How does gasification work and how is it sustainable?
Sustainable transport. Gasification is a process that converts organic- or fossil fuel-based carbonaceous materials into carbon monoxide, hydrogen and carbon dioxide. This is achieved by reacting the material at high temperatures (>700 °C), without combustion, with a controlled amount of oxygen and/or steam.
What can be produced by an entrained flow gasifier?
The tar, oil, phenols, and other liquids produced from devolatization of coal inside the gasifier are decomposed into hydrogen (H 2 ), carbon monoxide (CO) and small amounts of light hydrocarbon gases. Entrained-flow gasifiers have the ability to handle practically any coal feedstock and produce a clean, tar-free syngas.
Why is gasification efficiency lower than fixed bed gasifier?
Fuel throughput is higher than for the fixed bed, but not as high as for the entrained flow gasifier. The conversion efficiency can be rather low due to elutriation of carbonaceous material. Recycle or subsequent combustion of solids can be used to increase conversion.
How does the reversible gas phase work in gasification?
In addition, the reversible gas phase water-gas shift reaction reaches equilibrium very fast at the temperatures in a gasifier. This balances the concentrations of carbon monoxide, steam, carbon dioxide and hydrogen.
What kind of gas is used in gasification?
Gasification is a technological process that can convert any carbonaceous (carbon-based) raw material such as coal into fuel gas, also known as synthesis gas (syngas for short).
Which is the best description of a gasifier?
The generic gasifier types are described in Fig. 10.8. These are fixed bed gasifiers, fluidized bed gasifiers, and entrained flow gasifiers ( Beychok, 1974a,b, 1975Beychok, 1974aBeychok, 1974bBeychok, 1975; NNFCC, 2009 ). A brief description of these gasifiers is presented below. Figure 10.8. Generic gasifiers. E.E. Robertson,
What makes a gasifier better than a down draft gasifier?
In this way, the producer gas does not flow through the high temperature combustion zone and tar content in the producer gas is higher whereas the energy efficiency is also higher than those of the down draft gasifiers. In addition, this type of gasifier can handle solid fuel with relatively high moisture content of up to 50%.