Sequential Hydrothermal Processing of Sewage Sludge to Produce Low Nitrogen Biocrude

Joscha Zimmermann; Klaus Raffelt; Nicolaus Dahmen

doi:10.3390/pr9030491

Sequential Hydrothermal Processing of Sewage Sludge to Produce Low Nitrogen Biocrude

Processes ◽

10.3390/pr9030491 ◽

2021 ◽

Vol 9 (3) ◽

pp. 491

Author(s):

Joscha Zimmermann ◽

Klaus Raffelt ◽

Nicolaus Dahmen

Keyword(s):

Citric Acid ◽

Sewage Sludge ◽

Solid Material ◽

Hydrothermal Liquefaction ◽

Hydrothermal Processing ◽

Subsequent Step ◽

Pre Treatment ◽

Nitrogen Containing Compounds ◽

Low Nitrogen

A hydrothermal pre-treatment has been developed to improve sewage sludge quality or to produce low nitrogen biocrude via hydrothermal liquefaction (HTL) in a subsequent step. The mild hydrothermal pre-treatment (150 °C) step was performed with deionized water, sulfuric acid (0.5 M), or citric acid (0.5 M) to solubilize nitrogen containing compounds in the aqueous supernatant. Downstream, the residual solid material was liquefied with the addition of sodium carbonate via hydrothermal liquefaction (350 °C). The pre-treatment with citric acid transferred up to 66.7 wt. % of nitrogen into the aqueous supernatant, while 62.0 wt. % of carbon was recovered in the solid. Due to the pre-treatment lipids retained in the sewage sludge solid, which increased the favored biocrude yield up to 42.9 wt. % and the quality evaluating value H/Ceff ratio significantly to 1.48. Multi-method characterization of the resulted biocrude samples showed a lower concentration of N-heterocycles, while long-chain aliphatics and free fatty acid are increased.

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Bio-Crude Production through Aqueous Phase Recycling of Hydrothermal Liquefaction of Sewage Sludge

Energies ◽

10.3390/en13020493 ◽

2020 ◽

Vol 13 (2) ◽

pp. 493 ◽

Cited By ~ 9

Author(s):

Ayaz A. Shah ◽

Saqib S. Toor ◽

Tahir H. Seehar ◽

Rasmus S. Nielsen ◽

Asbjørn H. Nielsen ◽

...

Keyword(s):

Sewage Sludge ◽

Aqueous Phase ◽

Energy Recovery ◽

Solid Phase ◽

Hydrothermal Liquefaction ◽

Water Soluble ◽

Commercial Scale ◽

Water Soluble Compound ◽

Soluble Compound

Hydrothermal liquefaction (HTL) is a promising technology for the production of bio-crude. However, some unresolved issues still exist within HTL, which need to be resolved before its promotion on a commercial scale. The management of the aqueous phase is one of the leading challenges related to HTL. In this study, the sewage sludge has been liquefied at 350 °C with and without catalyst (K2CO3). Subsequently, aqueous phase recycling was applied to investigate the effect of recycling on bio-crude properties. Obtained results showed that the energy recovery in the form of bio-crude increased by 50% via aqueous phase recirculation, whereas nitrogen content in the bio-crude was approximately doubled after eight rounds of recycling. GCMS characterization of the aqueous phase indicated acetic acid as a major water-soluble compound, which employed as a catalyst (0.56 M), and resulted in a negligible increase in bio-crude yield. ICP-AES highlighted that the majority of the inorganics were transferred to the solid phase, while the higher accumulation of potassium and sodium was found in the aqueous phase via successive rounds of recycling.

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Extraction and Characterization of Biogenic Silica Obtained from Selected Agro-Waste in Africa

Applied Sciences ◽

10.3390/app112110363 ◽

2021 ◽

Vol 11 (21) ◽

pp. 10363

Author(s):

Clement Owusu Prempeh ◽

Steffi Formann ◽

Thomas Schliermann ◽

Hossein Beidaghy Dizaji ◽

Michael Nelles

Keyword(s):

