EXAM

Question 1

Using diagrams, describe the structure of lignocellulose

Answer 1

cELLULOSEIS IN LONGITUDINAL CHAINS, lignin and hemicellulose interact together to give the strength of the plant.. But the ratios can differentiations from last to plant depending on growth time and need for strength/structure.

Question 2

Discuss how lignocellulose can be broken down into its constituents.

Answer 2

Lignocellulose can be split up into lignin, cellulose and hemicellulose. Hemicellulose is branched and unbranched mixed sugar chains
How to unlock Lignocellulose
-traditional pulping
- supercritical steam developments
- microbial breakdown

Lignin can be extracted from the biomass feedstock by either milled wood lignin being milled and determining the amount of lignin solubilised, extracting it with organic solvent, e.g. dioxane this will result in. 25-50% of available lignin. TREAT WITH CELLULASES.
You could also use other methods like anaerobic digestion.

Microbial breakdown of lignocellulose you could use white rot fungi which degrades both lignin and cellulose but preferentially attacks lignin. Brown rot which efficiently attacks cellulose and leaves lignin intact but modified. Soft rot is similar to brown rot but attacks cellulose-rich layers. Bacteria less well studied and may act synergistically.

ORGANOSOLV process can separate out the lignocellulose into its individual components. First the biomass goes under mild acid digestion using a strong diluted acid. Simultaneous acid digestion and solvent seperation. The components are then recovered: insoluble cellulose, organic soluble lignin, and water soluble hemicellulose.

There is multiple ways to extract ligin from lignocellulose:
1.kraft and sulphite pulping which requires the steps od, milling cooking and 150 degrees C, NaOH and Na2s and reovery, then blowing and screening and processing. There is 7 tonnes of black liquor per tonne of pulp which could be burned as a fuel when mixed with diesel.

Question 3

Using examples discuss how each of the three major components of lignocellulose can
be utilised for the production of high value products.

Answer 3

Lignin- lignin can be converted into vanillin an extremely high-value product however, the more it is mass produced the more the value of vanillin will decrease.

If you can reorientate the fibres extracted from hemicellulose, cellulose and lignin, cellulose fibres are extremely strong so if you can reorientate them you can have an alternative of carbon fibre. This alternative would be able to be broken down and recycled, and incinerated.

Phenolic resins used in furniture and components in a house can be produced from lignin removing the risk of allergies to formaldehyde.

sugars like c6 being made into sorbitol

Hydrogenated cellulose becomes a high value substance as it goes into hand cream and face cream

Question 4

The attitude of world governments towards biofuels fluctuates. Discuss the drivers for
their initial introduction.

Answer 4

In the 1970’s there was an oil crisis where the price of oil soared, this caused an initial boom of investment into biofuels. In Brazil the country had some hefty debts to the US and grew an enormous amount of sugarcane. During the oil crisis the Brazillian Government realised they could sell their oil stores at a higher price than usual and fix some of their debt. The government then committed itself as a country to start the proAlcool (pro alcahol) programme. The US government gave them fixed loans to create refineries and it allowed them to start producing ethanol from their sugar crops, this stabalised the price of sugar and provided a whole new economy for Brazil.
In

CLEAN AIR ACT 1956 DUE TO SMOG AND DAMAGE TO BUILDING BC OF AIR POLLUTION
oil crisis 1973 price of oil through roof and being not available this is when biofuels start to kick in as an alternative crude oil.

BUT IN THE UK THE RFTO IN 2008 WAS PROBS THE KEY DATE IN UK FOR BIOFUELS

copenhagenkyoto, eu energy policy, target 20% GHG reduction by 2020

Question 5

Using examples illustrate the ongoing concerns about biofuels and how governments have adjusted their approach in response.

Answer 5

PALM OIL DEVESTATION AND THEN THE EU TURNING THEIR BACK AND ENDING THE USE/ENCOURAGEMENT OF 1ST GEN BIOFUELS ENCOURAGING THE USE OF 2ND GEN AND 3RD GEN FUEL .
saying that they will postpone the biofuel content increase for a few years which caused plants to shut down. Uk vivergo fuel plant hull 2018.

Food security in 2006+2005 tortilla riots which changed the view on biofuels, do they compete with food??

caused the brazillian government to put a policy in place to remedy the backlash for loss of rainforest. They banned land use change from rainforests and any area of high biodiversity

Question 6

Microbes are essential to biotechnology and are important in the formation of some biofuels. Describe how they are being utilised in the production of different biofuels and discuss how important they might be in making the process economically viable.

Answer 6

YES fungi and bacteria and yeast.
In the v first place micororganisms rhizobacteria can be used to increase crop yield . Antibiotics

Yeast is used heavily in the fermentation processs for biofuels.
Fungi can be used to extract lignin, white rot is especially good at degrading biomass it degrades both lignin and cellulose bu primarily lignin.

ALGAE can

Question 7

Using diagrams, describe the structure of lignin and discuss potential products which can be generated from it and current problems with their production.

Answer 7

lignin aromatic ring stuctures

Question 8

EU and UK governments have suggested that a bio-based economy offers a sustainable future. Using examples, discuss the pros and cons of this argument.

Answer 8

Depends on your definition of sustainable
pros: 
reduce GHG, including climate change 
reduces pollutants
new job sector in rural parts of countries, 
gives agriculture a stake in fuels 
Prevents waste 
1st gen no but 2nd gen yeee

CONS:

• ILUS including lack of biodiversity PALM OIL IDONESIA
• LUC
• Eutrophication
• fertilisers
• indigenous people having their land and their rights taken away
• what about the producing side of bio based economy, fueling the tractors and the plants
• food requirements, as global population booms we are going to need that land for food

Question 9

Discuss how microbes and their enzymes are being utilised to convert biomass to high value products.

Answer 9

FUNGI + BACTERIA

FUNGI OMEGA 3 FATTY ACIDS