Stages Of Mass Loss Research Articles

Investigation on self-sustained combustion, NOx emissions, and ash characteristics of coal slime in a lab-scale fluidized bed

Incineration of coal slime in the fluidized bed boiler is an efficient means of energy recovery and environmental protection. In this study, combustion behaviors and NOx emissions of coal slime were studied using a lab-scale fluidized bed reactor. Besides, the fundamental characteristics of coal slime and its ash were explored coupled with a particle size analyzer, X-Ray Diffraction (XRD), thermogravimetric analysis (TGA), automatic specific surface, porosity analyzer, etc. It revealed that the range of 350–640 °C was the main mass loss stage with more than 92% of the total loss during combustion through the thermogravimetric analysis, guaranteeing good burnout performance. The challenges of fluidization and burnout of C-type particles accounting for 36.59% of coal slime were solved by mixing the water with coal slime to enhance its agglomeration and thermal explosion. Through the coupling of multiple operating parameters such as primary and secondary air rate, secondary air height, the oxygen content of flue gas, etc., reasonable furnace temperature and reduction zone distribution can be achieved. In addition, it was found that the migrations of most heavy metals are correlated with the proportion of fine particles in coal slime during combustion. The high content of alkaline substances of coal slime leads to a slightly slagging propensity below 900 °C due to the prevention of eutectics formation. Pore analysis implies that bottom ash and fly ash show different trends in the specific surface area and pore volume compared to the coal slime during combustion.

Fire hazard analysis of Mediterranean Genista Salzmannii: Pyrolysis and kinetic characterization

The present article aims to enhance the understanding of the solid-state thermal degradation behavior and pyrolysis kinetics of Mediterranean Genista Salzmannii Needles (GSN) to support wildland fire research. In fact, proximate, ultimate and microstructural analyses were performed to characterize forest fuel-based material. In addition, a thermogravimetric system coupled with Fourier Transform Infrared spectrometry (TG-FTIR) was used to analyze the pyrolytic behavior and the evolved gaseous products. Experiments included testing both grinded and intact (cut GSN) forms of GSN, which can provide reliable information for pyrolysis models. Slow (20 and 40 °C/min) and quasi-fast (60, 80 and 100 °C/min) heating rates were applied for the TG-FTIR experiments, in order to get close from the actual conditions of wildland fires (preheating/smoldering and flame region, respectively). Furthermore, the kinetic triplet was determined at five heating rates by means of two iso-conversional methods (Flynn–Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS)) coupled with one model fitting method (Coats Redfern). A numerical simulation was applied to adequately estimates these parameters. The analysis findings revealed that GSN has a high content of volatile and carbon. The rapid pyrolysis zone (200–600 °C) was considered as the main stage of mass loss. The cut GSN was characterized by a higher mass loss rate compared to the grinded GSN. The dominant gases released during pyrolysis were CO2, CO bond, CC bond, CH and/or CO bond, aliphatic C-H (existence of CH4) and H2O. Moreover, kinetic analysis between 180 and 650 °C revealed that the average apparent activation energy (Eα) derived from FWO and KAS of the cut GSN (206.7, 242.2 and 376.6 kJ/mol for stage 1, 2 and 3, respectively) was slightly higher than those of grinded GSN (176.9, 203.7 and 360.1 kJ/mol for stage 1, 2 and 3, respectively). The different Eα distribution was mainly due to the compact physical structure of the cut GSN. The thermal decomposition of hemicellulose (0.05 < α < 0.35) and cellulose (0.35 < α < 0.75) were best described by the random nucleation and nuclei growth mechanisms (A1/3 and A1/2, respectively). Char formation (α > 0.75) was the most complex process and was found to be consistent with the high-order reaction model. Finally, the simulated data of conversion based on the obtained kinetic triplet exhibited a good agreement with the experimental data.

