What is Lignocellulose

What is lignocellulose? Lignocellulose refers to the specific structure of biomass. The main constituents of lignocellulosic biomass comprises lignin, hemicellulose and cellulose. This is a complex structure in which the cellulose is surrounded by a monolayer of hemicellulose and embedded in a matrix of hemicellulose and lignin. Furthermore lignin specifically creates a barrier to enzymatic attack while the highly crystalline structure of cellulose is insoluble in water while the hemicellulose and lignin create a protective sheath around the cellulose. This structure can be seen in the image below.
http://www.engineeringnews.co.za/article/secondgeneration-biofuels-may-offer-a-way-forward-2008-10-31
This structure of lignocellulose therefore plays a huge role in inhibiting degradation of the hemicellulose and cellulose structure to monomeric sugars which is necessary to effectively convert biomass into ethanol. Processing of lignocellulose is therefore essential for the conversion of lignocellulosic biomass to biofuel such as bio-ethanol.

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Steam Gun Arrival

Steamgun? What is that? This is a piece of equipment that is used in preatreatment of biomass so that Bio-ethanol can be produced. We have one arriving here early next week which is to be incorparated into our lignocellulosic research facilites.

So how does it work and what is its purpose? Let me start with its purpose. As I’ve mentioned it is used in pretreatment which in short opens up the biomass structure to  enzymatic attcack. Once pretreated, enzymes are able to efficiently attack the structure of the biomass and convert it into fermentable sugars. The fermentable sugars can then be fermented into bio-ethanol. Without pretreatment the structure of the biomass is basically inpenetrable and immune to enzymatic attack which results in extremely low ethanol yields.

So how does the steamgun pretreat the biomass material? It achieves this by placing the biomass under high pressure and temperature through steam addition to the material for a certain period of time. At the end of the pretreatment the pressure is suddenly released which cause the material to explode making it more accessible to enzymatic attack. This is in short how the steamgun works but I will have to explain it a bit more in detail the effect and advantages of pretreatment technologies. Hopefully soon I will upload pictures of our new steamgun.

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Biofuel Technology

Currently biofuel falls into two general technology cateregories. These are first and second generation biofuels. First generation biofuel’s are produced from food or energy crops such as sugarcane, corn, maize and sorghum and compete directly with food production. Second generation biofuel on the otherhand is primarily produced from biomass that is not used for food production. For example, the biomass used  in second generation bio-ethanol production comes from agricultural residues, hardwoods, softwoods and grasses. These are what are known as lignocellulosic materials which is the scientific  name refering to the structure of these sources.

These types of materials are the way forward for bio-ethanol production as they do not compete with food and energy crops. Agricultural residues specifically are interesting to me as they are the residues left over after processing. An example of this is bagasse which is the residue from sucar cane processing which is typically burnt to supply energy to a sugar cane plant and which results in large releases of CO2. Producing bio-ethanol from bagasse is therefore an interesting and important alternative which needs to be looked at.

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South Africa vs. Brazil

So what are the factors that have contributed to Brazil being the second largest producer of Bio-ethanol (they currently produce 30-35% of the world’s ethanol) after the USA. I mean they have a similar climate to us here in South Africa, they are also a third world country and have an economy that is similar to ours. And yet South Africa is far behind Brazil in terms of Bio-ethanol production.

The main reason for their success come during the oil crisis in 1973 when the Brazilian government implemented what was known as the “Proalcohol” or “National alcohol program”, which was hoped to move Brazil towards energy independance. This program was extremely effective in that today bio-ethanol accounts for around 50% of their gasoline/petrol consumption.

So what made this program so successful:
1. Tax incentives and government subsidies for bioethanol producers.
2. Mandatory mixing of ethanol with petrol, which today is set at 1:3 (E25)
3. Development of flexi-fuel vehicles which can run on any proportion of ethanol:petrol

Interestly enough I was reading the other day on the Department of Minerals and Energy’s website and was suprised to find that bio-ethanol producers in South Africa qualify for a 100% tax return on there bio-ethanol sales which works out to around R1.20 per litre of bio-ethanol sold. I was also interested to find out that in their white paper on renewable energy for 2013, they aim at making it mandatory for petrol to contain 8 – 10% bio-ethanol.

So where does that leave South Africa’s Bio-ethanol economy? Personally taking Brazil as an example, I think in a extremely promising situation and I am looking forward to seeing what happens. A move towards independance from fossil fuels and the price of oil is in my opinion a good one.

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What are Biofuels

Today a friend of mine asked me what biofuel’s are. So for those of you who haven’t a clue I’m hoping this helps.

So what are biofuels? Biofuels are fuels that are produced from biomass or in simpler terms “plant” matter. In short, they are fuels that can be used as substitutes for petrol, diesel and the like. Currently the drive for biofuel’s is being pushed by an unstable oil price and global warming which has resulted in many countries desiring to move away from their dependance on fossil fuel’s.

Brazil is one of the most notable, having started somewhere in the early 1970’s with the production of bio-ethanol, a biofuel produced from sugar cane. As an aside, ethanol and bio-ethanol is basically the same thing. Bio-ethanol is just the name they use when its meant as fuel. Anyway today in Brazil it is mandatory for cars to have a petrol blend consisting of at least 25% ethanol. Interestingly enough I was asking a new colleague of mine who has recently arrived from Brazil to join our research team and he was surprised to learn that it is not standard for Bio-ethanol to be sold at a petrol station.

Petrol and ethanol gas station in Brazil

Bio-ethanol filling station in brazil

Bio-ethanol filling station in brazil

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Hello

Welcome to my new blog. This is something that I have been meaning to start for a while but have been lacking inspiration. Recently I started a new job at the University of Stellenbosch involving research and development in the field of Biofuel’s and I thought that this would be a great topic to blog about. I hope you enjoy and find the posts on this site informative and interesting. I will try to keep my blogs focussed on the world of biofuels and specifically what is happening with regards to 2nd generation biofuels.

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