biogas energy

Biogas EnergyGROUP 9, speakers:

I. Hillary Hugh Chinjodzi, 139282

II. Razık Can Pahalı, 15002697

III.Mohamad Fallaha, 149107

IV. Mbusiwesizwe Ndlovu, 143085

Presentation Outlite:a) Biogas Definition, pg. 1/2b) Typical Composition of Biogas,

pg. 3/4c) Biogas Energy, pg. 5d) Where does biogas come from?

pg. 6/7e) Conversion of organic waste

into biogas, pg. 8f) Statistics, pg. 9g) Manure Gasification,

pg. 10/12h) Gasifiers, pg. 13

i) Types of gasifiers, pg. 14j) How does gasification happen

in a fluidized bed gasifier ?pg. 15 / 17

k) Animal manure digeste, pg. 18l) Advantages of Biogas Energy,

pg. 19/20m) Disadvantages of Biogas

Energy, pg. 21

Biogas Definition• Biogas is a mixture of different gases produced by the

breakdown of organic matter in the absence of oxygen.

• Anaerobic digestion is one of the processes which produces biogas (micro-organisms breakdown biodegradable material by fungi, bacteria).

• Fermentation used in industrial processes, natural processes on soils, lakes are some of the other processes.

Speaker: Hillary Hugh Chinjodzi, 139282 1

Biogas Definition (continued)

• Biodegradable material, organic matter examples are food scraps, human and animal waste, manufactured products like paper.

• Biogas is a methane rich flammable gas that results from the decomposition of organic waste material.


Typical Composition of Biogas• Biogas is primarily methane, carbon dioxide and some small

amounts of hydrogen sulfide and moisture.

Compound Molecular Formula PercentageMethane CH4 50% - 75%Carbon Dioxide CO2 25% - 50%Nitrogen N2 0 – 10%Hydrogen H2 0 – 1%Hydrogen Sulphide H2S 0 – 3%Oxygen O2 0 - 0


Typical Composition of Biogas (continued)

• These gases can be combusted or oxidized with oxygen to release energy.


Biogas Energy

• Energy release allows biogas to be used as a fuel, for heating purposes , for instance cooking.

• It can also be used in a gas engine to convert energy into electricity and heat.

• It is the use of biogas to produce heat and power.


It can be captured from landfill sites where organic waste has been rotting under the ground.

Where does biogas come from?

Speaker: Razık Can Pahalı, 15002697 6

Vegetation: When vegetation

decomposes, it gives off methane gas

Farm and ranch animals: Cattle,

chickens, sheeps, pigs produce manure.

Sewage: Human waste in anaerobic digesters produces

methane.


Conversion of organic waste into biogas

1. Uncontrolled anaerobic digestion• Wetlands and Ponds: One common occurrence is swamp gas, also known

as “Will-o-the-Wisp”. It caused by rotting vegetation and their leafs.• Landfills: 60 million tons of waste material are disposed in the landfills

annually. To prevent methane from escaping into the atmosphere, it is collected and flared.

2. Controlled anaerobic digestion• Sewage Treatment Plants: Sewage treatment plants are designed to clean

the water from the sewage and in the process can generate large amounts of methane. The methane can be either flared or used for power production.

• Cattle Manure Digesters: Instead of releasing methane into the atmosphere, however, we have captured all the methane biogas. When we burn that methane, we create lots of electricity that we sell to the utility company.


Total world energy consumption statistics (2015)Speaker: Razık Can Pahalı, 15002697 9

Gasification is a simple, safe and efficient waste conversion process that substantially reduces the weighted volume of the gasifying media and destroys all dangerous materials emissions.

Manure Gasification

Speaker: Mohamad Fallaha, 149107 10

• Converts solid waste into energy and valuable chemical products such as Bio oil and Synthesis gas “Syngas”

• Bio oil can be refined into adhesives, Plastics, fragrances, flavourings, chemicals and fuels.

• Syngas is a clean fuel similar to natural gas, it can be used for power generation since its flammable.

• Any organic materials can be used for the gasification process. • Solids from dairy cow or poultry manure produces very efficient

energy .

Manure Gasification (continued)


Manure Gasification (continued)Gasification is close to fire or a combustion but it occurs in a closed vessel, which makes it a clean alternative to incineration.


GasifiersIncinerators use large amounts of air to burn the solid waste to produce heat and generate electricity but it also produce pollutants and they leave ash that must be carefully disposed of.


Gasifiers: Types of gasifiers (continued)

There are five types of gasifiers:I. Updraft Gasifier or counter current gasifier.II. Downdraft gasifier or co-current gasifier.III. Entrained flow gasifier.IV. Plasma gasifier.V. Fluidized bed gasifier.


How does gasification happen in a fluidized bed gasifier ? 1) Coal or sand are generally used as a bed inside

the gasifier.2) Air is distributed evenly from the bottom of the

gasification vessel creating the fluidized effect on the sand layer.

3) The vessel temperature must be around 860 degrees using in bed tube heater.

4) Dried manure is added to the gasifier in addition to oxygen and/or steam.

5) The high temperature causes the dried manure molecules to break apart to form gases that includes hydrogen molecules H2 and Carbon C and small amounts of Methane.


6) Those gases are then transferred into another vessel or container and combined under pressure to form Syngas.

7) During this process Tar, Ammonia, Sulfur, and Carbon dioxide are produced and special catalysts or filters are used to convert these compounds into additional syngas.

8) The remaining ash or Char is an activated carbon which can be used for emission filtration and fertilizer.

Speaker: Mohamad Fallaha, 149107

How does gasification happen in a fluidized bed gasifier ? 16

• By separating methane from the biogas it can be used to generate electricity or sent through pipe lines as a usable gas.

• Biogas consists of about 40% useless carbon dioxide which needs to be removed from the biogas and there are many ways to get rid of CO2 and one of them is to let the biogas go through a solution of Sodium Hydroxide “NaOH” which will absorb a lot of CO2.

Biogas can be used to produce heat and power


Representation of animal manure digester:Speaker: Mbusiwesizwe Ndlovu, 143085 18

Advantages of Biogas EnergyRenewable source of energy: it’s considered a renewable energy because it’s often produced from materials that form sewage and waste products.Non-polluting: the production of bios gas does not require oxygen, which means that resources are conserved by not using any further fuel.Reduces Landfills: it also uses up waste material found in landfills, dump sites and even farms, allowing for decreased soil and water pollution.Cheaper Technology: it can be used to produce electricity and for the purpose of heating as well.

Speaker: Mbusiwesizwe Ndlovu, 143085 19

Advantages of Biogas Energy (continued)

Large number of jobs: Work opportunities are created for many people in these plants.Little capital investment: Biogas are easy to set up and require little capital investment on a small basis. In fact many farms can become self-sufficient by utilizing biogas plants and waste material produced by their livestock each day. Reduces Greenhouse Effect: It reduces by utilizing the gases being produced in landfills as forms of energy.


Disadvantages of Biogas EnergyContain Impurities: biogas contains a number impurities even after refining processes have been put in place. When used as fuel for compression. It can become corrosive to the metal parts of the engines.Unstable: it is prone to explosion if the methane comes in contact with oxygen and become flammable in natureNot attractive on a large scale: it is not economically viable and it is very difficult to enhance the efficiency of the biogas systems.Little Technology Advancements: little new technology has been introduced for streamlining the process and making it more cost effective.


Thanks for your attention Is there any question related with this topic?

22

biogas energy

Environment