Production of H-2-rich syngas from excavated landfill waste through steam co-gasification with biochar

• Gasification of excavated landfill waste is one of the promising options to improve the added-value chain during remediation of problematic old landfill sites. Steam gasification is considered as a favorable route to convert landfill waste into H-2-rich syngas. Co-gasification of such a poor quality landfill waste with biochar or biomass would be beneficial to enhance the H-2 concentration in the syngas, as well as to improve the gasification performance. In this work, steam co-gasification of landfill waste with biochar or biomass was carried out in a lab-scale reactor. The effect of the fuel blending ratio was investigated by varying the auxiliary fuel content in the range of 15-35 wt%. Moreover, co-gasification tests were carried out at temperatures between 800 and 1000 degrees C. The results indicate that adding either biomass or biochar enhances the H-2 yield, where the latter accounts for the syngas with the highest H-2 concentration. At 800 degrees C, the addition of 35 wt% biochar can enhance the H-2 concentration from 38 to 54 vol%, and lowering the tar yield from 0.050 to 0.014 g/g-fuel-daf. No apparent synergetic effect was observed in the case of biomass co-gasification, which might cause by the high Si content of landfill waste. In contrast, the H-2 production increases non-linearly with the biochar share in the fuel, which indicates that a significant synergetic effect occurs during co-gasification due to the reforming of tar over biochar. Increasing the temperature of biochar co-gasification from 800 to 1000 degrees C elevates the H-2 concentration, but decreases the H-2/CO ratio and increases the tar yield. Furthermore, the addition of biochar also enhances the gasification efficiency, as indicated by increased values of the energy yield ratio.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering (hsv//eng)

Keyword

Co-gasification

Landfill waste

Landfill mining

Hydrogen production

Waste to energy

Biomass

Publication and Content Type

ref (subject category)

art (subject category)