Hydrogen Production from Sewage Sludge by Steam Gasification

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Hydrogen Production from Sewage Sludge by Steam
Gasification

• Pisuthi Klinkajorn

Supervisor Dr. Lu Aye
International Technologies Centre
(IDTC) Department of Civil and Environmental
Engineering The University of Melbourne
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Outline

• Introduction
• A proposed solution
• Approach
• Work in progress
• Further work

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Environment problem and Energy Crisis
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A proposed solution
Decision - What type of reactor? (fixed bed or
fluidized bed) - What type of gasify agent? (air
or O2 or steam gasification)
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Significant differences between fixed bed and
fluidized bed
Source Warnecke 2000

• Gasification in fixed bed also
• Low moisture content require
• Partial ash agglomeration when using some
  agriculture residues (Columba et al. 1999) and
  Tar and SS aggregation problem at grate and wall
  in SS gasification ( Midili et al. 2002)
• Low H2 conversion _at_ high SS feedrate (gt8.92 kg/h
  ( Midili et al. 2002))

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Effect of gasifying agents

• H2 production with different gasifying agents
• - Steam gtSteamO2gtO2gtair
• Energy requirement for H2 production
• - SteamgtSteamO2gtO2 and air

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Objective

• To model SSSG
• To validate the model of SSSG
• To obtain the most economical condition in H2
  producing gas product from sewage sludge

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Approach

• Developing a computer model which enables
• Predicting the transient state of SSSG in reactor
• Exploring the optimum conditions for H2
  production without external heat input
• Experiments which allow
• Validating the computer model
• Testing the optimum conditions for H2 production

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Stoichiometric reaction model of SS
H2 production
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Schematic of Energy Balance
Energy requirement Energy required for heat up
SS and gasifying agent to reactor temperature
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Energy requirement in H2 production
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Proposed test rig
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Further investigations

• Gibbs free energy minimization
• - Exploring a limit of hydrogen production when
  the equilibrium is reached
• Design of all equipments of a test rig
• - Ash, one of important characteristics of SS,
  might cause problems in operation

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Thank you !