Hydrothermal upgrading of algae paste in a continuous flow reactor

Patel, Bhavish; Hellgardt, Klaus

doi:10.1016/j.biortech.2015.04.012

Cited by 57 publications

(18 citation statements)

References 30 publications

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“…However, the effect of Residence Time (RT) on inorganics concentration in the aqueous phase is unknown. Particularly, recent studies (Faeth et al, 2013, Patel and Hellgardt, 2015and Patel and Hellgardt, 2013 have suggested that HTL can be carried out at shorter RT and as a result, it is necessary to observe the partitioning of inorganics with respect to RT and to evaluate the feasibility to re-use the aqueous phase obtained at these reaction conditions. An alternative to nutrient reclamation is to digest the carbon-containing aqueous phase and recover energy via AD.…”

Section: Introductionmentioning

confidence: 99%

Hydrothermal upgrading of algae paste: Inorganics and recycling potential in the aqueous phase

Patel

Guo

Chong

et al. 2016

Science of The Total Environment

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Hydrothermal Liquefaction (HTL) for algal biomass conversion is a promising technology capable of producing high yields of biocrude as well as partitioning even higher quantity of nutrients in the aqueous phase. To assess the feasibility of utilizing the aqueous phase, HTL of Nannochloropsis sp. was carried out in the temperature range of 275 to 350°C and Residence Times (RT) ranging between 5 and 60min The effect of reaction conditions on the NO3(-),PO4(3-),SO4(2-),Cl(-),Na(+),andK(+) ions as well as Chemical Oxygen Demand (COD) and pH was investigated with view of recycling the aqueous phase for either cultivation or energy generation via Anaerobic Digestion (AD), quantified via Lifecycle Assessment (LCA). It addition to substantial nutrient partitioning at short RT, an increase in alkalinity to almost pH10 and decrease in COD at longer RT was observed. The LCA investigation found reaction conditions of 275°C/30min and 350°C/10min to be most suitable for nutrient and energy recovery but both processing routes offer environmental benefit at all reaction conditions, however recycling for cultivation has marginally better environmental credentials compared to AD.

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Section: Introductionmentioning

confidence: 99%

Hydrothermal upgrading of algae paste: Inorganics and recycling potential in the aqueous phase

Patel

Guo

Chong

et al. 2016

Science of The Total Environment

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“…The high oxygen content in the fossil bio-crude oil suggests that the fossil bio-crude oil contains more reactive compounds than coal tar (Vreugdenhil and Zwart, 2009). However, the high oxygen content results in the lower HHV, and hence the lowering of the oxygen content of the fossil bio-crude oil would be required to improve the heating value (Patel and Hellgardt, 2015).…”

Section: Resultsmentioning

confidence: 99%

Pyrolytic topping of coal-algae composite under mild inert conditions

Baloyi

Dugmore

2019

J. energy South. Afr.

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Co-processing of coal and biomass has been a focus of several research studies aimed at addressing the negative environmental attributes associated with thermal processing of coal alone, as well as improving the thermal behaviour of coal. Biomass materials are regarded as a clean, renewable source, so thermal co-processing of biomass with coal is considered an effective way to utilise coal in a sustainable manner. In this study, coal fines were blended with Scenedesmus microalgae slurry to form a coal-algae composite. Pyrolytic topping of coal-algae composite was performed at 450 ºC on a batch reactor. Parent fuels and resultant chars were analysed for their proximate properties using an Eltra thermostep TGA; a Vario EL cube Elementar was used to determine the elemental composition of the chars and oils. A simulated distillation (SimDis) method was used to determine the boiling point distribution of the produced oils. The objective of the study was to examine the effects of microalgae slurry on the pyrolytic behaviour of waste coal fines with respect to product yields, composition and quality. Results showed that the yields of volatile components from pyrolysis of coal-algae composite were high compared with those from pyrolysis of coal alone. A significant degree of deoxygenation, dehydrogenation and denitrification was observed in coal-algae char than coal char. SimDis results showed that the fossil bio-crude oil has different boiling point characteristics from coal tar. The study has shown that microalgae slurry has potential to influence the pyrolytic behaviour of waste coal under mild inert conditions.

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“…The common HTL product upgrading process might apply physical and chemical separation through application of filters, solvents, distillation, hydrogenation, cracking, esterification, and hybrid processes [27,35,38,54,71,72]. For upgrading biocrude by hydroprocessing [54,70] continuous one or two-step reactor systems with or without catalyst might be applied [34,70,[73][74][75]. However, it should be noted that in certain cases, e.g., with the use of heterogeneous catalyst, they are prone to inactivation such as coking which may lead to a serious outcome [27].…”

Section: Upgrading Of Htl Productsmentioning

confidence: 99%

“…-Simulated distillation (Sim-Dist) to find boiling point distributions. -Attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR) to study chemical bonds in extracted biocrude [23,73,86]. In addition to experimental analysis, various experimentbased predictive models were proposed to predict the characteristics of HTL products such as yield, HHV, etc.…”

Section: Feedstocks and Products Analysismentioning

confidence: 99%

Continuous Hydrothermal Liquefaction for Biofuel and Biocrude Production from Microalgal Feedstock

Lababpour¹

2018

ChemBioEng Reviews

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Microalgal biomass processing by continuous hydrothermal liquefaction (HTL) has recently received much interest and can be used to convert microalgal biomass to biocrude oil and drop‐in fuels. This review focuses on the conversion of microalgae biomass to energy production through continuous HTL processes. In addition, processes for upgrading feedstocks and biocrude are also discussed. The feed of the biomass slurry is treated according to size and moisture regulations. Following separation of the gaseous, liquid, and solid phases, the determination of elemental, physical, and chemical fragments, yield of energy, and other properties of the various products is carried out. Homogeneous or heterogeneous catalysts improve the biocrude yield and quality as does higher moisture content. The high percentage of N2 and O2 in the feedstock results in lower quality products. This may be resolved through pre‐processing of the biomass, controlling of HTL processes conditions, and post‐upgrading processing of the HTL products. The promising potential of microalgae biomass for biocrude and drop‐in fuels may have an important contribution to the world's renewable energy sources through HTL in the near future.

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Hydrothermal upgrading of algae paste in a continuous flow reactor

Cited by 57 publications

References 30 publications

Hydrothermal upgrading of algae paste: Inorganics and recycling potential in the aqueous phase

Hydrothermal upgrading of algae paste: Inorganics and recycling potential in the aqueous phase

Pyrolytic topping of coal-algae composite under mild inert conditions

Continuous Hydrothermal Liquefaction for Biofuel and Biocrude Production from Microalgal Feedstock

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