum: e49ade371f7b72399e80afc6636e0ff0 (MD5)","Item marked as restricted to the 'Administrator' Group (id=1) by William Ingram (wingram2@illinois.edu) on 2012-02-01T00:57:02Z Item is restricted until 2014-02-01T00:56:58Z","Item reinstated by Sarah Shreeves (sshreeve@illinois.edu) on 2014-02-01T11:00:33Z Item was in collections: Dissertations and Theses - Civil and Environmental Engineering (ID: 672) Graduate Theses and Dissertations at Illinois (ID: 204) No. of bitstreams: 3 Chen_Yanju.pdf.txt: 418754 bytes, checksum: 856b98eb004bb186bceaf48d5deffb90 (MD5) Chen_Yanju.pdf: 5240257 bytes, checksum: ecf93f2c8fb19224cb0b3be1bdb23f23 (MD5) license.txt: 4058 bytes, checksum: e49ade371f7b72399e80afc6636e0ff0 (MD5)","Item released from any restrictions by Sarah Shreeves (sshreeve@illinois.edu) on 2014-02-01T11:00:33Z"],"dc:identifier":["http://hdl.handle.net/2142/29520"],"dc:language":["en"],"dc:rights":["Copyright 2010 Yanju Chen & Tami C. Bond"],"dc:subject":["Carbonaceous aerosols","optical properties","absorption","organic carbon","black carbon","biofuel combustion","cookstove","emission"],"dc:title":["Characterization of carbonaceous aerosols from biofuel combustion: emissions and climate relevant properties"],"dc:type":["Dissertation / Thesis","text"],"thesis:degree_discipline":["Environ Engr in Civil Engr"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:27Z"}