Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8869992 | Waste Management | 2018 | 8 Pages |
Abstract
Gasification of landfill leachate in supercritical water using batch-type reactor is investigated. Alkali such as NaOH, KOH, K2CO3, Na2CO3 is used as catalyst. The effect of temperature (380-500â¯Â°C), retention time (5-25â¯min), landfill leachate concentration (1595â¯mgâ¯Lâ1-15,225â¯mgâ¯Lâ1), catalyst adding amount (1-10â¯wt%) on hydrogen mole fraction, hydrogen yield, carbon gasification rate, COD, TOC, TN removal efficiency are investigated. The results showed that gaseous products mainly contained hydrogen, methane, carbon dioxide and carbon monoxide without addition of catalyst. However, the main gaseous products are hydrogen and methane with addition of NaOH, KOH, K2CO3, Na2CO3. In the absence of alkali catalyst, the effect of temperature on landfill leachate gasification is positive. Hydrogen mole fraction, hydrogen yield, carbon gasification ratio increase with temperature, which maximum value being 55.6%, 107.15â¯molâ¯kgâ1, 71.96% is obtained at 500â¯Â°C, respectively. Higher raw landfill leachate concentration leads to lower hydrogen production and carbon gasification rate. The suitable retention time is suggested to be 15â¯min for higher hydrogen production and carbon gasification rate. COD, TOC and TN removal efficiency also increase with increase of temperature, decrease of landfill leachate concentration. In the presence of catalyst, the hydrogen production is obviously promoted by addition of alkali catalyst. the effect of catalysts on hydrogen production is in the following order: NaOHâ¯ï¼â¯KOHâ¯ï¼â¯Na2CO3â¯ï¼â¯K2CO3. The maximum hydrogen mole fraction and hydrogen yield being 74.40%, 70.05â¯molâ¯kgâ1 is obtained with adding amount of 5â¯wt% NaOH at 450â¯Â°C, 28â¯MPa, 15â¯min.
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Authors
Gong Weijin, Li Binbin, Wang Qingyu, Huang Zuohua, Zhao Liang,