Hydrothermal Carbonization of Various Paper Mill Sludges: An Observation of Solid Fuel Properties

• Author: Saha, Nepu ; Saba, Akbar ; Saha, Pretom ; McGaughy, Kyle ; Franqui-Villanueva, Diana ; Orts, William ; Hart-Cooper, William ; Reza, M.
• Subjects: Alternative energy sources ; Biomass energy ; Branches ; Cellulose ; Coal-fired power plants ; combustion indices ; Decarboxylation ; deinked sludge ; Deinking ; Dewatering ; fiber rejects ; Fibers ; Fillers ; Flotation ; fuel properties ; Hemicellulose ; hydrochar ; Impurities ; Kinetics ; Metals ; Microorganisms ; Monomers ; Organic compounds ; Paper mills ; Polymerization ; Polymers ; Primary sludge ; Raw materials ; Renewable resources ; secondary sludge ; Sludge ; Sludge thickening ; Solid fuels ; Thermogravimetric analysis ; Wastewater treatment
• Is Part Of: Energies (Basel), 2019-03, Vol.12 (5), p.858
• Description: Each year the pulp and paper industries generate enormous amounts of effluent treatment sludge. The sludge is made up of various fractions including primary, secondary, deinked, fiber rejects sludge, etc. The goal of this study was to evaluate the fuel properties of the hydrochars produced from various types of paper mill sludges (PMS) at 180 °C, 220 °C, and 260 °C. The hydrochars, as well as the raw feedstocks, were characterized by means of ultimate analysis, proximate analysis, moisture, ash, lignin, sugar, and higher heating value (HHVdaf) measurements. Finally, combustion indices of selected hydrochars were evaluated and compared with bituminous coal. The results showed that HHVdaf of hydrochar produced at 260 °C varied between 11.4 MJ/kg and 31.5 MJ/kg depending on the feedstock. This implies that the fuel application of hydrochar produced from PMS depends on the quality of feedstocks rather than the hydrothermal carbonization (HTC) temperature. The combustion indices also showed that when hydrochars are co-combusted with coal, they have similar combustion indices to that of coal alone. However, based on the energy and ash contents in the produced hydrochars, Primary and Secondary Sludge (PPS2) could be a viable option for co-combustion with coal in an existing coal-fired power plant.
  
• Publisher: Basel: MDPI AG
  
• Language: English
  
• Identifier: ISSN: 1996-1073
  EISSN: 1996-1073
  DOI: 10.3390/en12050858
  
• Source: DOAJ Directory of Open Access Journals
  GFMER Free Medical Journals
  ROAD: Directory of Open Access Scholarly Resources
  ProQuest Central