A Presentation on

Plasma gasification of

solid waste into fuel

PRESENTED BY DIVYA GUPTA

BE III YRDEPARTMENT OF CHEMICAL ENGINEERING

MBM ENGINEERING COLLEGEJAI NARAYAN VYAS UNIVERSITY JODHPUR (RAJASTHAN)- 342001

Introduction Rapid industrialization and urbanization have led

to increase in solid waste and depletion of natural energy resources.

The solid waste “problem” is solution to our energy needs.

Solid waste management need to adopt some strategies:

• Material recycling.• Elimination of land filling disposal.• Resource recovery through waste processing.• Biological and thermal process result in recover

of compost and energy.

Global Challenges & Opportunities

Challenges Global generation of Solid Waste will double by 2025. Solid waste generated by 300 million people living in

urban India is 30 million tonnes per year. 1,00,000 MT SW generation every day in India.

Opportunities SW is the only alternative waste to energy generation.

SW supplies 10% of global power. The high heating value of SW indicates the need of

waste to energy plants. Plasma gasification is the unique opportunity to

mitigate the above challenges.

Methods for removal of waste• Oldest method, waste disposed in

landfills.• Waste digested anaerobically and

produce biogas used as source of heating.

Land filling • Mass burn technology in presence of

oxygen• Waste burn in incinerators and

converted into ash and harmful greenhouse gases.

Incineration

• Thermal treatment in the absence of oxygen at low temperature.

• Syngas, pyrolysis liquid and coke obtained as products.

Pyrolysis • Partial oxidation of waste at high

temperature.• Products are low quality syngas, slag and

metals.

Gasification

• Waste is converted into syngas and vitrified slag at very high temperature.

• No emission of greenhouse gases.

Plasma Gasificatio

n

Process ComparisonsProcess Electricity

production (kWh/ton)

Plasma advantage

Incineration 544 50%

Pyrolysis 571 40%

Conventional Gasification

685 20%

Plasma arc Gasification

816 -

Origin of Plasma• Plasma is a fourth state of matter.• Discovered by British physicist Sir William Crookes in 1879. • Heating a gas at very high temperature lead to

ionization of atoms and turns it into plasma.• Natural plasma can be seen in lightning, sun stars,

comet etc.• Firstly used by metal industry in 1800 in

metallurgical, mechanical operations and in 1900 chemical industry made acetylene from natural gas.

• Plasma technology used by NASA in 1960 and become popular.

•Plasma consists high electrical conductivity, more independently acting species, high velocity particles and particles interact at long range through electric or magnetic forces.•Man made plasma produced by plasma torches using electricity as a heating source and air as ionized gas.•The plasma torches create the flow of plasma by using a 650V DC or AC and generate the temperature of about 2000-20,000°C.

Plasma Gasification Process

Municipal solid wasteLow level

radioactive waste

Biomedical waste

Waste coalSteel scrap

Asbestos and

asbestos containing material

Incinerator ash

Feedstock

Plasma Gasifier Gasifier is the central component of

the plasma gasification process. The gasifier equipped with its

components plasma torches, air or oxygen as ionized gas and feedstock.

The plasma arc converts organic waste into synthetic gas and inorganic material into vitrified slag.

The gasifier is maintained under negative pressure about -5mm due to minor air in leakage.

The inside of vessel lined with refractory and sealed with stainless steel.

The chemical reactions take place are C + H2O CO + H2

C + CO2 2CO

Products • The major products are synthesis gas and

vitrified slag.• Syngas has a high temperature cooled

down through heat recovery units.• Syngas as a fuel for electricity generation.• Rock like vitrified slag as construction

aggregates.• Other products are hydrochloric acid,

hydrogen sulfide obtained from syngas cleaning.

Conclusion Plasma gasification holds a potential to add to the supply of renewable energy resource in these times of uncertain energy supplies.

Any material can be processed in plasma arc system. To achieve a favorable energy balance the volume of inorganic should be minimized.

There is no emission of harmful greenhouse gases. Concentrations of dioxins are very low as compared to incineration due to high temperature.

Plasma gasification technology has a high operating cost and capital cost due to high electrical power requirement

References

• 2009 BP statistical review of world BP plc. 57th edition 45p.

• Lisa Zyga (2012) plasma gasification transforms garbage into clean energy, science blogger. Inventorspot.com, via: popular science

• Helsen, L.,2000 low temperature pyrolysis of CCA treated wood waste. PhD. Thesis, Heverlee, KU Leven.

• Manual of solid waste 2008

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