Hydrogen production from fruit waste through dark fermentation

Hydrogen production from fruit waste through dark fermentation

Khamdan Cahyari

^1,2

, Siti Syamsiah

²

, Sarto

²

, Mohammad J. Taherzadeh

¹

1

School of Engineering, University of Borås, 501 90 Sweden

2

Chemical Engineering, Gadjah Mada University, 552 28 Indonesia

Objectives

This research was meant for investigating the possibility to produce hydrogen from waste of whole fruits generated from agriculture sectors and/or fresh fruit grocery market through dark fermentation process.

Figure 1. General overview of the research

Further Info:

Khamdan Cahyari Khamdan.Cahyari@hb.se Ph. + 46 704 816353 [www.hb.se]

Background

There were more than 400 million tons of fresh fruits being harvested in 2009 to meet global demand. Throughout the cultivation until consumption, some portion of the fruits turn into waste. According to Global Food Losses, at least 10% of fresh fruits turn into waste during cultivation in agriculture sectors (Figure 2). Among the fruits, global top four fruit commodities i.e. melon, banana, apple, and grape were selected as feedstock for the experimental investigation (Figure 3).

Figure 3. Quantity of Fresh Fruit Harvested in 2009 (FAOSTAT UN)

Figure 2. Global Fruit and Vegetables Losses (Food Losses, FAO UN 2011)

Conclusion

Fruit waste is potential raw material for producing renewable H

₂

through dark fermentation without any methane gas being detected. It benefits downstream purification process for further application such as fuel for fuel cell, internal combustion engine. Considering 10% of global harvested fruits being wasted, total potential H

₂

production from the four selected fruits reachs 726 million cubic metric .

Methodology

Fruit waste containing organic polymers e.g. carbohydrate is subjected to dark fermentation process in which the polymers are hydrolyzed to sugars. In the presence of microorganisms e.g.

Clostridia, Enterobacteriaceae, sugars are converted into H

₂

, volatile fatty acids, alcohols (Figure 4.left). Batch biohydrogen production was conducted using serum vial bottles for this research purpose through sequential steps such as grinding, mixing, pH adjustment and incubation at thermopholic condition 55 °C (Figure 4.right)

Figure 4. Metabolic pathways of dark fermentation and

technical methodology. Adapted from (Hallenbeck, Ghosh et al.

2009)

Results and Discussion

Dark fermentation of the selected fruits waste was conducted successfully to produce H

₂

, without any methane gas being detected.

Among the four, banana yielded higher H

₂

with potential global production more than 309 million cubic metric based on the 10% of harvested banana in 2009 being wasted. Simulation calculation of H

₂

production from the four fruits is presented in Table 1. Total H

₂

production can reach 726 million m

³

.

4 ^th Conference: Hydrogen and Fuel Cells in The Nordic Countries, October 25 ^th – 26 ^th 2011, Malmö, Sweden

H₂

H₂

H₂

H₂

H₂ H₂

Fermentation tank

0%

10%

20%

30%

40%

50%

60%

Europe North America

& Oceania

Industrialized Asia

Subsahara Africa

North Africa, West & Central

Asia

South &

Southeast Asia

Latin America

Food losses ‐ Fruits & Vegetables

Consumption Distribution Processing Postharvest Agriculture

Global Food Losses, FAO  2011

0 10 20 30 40 50 60 70 80 90 100 110

Production (tonnes) Millions

Source: FAOSTAT 2009

No Fruits Quantity (tons)

^a

Percent Wasted

H

₂

Yield (mmol/g VS)

Potential H

₂

Production ( STP m

³

)

1 Melon 101 000 000 10 5,96 185 808 197

2 Banana 95 000 000 10 8,61 309 093 490

3 Apple 71 700 000 10 7,30 153 941 162

4 Grape 66 900 000 10 7,28 77 457 569

Total 726 300 418

Table 1 Potential H

₂

production from fruit waste

aVolume of harvested fruit in 2009 (FAO UN)