Sharif Digital Repository

In this study, the biological process of producing polyhydroxybutyrate (PHB), a biodegradable polymer, using methane as the carbon source and nitrate as the nitrogen source was numerically modeled and simulated in an 8 m height and 0.5 m diameter bubble column bioreactor. The primary goal was to develop a time-dependent model capable of simultaneously describing biomass growth, substrate consumption, and polymer production, while accounting for gas–liquid mass transfer and momentum transfer. The modeling was performed under sufficient aeration, and any complications arising from strain swelling due to intracellular accumulation were neglected. Initially, a biomass growth model based on a... 

In recent years, the production of biodegradable plastics from renewable resources has been proposed as an effective solution to address the issue of fossil fuel-based plastic accumulation. Recently, the technology of converting methane into biodegradable plastics has emerged as an effective process in this field. The advantages of this process include reducing the accumulation of fossil fuel-based plastics in the environment, lower production costs due to the use of inexpensive raw materials, and decreasing greenhouse gas emissions. In this process, methanotrophic microorganisms convert methane into biodegradable plastics in two stages: biomass growth and plastic production under...