Hydrochar production by hydrothermal carbonization of faecal sludge

Fakkaew, Krailak; Koottatep, Thammarat; Pussayanavin, Tatchai; Polprasert, Chongrak

doi:10.2166/washdev.2015.017

Cited by 31 publications

(16 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…lancea biomass is responsible for the increase in the fixed carbon and calorific value, with the majority of the lignin remaining in the solid hydrochar. The increase observed in the fixed carbon of this biomass is in agreement with that reported by Fakkaew et al, Kambo and Dutta, and Hoekman et al A decrease was also noted in the moisture content of the hydrochars, as well as in the ash content of the products. The decrease noted in the ash content of the hydrochars could be a result of the decomposition of the inorganic carbonates and oxides of minerals within the biomass into the process water liquid phase.…”

Section: Resultssupporting

confidence: 92%

Hydrothermal Carbonization of Searsia lancea Trees Grown on Mine Drainage: Processing Variables and Product Composition

et al. 2021

View full text Add to dashboard Cite

A 12-year-old planted woodlands Searsia lancea tree, grown on acid mine drainage for phytoremediation of polluted groundwater on gold and uranium mines in South Africa, was used in this research. The research describes the fuel-related characteristics and the influence of different operating conditions on the hydrothermal carbonization of the biomass and the combustion profiles of discard coal/biomass hydrochar pellets. The raw biomass was treated at temperatures ranging from 200−280 °C and residence time of 30−90 min. The hydrochar produced at 280 °C and residence time of 90 min had the highest calorific value of 29.71 MJ/kg compared to 17.23 and 16.73 MJ/kg obtained from the raw biomass and discard coal, respectively. Regression equations developed using the central composite design (CCD) indicated that the values obtained experimentally agree with the predicted values from the models for mass yield, calorific value, and ash content. The reactivity tests showed that the 100% hydrochar pellet had the highest reactivity and lowest ignition and burnout temperature compared to biocoal pellets and discard coal. The process water contained relatively low concentrations of major elements, and the study had shown that different high-grade biocoal pellets can be produced from the S. lancea tree.

show abstract

Section: Resultssupporting

confidence: 92%

Hydrothermal Carbonization of Searsia lancea Trees Grown on Mine Drainage: Processing Variables and Product Composition

et al. 2021

View full text Add to dashboard Cite

show abstract

“…A major advantage of HTC over DT is the ability to utilize wet feedstocks and avoid the complexity and cost of pre-drying. This feedstock flexibility is illustrated in numerous recent literature reports describing use of HTC to treat food wastes [13][14][15], agricultural residues [16][17][18][19], sewage sludge [20,21], municipal solid waste [22,23], pulp mill streams [24][25][26][27], and other feedstocks [28][29][30][31][32]. Kambo and Dutta recently compared DT and HTC processes, along with their respective solid products [33,34].…”

Section: Introductionmentioning

confidence: 99%

Hydrothermal carbonization (HTC) of loblolly pine using a continuous, reactive twin-screw extruder

Hoekman

Broch

Felix

et al. 2017

Energy Conversion and Management

View full text Add to dashboard Cite

Hydrothermal carbonization (HTC) has become an accepted means of converting a wide variety of lignocellulosic feedstocks into solid hydrochars, which have improved physical and chemical properties compared to raw biomass. To date, HTC applications have involved batch or semicontinuous process systems, which has limited their economic viability. The work presented here describes a fully-continuous HTC process, made possible by use of a specially modified twinscrew extruder (TSE). The reaction time within this fast HTC (FHTC) reactor system is very short (20-30 sec.) as compared to a typical batch reactor. Therefore, the concept of reaction "severity factor" is used when comparing the FHTC products with those produced in other reactor systems. While solid hydrochar produced in the FHTC system has different physical properties than hydrochar from batch reactor systems, these materials exhibit similar energy densification and pelletization behavior, when produced under comparable severity conditions. However, total hydrochar yields are considerably higher from the FHTC reactor compared to batch reactor systems. This is a consequence of the de-pressurization process in the FHTC system, whereby most water-soluble organic products are retained in the hydrochar, rather than exiting the process in a separate aqueous product stream. FHTC treatment of loblolly pine at a severity factor of 5.3 (290 °C) produced a hydrochar yield of nearly 85% (based on dry feedstock mass). Condensation of the flashed vapor products provided a relatively clean water stream, containing only 1.2% organicsprimarily furfural and acetic acid. Recovery of these organics and recycling of the condensed water would further improve the cost-effectiveness of FHTC operations.

show abstract

“…Acetic acid, glycolic acid, and ethanol were the primary components of the liquid fraction [53]. These liquid by-products are clearly in need of further treatment, such as anaerobic digestion, in order to reduce pollution and produce usable biogas [54]. CO 2 was the predominant component of the gas output, with trace amounts of CO, CH 4 , and H 2 also present [55].…”

Section: Solid Yieldmentioning

confidence: 99%

Comparative study of solid biofuels derived from sugarcane leaves with two different thermochemical conversion methods: wet and dry torrefaction

2021

View full text Add to dashboard Cite

This work describes the conversion of sugarcane leaves into biocoal with two thermal processes: wet torrefaction (subcritical water, 175-250 °C) and dry torrefaction (nitrogen atmosphere, 225-300 °C). The residence time was 30 min for both processes. The effects on physical and energy characteristics, including mass and energy yield, proximate and ultimate analyses, fiber analysis, higher heating value (HHV), structural parameters determined by Fourier-transform infrared spectroscopy, and O/C and H/C atomic ratios were used for comparisons. The results showed that increasing the reaction temperature lowers the mass yield; however, it also significantly improves the fuel ratio of torrefied samples. The highest HHV of wet and drytorrefied samples were 23.31 and 22.07 MJ/kg, respectively. The best removal of ash and sulfur content was obtained under wet torrefaction. Moreover, wet torrefaction was recommended as a suitable process for hemicellulose depolymerization. At 250 °C, the wet-torrefied sample had the highest fuel ratio (0.48) and was suited for biomass co-firing. The finding that wet-torrefied samples reached the same range of lignite at lower reaction temperatures than dry-torrefied samples was particularly intriguing. Torrefaction at the temperatures below 250 °C did not prove to have a statistically significant effect on the energy properties of the dry-torrefied samples. Therefore, wet torrefaction is a promising process in the thermochemical conversion of sugarcane leaves into solid biofuel.

show abstract

Hydrochar production by hydrothermal carbonization of faecal sludge

Cited by 31 publications

References 23 publications

Hydrothermal Carbonization of Searsia lancea Trees Grown on Mine Drainage: Processing Variables and Product Composition

Hydrothermal Carbonization of Searsia lancea Trees Grown on Mine Drainage: Processing Variables and Product Composition

Hydrothermal carbonization (HTC) of loblolly pine using a continuous, reactive twin-screw extruder

Comparative study of solid biofuels derived from sugarcane leaves with two different thermochemical conversion methods: wet and dry torrefaction

Contact Info

Product

Resources

About