Investigation of biomass (pine wood) gasification: Experiments and Aspen Plus simulation

Abstract

Biomass gasification is currently a hot research topic. To achieve a high hydrogen content in the product gas, the gasification feedstock used in this study is air‐dried pine woodchips. Experiments are performed in a downdraft gasifier by varying the operation parameters of the particle size (60 mesh, 80 mesh, 100 mesh), temperature point (700, 750, 800, 850, 900°C), and steam‐to‐biomass mass (S/B) ratio (0, 0.7, 1.4, 2.1, 2.8). The main effects of particle size, temperature, and S/B ratio on the composition of the product gas are analyzed to predict the optimal operation parameters of biomass feedstock. For pine woodchip gasification, the optimal particle size is 80 mesh or 0.17 mm, the preferred temperature is 850°C, and the optimal S/B ratio is 1.4. Although there is an error between the experiment and the simulation, the difference is not significant. The Aspen Plus model can provide guidance for the gasification of pine woodchips and can be extended to the gasification of other kinds of biomass.

Effect of Woody Biomass Gasification Process Conditions on the Composition of the Producer Gas

“…As can be seen, CO is the main combustible gas in all cases, with concentrations ranging from 9-35 vol%. This study's CO concentrations are comparable and within the same range as those derived from other studies [30][31][32]34,[36][37][38]]. In the above-mentioned studies, the concentration of H 2 ranged from 2-35 vol% compared to a concentration from 4.0 to 4.3 vol% obtained in the producer gas from the gasification of the currently studied WB, which was similar to the results of Joka et al, Inayat et al, and Poskrobo et al [31][32][33].…”

“…The concentration of CH 4 from the studied WB was within the same range as in most of the reviewed studies. A slightly higher concentration of CH 4 was obtained in the current study (4.1-5.2 vol%) compared to that of 1-5 vol% obtained from other studies using fixed-bed reactors [30,31,34,37,38]. The CO 2 concentration was lower in the current study (1.9-3.9 vol%) compared to that of other studies using WB (9.5-15 vol%) [30,31,34,37].…”

“…As the temperature increased, reactions R 2 , R 4 , and R 5 moved toward the production of products, including H 2 and CO. This was also observed by Huang et al [38] and by Halim et al [40], where an increment in H 2 occurred at higher temperatures due to methane dry and steam-reforming reactions (R 4 and R 5 ). This effect on the yield of H 2 was also noticed by Ahmad et al [7] due to the water-gas and steam-reforming reactions (R 2 and R 5 ).…”

“…Additionally, the water-gas reaction (R 2 ) may have had a more considerable contribution than the Boudouard reaction (R 1 ) for the production of H 2 and CO, as at higher bed temperatures, this reaction (R 2 ) has a faster reaction rate, as also explained by Almeida et al [39]. The equilibrium constants (K) of some reactions are more sensitive to temperatures, such as the K of R 4 , which is significantly more sensitive than that of R 1 and R 2 [38]. As the reactions mentioned above and their equilibrium constants were favored at higher temperatures, the WB underwent an increased heat transfer and production of H 2 , CO, and CH 4 , producing a higher-quality producer gas.…”

Challenges and Opportunities of Modeling Biomass Gasification in Aspen Plus: A Review

“…Even though each study handles the modeling process from a different technological perspective, the main goal is the development of a realistic process model with high efficiency and product quality. The number of studies dealing with biomass gasification has significantly increased, especially within the last decade , and there are many review studies based on a variety of aspects . However, as compiled in Tab.…”