Full text
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| Author(s): |
Igor Lucas Rodrigues Dias
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia Química |
| Defense date: | 2021-08-04 |
| Examining board members: |
Adriano Pinto Mariano;
Rubens Maciel Filho;
Valdir Apolinário de Freitas
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| Advisor: | Jean Christophe Stefen Gilles Bonhivers; Adriano Pinto Mariano |
| Abstract | |
Solventogenic Clostridium species responsible for the ABE fermentation (Acetone-Butanol-Ethanol) are strongly inhibited by butanol, resulting in dilute processes with low energy efficiency and large stillage production. Possible solutions include fermentation technologies with integrated product recovery. Among these technologies, vacuum fermentation attracts attention due to its simplicity. However, previous studies have demonstrated that the energy cost to condensate the vapors generated during the boiling of the fermentation broth is prohibitive. To try to solve this problem of vacuum fermentation, we developed a condensation system based on ejectors operated with an organic solvent to generate the vacuum. The organic solvent is ethylene glycol, which is reused in the product purification step by distillation. Different configurations have been proposed for the process with ethylene glycol ejectors. Moreover, we developed other scenarios using steam ejectors and compressors. Studies were conducted using process simulation in Aspen Plus®, and the efficiency of the proposed process (vacuum fermentation/condensation/distillation) was assessed by energy (pinch analysis) and economic analyses. Replacing compressors with ejectors significantly reduces electricity consumption but increases the demand for other utilities. Of all the processes developed, the plant with only compressors had the lowest total cost (209.8 US$/ton butanol) followed by the plant with ethylene glycol steam ejectors (233.7 US$/ton butanol). Both cases were more economical than the conventional process without vacuum (235.3 US$/ton butanol). The advantage of the new processes is even greater for lower electricity costs and high investment costs. We conclude that ABE fermentation in a vacuum flash type with compressor and/or ethylene glycol ejector has the potential to have a total cost lower than the conventional process without vacuum if there are energetic integrations. In addition to the economic benefits, the plants developed were compact and cause less environmental impact with excessive fertigation of the stillage (AU) | |
| FAPESP's process: | 19/03019-0 - Development of a vacuum and condensation system to recover acetone-butanol-ethanol from fermentation broths |
| Grantee: | Igor Lucas Rodrigues Dias |
| Support Opportunities: | Scholarships in Brazil - Master |