Effect Of Demineralization Research Articles

Effects of fixation and demineralization on histomorphology and DNA amplification of canine bone marrow.

Fixation and demineralization protocols for bone marrow (BM) across diagnostic laboratories are not standardized. How different protocols affect histomorphology and DNA amplification is incompletely understood. In this study, 2 fixatives and 3 demineralization methods were tested on canine BM samples. Twenty replicate sternal samples obtained within 24 hours of death were fixed overnight in either acetic acid-zinc-formalin (AZF) or 10% neutral-buffered formalin (NBF) and demineralized with formic acid for 12 hours. Another 53 samples were fixed in AZF and demineralized with hydrochloric acid for 1-hour, formic acid for 12 hours, or ethylenediamine tetraacetic acid (EDTA) for 24 hours. Histologic sections were scored by 4 raters as of insufficient, marginal, good, or excellent quality. In addition, DNA samples extracted from sections treated with the different fixation and demineralization methods were amplified with 3 sets of primers to conserved regions of T cell receptor gamma and immunoglobulin heavy chain genes. Amplification efficiency was graded based on review of capillary electrophoretograms. There was no significant difference in the histomorphology scores of sections fixed in AZF or NBF. However, EDTA-based demineralization yielded higher histomorphology scores than demineralization with hydrochloric or formic acid, whereas formic acid resulted in higher scores than hydrochloric acid. Demineralization with EDTA yielded DNA amplification in 29 of 36 (81%) samples, whereas demineralization with either acid yielded amplification in only 2 of 72 (3%) samples. Although slightly more time-consuming and labor-intensive, tissue demineralization with EDTA results in superior morphology and is critical for polymerase chain reaction (PCR) amplification with the DNA extraction method described in this article.

Effect of demineralization on waste tire pyrolysis char physical, chemical characteristics and combustion characteristics

Waste tire carbon black particles (CBp) are the main pyrolysis products of waste tires (WT), and CBp is difficult to use directly. This work mainly focuses on the physicochemical and combustion characteristics of demineralized CBp (DCBp) to explore the resourceful utilization of CBp resources in large quantities. This work also provides a comprehensive comparison with CBp and other carbon-based solid fuels. The results show that most of the minerals in CBp can be removed by chemical demineralization treatment (Ash content of DCBp <0.11 %). DCBp has a more developed pore structure than CBp. The deashing process affects the degree of loosening and stacking of the graphitic carbon microcrystalline structure, and the relative content of oxygen-containing functional groups in CBp to a minor extent. The deashing process leads to a decrease in the relative strength of the cross-linked stable structure and an increase in the disordered structure of carbon in CBp. The volatile fraction to fixed carbon ratio of DCBp is only 0.0467, and a large number of catalytic alkali metal elements and alkaline earth metal elements are removed in the demineralization process, which makes the early combustion of DCBp more difficult. As the combustion reaction proceeds, the internal pores of the particles are opened, and the micropores and mesopores in DCBp provide a larger surface area for the reaction. In addition, the decrease in the relative strength of the cross-linked stable structure and increases in the disordered structure of carbon can increase the intermolecular collision frequency during the combustion process, thus improving the burnout characteristics of DCBp. The above results indicate that DCBp has the potential to be used as fuel for large-scale resource utilization.

Demineralization enhances the physicochemical properties of hydrolyzed collagen powders derived from cannonball jellyfish (Stomolophus meleagris)

