Gasifiers have been employed worldwide for a wide range of feedstocks, such as coal, biomass, and various waste materials. Figure 16.1 shows the status of gasification, showing its present and planned capacities. At present the energy production from gasification is around 60 GWth. In coming years, the energy production from gasification is set to grow rapidly reaching around 150 GWth by 2014, which is 1.5 times more than what is used at present.

Figure 16.2 shows the application of gasification. Presently, the product gas from the gasification process is used for chemical production and makes little contribution to power generation. However, growth of gasification in the future is predicted to be towards power generation.

Gasification will be a ‘breakthrough’ technology, as it combines the economic advantages of coal with the environmental benefits of natural gas. Because of its

huge resources, coal will remain a primary energy for power generation. However, environmental concerns will restrict its use. A safe route for the power company will then be to gasify the coal and use the syngas for power generation. Development of IGCC will be seen to increase in the near future as it is proved to be commercially and technically more attractive than convectional power generation. In the coming decades, a first and second generation IGCC plant is projected to be in the market. Gasification also offers an opportunity to capture carbon dioxide at a significantly lower cost as compared with other fossil-fuel — based technologies.

Natural gas has been used for power generation but in greater part for chemical production. In the US more than 70% of chemicals are derived from natural gas

and every $1.00 increase in the cost of natural gas adds $3.7 billion in costs to the industry (http://www. clean-energy. us/facts/gasification. htm). At present, the demand in the US for natural gas has already exceeded the supply, which predicts there will be a rise in price and the chemical industry will look for an alternative option. The only way to replace natural gas is to produce syngas through gasification and then use it for chemical production instead of natural gas. Another major area of gasification will be production of hydrogen, which will eventually reduce the use of petroleum in vehicles.

Waste is considered no longer as a waste; rather it is looked at as an alternative energy source. A commonly used methods for disposing of municipal solid waste is incineration, which is facing huge criticism for not being environmentally friendly, as it emits high amounts of harmful dioxins, as well as NOx and SOx. Gasification, on the other hand, for being more efficient in breaking down hazardous dioxins and furans into simple gases, has already been seen as an alternative to incineration. Indirect co-firing using a biomass gasifier and then combusting the product gas in a boiler has given new direction to the co-firing system.

Gasification has the advantage of being fuel flexible, as it can take different types of fuel. That is important when fuel prices are volatile and its availability is not reliable.

A technical challenge to gasification could be tar formation. But with the use of a catalyst and some modification in design, the tar can be effectively controlled. With stringent environmental regulations, its cost advantages will be better.