Article CC BY 4.0
refereed
published

Influence of acids and alkali as additives on hydrothermally treating sewage sludge : Effect on Phosphorus Recovery, Yield, and Energy Value of Hydrochar

Affiliation
Department of Waste and Resource Management, Faculty of Agricultural and Environmental Sciences, University of Rostock, Rostock, Germany
Ekanthalu, Vicky Shettigondahalli;
Affiliation
Department of Waste and Resource Management, Faculty of Agricultural and Environmental Sciences, University of Rostock, Rostock, Germany
Narra, Satyanarayana;
Affiliation
Department of Waste and Resource Management, Faculty of Agricultural and Environmental Sciences, University of Rostock, Rostock, Germany
Sprafke, Jan;
Affiliation
Department of Waste and Resource Management, Faculty of Agricultural and Environmental Sciences, University of Rostock, Rostock, Germany
Nelles, Michael; Shettigondahalli Ekanthalu, Vicky

The high moisture content present in sewage sludge hinders the use of sewage sludge in incineration or energy application. This limitation of moisture present in sewage sludge can be obviated by using the hydrothermal carbonization (HTC) process. In sewage sludge management, the HTC process requires less energy compared to other conventional thermo-chemical management processes. The HTC process produces energy-rich hydrochar products and simultaneously enables phosphorus recovery. This study investigates the influence of organic acids, inorganic acid, and alkali as additives on phosphorus transformation, yield, proximate analysis and the heating value of subsequently produced hydrochar. The analysis includes various process temperatures (200 °C, 220 °C, and 240 °C) in the presence of deionized water, acids (0.1 M and 0.25 M; H₂SO₄, HCOOH, CH₃COOH), and alkali (0.1 M and 0.25 M; NaOH) solutions as feed water. The results show that phosphorus leaching into the process-water, hydrochar yield, proximate analysis, and the heating value of produced hydrochar is pH- and temperature-dependent, and particularly significant in the presence of H₂SO₄. In contrast, utilization of H₂SO₄ and NaOH as an additive has a negative influence on the heating value of produced hydrochar.

Cite

Citation style:
Could not load citation form.

Access Statistic

Total:
Downloads:
Abtractviews:
Last 12 Month:
Downloads:
Abtractviews:

Rights

Use and reproduction:

Export