Anaerobic Co-Fermentation of Crude Glycerol and Oilseed Meal from Biodiesel Anaerobic Co-Fermentation of Crude Glycerol and Oilseed Meal from Biodiesel Production to Ethanol and HydrogenProduction to Ethanol and Hydrogen

Lijun Wang, Abolghasem Shahbazi and Michele MimsBiological Engineering Program, North Carolina Agricultural and Technical State University, Greensboro, NC 27411

Process Chemistry

ObjectivesDevelop a biological process for conversion of low-quality glycerol and oilseed meals into hydrogen for process energy supply and ethanol for the transesterification reaction in a biodiesel production facility.

Problem StatementA biodiesel process for production of methyl esters from vegetable oil• consumes light alcohols and energy, and • produces low-quality glycerol and oilseed meals

Materials and Method

Fig. 2. Anaerobic fermentation system

Fig. 1. Anaerobic metabolism pathway of glycerol fermentation for ethanol production.

Results

Conclusions and Future Research

A fermentation system and analytical protocol have been set up for the biological conversion of crude glycerol from biodiesel production to ethanol and hydrogen. The preliminary data show that ethanol could be produced from crude glycerol using E. aerogenes. Future work will be focused on: (1) investigation of the effect of impurity of glycerol, process conditions and feedstock supplement on the performance of the microorganism, (2) production of mutants with a high tolerance to the impurity and high concentration of glycerol, and (3) determination of fermentation mechanism and kinetics.

)HCO(or OCHOHHC(OH)HC 222252ismMicroorgan

353

353Catalyst

52 (OH)HC esters Ethyl 3OHH3C(oil) deTriglyceri ~ 0.32 MJ/kg biodiesel produced

1/3 of ethanol supply

Microorganism: Enterobacter aerogenesFermentation media: 10 % crude glycerol (including 34% of glycerol) solution (by mass) supplemented with 25 g Basal media, 10 g tryptone, 6 g yeast extract, 5 g lactose, 10 g NaCl, and 1.5g bile salts in 1 liter of deionized waterFermentation conditions: operated at 37oC and 150 rpm agitation, and sparged with argon gas Analysis: The concentrations of glycerol, ethanol, succinate and acetate were determined by a HPLC

Fig. 3. HPLC profile for the sample taken after 12 h reaction.

Redox balance may be achieved by the production of Formate (or CO2 and H2) -e.g., Enterobacter aerogenes [Ito et al., J Biosci Bioeng 100:260-5], Succinic acid under CO2-e.g., E.coli [Dharmadi et al. Biotechn Bioeng 94: 821-9], and 1,3 propandeiol-e.g., Klebsiella pneumoniae [Zhang et al., Biochem Eng J 37: 256-60] .

5 g/l0.46 g/l0.93 g/lPyruvate-formate lyase

Formate hydrogenlyase

Alcohol dehydrogenase

Glycerol

GlpF

DHA

DHAP

GDH

Glycerol

DHAK

Glycolysis

NAD+

NADH

ATP

ADP

NAD+

NADH

2 ATP

2 ADP

Pyruvate

EtOH

NADH

NAD+

Acetyl CoA + Formate

Acetaldehyde

AdhE

NADH

NAD+

AdhE

CO2 + H2

FHL PFL

Succinic acid CO2 + 2 H

GDHt 3-HPA

NADH NAD+

1,3-Propanediol

nic acid

PDOR

PEP

A Continuous Process with a Heterogeneous Catalyst for Biodiesel Production A Continuous Process with a Heterogeneous Catalyst for Biodiesel Production from Wasted oil and Fatfrom Wasted oil and Fat

ObjectivesDevelop heterogeneous catalysts and a continuous process for biodiesel production from used vegetable oil and animal fat.

Problem Statement

A existing biodiesel process for production of methyl esters from vegetable oil and animal fats with a homogeneous catalyst

• requires high-quality feedstock with low free fatty acid and moisture contents• requires a complex and expensive separation process to purify biodiesel and by-product of glycerol with dissolved catalyst, and • operates in a batch mode.

Materials and Method

Fig. 1. A laboratory tubular reactor system.

On-going Research Activities

1. Continue to build the experimental platform for preparation and characterization of heterogeneous catalysts, investigation of continuous heterogeneously catalyzed reactions, and analyses of oily feedstock and biodiesel,

2. Conduct experiments on the platform to evaluate the performance of developed heterogenous catalysts for biodiesel production from used vegetable oil and animal fat, and

3. Conduct a life cycle cost analysis for production of biodiesel from used vegetable oil and animal fat.

1. Solid base catalyst development

Solid base catalysts are developed by exchanging zeolite with alkali metal cations. The surface area, pore size and pore distribution of the catalysts are characterized. The protocol for the catalyst preparation and characterization will be developed.

2. A continuous flow reaction system

A reaction system as shown in Fig. 1 has been ordered for catalyst evaluation and continuous flow process analysis. The main components of the system include a mixer, tubular reactor, oven, sample valve and back pressure regulator. The reaction unit is capable of handling up to four inputs. A 40 ml tubular reactor will be used in the reaction system to evaluate the effects of temperature, pressure, flow rate (or residence time), oil to alcohol ratio and heterogeneous catalysts on the conversion efficiency and quality of biodiesel produced from used vegetable oil and animal fat.

3. Feedstock and biodiesel analysis

An analytical platform including gas chromatograph is being set up to evaluate the quality of oil or fat feedstock and biodiesel.

Lijun Wang and Abolghasem Shahbazi Biological Engineering Program, North Carolina Agricultural and Technical State University, Greensboro, NC 27411

New source of ethanol? Look at cattails. A&T is.

Greensboro News & Record July 28, 2008

N.C. A&T's Abolghasem Shabazi at the campus' research farm.