Perpustakaan Digital ITB

Oil sludge is a hazardous refinery waste with considerable hydrocarbon content, while rice husk is an abundant lignocellulosic residue with potential for hydrogen-rich gasification. This study investigated the steam co-gasification of oil sludge and rice husk to evaluate the effects of feedstock blend ratio and gasification temperature on syngas composition, hydrogen production, and syngas quality, while quantifying the interaction between the two feedstocks. Experiments were conducted in a laboratory-scale horizontal fixed-bed gasifier using steam at a nominal steam-to-feedstock ratio of 2.4. Four oil sludge-to-rice husk mass ratios (100:0, 66.7:33.3, 33.3:66.7, and 0:100) were tested at 700, 800, and 900 °C. The produced gas was analyzed by gas chromatography, and absolute gas-species yields were determined using nitrogen as an internal tracer. Feedstock interactions were evaluated using the mean error (ME) and root-mean-square (RMS) framework. Increasing temperature generally increased hydrogen concentration and reduced methane concentration, although hydrogen yield did not increase monotonically for all feedstocks. The highest hydrogen concentration of 62.6 vol% was obtained at 900 °C using the 66.7:33.3 blend, whereas the highest absolute hydrogen yield of 0.01432 g H?/g feed was obtained from pure rice husk at 900 °C. The ME–RMS analysis indicated near-additive hydrogen production, with RMS values of 3.0% and 18.0% for the sludge-rich and husk-rich blends, respectively. In contrast, CO and CO? were consistently inhibited, with CO? showing the strongest interaction and reductions of 51.0–89.7% relative to the additive baseline. Regarding overall syngas performance, the 33.3:66.7 blend at 900 °C provided the most favorable blended condition, exceeding the linear additive baselines by 16.3% in HHV, 16.9% in H?/CO ratio, and 20.4% in energy yield. These results demonstrate that blending primarily modifies syngas quality through species-selective interactions rather than producing a synergistic increase in absolute hydrogen production.