Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Green chemistry: The sweet conversion of a by-product

22.11.2012
The waste plant materials remaining from palm oil extraction processes can now be converted into a useful sugar

Palm oil extraction annually produces approximately 13 million tons of waste plant matter. Some of this by-product, known as empty fruit bunch (EFB), is currently incinerated to produce heat and electricity to run palm oil mills, but it is now on the path to a sweeter use.

By adapting and optimizing an established technique to convert sugarcane bagasse and corn stover to the useful sugar xylose, a research team in Singapore, led by Jin Chuan Wu from the A*STAR Institute of Chemical and Engineering Sciences, has experimentally extracted high yields of xylose from EFB1.

EFB contains xylan, which is a carbohydrate made up of units of xylose. Xylan is very susceptible to being broken down to these individual sugar molecules in the presence of mild acid. Known as hydrolysis, this process is not widely applied to EFB — despite its well-established use for converting sugarcane bagasse and corn stover — because of difficulties in making it cost effective. The key to Wu and his team’s success was the combination of acids they selected for hydrolyzing EFB: sulfuric (H2SO4) and phosphoric acid (H3PO4). “The combined use of H2SO4 and H3PO4 has a synergistic effect in improving sugar yields,” explains Wu.

Since the elements sulfur and phosphorus are essential for the fermentation of xylose using microbes, the researchers’ combination of acids will play a fundamental role in the further conversion of xylose into other useful chemicals, such as the sugar substitute xylitol, lactic acid and ethanol. After hydrolysis and neutralization, these acid components can be used directly in a microbial fermentation. Hydrolysis requires the levels of these elements to be low, with higher levels being detrimental. In previous EFB hydrolysis techniques, higher concentrations of acids were used, but the levels of sulfur and phosphorous were too high for the microbial fermentation stage.

After discerning the right combination of mild acids, Wu and his team used computer modeling followed by supporting experiments to find the optimal conditions for hydrolysis. They obtained xylose yields of 80–90%. The conditions they optimized included the concentrations of the two acids, the reaction temperature, the dilution of the solution and the size of the EFB particles.

"Next, we will convert the sugars into lactic acids by microbial fermentation using lactic acid bacteria,” explains Wu. This lactic acid will be used for producing polylactic acid: a renewable and completely biodegradable biopolymer, that he says is stable at high temperatures and has broad applications.

The A*STAR-affiliated researchers contributing to this research are from the Institute of Chemical and Engineering Sciences

Journal information

Zhang, D., Ong, Y. L., Li, Z. & Wu, J. C. Optimization of dilute acid-catalyzed hydrolysis of oil palm empty fruit bunch for high yield production of xylose. Chemical Engineering Journal 181–182, 636–642 (2012)

A*STAR Research | Research asia research news
Further information:
http://www.a-star.edu.sg
http://www.researchsea.com

More articles from Life Sciences:

nachricht How Cells Take Out the Trash
23.04.2014 | NIH, National Institute of General Medical Sciences (NIGMS)

nachricht Ravens understand the relations among others
23.04.2014 | University of Vienna

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Anzeige

Anzeige

Event News

Siemens at the 2014 UIC ERTMS World Conference in Istanbul

01.04.2014 | Event News

AERA Meeting: German and US-American educational researchers in dialogue

28.03.2014 | Event News

WHS Regional Meeting: International experts address health challenges in Latin America

24.03.2014 | Event News

 
Latest News

Building Stronger Bridges

23.04.2014 | Architecture and Construction

How Cells Take Out the Trash

23.04.2014 | Life Sciences

The Surface Area of the Digestive Tract "only" as Large as a Studio Apartment

23.04.2014 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>