Table 2. Effect of Gasification Parameters on Syngas Yield, Composition, and Hydrogen Contenta.
| biomass type | reactor type | catalyst | operation conditions | gasification agent | syngas yield and composition | hydrogen content | ref |
|---|---|---|---|---|---|---|---|
| switchgrass (SG), pine residue (diameter of ≤2 in. and of ≤6 in.) | bench-scale fluidized bed | catalyst bed material: sand, CaO + sand, Al2O3, and CaO + Al2O3 | –780 °C and ER ≈ 0.32 | air/steam | H2 (32.1%), CO (7.5%), CO2 (21.8%), CH4 (2.5%), C2H2 (0.01%), C2H4 (1.9%) | The highest H2 of 32.1 vol % with S/B of 2.34 for Pine6 using the CaO + Al2O3 bed material. | (117) |
| steam-to-biomass ratios (S/B) (0.74, 1.23, 1.85, and 2.34) | |||||||
| cellulose, hemicellulose, lignin, poplar leaf, Chinese cabbage, and orange peel | updraft fixed-bed reactor | no catalyst | varied temperature range (920–1220 °C) | steam | H2 (54%), CO (26.2%), CO2 (18.8%), CH4, C2H4 (−), and C2H2 (−) for lignin at 920 °C | The highest H2 yields for cellulose, hemicellulose, and lignin were 0.27 N m3/kg (1220 °C), 0.30 N m3/kg (1220 °C), and 0.88 N m3/kg (1020 °C), respectively. | (114) |
| wood pellets | bench-scale fixed-bed gasifier | no catalyst | high temperature (800–1435 °C) | steam | H2 (60%), CO (≈13%), CO2 (≈18%), CH4 (≈6%), C2H4 (≈1%), and C2H2 (≈1%) | The maximum volume percentage of H2 was 60% at 917 °C with 9.0 g/min of steam flow rate. | (118) |
| steam flow rates (3.9, 4.7, 5.5, 6.8, 9.0, 9.8, 11.1, 15.7, and 17.3 g/min) | |||||||
| municipal solid waste | tube reactor | no catalyst | different temperatures (700, 800, 900 °C), ERs (0.1, 0.2, 0.3), and residence times (10, 20, 30 min). | air | H2 (32 mol %), CO (34.7 mol %), CO2 (28.6 mol %), and CH4 (4 mol %) | The highest H2 yield of 32 mol % was achieved at 900 °C with an ER of 0.25 and 20 min of residence time. | (107) |
| citrus peel | bench-scale fluidized-bed reactor | no catalyst | different temperature range (700–850 °C) | air-steam | H2 (26.5%), CO (≈8%), CO2 (20%), N2 (≈42%), and CH4 (≈3%) at 750 °C and S/B = 1.25 for experimental results | The highest H2 yields of 0.65 and 0.69 N m3/kg were achieved at 750 °C and S/B = 1.25 for the experimental and simulated results, respectively. | (119) |
| (S/B) (0.5–1.25) | |||||||
| banana peel | fixed-bed gasifier | no catalyst | different steam-to-carbon ratios (S/C) (0, 0.6, 1.4, 4.3, 7.2, 14.5, 21.7, 28.9, and 36.1) | steam | CO2 (≈33%), CH4 (≈2%), C2 (≈2%), CO (≈8%), and H2 (≈58%) | The maximum value of 76.1 mL/g of H2 yield was achieved at S/C = 21.7 and a temperature of 1023 K. | (120) |
| algal biomass (Nannochloropsis sp) | hydrothermal carbonization (HTC) and a laboratory-scale quartz tube reactor | no catalyst | for HTC (180–220 °C) and reaction time (2, 6, 12 h) | steam | H2 (≈46%), CO (≈32%), CO2 (≈16%), and CH4 (≈6%) of feedstock of HC-180 °C-12 h at 800 °C with S/B ratio of 3 | The maximum H2 concentration of 48.6% was achieved with HC-220 °C-12 h, whereas further gasification optimization was continued with feedstock of HC-180 °C-12 h due its high EREtotal. | (121) |
| gasification temperature (700–900 °C) | |||||||
| S/B ratio (1–3) |
a
Abbreviations: equivalence ratio (ER), steam-to-biomass ratios (S/B), steam-to-carbon ratios (S/C), hydrothermal carbonization (HTC), total energy recovery efficiency (EREtotal).