Advantages of gasification over combustion are as follows.

1. Gasification is a thermo-chemical conversion process, where the feed is converted into more valuable, environmentally friendly gaseous products that can be used for chemical, fuel, and energy production. The gaseous product can be converted to hydrogen or liquid fuels by reforming or by Fischer — Tropsch synthesis, respectively. The objective of combustion, on the other hand, is to thermally destruct the feed material and produce heat.

2. There is higher potential for overall energy efficiencies and conversion of difficult-to-handle feed materials into a gaseous fuel that can be handled with greater ease in conventional equipment designed for natural gas. For example, a producer gas flame can easily be burned with low NOx emissions, a gas flame can be easily directed to a certain heating zone, and each burner can be controlled easily.

3. The volume of gas produced is much lower in gasification than in combustion, thus a relatively smaller unit is required for the gas cleaning process.

4. The solid by-products of gasification are char (low-temperature gasification) and slag (high-temperature gasification). Char is used for various applications in the form of activated carbon, while slag, considered as non-hazardous, can be used as admix for road construction material. The by-product from combustion is mainly bottom ash, consisting of the mineral matters and unreacted carbon. The bottom ash is found to have a leaching property, thus it is considered to be hazardous. So, the solid by-products from gasification are useful and also environmentally friendly, while combustion produces a hazardous by-product.