[For further information on the FAO Biotechnology Forum see the Forum website.
Note, participants are assumed to be speaking on their own behalf, unless they state otherwise.]
Sent: 10 December 2008 10:51
Subject: 66: Use of cellulases for LC biomass in developing countries
I am Dele Raheem from Nottingham, UK, again.
The background document to this conference raised an important aspect on the conversion of lignocellulose (LC) biomass to liquid biofuels and the use of cellulases in the economics of the operation. [From Section 5.2 of the background document: "Most of the world's industrial enzymes (60%) are produced in Europe, while the remaining 40% come from the United States and Japan, although countries like China, India and South Korea are likely to play a greater role in the future (Bon and Ferrara, 2007). For conversion of LC biomass to liquid biofuels, use of cellulases plays a key role in the economics of the operation. How realistic is it for developing countries to produce their own cellulases? Can regional co-operation be important here?"...Moderator].
The use of enzymes (cellulases) in the conversion of LC biomass in developing countries has a great potential in wealth generation on an industrial scale. Hopefully this scenario will manifest itself in the nearest future. The value of the world enzyme market has rapidly increased recently from 110 million pounds sterling in 1960, 200 million pounds sterling in 1970, 270 million pounds sterling in 1980, 500 million pounds sterling in 1985 to an estimated 1,000 million pounds sterling for 1990, representing an increase from 10% of the total catalyst market in 1980 to almost 20% in the 1990s (Chaplin and Bucke, 1990). With the current interest in the field of bioenergy, this trend will definitely be on the increase. This increase is reflected in the rise in the number of enzymes available on an industrial scale at relatively decreasing cost and the increasing wealth of knowledge concerning enzymes and their potential applications. [Chaplin, M.F. and C. Bucke. 1990. Enzyme Technology. Cambridge University Press...Moderator].
The cost of enzymes for use at the research scale is often very high. Where there is a clear large-scale need for an enzyme its relative cost reduces dramatically with increased production. Investment in this area of business is likely to be a better option in the future for developing countries in turning wastes to wealth. Scale-up operations that utilize cellulases derived from fungal strains (such as Trichoderma reesei, Aspergillus flavus) on waste of agricultural materials as in LC biomass such as cobs from corn, sawdust, baggase etc. The optimal conditions for the production of cellulases and from which substrate the yield is highest, should be given primary considerations. The purification steps on an industrial scale to yield the highest output will play important roles in the economics scale.
The development of any commercial enzyme is a specialised business which is usually undertaken by a handful of companies that have high skills in screening for new and improved enzymes, fermentation for enzyme production, large scale enzyme purifications, formulation of enzymes for sale and dealing with the regulatory authorities. To this end, developing countries need to cooperate more on a regional basis and internationally.
Dr. Dele Raheem
2 Broadholme Street,
Email: draheem (at) gmail.com
Tel: +44 7747156868
Sent: 10 December 2008 12:39
Subject: 67: Biogas production - potential, large plants, education program
My name is Emma Kreuger. I am a PhD student at the Department of Biotechnology at Lund University, Sweden. I am working with anaerobic digestion (biogas production) from lignocellulosic feedstocks.NATURE HAS THE BIOTECHNOLOGY
I believe that developing countries (as well as developed) do not need to focus on genetic engineering at this stage. There is still so much more to find in nature, we just need to know what to look for, and how to utilize it when found (which is biotechnology). The energy potential in rest products is much larger than what is usually acknowledged. It can be utilized today with our current state of knowledge on biogas production through anaerobic digestion. [As written in the Background Document: "In the absence of oxygen, certain bacteria will ferment biomass into methane and carbon dioxide, a mixture called biogas. In this anaerobic digestion process (i.e. without oxygen), the feedstocks used to obtain biogas may include sewage sludge, agricultural by-products and wastes (especially animal manure), industrial wastes (e.g. organic solid wastes) or municipal solid wastes"...Moderator].HIGH POTENTIAL IN BIOGAS PRODUCTION
In Sweden the biogas potential from rest products from society (sewage sludge, food waste and industrial waste) and agriculture (manure, straw etc) has been approximated to 1700 kWh (kilowatt hour) per person and year (based on simple technologies and a low conversion degree, the actual potential is higher), forestry rest products are not included. About 70% of this potential can be found in agriculture.
The farming community could strengthen its position in society by converting rest products. In 2004, India and Africa used 4200-4300 kWh per person and year, of which 300-400 kWh was electricity (I'm not sure if the burning of agricultural rest products are included in these figures). If India and Africa have similar amounts of rest products per capita as Sweden, the farmers could supply almost half of the energy demand of the countries by utilising only rest products (figures based on 2004, forestry products not included).
