Syngas combustion in practical devices

Syngas combustion in gas turbine engines (i) using an IGCC facility is quite promising for efficient, low-emission power generation, and for carbon capture and storage. Research in this area has focused on using syngas in natural gas-fired combustors (Monteiro, 2011). Similarly, some studies (Luessen, 1997; Colantoni et al., 2010; Boehman et al., 2008) have demonstrated the viability of using syngas in spark ignition (SI) and compression ignition (CI) engines. Sahoo et al. (2011) examined the effects of using syngas on the performance and emission characteristics in a diesel engine operating in a dual-fuel mode, using a combination of diesel pilot injection and syngas fumigation in the intake air (Boeman et al., 2008). In this mode, the ignition is initiated through the auto ignition of diesel fuel. Results indicated that the engine performance and emissions are strongly influenced by the syngas composition, depending upon the load and other conditions. In general, increasing the H2 fraction in syngas was found to improve engine performance, reduce CO and hydrocarbon emissions, but increase NOX emissions. Thus, further experiments and simulations are needed to optimize the engine performance and emissions for various operating conditions and syngas composition. Research should also focus on examining the use of syngas in new engine designs, such as HCCI (Homogeneous Charge Compression Ignition) and low temperature combustion.

The use of syngas in SI engines also offers advantages, such as better anti-knocking prop­erties and operation with leaner mixtures. Improved knock resistance is due to the presence of CO and CH4, and enables operation at a higher compression ratio, leading to higher thermal efficiency. However, a higher burning rate due to the presence of H2 can result in higher end gas temperature and increased propensity to knocking. The presence of H2 can also increase

Table 2.4. Representative biogas compositions based on two common feed stocks.

Chemical species

Biogas 1

Agricultural waste

Biogas 2 Household waste
















NOX emissions, which may be controlled by using leaner mixtures (Boeman et al., 2008). Bika et al. (2011) examined such issues by performing single cylinder experiments for different syngas compositions, compression ratios, and equivalence ratios. For a given Ф and spark timing, the knock limited compression ratio was observed to increase with increasing CO fraction. The burn duration and ignition lag also increased with increasing CO fraction.