title: Partial oxidation of sewage sludge briquettes in a updraft fixed bed.
abstract: The fixed bed reaction of sewage sludge briquettes was investigated to evaluate the potential applications to gasification, combustion, or production of biochar as soil ameliorator. The reaction had two distinctive stages: ignition propagation and char oxidation. The ignition front of the sludge briquettes propagated at a lower speed, which significantly increased the stoichiometric ratio of overall combustion reaction and peak temperatures. The ignition front also had irregular shapes due to the channeling effects. During the char oxidation stage, the sludge ash agglomerated because of the slow reaction rate and increased CO2 formation. Because of low energy content in the product gas, the large briquettes were not favorable for syngas production. In addition, the low burning rates and ash agglomeration could cause problems in the operation of a grate-type furnace for combustion. However, the char accumulated above the ignition front had similar properties with that from pyrolysis under inert atmosphere. Therefore, the fixed bed reaction under partial oxidation conditions can be applied to produce biochar as soil ameliorator from the sludge briquettes without external heat supply.
authors: School of Mechanical Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea.
authors: Minsu
authors: M
authors: Kim
authors: School of Mechanical Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea.
authors: Yongwoon
authors: Y
authors: Lee
authors: School of Mechanical Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea.
authors: Jinje
authors: J
authors: Park
authors: School of Mechanical Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea. Electronic address: cryu@me.skku.ac.kr.
authors: Chankook
authors: C
authors: Ryu
authors: Department of Civil and Environmental Engineering, Hanbat National University, Daejeon 34158, Republic of Korea.
authors: Tae-In
authors: TI
authors: Ohm
mesh_terms: D002606:Charcoal / Q000032:analysis*; D006358:Hot Temperature; D010084:Oxidation-Reduction; D012037:Refuse Disposal; D012722:Sewage / Q000737:chemistry*; D018505:Waste Management / Q000379:methods*
chemical_list: D012722:Sewage; C540010:biochar; D002606:Charcoal
keywords: Biochar; Burning rate; Combustion; Fixed bed; Ignition front; Sewage sludge