Dr Janaki Krishna (message 64) provides us with an excellent example of a village utilizing the manure in a resource efficient manner. Other substrates can also be added, such as ground straw, pasteurized human feces, industrial rest products etc.
A high utilisation degree of rest products can be achieved with natural microorganisms. 50-90% of the energy in most biomass (including biomass with high content of cellulose and even woody biomass, see Turick et al. 1991) can be recovered in methane without advanced pre-treatment technologies. A nutrient rich residue is left (almost no losses of nutrients during degradation). Non-degraded biomass can be returned to the agricultural land as soil improver or can be separated and used for electricity and heat production through incineration. [Turick, C.E. et al. 1991, Methane fermentation of woody biomass. Bioresource Technology 37: 141-147. Its abstract begins "Woody biomass has been previously considered to be highly refractile to anaerobic digestion without extensive pretreatment. However, this study has demonstrated that high rates and ultimate methane yields may be obtained in batch assays without pretreatment, other than some particle size reduction"...Moderator].LARGER BIOGAS PLANTS FOR MORE EFFICIENT UTILISATION OF THE SUBSTRATE
Two key features for efficient biogas production is a stable temperature (max 1 C variation) and a stable supply of feedstock. It will probably be easier for larger plants to fulfill these demands and, in this aspect, biogas plants owned by cooperatives are advantageous to single household plants (other aspects are given by Wim Polman in message 49).INTERNATIONAL EDUCATION PROGRAM
Without sound knowledge about anaerobic digestion, the production of biogas can be very problematic (especially when using waste products other than manure). It will be interesting to hear the responses to the question posted by Wim Polman (message 60) about the role and presence of support institutions as a link between research and development (RD) and small-scale farmers development. To increase this link, I would like to suggest an international education program in biogas production to educate advisors in developing countries.
The education program should include a mix of high-level university education and practical training at biogas plants that utilise mixtures of substrates. Practical training could include work at plants in developed as well as developing countries. Hopefully the experienced plant operators would be willing to share their knowledge. The students will achieve an applicable knowledge in biotechnology and can further teach biogas plant operators. An Internet site for presenting information about biogas plants around the world would also be very useful for developing as well as the developed countries. Is there anyone reading this who is in a position to initiate such a program? This could be an investment of 'help-the-climate'-money that would pay back. Possibly, the EU could support the program.
Finally, I would like to post a question to all readers active in developing countries. How well are the single household or small farm biogas plants working? Do you believe in community level cooperative biogas plants (like the ones referred to in message 64)?
Department of Biotechnology
emma.kreuger (at) biotek.lu.se
+46 222 81 93
Sent: 10 December 2008 17:01
Subject: 68: Thermo-chemical vs. biochemical conversion of LC biomass
This is Uwe Bruenjes, from Mexico, again.
In my opinion we are focussing too much on producing biofuels from biomass, instead of producing biomass FOR biofuels. As I mentioned in my introduction (message 8), I promote environmentally benign technologies. Consequently, I try to stay alert regarding the latest news in this area, so I'm aware that bio-conversion (as opposed to chemical conversion) is extremely slow. How long does it take to convert biomass into methane gas, with an acceptable efficiency? It takes at least days, if not weeks. Nevertheless, I found a process that converts cellulose into combustible hydrocarbons in a matter of minutes. That tells me there is no chance that biochemistry might become the prefered way of producing biofuels one day. Therefore I think here we should focus on producing suitable biomass FOR biofuel production, leaving the conversion process itself to the chemists. That would be more efficient overall.
Last of all, I agree that there is abundant cellulosic waste for this purpose. Apparently it is the most abundant organic matter on Earth. If there was a way to make this substance more readily "convertible", that would be a great contribution to everybody's attempt to alleviate contamination from non-renewable energy sources.
Calle Plan de Guadalupe #4025
Col. Los Nogales
Cd. Juarez, Chih. 32350
ubrunjes (at) yahoo.com
[This message from Uwe raises for the first time in the conference the issue of the relative merits of the two main approaches to conversion of lignocellulosic (LC) biomass to biofuels, one that may involve biotechnologies and the other no. Further comments on this issue are welcome. Quoting from the background document: "As mentioned in Section 2.3, LC biomass can be converted to biofuels through two major routes, by thermo-chemical or biochemical processing, where only the latter involves extensive applications of biotechnology. For developing countries wishing to produce second-generation liquid biofuels, are there strong arguments in favour of one of the processing routes over the other?"...Moderator]