Chemical Engineering Teaching in COVID-19 Times: Successfully Adapting a Capstone Design Course to a Remote Format.

The coronavirus COVID-19 pandemic required educational institutions to adapt face-to-face to remote teaching. This study reports the experience in the first semester of 2020 for a Chemical Engineering Capstone Design Course at the University of Campinas in Brazil. In this course, senior year students develop a group project, in which they simulate a chemical plant and evaluate its technoeconomic feasibility.

Three-stage repeated-batch immobilized cell fermentation to produce butanol from non-detoxified sugarcane bagasse hemicellulose hydrolysates.

To enable the production of butanol with undiluted, non-detoxified sugarcane bagasse hemicellulose hydrolysates, this study developed a three-staged repeated-batch immobilized cell fermentation in which the efficiency of a 3D-printed nylon carrier to passively immobilize Clostridium saccharoperbutylacetonicum DSM 14923 was compared with sugarcane bagasse. The first stage consisted of sugarcane molasses fermentation, and in the second stage, non-detoxified sugarcane bagasse hemicellulose hydrolysates (SBHH) was pulse-fed to sugarcane molasses fermentation. In the next four batches, immobilized cells were fed with undiluted SBHH supplemented with molasses, and SBHH-derived xylose accounted for approximately 50% of the sugars.

Sugarcane bagasse hydrolysates as feedstock to produce the isopropanol-butanol-ethanol fuel mixture: Effect of lactic acid derived from microbial contamination on Clostridium beijerinckii DSM 6423.

Enzymatic hydrolysis of lignocellulose under industrial conditions is prone to contamination by lactic acid bacteria, and in this study, a cellulose hydrolysate produced from dilute-acid pretreatedsugarcane bagasse contained 13 g/L lactic acid and was used for IBE production by Clostridium beijerinckii DSM 6423. In fermentation of the cellulose hydrolysate supplemented with sugarcane molasses for nutrients and buffering of the medium (40 g/L total sugar), 92% of the lactic acid was consumed, and the butanol yield was as high as 0.28 (7.

Biochemical conversion of sugarcane bagasse into the alcohol fuel mixture of isopropanol-butanol-ethanol (IBE): Is it economically competitive with cellulosic ethanol?

This work presents a techno-economic analysis of the production of isopropanol, butanol, and ethanol (IBE) from sugarcane bagasse using clostridia and compares IBE with cellulosic ethanol for the minimum selling price (MSP) and sustainability aspects. The MSPs of the fuels are similar (15 USD/GJ) provided that glucose and xylose are effectively utilized in both processes, and the IBE process is equipped with a genetically-modified Clostridium species with enhanced IBE yield and a highly productive continuous bioreactor with integrated product recovery. Notably, these technologies can reduce the size (from 23 × 3785-m to 3 × 3027-m fermentation tanks) and the wastewater footprint (from 50 to 10 m/m IBE) of the IBE plant.

Resolving mismatches in the flexible production of ethanol and butanol from eucalyptus wood with vacuum fermentation.

In flexible ethanol-butanol plants, low tolerance to butanol by solventogenic clostridia (and resulting dilute fermentation) results in considerable number of empty fermentors whenever production focuses on ethanol. This research identified scenarios in which vacuum fermentation (in-situ vacuum recovery) may be applied to solve this problem. We conducted ethanol (Saccharomyces cerevisiae) and ABE (Clostridium beijerinckii NCIMB 8052) batch vacuum fermentations of eucalyptus hydrolysates according to the distribution of sugars in a flexible plant.

Process design and economics of a flexible ethanol-butanol plant annexed to a eucalyptus kraft pulp mill.

This work proposes a strategy, from a process design standpoint, for pulp companies to enter the Brazilian ethanol market. The flexible plant converts eucalyptus-derived glucose to either ethanol or butanol (according to market conditions) and xylose only to butanol production. Depending on the biomass pretreatment technology, Monte Carlo simulations showed that the Net Present Value (NPV) of the flexible plant increases by 20-28% in relation to an ethanol-dedicated plant.

Optimization of lipids production by Cryptococcus laurentii 11 using cheese whey with molasses.

This study aimed the optimization of culture condition and composition for production of Cryptococcus laurentii 11 biomass and lipids in cheese whey medium supplemented with sugarcane molasses. The optimization of pH, fermentation time, and molasses concentration according to a full factorial statistical experimental design was followed by a Plackett-Burman experimental design, which was used to determine whether the supplementation of the culture medium by yeast extract and inorganic salts could provide a further enhancement of lipids production. The following conditions and composition of the culture medium were found to optimize biomass and lipids production: 360 h fermentation, 6.

Utilization of pentoses from sugarcane biomass: techno-economics of biogas vs. butanol production.

This paper presents the techno-economics of greenfield projects of an integrated first and second-generation sugarcane biorefinery in which pentose sugars obtained from sugarcane biomass are used either for biogas (consumed internally in the power boiler) or n-butanol production via the ABE batch fermentation process. The complete sugarcane biorefinery was simulated using Aspen Plus®. Although the pentoses stream available in the sugarcane biorefinery gives room for a relatively small biobutanol plant (7.

Butanol production in a first-generation Brazilian sugarcane biorefinery: technical aspects and economics of greenfield projects.

The techno-economics of greenfield projects of a first-generation sugarcane biorefinery aimed to produce ethanol, sugar, power, and n-butanol was conducted taking into account different butanol fermentation technologies (regular microorganism and mutant strain with improved butanol yield) and market scenarios (chemicals and automotive fuel). The complete sugarcane biorefinery with the batch acetone-butanol-ethanol (ABE) fermentation process was simulated using Aspen Plus®. The biorefinery was designed to process 2 million tonne sugarcane per year and utilize 25%, 50%, and 25% of the available sugarcane juice to produce sugar, ethanol, and butanol, respectively.

Bioproduction of butanol in bioreactors: new insights from simultaneous in situ butanol recovery to eliminate product toxicity.

Simultaneous acetone butanol ethanol (ABE) fermentation by Clostridium beijerinckii P260 and in situ product recovery was investigated using a vacuum process operated in two modes: continuous and intermittent. Integrated batch fermentations and ABE recovery were conducted at 37 °C using a 14-L bioreactor (7.0 L fermentation volume) containing initial substrate (glucose) concentration of 60 g/L.

Dynamics and control strategies for a butanol fermentation process.

In this work, mathematical modeling was employed to assess the dynamic behavior of the flash fermentation process for the production of butanol. This process consists of three interconnected units as follows: fermentor, cell retention system (tangential microfiltration), and vacuum flash vessel (responsible for the continuous recovery of butanol from the broth). Based on the study of the dynamics of the process, suitable feedback control strategies [single input/single output (SISO) and multiple input/multiple output (MIMO)] were elaborated to deal with disturbances related to the process.

Biodegradability of commercial and weathered diesel oils.

This work aimed to evaluate the capability of different microorganisms to degrade commercial diesel oil in comparison to a weathered diesel oil collected from the groundwater at a petrol station. Two microbiological methods were used for the biodegradability assessment: the technique based on the redox indicator 2,6 -dichlorophenol indophenol (DCPIP) and soil respirometric experiments using biometer flasks. In the former we tested the bacterial cultures Staphylococcus hominis, Kocuria palustris, Pseudomonas aeruginosa LBI, Ochrobactrum anthropi and Bacillus cereus, a commercial inoculum, consortia obtained from soil and groundwater contaminated with hydrocarbons and a consortium from an uncontaminated area.