High mineral contents in invertebrate marine gelatin powders can adversely affect their gelling and viscoelastic properties. This study investigated the effect of demineralization via dialysis on the physicochemical properties of hydrolyzed invertebrate collagen (HIC) from cannonball jellyfish (CBJ). CBJ was partially hydrolyzed, demineralized, and pulverized to produce dialyzed gelatin (D-SDJ) powders. Partially hydrolyzed and non-dialyzed (H-SDJ) powders were used as the control. Demineralization reduced ∼99% of the minerals (mainly Na+, Ca2+, and Mg2+), 86% of the bulk density, and 90% of particle agglomeration while increasing the crude protein content by about 168%; this resulted in jellyfish gelatin powders with enhanced gelling and thickening properties. Gelatin solutions prepared with demineralized powders showed roughly double the Bloom strength than those prepared with non-demineralized powders. Additionally, demineralization increased the yield stress and apparent viscosity of the jellyfish gelatin gels without affecting the powders' amino acid profile and their isoelectric point (approximately 4.4). The gelatin powders contained all indispensable amino acids throughout processing, with tryptophan as the limiting amino acid. This study demonstrates the critical need to incorporate a demineralization step when producing HIC powders derived from CBJ. This novel raw material was successfully used to produce functional HIC powders with potential applications ranging from foods to cosmetics, biomaterials, pharmaceuticals, medicine, and more.

Elasticity and material anisotropy of lamellar cortical bone in adult bovine tibia characterized via AFM nanoindentation

The research focuses on the evaluation of the mechanical properties of osteonal cortical bone at the lamellar level. Elastic properties of the mid-diaphysis region of the bovine tibia are investigated via cantilever-based nanoindentation at the submicron length scale utilizing Atomic Force Microscopy, where the force-displacement curves are used for the elastic assessment using the Derjaguin-Muller-Toropov model to calculate indentation modulus. Variations of the modulus and the directional mechanical response of the osteonal bone at different distances from the Haversian canal are investigated. Additionally, the effects of demineralization on the indentation modulus are discussed. It was found that in the axial direction, the first and last untreated thick lamella layers show a significant indentation modulus difference compared to all other layers (4.26 ± 0.4 and 4.6 ± 0.3 GPa vs ∼3.5 GPa). On the other hand, the indentation modulus of transverse thick lamella layers shows a periodic variation between ∼3 ± 0.7 GPa and ∼4 ± 0.3 GPa from near the Haversian canal to near the interstitial bone. A periodic variation in the anisotropy ratio was found. Mineral content was quantified via energy-dispersive X-ray microanalysis at different levels of mineralization and shows a positive correlation with the indentation modulus.

Disaggregated Nano-Hydroxyapatite (DnHAP) with Inhibitory Effects on Biofilms and Demineralization

Nano-hydroxyapatite (nHAP) is considered a biocompatible agent that promotes the remineralization of dental hard tissue; however, its antibacterial efficacy is under scientific discussion. Therefore, this investigation aimed to specify the inhibitory effects of disaggregated nano-hydroxyapatite (DnHAP) on regrown biofilms and demineralization. Regrown biofilm models of single-species (Streptococcus mutans), dual-species (S. mutans and Candida albicans), and saliva-derived microcosm biofilms were established in vitro. Repeat treatment with DnHAP was applied to biofilms. The viability, lactic acid, biofilm structure, biomass, the inhibitory effect of demineralization, and virulence factors’ expression were determined. In addition, the biofilm microbial community was analyzed by 16S ribosomal RNA gene sequencing. DnHAP inhibited metabolism, lactic acid production, biomass, and water-insoluble polysaccharide production (P < 0.05) of regrown single/dual-species biofilms. Concerning the saliva-derived biofilms, samples treated with DnHAP showed lower biofilm metabolic activity without significant differences from samples treated with sterile deionized water (P > 0.05); in addition, saliva-derived biofilms treated with DnHAP exhibited lower lactic acid production (P < 0.05). The demineralization of bovine enamel was the lowest in the DnHAP group, as detected by transverse microradiography, and the lesion depth and volume decreased significantly (P < 0.05). The application of DnHAP did not change the diversity of regrown saliva-derived microcosm biofilms. In conclusion, this investigation showed that DnHAP could be a promising solution for the management of regrown biofilms to combat dental caries.

