• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Energy Resources - Concept 3 Renewable energy sources.

Extracts from this document...


Energy Resources - Concept 3 Renewable energy sources Energy from Biomass Traditionally, wood is the main form in which biomass is used as an energy source. The biomass is used to boil water to provide steam to turn turbines. In Great Britain most commercially produced wood is used for timber, but when a conifer plantation is felled, there are branches and low-grade timber that can be used for fuel. Straw left over from harvesting cereal crops can also be used to produce energy. When used for energy the cost of collecting, storage and transporting bulky problems is a problem. Most examples rely on a community-based collection used locally in a close plant or used on the farm that produced the straw and is widely used in Denmark and the USA. Stubble used to be burnt, but this was made illegal in the UK. Most stubble is used for bedding. When burnt straw leaves ash, which contains nutrients, which can quickly be extracted from the soil by the new crop. This method is still used in many developing countries. It is very rarely ploughed in as it takes along time to biodegrade and as it does so it creates anaerobic pockets in the soil. ...read more.


Ethanol is a much cleaner fuel and produces much less pollution, but it is much more expensive to produce. Especially as the farmers can also sell the crop to be made into refined sugar. This production is unlikely ever to work due to politics and the oil industry. In the end it can not be considered as a real alternative ,as 80-90% of it is made from a fossil fuel. Once the sugar is extracted the fibrous residue (bagasse) is dried and then burnt as a fuel to ferment the malasses. 1) Growing and cropping of sugar. 2) Extraction of sugars by crushing and washing cane. 3) Crystallization out of sucrose (for sale) leaving the syrup of glucose and fructose (molases) 4) Fermentation of molasses to yield dilute alcohol. 5) Distillation of dilute alcohol to give pure ethanol, using bagasse as a power source. A more promising is oilseed rape which has been used to power buses in certain areas of the UK as part of a trial and in Italy, it is added to diesel and can be added to make up 30% of the mixture (rpae methyl ester, RME). It produces fewer sooty particles and no sulphur dioxide. ...read more.


The digestion process occurs in 3 stages: 1) Aerobic bacteria convert lipids and carbohydrates in the biomass into sugars, fatty acids, amino acids and glycerol by hydrolysis (0-10 days, acids cause pH to fall). 2) Acetogenic bacteria convert sugars and other products of stage 1 into short-chain fatty acids e.g. acetic acid = acetogenesis (stages 2+3, 10-45 days acids used up, pH increases, methane produced.). 3) Anaerobic bacteria convert the fatty acids into methane = methogenesis. Conditions must be anaerobic as the bacteria are only active when there is no oxygen present. They are called obligate anaerobes. Temperatures must be kept between 30-40o because the bacteria are sensitive to temperature changes. The reactions take place in a digester. It must be i) Strong and large enough to hold large volumes of liquid and withstand pressure build up. ii) Gas-tight and allow aerobic conditions to be maintained. iii) Have an inlet for loading material, an outlet for the gas and a way of unloading the residue. iv) be buried in the ground to help withstand pressure and act as an insulator. Often several digesters are used together to maintain a continuous supply of gas. It provides a useful way of getting rid of animal waste. (eutrophication) Osman Khan 12 RF 28/04/07 ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Energy, Respiration & the Environment section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Energy, Respiration & the Environment essays

  1. Marked by a teacher

    To make sure we have plenty of energy in the future, it's up to ...

    4 star(s)

    What is a fossil fuel? A fossil fuel is a fuel, which was made millions of years ago from the remains of dead animals or plants. In most cases these remains became covered with mud or other sediments which, over many years, changed into rock.

  2. Investigate the effect of bile salt concentration on the digestion of milk by the ...

    As I predicted, the rate of reaction increased with increasing bile salt concentration. There was only one anomalous result in the averages at 4% bile salt concentration. The graph shows an increase in the rate of reaction of lipase with increased bile salt concentration.

  1. Moscow, Russian Federation Summer-time pollution and summer smog problems

    According to Table 1, O3 is the most hazardous substance that occurs in Moscow in high concentrations during summer time. Figure 4. Comparison of O3 mean monthly values and O3 maximum permissible values (Lokoshenko and Elansky 2006; Mosecomonitoring 2010; Roshydromet 2010).

  2. Why the Body Needs Energy? Every living cell within the ...

    * The inside layer of an artery is very smooth because it's allowing the blood to flow quickly. * The outside layer of an artery is very strong because it's allowing the blood to flow forcefully. * The oxygen-rich blood enters the capillaries where the oxygen and nutrients are released.

  1. ancient and coppiced woodland

    Glucose is broken down in the four stages: glycolysis, the link reaction, the Krebs cycle and oxidative phosphorylation. In anaerobic conditions glucose is completely oxidised and carbon dioxide, water and energy are the products. In coppiced woodlands the light energy increases the air and soil temperature which increases the rate of respiration in the species in the coppiced woodland.

  2. Investigation into the effect of different sugars on alcohol fermentation

    1 molecule of lactose can form 4 molecules of ethanol. Sucrose: Sucrose is another disaccharide sugar that consists of Glucose and Fructose. As this contains 2 of the sugars that are in this experiment, there is a chance that it could be the most effective sugar.

  1. The Pancreas is a large gland that forms part of the Endocrine System, but ...

    One of the best-understood causes of pancreatitis is gallstones. Insoluble crystals of bile salts cause them. If a gallstone escapes from the gall bladder and gets stuck in the bile duct pancreatic juice and bile back up in the pancreas and gall bladder.

  2. chemistry of renewable resources

    It is easy to transport along pipes, and gas power stations produce comparatively little pollution. Other fossil fuels are being investigated, such as bituminous sands and oil shale. The difficulty is that they need expensive processing before we can use them.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work