The gasification system in its commercial development may face the following technical and non-technical challenges (Basu, Acharya, and Dutta, 2009).

Technical barriers

1. Availability is the most important factor that prevents the wide scale use of gasifiers in the mainstream energy industries. Present day gasifiers have not reached the standard (>90%) expected in utility industries. The 140 MW high-temperature Winkler gasifier of Rheinbrau started with an availability of 45%, which rose to 89% in 1997 (Renzenbrink et al, 1997). This forced EPC to specify a stand-by gasifier in order to meet the overall unit availability matching the industry standard.

2. Complex operation due to a large amount of ancillary equipment, such as oxygen separation units (OSU), gas sweeteners, etc.

3. Gasification of high alkali biomass (agglomeration problems), RDF, and waste (mercury removal problem).

4. Tar control in order to avoid the problems in gas cooling and filtration, as well as its removal without producing toxic waste water.

5. Poor carbon conversion is a major problem. It has been less than 90.5%. High carbon levels in ash reduces the ash quality, and deprives the plant owners from the revenue expected from the sale of gasifier ash for their end-use. High carbon in ash imposes an additional burden of disposal cost.

Non-technical barriers

Beside the above technical challenges, several other challenges retarded the market penetration of gasification.

1. higher investment;

2. fuel availability and price level for non-conventional fuels, such as biomass;

3. subsidies available for biomass-only plants but not for co-firing;

4. economic competitiveness with steam cycles, co-firing, etc.;

5. complicated and costly means of power production;

6. small difference in efficiency compared with steam cycles.

The economics of gasification are heavily dependent, however, on the nature of the feedstock and on the location of the gasifier relative to both the source of the feedstock and to the ultimate user of the product (see Table 16.1).