Facile Characterization of Titanium Dioxide Nano- particles Prepared via Hydrothermal Method with in-situ Surface Modification

Aim: The present study is focused on the synthesis and characterization of titanium dioxide nanoparticles prepared via the hydrothermal method prepared via in-situ surface modification. &#x0D; Purpose of the study: The proposed research is based on the requirement of alternate antimicrobial therapies. The global misuse and overuse of antibiotics have given rise to the antibiotic resistance crisis. The emergence of multi-drug resistant bacteria has failed the conventional treatment methods involving antibiotics. To meet the need for efficient alternate strategies, metal oxide nanoparticles such as titanium dioxide are explored since it's known for their preventing and treating infections.&#x0D; Method: Titanium dioxide nanoparticles were successfully synthesized via hydrothermal and Surface modification of nanoparticles in dehydrated ethanol at room temperature. The obtained nanoparticles are characterized by utilizing Scanning Electron Microscope, Transmission Electron Microscope, Energy Dispersive X-ray Spectroscopy, Zeta Potential Analysis, Thermogravimetric analysis, and Fourier transform Infrared spectroscopy. &#x0D; Results: According to scanning electron microscopy and transmission electron microscopy, the morphological analysis of the synthesized titanium dioxide was spherical shaped and had an average size of 5-20nm and a size distribution of 14-20nm. The Energy Dispersive X-ray spectroscopy analysis depicted the percentage of elements in TiO2 as Ti (47.10%) and O2 (52.90%). The zeta potential for titanium dioxide was reported as -13.39, and the negative value indicated superior physical stability of nanoparticles in a suspension. The Fourier Transform Infrared spectroscopy peak at 1417.68 indicated the O-Ti-O bond in anatase morphology. While Thermogravimetric analysis showed three main stages of mass loss, there was no mass loss after 503°C, which started oxide formation.&#x0D; Conclusion: It was concluded from the present study that the synthesis of titanium dioxide is an economical process and yields excellent nanoparticles via the hydrothermal method. Characterization of the nanomaterial allowed us to determine the thermal stability, morphology, and purity of titanium dioxide nanoparticles.

Pyrolysis Decomposition Kinetics of Microcrystalline Cellulose and Curaua Fiber: Insight of Reaction Models by Using Vyazovkin Method

ABSTRACT This paper provides a full understanding of the pyrolysis mechanism of plant biomass (curaua) and cellulose – two materials that involve complex degradation stages. The chemical/physical reactions occurring in the corresponding mass loss stages are described in detail for each material. Multi-step degradation stages are identified by using Vyazovkin and Flynn–Wall–Ozawa methods and the individual contribution are discussed in terms of the chemical and physical steps involved in the process. The determination of multi-stages processes are rapidly determined applying an easy-to-use method as a first approach. We expect that this study helps to develop an understanding of the thermal degradation for future complex materials as well as to establish the initial guesses and to give an insight into the overall biomass decomposition. Final results can help to design of pyrolysis reactor and to develop new kinetic approaches.

Improving the safety of oil and gas facilities by improving flame retardants

Introduction. One of the ways to reduce the fire hazard at industrial facilities is the application of intumescent coatings. It is known that intumescent compositions are multicomponent composite materials, whose effectiveness is due to complex chemical transformations of the components of the studied flame retardant exposed to high temperatures. In this regard, the problem of studying the physicochemical processes and thermophysical characteristics of flame retardant thermal expansion materials is in demand and relevant.The purpose of this article is to analyze the thermophysical properties of water- and acrylic compound-based intumescent flame retardants to improve the safety of oil and gas facilities.To accomplish this purpose, the following objectives were attained:studying acrylic dispersion-based intumescent flame retardant materials using methods of thermal analysis;analyzing aqueous dispersion-based intumescent flame retardant materials using methods of thermal analysis;making a comparative analysis of the thermo-oxidative degradation of the studied flame retardant materials.Methods. During the study, thermogravimetric analysis, differential thermogravimetric analysis, differential scanning calorimetry, and quadrupole mass spectrometry were chosen as the main methods.Results. As a result of the studies performed using methods of synchronous thermal analysis of water- and acrylic compound-based intumescent flame retardants, the similarity of ongoing physicochemical processes was identified, including the presence of four main stages of mass loss and a high exothermic effect. This high thermal effect has proven high flammability of the studied flame retardant materials.Conclusions. Following the analysis, the authors have concluded that intumescent flame retardants, containing acrylic vinyl acetate emulsion and aqueous dispersion, begin to lose their performance characteristics, necessary for a flame retardant material, when the temperature reaches approximately ~600 °C.

