Javascript must be enabled for the correct page display

Synas to Bio-ethanol Fermentation

Randolph, Caelan and Bos, Remco and Bosch, Patrick and Wijaya, Jeff (2018) Synas to Bio-ethanol Fermentation. Bachelor's Thesis, Chemical Engineering.


Download (4MB) | Preview
[img] Text
Restricted to Registered users only

Download (118kB)


Minimizing waste and environmental impact of industrial installations is a relevant concern in 2018, and a modern engineer is more so than ever asked to solve nvironmental challenges pertaining to future and legacy technology. An area with large waste streams, and great potential for innovation is the steel industry, which produces large volumes of toxic and greenhouse gasses like carbon monoxide and carbon dioxide. Typically, said gasses are burned, but steel furnace exhaust gasses have a very low heating value, being ten times less productive than natural gas. A possible alternative to burning said gas is to convert it into a useful product. As early as the 1990s, publications arose discussing the conversion of synthetic gas (syngas) using the wood-ljungdahl pathway, a metabolic pathway used by anaerobic microbes to convert carbon monoxide and carbon dioxide to products like acetic acid and ethanol, among other less prominent products. One of the first microbes studied in this fermentation process was Closterium ljungdahlii. Despite the early discovery of the wood-Ljungdahl pathway and the possibilities Closterium ljungdahlii offered in syngas conversion, very few implementations of syngas bio-fermentation processes exist, and none at significant industrial scale. In order to assess the potential of syngas bio-fermentation in conjunction with steel gas waste streams, this paper examines the economic viability of said process by designing a syngas bio-fermentation plant using exhaust gasses of a TATA steel plant in southern Holland. This paper begins by introducing Closterium ljungdahlii, the microbe of choice, and the pathway used in the bioreactor. Next, reactor choice and design occur, followed by a syngas pretreatment design, then product purification design. The design process involves both theoretical design calculations, and process simulation using Aspen Plus. Lastly, the cost and turnover of said installation is examined to determine whether such a project is viable. Cost analysis was achieved using Aspen Plus Economic Analyzer, and process costing theory from Chemical Engineering Design by Towler and Sinnot. Our findings estimate a near $8.64 billion-dollar project investment cost, with a $1.8 billion-dollar turnover on ethanol sales from the plant annually, which based on a 6 Mton per annum steel output. The process wass found to be extremely energy intensive, with the plant under steady state operation estimated to consume nearly 5.93GW. Due to the large energy demands of product purification and syngas pretreatment, the process was found to be un-economical. Advice and possible economizing strategies are included to shed light on how this process could become more economically viable in the concluding statements.

Item Type: Thesis (Bachelor's Thesis)
Supervisor name: Winkelman, J.G.M.
Degree programme: Chemical Engineering
Thesis type: Bachelor's Thesis
Language: English
Date Deposited: 03 Jul 2018
Last Modified: 11 Jul 2018 11:55

Actions (login required)

View Item View Item