Gasifiers are viable alternative for producing heat and power with minimal adverse impact on the environment. The gasification technology is now considered to be in an advanced stage of development. Hence there is huge expectation from the user industry for its application. For a country like India with its vast agricultural residues, there is a huge requirement for an efficient power generation system. In this regard careful studies are required to select an appropriate gasification technology to suit the available fuels. In this paper different types of gasifiers namely updraft, downdraft, bubbling fluidized bed and entrained bed are compared and their suitability for various applications are evaluated. The technological developments achieved so far and requirements of further developments are also analyzed. A systematic comparison of the performance of various gasifiers is carried out and their unique features are discussed. From the comparative study, specificity of gasifier design is brought out highlighting their merits and possible application potential. The study also brought-out the fact that a universal design concept cannot be achieved to meet the requirements of all possible applications for gasification process.
