What is the process of underground coal gasification?

Underground coal gasification (UCG) is an industrial process which converts coal into product gas. UCG is an in-situ gasification process, carried out in non-mined coal seams using injection of oxidants and steam. The product gas is brought to the surface through production wells drilled from the surface.

What is underground coal gasification Upsc?

In-situ gasification of coal – or Underground Coal Gasification (UCG) – is the technique of converting coal into gas while it is still in the seam and then extracting it through wells.

Is underground coal gasification fracking?

Unlike fracking, which involves pumping fluid into coal seams to cause fractures, in UCG the entire process takes place underground within the coal body. Coal is ignited by injecting oxygen into the coal seam.

How does coal gasification work?

Gasification works by mixing coal with oxygen, air, or steam at very high temperatures without letting combustion occur (partial oxidation). Most of today’s pulverized coal power plants burn coal (combustion) to generate steam for use in a turbine.

What is UCG in mining?

Underground Coal Gasification (UCG) takes advantage of the same chemical reactions of coal to produce product gases, as those occurring in conventional gasifier reactors.

What is the main reason for coal liquefaction?

coal liquefaction, any process of turning coal into liquid products resembling crude oil. The two procedures that have been most extensively evaluated are carbonization—heating coal in the absence of air—and hydrogenation—causing coal to react with hydrogen at high pressures, usually in the presence of a catalyst.

How is coal gasification work?

What is coal gasification with example?

Coal gasification is the process of producing syngas—a mixture consisting primarily of carbon monoxide (CO), hydrogen (H2), carbon dioxide (CO2), methane (CH4), and water vapour (H2O)—from coal and water, air and/or oxygen. Historically, coal was gasified to produce coal gas, also known as “town gas”.

What are the steps of gasification?

Gasification is made up for five discrete thermal processes: Drying, Pyrolysis, Combustion, Cracking, and Reduction.

What are three main type of gasifiers?

Based on the gas–solid contacting mode, gasifiers are broadly divided into three principal types (Table 6.1): (1) fixed or moving bed, (2) fluidized bed, and (3) entrained flow.

What are the types of reactor used for coal gasification?

Gasification reactors can be grouped into the following three main categories: moving-bed gasifiers, fluidized-bed gasifiers, and entrained-flow gasifiers.

What are the benefits of coal gasification?

Coal gasification methods also sought to remove impurities like sulfur and mercury from coal to make it a more efficient source of energy. These methods of using energy more efficiently lead to recycling the ash from coal gasification into a concrete aggregate rather than sending it to a landfill.

What is the difference between coal gasification and coal liquefaction?

The process involves gasification of coal, which in turn will produce synthetic gas (a mix of CO+H2). The synthetic gas can be liquefied to its fuel equivalent in presence of cobalt/iron-based catalysts at higher pressure and temperature. However, liquefied coal emits twice as much CO2 as burning oil.

What is the principle of gasification?

2.1 Principles of the technology. Gasification is a thermochemical process that involves heating the waste plastic at 700–1100°C with a controlled amount of oxygen, air, oxygen-enriched air, and/or steam to produce industrial gas mixtures called “synthesis gas,” or syngas.

Is gasification of coal underground or surface?

CONCLUSIONS  Both Underground and Surface gasification are proven technologies.  Technologies can be sourced for both underground and surface gasification of coal with the joint efforts of Indo- US working group on coal.  According to coal mineing act the captive plant are can produced syngas . 16.

What is underground coal gasification (UCG)?

Underground coal gasification (UCG) is an industrial process, which enables coal to be converted into product gas. UCG is an in-situ gasification process carried out in non- mined coal seams using injection of oxidants, and bringing the product gas to surface through production wells drilled from the surface.

What is gasification?

3. What is Gasification  Gasification is a process that converts carbonaceous material, Such as fossil fuels and biomass in to a mixture of mostly hydrogen and carbon monoxide ( called Synthesis gas & Syngas)  The syngas can be burned as a fuel or processed to produced chemical and other fuels

How much gas is produced from one ton of coal?

• About 350 m3 gas can be produced per tonne of coal. • Bye products of significant commercial value will be hydrocarbons, phenols, anhydrous NH3and clean water • UCG overcomes hazards of underground and open cast mining operations. • In UCG process, ash/ slug removal is not required as they remain in the cavities.