Citric Acid ◽

Biogenic Silica ◽

Food Production ◽

Value Added ◽

Emission Spectrometry ◽

Biomass Fuels ◽

X Ray ◽

Biomass Residues ◽

Pre Treatment

Increased amounts of available biomass residues from agricultural food production are present widely around the globe. These biomass residues can find essential applications as bioenergy feedstock and precursors to produce value-added materials. This study assessed the production of biogenic silica (SiO2) from different biomass residues in Africa, including cornhusk, corncob, yam peelings, cassava peelings and coconut husks. Two processes were performed to synthesize the biogenic silica. First, the biomass fuels were chemically pre-treated with 1 and 5% w/v citric acid solutions. In the second stage, combustion at 600 °C for 2 h in a muffle oven was applied. The characterization of the untreated biomasses was conducted using Inductively coupled plasma—optical emission spectrometry (ICP-OES), thermal analysis (TG-DTA) and Fourier-transform infrared spectroscopy (FTIR). The resulting ashes from the combustion step were subjected to ICP, nitrogen physisorption, Energy dispersive X-ray spectroscopy (EDX) as well as X-Ray diffraction (XRD). ICP results revealed that the SiO2 content in the ashes varies between 42.2 to 81.5 wt.% db and 53.4 to 90.8 wt.% db after acidic pre-treatment with 1 and 5 w/v% acid, respectively. The relative reductions of K2O by the citric acid in yam peel was the lowest (79 wt.% db) in comparison to 92, 97, 98 and 97 wt.% db calculated for corncob, cassava peel, coconut husk and cornhusk, respectively. XRD analysis revealed dominant crystalline phases of arcanite (K2SO4), sylvite (KCl) and calcite (CaCO3) in ashes of the biomass fuels pre-treated with 1 w/v% citric acid due to potassium and calcium ions present. In comparison, the 5 w/v% citric acid pre-treatment produced amorphous, biogenic silica with specific surface areas of up to 91 m2/g and pore volumes up to 0.21 cm3/g. The examined biomass residues are common wastes from food production in Africa without competition in usage with focus application. Our studies have highlighted a significant end-value to these wastes by the extraction of high quality, amorphous silica, which can be considered in applications such as catalyst support, construction material, concrete and backing material.

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Screening of Actinomycetes For α-amylase Inhibitors Production

Current Enzyme Inhibition ◽

10.2174/1573408015666190110130544 ◽

2019 ◽

Vol 15 (1) ◽

pp. 41-45

Author(s):

Shivabai Chandwad ◽

Sudhakar Gutte

Keyword(s):

Inhibitory Activity ◽

Enzyme Inhibitors ◽

Spectroscopic Method ◽

Solid Material ◽

Soil Samples ◽

Assay Method ◽

Novel Drugs ◽

Pre Treatment ◽

Diabetic Treatment ◽

Amylase Inhibitors

Background:Diabetes mellitus is the most common and fastest growing disease in the world. One of the therapies to treat diabetes is the inhibition of α-amylase activity by inhibitors from microbial and plant source. Actinomycetes are potential sources of enzyme inhibitors, drugs, amino acids, vitamins etc.Objective:Our work mainly highlights the isolation of actinomycetes from soil samples of different habitats and screening of α -amylase inhibitors.Methods:Actinomycetes were isolated from soil samples of different habitats by different methods; these include a variety of pre-treatment of soil samples in combination with an appropriate supplement medium with selective antibacterial agents. Isolated actinomycetes grown in fermentation condition and metabolites were extracted with Isopropyl alcohol and concentrated to obtain solid material. The extract of each isolate was tested for α -amylase inhibition using starch Iodine plate method and DNS- spectroscopic method.Results:Total 110 actinomycetes strains were isolated from various sources. Among 110 extracts of actinomycetes, eight extracts have shown positive results for α-amylase inhibition in starch Iodine plate assay method. Extracts selected from primary results were used for the confirmation of inhibitory activity using DNS- spectroscopic method. Out of eight extracts, six extracts showed Porcine pancreatic α -amylase inhibitory activity ranging from 40-86%. The actinomycetes strains that produce α -amylase inhibitory activity are A-24, A-29, B-5, B-18, C-15 and D-24.Conclusion:These results show that actinomycetes are a potential source for α -amylase inhibitors, which may lead to valuable novel drugs for diabetic treatment.

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Characterization of cellulose biodegradation kinetics in wastewater in view of increasing a WRRF’s capacity by a pre-treatment sieve step

Proceedings of the Water Environment Federation ◽

10.2175/193864717822156055 ◽

2017 ◽

Vol 2017 (7) ◽

pp. 4255-4262

Author(s):

Elena Torfs ◽

Julie Doucet ◽

Domenico Santoro ◽

Dang Ho ◽

Medhavi Gupta ◽

...

Keyword(s):

Biodegradation Kinetics ◽

Pre Treatment

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Characterization of Phosphate Coatings: Influence of the Acid Pickling Conditions

Materials ◽

10.3390/ma14041048 ◽

2021 ◽

Vol 14 (4) ◽

pp. 1048

Author(s):

Belén Díaz ◽

X. Ramón Nóvoa ◽

Carmen Pérez ◽

Sheila Silva-Fernández

Keyword(s):

Citric Acid ◽

High Strength ◽

Acid Pickling ◽

Acid Cleaning ◽

Inorganic Acids ◽

Phosphate Coatings ◽

Acid Bath ◽

Coating Morphology ◽

Coating Weight

This research emphasizes the importance of the acid cleaning prior to the phosphate development on high-strength steel rods. It compares the phosphate properties achieved after different acid-pickling conditions. The most common inorganic acids were considered in this study. Additionally, taking into account the environmental and safety concerns of these acids, the assessment of a less harmful organic acid is presented. This study revealed significant differences in the coating morphology and chemical composition whereas no great changes were found in terms of the coating weight or porosity. Thus, hydrochloric and sulfuric acid promote the growth of a Fe-enriched phosphate layer with a less conductive character that is not developed after the pickling with phosphoric acid. The phosphate developed after the citric acid pickling is comparable to that developed after the inorganic acids although with a porosity slightly higher. The temperature of the citric acid bath is an important parameter that affects to the phosphate appearance, composition, and porosity.

