26 July 2011
Richardson Bursar Joseph Ikwebe reports from the World Renewable Energy Congress (WREC) 2011, which took place from Sweden, 8-13 May 2011.
WREC was held in the very pleasant city of Linköping. The conference was based on the theme 'Future Trends and Applications in Renewable Energy Technologies and Sustainable Development.' It focused on future challenges and opportunities for renewable energy technology and sustainable energy systems, as well as climate change issues. The conference consisted broadly of scientific and social programmes. The scientific programme was made up of sixteen keynote lectures given by a number of international professionals, specifically invited for their expertise in the field of renewable energy.
There were also fourteen parallel sessions over five days with 3 - 7 presentations during each session covering 15 different broad topics. Examples of the topics are; Bioenergy technology, climate change issues, fuel cells, energy end-use efficiency issues, low energy architecture, industrial energy efficiency, marine and ocean technology, photovoltaic technology, policy issues, and a number of other interesting topics. On the whole, there were over 600 peer-reviewed scientific papers by delegates from more than 70 countries around the world. As part of the scientific programme, there were also an EU workshop on renewable energy ('Implementing 20% renewable - the EU story') and a second workshop on biofuels ('Expanding the Transport Biofuels Markets') by Cross Border Bioenergy and Svebio. Professional excursion tours to Tekniska Verken - waste incineration and biogas production facility, Siemens - solar steam turbines, Lambohov - passive houses and Linköping University - energy efficiency were among the highlights of the scientific programme.
The social programme included a guided tour of the city of Linköping, boat trip on Kinda Canal, visit to the Air Force museum and a bus excursion to the medieval town of Vadstena.
The title of my scientific paper and a brief abstract are presented below:
Intensification of Bioethanol Production by Simultaneous Saccharification and Fermentation (SSF) in an Oscillatory Baffled Reactor (OBR)
Bioethanol is an alternative transport fuel produced mainly by the biochemical conversion of biomasses. This can be carried out efficiently and economically by simultaneous saccharification and fermentation (SSF): a process which integrates the enzymatic saccharification of the cellulose to glucose with the fermentative synthesis of ethanol. However, the SSF unit operation still contributes nearly 50% to the cost of ethanol production. For cellulosic ethanol to be cost competitive, there is the need to intensify the production process in smaller, more efficient and more economical bioreactors.
In this work, SSF was performed in an intensified form of plug flow reactor, called the Oscillatory Baffled Reactor (OBR). The OBR is a continuous tubular reactor fitted with equally-spaced orifice plate baffles. An oscillatory component, provided by moving bellows in this design, is superimposed on the net flow through the reactor, generating short-lived vortices due to the interaction of the oscillating fluid with the baffles.
This results in uniform mixing in each of the inter-baffle regions, with each behaving as a stirred tank reactor (STR), producing a plug flow residence time distribution (RTD) for the reactor as a whole, in which the mixing effects are largely decoupled from the mean flow (unlike conventional PFRs).
The process was evaluated using 2.5% SigmaCell cellulose, 40 FPU cellulase loading/g of cellulose and 10% cellobiase. Saccharomyces cerevisiae was employed as the fermenting organism at 38 oC and pH 4.8. In the first part of this work the use of the OBR resulted in a 7% increase in glucose yield compared to a shake flask, after 48 h of saccharification and 8.0 g/L ethanol in the OBR. This represented 89.8 % of the theoretical yield, as compared to 7.7 g/L in the shake flask representing 81.29%, a difference of 9 percentage point. This increased glucose yield is attributable to better mixing in the OBR.
My presentation at the conference was well received and the technology seen as promising. The comments and feedbacks were positive and constructive. New ideas were gleaned from experts in the field and would provide fresh insights and direction in my research. The experience and opportunity to mix-up and network with world - renowned experts and professionals in renewable energy is unforgettable. To a large extent, I believe, attending this conference will be a massive lift to my CV and enhance my career prospect in no small measure.
It is worth mentioning that Sweden is a beautiful country with one of the highest standard of living in the world. Hence, it is very expensive to get by. It is the leading country in Europe in terms of meeting its renewable energy obligations. It may not be the best place for a cheap holiday but it certainly one of the cleanest and orderly countries on earth.
Joseph Ikwebe
Newcastle University
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