Doctoral Dissertations

Keywords and Phrases

Biogas Production; Upgrading The Biogas Quality; Wastewater Treatment


"The non-hazardous waste management hierarchy of the US EPA calls for “Reduce, Reuse, and Recycle” (or the three R’s) of wastes. The anaerobic digestion process is one of the most important methods that used to treat the wastes and at the same time generate energy out of it. The anaerobic digestion process generates a mixture of methane and carbon dioxide gases which is known as biogas.

The biogas composition is about 50-70% methane and 10-30% of carbon dioxide and trace amount of other gases like hydrogen and hydrogen sulfide. This biogas can be used in power generation, heating systems and in combined heating and powering systems. Also, it could be upgraded to improve its quality and make is utilized in all equipment used for natural gas with a minimal adjustment due to the lower BTU contents for methane gas.

Three papers were written and submitted regarding the biogas production and the liquid waste water treatment. The first paper focuses on developing a process modeling simulation by aspen plus for the anaerobic digestion process and on conducting a sensitivity analysis to investigate the parameters that could upgrade the biogas quality. The second paper focuses on the effect of hydraulic retention time of the substrate on the biogas production. This investigation conducted in a two-stage high rate expanded granular sludge bed reactor under different variables like substrate concentration, organic loading rate, and operating temperature. The third paper focuses on upgrading the biogas quality and quantity in a two-stage expanded granular sludge bed reactor by investigating the effect of injecting the pre-acidification gas (the first stage), which is mainly produced a gas mixture consist of hydrogen and carbon dioxide) into the second stage (the expanded granular sludge bed reactor)--Abstract, page iv.


Smith, Joseph D.

Committee Member(s)

Al-Dahhan, Muthanna H.
Ludlow, Douglas K.
Luks, Christi Patton
Dogan, Fatih


Chemical and Biochemical Engineering

Degree Name

Ph. D. in Chemical Engineering


Missouri University of Science and Technology

Publication Date

Spring 2018

Journal article titles appearing in thesis/dissertation

  • Simulation of two-stage anaerobic digestion for methane production
  • The impact of hydraulic retention time and operating temperature on biofuel production and process waste water treatment
  • The pre-acidification gas impact on upgrading the biogas produced in expanded granular sludge bed reactor


xiv, 139 pages

Note about bibliography

Includes bibliographic references.


© 2018 Haider Al-Rubaye, All rights reserved.

Document Type

Dissertation - Open Access

File Type




Thesis Number

T 11262

Electronic OCLC #