Effect of demineralization and ball milling treatments on the properties of Arundo donax and olive stone-derived biochar

The structural and physio-chemical properties of biochar are crucial to determining biochar’s quality and the adequate application. Specifically, the large porosity of biochar has been known as a favorable feature, especially for environmental remediation. In this regard, physical and chemical modifications have been used to improve biochar’s porosity which requires high-energy consumption and involves chemical agents. The objective of this study was to prepare biochar with developed porosity using mild treatments. Arundo donax and olive stone were demineralized by a water-washing method. Treated and non-treated biomasses were pyrolyzed, and part of the derived samples was subjected to wet ball milling. Samples were characterized with proximate, Fourier transform infrared, particle size, and physisorption analyses. The effect of demineralization depended on the biomass type, as ash reduction only influenced Arundo donax-derived biochar, which was attributed to the difference in initial ash content that was relatively low for olive stone. The carbonization yield decreased by 46% for the Arundo donax biomass after demineralization. Moreover, demineralization expanded the surface area and total pore volume of the Arundo donax biochar. The ball milling was effective in producing micro-sized biochar particles with a mean size ranging between 30 ± 2 µm and 42 ± 2 µm and between 13 ± 1 µm and 22 ± 2 µm for Arundo donax and olive stone without and with demineralization, respectively. Ball milling increased the surface area of non-demineralized Arundo donax by 47% and demineralized Arundo donax by 124%. Additionally, ball milling increased the surface area of non-demineralized olive stone by 65% and demineralized olive stone by 62%.Graphical abstract

Effect of demineralization on pyrolysis characteristics of LPS coal based on its chemical structure

The critical issue in developing mature Oxy-Coal Combustion Steam System technology could be the reactivity of demineralized coal which, is closely related to its chemical structure. The chemical structures of Liupanshui raw coal (LPS-R) and Liupanshui demineralized coal (LPS-D) were analyzed by FTIR and solid-state 13C-NMR. The pyrolysis experiments were carried out by TG, and the pyrolysis kinetics was analyzed by three iso-conversional methods. FTIR and 13C-NMR results suggested that the carbon structure of LPS coal was not altered greatly, while demineralization promoted the maturity of coal and the condensation degree of the aromatic ring, making the chemical structure of coal more stable. The oxygen-containing functional groups with low bond energy were reduced, and the ratio of aromatic carbon with high bond energy was increased, decreasing the pyrolysis reactivity. DTG curve-fitting results revealed that the thermal weight loss of LPS coal mainly came from the cleavage of aliphatic covalent bonds. By pyrolysis kinetics analysis of LPS-R and LPS-D, the apparent activation energies were 76 ± 4 to 463 ± 5 kJ/mol and 84 ± 2 to 758 ± 12 kJ/mol, respectively, under different conversion rates. The reactivity of the demineralized coal was inhibited to some extent, as the apparent activation energy of pyrolysis for LPS-D increased by acid treatment.

Experimental Study on Catalytic Action of Intrinsic Metals in Coal Spontaneous Combustion.

In order to study the effect of inherent metals in coal on spontaneous combustion, Hongmiao lignite and Hongqingliang long-flame coal were demineralized by hydrochloric acid, the raw coal and demineralized coal were characterized by Fourier transform infrared spectrometry, X-ray diffraction, and synchronous thermal analysis experiments, and the corresponding ash content was detected by inductively coupled plasma mass spectrometry. The results show that the effect of demineralization on the volatile matter of low-rank coal is small, and the change of crystallite structure is not significant. The removed parts are mainly water-soluble salts and soluble minerals, such as carbonates and metal ions, that are not tightly bound to the organic matter of coal structure. The removed metal elements are mainly alkali metals Na and K, alkaline earth metals Ca, Mg, Sr, and Ba, and transition metals Fe, Mn, Ti, and so forth. The temperatures corresponding to the end of weight loss, ignition, and maximum weight loss rates were elevated on the thermogravimetric curves of the demineralized coal samples. The heat absorbed by evaporation of water in coal and the heat released by oxidation and combustion of coal are decreased to different degrees, indicating that the spontaneous combustion tendency of coal after demineralization is reduced, and alkali metal, alkaline earth metals, and transition metals in coal have a catalytic effect on spontaneous combustion of coal. After adding the metal chelating agent ethylenediaminetetraacetic acid (EDTA), the apparent activation energy decreased by 33.08 and 2.42%, respectively. EDTA and the alkali metal, alkaline earth metal, or transition-metal ions formed a stable chelate in coal. The catalytic activity of metals is weakened or even lost, thereby inhibiting spontaneous combustion of coal, and verifying the catalytic effect of internal metals in coal on the spontaneous combustion of coal.

