Technical meetingDecember 1st 2014

Dr. Daniele SpinelliLaboratory Manager

     

www.solarisgroup.org

WPs - Solaris Biotechnology

• WP1 – Preliminary process design, selection of process components, supplier and market researchTask 1.1 (M1-M12) – Set up of batch fermentation process

• WP2 – Process component characterisation and optimisationTask 2.2 (M13-M30) – Experimental screening and optimization of downstream

procedures

Task 1.1 – Set up of batch fermentation process for metabolic description and downstream processing

• Microorganism: Clostridium acetobutylicum DSM 792 (freeze dried by DSMZ)

• Re-activation and crioconservation (20% glycerol at T = -80°C)

• Culture medium: Yeast Extract 5 g/L and D-Lactose (2-100 g/L)

• Temperature: 35°C

• Initial pH: 6-7

• Anaerobic conditions: nitrogen stream

Task 1.1 – Set up of batch fermentation process for metabolic description and downstream processing

Variation of culture medium to investigate effects on butanol yield:

Yeast extract (1 g/L)KH2PO4 (0.5 g/L)K2HPO4 (0.5 g/L)p-aminobenzoic acid (0.001 g/L)Thiamin (0.001 g/L)Biotin (1x10-5 g/L)MgSO4·7H2O (0.2 g/L)MnSO4·7H2O (0.01 g/L)Fe2SO4·7H2O (0.01 g/L)NaCl (0.01 g/L)Ammonium Acetate (2.2 g/L)

The Scientific Wolrd Journal, Volume 2014, Article ID 395754

11 g/L using 50 g/L date fruit

Task 1.1 – Set up of batch fermentation process for metabolic description and downstream processing

Concentration vs time profiles:

Lactose

Acetic acid

Butyric acid

Ethanol

Acetone

Butanol

Biomass density

pH monitored in order to investigate acidogenesis and solventogenesis phases

Time: 0-140 h

Gas chromatography

UV/visible spectrophotometry

• Adsorption

Task 2.2 – Experimental screening and optimization of downstream procedures, generation of data for

mathematical model verification

• Butanol can be desorbed by increasing the temperature to around 200°C.

• Greatly decrease of energy costs as ordinary distillation would require 73.3 MJ/kg butanol, while adsorption only would need 8.2 MJ/kg.

Task 2.2 – Experimental screening and optimization of downstream procedures, generation of data for

mathematical model verification

Biomass and Bioenergy 60 (2014) 222-246

Task 2.2 – Experimental screening and optimization of downstream procedures, generation of data for

mathematical model verification

• Liquid-liquid extraction

Appropriate organic solvent:

- compatible with the bacteria used for fermentation

- high distribution coefficient for butanol (minimize the amount of solvent needed and the product recovery cost)

- if the products are recovered from the solution by distillation, the solvent should be less volatile than the products.

- barely soluble in water, this to minimize solvent losses.

i.e. oleyl alcohol and oleyl alcohol/decane (50 wt%)

Task 2.2 – Experimental screening and optimization of downstream procedures, generation of data for

mathematical model verification

High distribution coefficient for butanol (primary C6-C11 alcohols)

ABE

Solv2 remove Solv1 from the fermentation broth (C9-C12 alkanes no azeotropes by distillation)

Novel dual extraction process for ABE fermentation

Separation and Purification Technology 124 (2014) 18-25

Best case:

Solv1: Decanol

Solv2: Decane

~ 4 MJ/kg butanol

Task 2.2 – Experimental screening and optimization of downstream procedures, generation of data for

mathematical model verification

• Gas stripping

Oxygen-free nitrogen or fermentation gases (hydrogen and carbon dioxide) are bubbled through the fermentation broth to strip away acetone, butanol and ethanol. Inert gas will be sparged through the fermentation broth during fermentation and volatile butanol will vaporize and go out with the gas stream in the top of the reactor.

Task 2.2 – Experimental screening and optimization of downstream procedures, generation of data for

mathematical model verification

Biomass and Bioenergy 60 (2014) 222-246

Task 2.2 – Experimental screening and optimization of downstream procedures, generation of data for

mathematical model verification

Environmental Engineering and Management Journal 11 (2012), 8, 1499-1504.

Eicosanol (high affinitytowards the butanol and low affinity towards the water)

butanol-water solution

butanol-eicosanol solution

Task 2.2 – Experimental screening and optimization of downstream procedures, generation of data for

mathematical model verification

• Pervaporation

This method involves the selective transport by diffusion of some components thrugh a membrane. A vacuum applied to the side of permeate. The permeated vapours should be condensed on low pressure side.

Membrane in this case ought to be a hydrophobic polymer since transportation of organic components from the fermentation broth is preferred.

Polydimethylsiloxane membranes and silicon rubber sheets are generally used for the pervaporation process.

The drawback of the method can be high costs to produce low pressure at low pressure side of the membrane.

Task 2.2 – Experimental screening and optimization of downstream procedures, generation of data for

mathematical model verification

i.e. silicalite-1/polydimethylsiloxane (PDMS)hybrid membranes (98 mg butanol/g)

Separation and Purification Technology 79 (2011) 375– 384

Task 2.2 – Experimental screening and optimization of downstream procedures, generation of data for

mathematical model verification

SS—steam stripping distillation; GS—gas stripping; Perv—pervaporation; Ext—liquid–liquid extraction; Ad—adsorption on to silicalite

Bioprocess Biosyst Eng (2005) 27: 215–222

-10%

-33%

-20%-3%

Method MJ/kg butanol

Steam stripping 24.2

Direct distillation 18.4

Extraction (oleyl alcohol) 13.3

Gas stripping 13.8

Adsorption-desorption 8.2

Extraction (mesitylene) 4.8

√√

Separation and Purification Technology 124 (2014) 18-25

Task 2.2 – Experimental screening and optimization of downstream procedures, generation of data for

mathematical model verification

Appl Microbiol Biotechnol (2014) 98:3463–3474