Litter quality and stream physicochemical properties drive global invertebrate effects on instream litter decomposition

Plant litter is the major source of energy and nutrients in stream ecosystems and its decomposition is vital for ecosystem nutrient cycling and functioning. Invertebrates are key contributors to instream litter decomposition, yet quantification of their effects and drivers at the global scale remains lacking. Here, we systematically synthesized data comprising 2707 observations from 141 studies of stream litter decomposition to assess the contribution and drivers of invertebrates to the decomposition process across the globe. We found that (1) the presence of invertebrates enhanced instream litter decomposition globally by an average of 74%; (2) initial litter quality and stream water physicochemical properties were equal drivers of invertebrate effects on litter decomposition, while invertebrate effects on litter decomposition were not affected by climatic region, mesh size of coarse-mesh bags or mycorrhizal association of plants providing leaf litter; and (3) the contribution of invertebrates to litter decomposition was greatest during the early stages of litter mass loss (0-20%). Our results, besides quantitatively synthesizing the global pattern of invertebrate contribution to instream litter decomposition, highlight the most significant effects of invertebrates on litter decomposition at early rather than middle or late decomposition stages, providing support for the inclusion of invertebrates in global dynamic models of litter decomposition in streams to explore mechanisms and impacts of terrestrial, aquatic, and atmospheric carbon fluxes.

Theoretical error of sectional method for estimation of shape memory polyurethane foam mass loss

IntroductionMeasuring in vivo degradation for polymeric scaffolds is critical for analysis of biocompatibility. Traditionally, histology has been used to estimate mass loss in scaffolds, allowing for simultaneous evaluation of mass loss and the biologic response to the implant. Oxidatively degradable shape memory polyurethane (SMP) foams have been implemented in two vascular occlusion devices: peripheral embolization device (PED) and neurovascular embolization device (NED). This work explores the errors introduced when using histological sections to evaluate mass loss. MethodsModels of the SMP foams were created to mimic the device geometry and the tetrakaidekahedral structure of the foam pore. These models were degraded in Blender for a wide range of possible degradation amounts and the mass loss was estimated using m sections. ResultsAs the number of sections (m) used to estimate mass loss for a volume increased the sampling error decreased and beyond m = 5, the decrease in error was insignificant. NED population and sampling errors were higher than for PED scenarios. When m ≥ 5, the averaged sampling error was below 1.5% for NED and 1% for PED scenarios. Discussion/ConclusionThis study establishes a baseline sampling error for estimating randomly degraded porous scaffolds using a sectional method. Device geometry and the stage of mass loss influence the sampling error. Future studies will use non-random degradation to further investigate in vivo mass loss scenarios.

The Catalytic Effect from Alkaline Elements on the Tar-Rich Coal Pyrolysis

Tar-rich coal has been widely concerned because of its high tar yield. Two kinds of tar-rich coals were studied by Thermogravimetric-Mass spectrometer-Fourier transform infrared (TG-MS-FTIR) to obtain the pyrolysis characteristics. TG-MS-FTIR was used to study the mass loss, gaseous compounds evolution, and functional group information of tar-rich coal during pyrolysis. Mass loss is mainly caused by water release and macromolecular decomposition. The results showed that there were two stages of mass loss in the pyrolysis process. In addition, the gas release signal detected by mass spectrometry is consistent with the functional group information detected by FTIR. The main gaseous products include H2, H2O, CO, CO2, and CH4. In addition, the effect of ash content on the pyrolysis of oil-rich coal and the catalytic effect of internal minerals on coal pyrolysis are also discussed, and the thermal pyrolysis characteristics of coke-rich oil coal are put forward. The results provide a new idea for the study of pyrolysis characteristics of tar-rich coal.

Insights into thermal behavior and gas evolution characteristics of ZnCP and CdCP by TG-FTIR-GC/MS analysis

As newly developed primary explosives, zinc carbohydrazide perchlorate (ZnCP) and cadmium carbohydrazide perchlorate (CdCP) exhibit excellent performances. However, their inherent thermal characteristics and mechanisms are rarely reported, seriously hindering their further applications. Therefore, an effective thermal analysis method is necessary to better evaluate their thermal properties. Based on this, this study aimed to investigate the thermal behavior and gas evolution characteristics of ZnCP and CdCP by a novel thermogravimetric analysis, fourier transform infrared spectroscopy and gas chromatography/mass spectrometry (TG-FTIR-GC/MS) technique. Consequently, the thermogravimetric-derivative weight loss (TG-DTG) curves indicated that ZnCP and CdCP had three mass-loss stages. Kinetic parameters were calculated using Flynn-Wall-Ozawa (FWO) method. The results showed that the average activation energy of ZnCP was higher than that of CdCP. Moreover, the evolved gases were monitored online by FTIR and GC/MS. The results illustrated that the main gaseous products evolved were H2O, CO2, CO, HNCO, HCN, N2O, N2 and NH3, respectively. Finally, we also proposed a possible decomposition pathway of transition metal carbohydrazide perchlorates. In a word, this study provides sufficient evidences for studying thermal behavior and mechanisms of ZnCP and CdCP. Meanwhile, it also provides a promising thermal analysis technique for transition metal carbohydrazide perchlorates in aerospace, military and civilian applications.