Synergistic remineralization of enamel white spot lesions using mesoporous bioactive glasses loaded with amorphous calcium phosphate.

Objectives: The purpose of this study was to create a new delivery system that can synergistically remineralize enamel white spot lesions (WSLs). Materials and methods: The delivery system (PAA-ACP@aMBG) was prepared by using aminated mesoporous bioactive glasses (aMBG) as the carrier loaded with polyacrylic-stabilized amorphous calcium phosphate (PAA-ACP). The materials were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD), inductively coupled plasma-optical emission spectrometry (ICP-OES), and so on. Forty-eight artificial WSLs enamel samples were randomized to four groups: artificial saliva (negative control, NC), casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), PAA-ACP@aMBG, and MBG. The effects of demineralization and remineralization of the enamel surface were compared by means of surface microhardness (SMH) measurements, surface color change measurements, fluorescence microscopy (FM), X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM). Results: There was no significant difference in the surface microhardness recovery rate (SMHRR) or color recovery rate (CRR) among the CPP-ACP group, PAA-ACP@aMBG group and MBG group (P>0.05), but these values were significantly higher than those in the NC group (p < 0.01). FM demonstrated that the remineralization depth in the PAA-ACP@aMBG group was significantly greater than that of the remaining three groups (p < 0.01). SEM analysis indicated that the enamel demineralization marks in the PAA-ACP@aMBG group, CPP-ACP group, and MBG group were obscured by mineral deposition. Conclusions: PAA-ACP@aMBG showed good mineralization properties, implying its great potential for clinical application.

The Effects of Demineralization on Reducing Ash Content in Corn and Soy Biomass with the Goal of Increasing Biofuel Quality

The increasing amount of residual waste presents several opportunities to use biomass as a renewable energy source. Agricultural biomass is a raw material with a high ash content, which can be a problem in any form of energy conversion. To obtain better quality biofuel, excess mineral matter must be removed. Demineralization is a simple form of mixing and washing biomass with various liquids to reduce ash content. Water, acetic acid, hydrochloric acid and nitric acid are common solvents used for this purpose. Ash is composed of different micro (Zn, Cu, Fe) and macro elements (Mg, Ca, K), which can have different consequences for the use of biomass for thermal energy. Different solvents have different effects on the individual elements, with inorganic acids having the greatest effect in demineralization processes, with a reduction in ash content of up to 80% for corn and about 99% for soybeans.

Effect of Demineralization on Gelatin Production from Grasshopper (Valanga nigricornis) as an Alternative of Halal Gelatin

Gelatin is a protein derivative product resulting from the collagen breakdown in a material. The protein content in dried grasshoppers, which are halal insects, reaches 40%. Hence, they have the potential to be produced as a substitute for non-halal gelatin. This study aims to determine the effect of various acid and base solvents and soaking time in the demineralization process on the characteristics of the gelatin. This study used a completely randomized design. The treatment of solvent types in the demineralization process used 6% HCl, 1% citric acid, 3% acetic acid, pineapple extract, and NaOH; while soaking times for treatment were 24 hours, 36 hours, and 48 hours. Each soaking time and solvent type in the demineralization process gave a significant effect on the yield value (P &lt; 0.05). Demineralization treatment using 6% HCl for 48 hours showed gelatin with the best yield than other treatments, i.e., gelatin with a moisture content of 9.93%, ash content of 1.11%, and pH 5. The characteristics of gelatin in this study are under SNI 06-3735 of 1995.