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Structural Characterization of a Polysaccharide from Gastrodia elata and Its Bioactivity on Gut Microbiota

Molecules ◽

10.3390/molecules26154443 ◽

2021 ◽

Vol 26 (15) ◽

pp. 4443

Author(s):

Jiangyan Huo ◽

Min Lei ◽

Feifei Li ◽

Jinjun Hou ◽

Zijia Zhang ◽

...

Keyword(s):

Molecular Weight ◽

Citric Acid ◽

Gut Microbiota ◽

Structural Characterization ◽

Hot Water ◽

Nmr Analysis ◽

Gastrodia Elata ◽

Hot Water Extraction ◽

Hydroxybenzyl Alcohol

A novel homogeneous polysaccharide named GEP-1 was isolated and purified from Gastrodia elata (G. elata) by hot-water extraction, ethanol precipitation, and membrane separator. GEP-1, which has a molecular weight of 20.1 kDa, contains a polysaccharide framework comprised of only glucose. Methylation and NMR analysis showed that GEP-1 contained 1,3,6-linked-α-Glcp, 1,4-linked-α-Glcp, 1,4-linked-β-Glcp and 1,4,6-linked-α-Glcp. Interestingly, GEP-1 contained citric acid and repeating p-hydroxybenzyl alcohol as one branch. Furthermore, a bioactivity test showed that GEP-1 could significantly promote the growth of Akkermansia muciniphila (A. muciniphila) and Lacticaseibacillus paracasei (L.paracasei) strains. These results implied that GEP-1 might be useful for human by modulating gut microbiota.

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A Novel Pyrometallurgical Recycling Process for Lithium-Ion Batteries and Its Application to the Recycling of LCO and LFP

Metals ◽

10.3390/met11010149 ◽

2021 ◽

Vol 11 (1) ◽

pp. 149

Author(s):

Alexandra Holzer ◽

Stefan Windisch-Kern ◽

Christoph Ponak ◽

Harald Raupenstrauch

Keyword(s):

Lithium Ion Batteries ◽

Lithium Iron Phosphate ◽

Process Development ◽

Removal Rate ◽

Continuous Process ◽

Lithium Ion ◽

Iron Phosphate ◽

Recycling Process ◽

Subsequent Step ◽

Pre Treatment

The bottleneck of recycling chains for spent lithium-ion batteries (LIBs) is the recovery of valuable metals from the black matter that remains after dismantling and deactivation in pre‑treatment processes, which has to be treated in a subsequent step with pyrometallurgical and/or hydrometallurgical methods. In the course of this paper, investigations in a heating microscope were conducted to determine the high-temperature behavior of the cathode materials lithium cobalt oxide (LCO—chem., LiCoO2) and lithium iron phosphate (LFP—chem., LiFePO4) from LIB with carbon addition. For the purpose of continuous process development of a novel pyrometallurgical recycling process and adaptation of this to the requirements of the LIB material, two different reactor designs were examined. When treating LCO in an Al2O3 crucible, lithium could be removed at a rate of 76% via the gas stream, which is directly and purely available for further processing. In contrast, a removal rate of lithium of up to 97% was achieved in an MgO crucible. In addition, the basic capability of the concept for the treatment of LFP was investigated whereby a phosphorus removal rate of 64% with a simultaneous lithium removal rate of 68% was observed.

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Scenario Analysis for Selecting Sewage Sludge-to-Energy/Matter Recovery Processes

Energies ◽

10.3390/en14020276 ◽

2021 ◽

Vol 14 (2) ◽

pp. 276

Author(s):

Francesco Facchini ◽

Giovanni Mummolo ◽

Micaela Vitti

Keyword(s):

Sewage Sludge ◽

Scenario Analysis ◽

Value Chain ◽

Circular Economy ◽

Solid Material ◽

Sludge Treatment ◽

Sewage Sludges ◽

Recovery Processes ◽

Sewage Sludge Treatment ◽

New Perspective

The sewage sludges are the byproducts of the wastewater treatment. The new perspective of the wastewater value chain points to a sustainable circular economy approach, where the residual solid material produced by sewage sludge treatments is a resource rather than a waste. A sewage sludge treatment system consists of five main phases; each of them can be performed by different alternative processes. Each process is characterized by its capability to recover energy and/or matter. In this paper, a state of the art of the sludge-to-energy and sludge-to-matter treatments is provided. Then, a scenario analysis is developed to identify suitable sewage sludge treatments plants that best fit the quality and flowrate of sewage sludge to be processed while meeting technological and economic constraints. Based on the scientific literature findings and experts’ opinions, the authors identify a set of reference initial scenarios and the corresponding best treatments’ selection for configuring sewage sludge treatment plants. The scenario analysis reveals a useful reference technical framework when circular economy goals are pursued. The results achieved in all scenarios ensure the potential recovery of matter and/or energy from sewage sludges processes.

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