Enhancement of the production of bio-aromatics from bamboo pyrolysis: Wet torrefaction pretreatment coupled with catalytic fast pyrolysis

Light aromatics are important organic building blocks in the chemical industry which can be produced by catalytic fast pyrolysis (CFP) of biomass. In this work, wet torrefaction pretreatment (WTP) was employed to improve the quality of bamboo by synergistic effect of deoxygenation and demineralization. Then, CFP was employed to produce bio-aromatics by using zeolite (e.g. HZSM-5, HY, Al-MCM-41, and USY) as catalyst. Results showed that WTP temperature (180–260 °C) had more significant influence on the mass yields of torrefied products compared to WTP duration (30–150 min). The maximum deoxygenation rate was 49.36% at WTP conditions of 260 °C and 150 min, and the maximum demineralization rate followed the order of 96.29% (K) > 94.54% (Na) > 90.33% (Mg) > 89.22% (Ca). Among the five types of zeolite catalyst tested, HZSM-5 (25) was the best catalyst to obtain bio-aromatics due to its unique pore size and reasonable acidity. The maximum yield of aromatics (25.46 ×107 a.u./mg) was obtained at the WTP temperature of 220 °C, biomass-to-catalyst ratio of 3:1, and CFP temperature of 850 °C. Toluene was the more favored monocyclic aromatic hydrocarbon formed during CFP compared to xylene and benzene.

Effect of demineralization on pyrolysis semi-coke physical and chemical characteristics and oxy-fuel combustion characteristics

With global green and low-carbon development, carbon emission reduction is imminent. Oxy-fuel combustion technology is considered to be one of the most promising carbon capture and carbon sequestration technologies. In this work, the physical and chemical characteristics and oxy-fuel combustion characteristics of semi-coke (SC) and demineralized semi-coke (De-SC) were studied. The result shows that, compared with 20% O2/80% CO2, under 30% O2/70% CO2 atmosphere, the ignition temperature and burnout temperature of De-SC are lower, the maximum combustion rate is higher, and the main combustion process can be clearly divided into homogeneous and heterogeneous combustion stages. Compared with SC, De-SC has a less developed pore structure and lower alkali metal and volatile content, which lead to higher ignition temperatures for De-SC. The demineralization process makes the microcrystalline structure of carbon looser and increases the relative content of oxygen-containing functional groups, which are all beneficial to increasing the reactivity of De-SC. The combustion method of De-SC is mainly the particle surface reaction. Only in the atmosphere of 30% O2/70% CO2 and the heating rate of 30 °C/min the combustion mode of De-SC is on the surface and inside the particles. Under different atmospheres, compared with SC, De-SC has lower activation energy and higher pre-exponential factor. The activation and pre-exponential of De-SC have a kinetic compensation effect. The results of this paper provide a theoretical basis for an in-depth understanding of the application of De-SC under oxy-fuel conditions.

Effect of demineralization on Yimin lignite by experiments and molecular simulation techniques

The structural changes of Yimin lignite after demineralization treatment were characterized by ultimate analysis, X–ray diffraction (XRD), 13C nuclear magnetic resonance (13C NMR) and X–ray photoelectron spectroscopy (XPS) in this study. The results showed that the number of carboxylic acid, phenolic hydroxyl and ether oxygen increased after demineralization treatment, while the number of aliphatic rings decreased and the length of aliphatic chain shortened. Based on the structural parameters, the single molecular models of raw coal and demineralized coal were constructed. In order to further analyze the changes in the three–dimensional configuration and potential energy of the large–scale molecular models before and after demineralization treatment, the periodic unit cells containing five single molecular models for raw and demineralized coal were constructed and evaluated by molecular simulation techniques. The results showed that the demineralization treatment affected the stability of the cross–linked structure of Yimin lignite molecules. The demineralization treatment has a greater impact on the electrostatic energy (EE) and the bond inversion energy (EI). For single molecules, Mulliken population analysis and frontier molecular orbital analysis results showed that the chemical reactivity of Yimin lignite molecules in nucleophilic and electrophilic reactions was weakened after demineralization treatment.

Effects of demineralization and devolatilization on fast pyrolysis behaviors and product characteristics of penicillin mycelial residues

In this study, the effects of demineralization and devolatilization methods including of water washing (WW), torrefaction (TF), washing-torrefaction (WT) and hydrothermal treatment (HT) on the fast pyrolysis characteristics of penicillin mycelial residues were studied. The materials and pyrolysis products were characterized by analysis methods including of thermogravimetric (TG), gas chromatograph (GC), gas chromatography-mass spectrometry (GC-MS), x-ray diffractometer (XRD), fourier transform-infrared spectroscopy (FT-IR) and x-ray photoelectron spectroscopy (XPS), etc. The results showed WW increased the yields of tar and decreased the yields of pyrolysis biochar due to the removal of alkali and alkaline earth metals (AAEMs), while TF and HT showed opposite results due the devolatilization. XPS and FT-IR results proved that the conversion from aliphatic C-(C, H) to aromatic groups C-O-C and CO was the key point for improving the aromatization of biochar. Pretreatments increased the relative proportions of N-containing heterocyclic compounds and phenolic compounds, reduced the proportions of O-containing heterocyclic compounds in pyrolysis tar. And TF and HT could eliminate the residual antibiotic and satisfy the principle of AMR harmless disposal.

Effects of demineralization on food waste biochar for co-firing: Behaviors of alkali and alkaline earth metals and chlorine.

A significant amount of chlorine, and alkali and alkaline earth metal (AAEM) in food waste has been a major limitation to the utilization of food waste as fuel. The present study aims to investigate the behavior of chlorine and AAEM in food waste biochar during pyrolysis, demineralization, and combustion. Food waste compost (FWC) and food waste feedstock (FWF) were selected as raw materials. Three different pyrolysis temperatures from 300 to 500°C and two demineralization processes, water and CO2-saturated water, were employed. As the pyrolysis temperature increased, crystallized salt was removed through demineralization, which further increased the heating value. Effective removal of chlorine was demonstrated in both demineralization methods. During demineralization, re-adsorption of Ca on food waste biochar occurred, which was alleviated by CO2-water demineralization. The total amounts of volatilized Cl and AAEM after CO2-water demineralization were reduced by 74.79-99.38% for FWF and 98.34-99.9% for FWC compared to raw biochar. Furthermore, slagging and fouling potentials for all food waste biochar samples were estimated using various indices. The proposed behavior of Cl and AAEM in food waste biochar during various fabrication conditions provides insight into how food waste biochar can be applied in thermos-electric power plant for co-firing with coal.

Effects of demineralization on the composition of microalgae pyrolysis volatiles in py-GC–MS

This study compared the volatiles distribution in analytical scale pyrolysis (py-GC–MS) of Nannochloropsis gaditana (marine microalgae) and Scenedesmus almeriensis (freshwater microalgae) and their demineralized counterparts. The role of inorganic elements and their removal via ultrasonic treatment, water washing and (in)organic acid leaching were elucidated. Principal component analysis (PCA) and grey relational analysis were applied to analyze the pyrolysis volatiles distribution and demonstrate the influence of inorganic elements in pyrolysis, respectively. Demineralization affects (breaks down) the chemical structure of carbohydrates, followed by (to a lesser extent) proteins and lipids. Acid leaching promoted hydrolysis and suppressed the catalytic effect associated to inorganic elements in subsequent pyrolysis, compared to ultrasonic treatment and water washing. Elements like K and Na had a larger catalytic influence on microalgae pyrolysis than Ca and Mg. The composition and pyrolytic formation mechanism of major product groups at 500 °C were studied, including anhydrosugars, phenolics, furans, carboxylic acids, alcohols, aliphatic hydrocarbons, aromatic hydrocarbons, N-heterocyclic compounds, nitriles and amides. The results indicate that demineralization shows positive effects on fast pyrolysis of microalgae: (1) by disrupting the cell wall and releasing the lipids and cellular contents. Based on the py-GC–MS peak area normalized to sample mass, the relative contribution of hydrocarbons in the pyrolysis vapors increased from 25.5 % (NG: Nannochloropsis gaditana) to 32.1 % (NG-HCl: Nannochloropsis gaditana, HCl treated), and from 16.1 % (SA: Scenedesmus almeriensis) to 22.4 % (SA-HCl: Scenedesmus almeriensis, HCl treated); (2) by decreasing the relative yields in O-containing compounds resulting from the suppressed catalytic effects of alkali and alkaline earth metals (53.3 % (NG) to 37.1 % (NG-HCl), 57.5 % (SA) to 47.8 % (SA-HCl)) that would otherwise have been present in non-demineralized microalgae feedstock. The effects of demineralization on the denitrogenation of pyrolysis vapors were not that obvious. Suggestions for potential full scale applications have been proposed.

Acid demineralization effect on the sonication-assisted solvent extraction of vitrinite coal of the Powder River Basin

Solvent-extraction of economic low-grade coals has gained recent interest as a way to produce new feedstocks for the synthesis of advanced carbon materials including polymers. Herein, we report the effect of coal demineralization by hydrochloric acid treatment on the sonication-assisted extraction of subbituminous coal from the Powder River Basin in Wyoming, USA at room temperature and the analysis of the initial and residual coals by FT-IR and solid-state 13C NMR. The applied demineralization reduced ash content from 9.9% to 7% without any notable change in the coal composition or structure. Despite leaving the mineral matter in the coal, the demineralization significantly increased the extraction yield for all applied solvents, for ethylenediamine from 8.1% to 15.2%, for pyridine from 4.9% to 12.4%, and acetone from 1.1% to 4.5%.

Ash-pretreatment and hydrothermal liquefaction of filamentous algae grown on dairy wastewater

Hydrothermal liquefaction (HTL) of wastewater microalgae is constrained by the high ash content in the biomass. High ash content causes slagging, fouling, and catalyst deactivation. In this study, batch experiments for hydrothermal liquefaction (HTL) of filamentous algae were carried out in a 1.8-L autoclave reactor to measure the effects of reaction conditions and demineralization on the yields and quality of the products. Nitric acid was the most efficient demineralization acid, halving ash content (27.1 to 13.5 wt%). HTL of untreated algae showed that, as temperature increased from 310 to 350 °C, total bio-crude oil (light + heavy) yield slightly increased (25.4 to 28.0 wt%, dry ash-free). HTL of demineralized algae gave higher total bio-crude oil yields (27.2 to 43.4 wt%, dry ash-free), greater energy recovery (29.5 to 50.9%), higher char yields (22.1 to 32.5 wt%, dry ash-free), and decreased energy consumption ratios (from 1.0 to 0.6) compared to HTL of untreated algae. Fourier transform infrared spectroscopy (FT-IR) of the feedstocks revealed slightly higher carbohydrate content in the acid-treated biomass compared to the untreated biomass. Both FT-IR and FT ion cyclotron resonance mass spectroscopy of the bio-crude oils showed no significant difference in the functional groups and heteroatoms in the hexane-soluble bio-crude oil derived from untreated and acid-treated biomass. These results demonstrate that demineralization of wastewater algae is relevant for improving the feasibility of algal wastewater-treatment-to-biofuel systems.

Effect of Demineralization on Pyrolysis Characteristics of LPS Coal Based on its Chemical Structure

Effect of Demineralization on Pyrolysis Characteristics of LPS Coal Based on its Chemical Structure