Kinetic study on pyrolysis of mustard stalk using thermogravimetric analysis

Mustard stalk (MS) was investigated for its thermal degradation and kinetics using thermogravimetric analysis (TGA) at 30 to 900 °C at four different heating rates (10, 20, 30, and 40 °C.min−1). Kinetic and thermodynamic parameters were determined within the active pyrolysis zone using three non-isothermal models viz. Flynn-Wall-Ozawa; Kissinger-Akahira-Sunose; and Starink method. The results indicate that MS undergoes thermal degradation experiencing different stages of mass loss like dehydration, active pyrolysis, and passive pyrolysis as main stages. The active pyrolysis stage resulted in maximum mass loss. The average activation energy (Eα) was 173.83; 173.18 and 172.94 kJ.mol−1 determined using FWO, KAS, and Starink model, whereas the average pre-exponential factor (A) was 2.22 × 1017, 3.21 × 1017, and 2.92 × 1017 respectively. Change in enthalpy (ΔH*), Gibbs free energy (ΔG*), and entropy (ΔS*) determined were in good agreement for all three methods.

Physicochemical characterization and cosmetic applications of Passiflora nitida Kunth leaf extract

Passiflora nitida Kunth, an Amazonian Passiflora species, is little studied, although the specie’s high biological potential. Herein the plant’s pharmacognostic characterization, extract production, antioxidant potential evaluation, and application of this extract in cosmetic products is reported. The physical chemical parameters analyzed were particle size by sieve analysis, loss through drying, extractive yield, total ash content, laser granulometry, specific surface area and pore diameter (SBET), differential scanning calorimetry, thermogravimetry (TG), and wave dispersive X-Ray fluorescence (WDXRF). Total phenol/flavonoid content, LC-MS/MS analysis, DPPH and ABTS antioxidant radical assays, cytotoxicity, melanin, and tyrosinase inhibition in melanocytes test provided evidence to determine the content of the major constituent. P. nitida dry extract provided a fine powder with mesopores determined by SBET, with the TG curve showing five stages of mass loss. The antioxidant potential ranged between 23.5-31.5 mg∙mL-1 and tyrosinase inhibition between 400-654 μg∙mL-1. The species presented an antimelanogenic effect and an inhibitory activity of cellular tyrosinase (26.6%) at 25 µg/mL. The LC-MS/MS analysis of the spray-dried extract displayed the main and minor phenolic compounds constituting this sample. The results indicate that P. nitida extract has promising features for the development of cosmetic formulations.

Thermogravimetric Experiment of Urea at Constant Temperatures.

There are still many unsolved mysteries in the thermal decomposition process of urea. This paper studied the thermal decomposition process of urea at constant temperatures by the thermal gravimetric–mass spectrometry analysis method. The results show that there are three obvious stages of mass loss during the thermal decomposition process of urea, which is closely related to the temperature. When the temperature was below 160 °C, urea decomposition almost did not occur, and molten urea evaporated slowly. When the temperature was between 180 and 200 °C, the content of biuret, one of the by-products in the thermal decomposition of urea, reached a maximum. When the temperature was higher than 200 °C, the first stage of mass loss was completed quickly, and urea and biuret rapidly broke down. When the temperature was about 240 °C, there were rarely urea and biuret in residual substance; however, the content of cyanuric acid was still rising. When the temperature was higher than 280°C, there was a second stage of mass loss. In the second stage of mass loss, when the temperature was higher than 330 °C, mass decreased rapidly, which was mainly due to the decomposition of cyanuric acid. When the temperature was higher than 380 °C, the third stage of mass loss occurred. However, when the temperature was higher than 400 °C, and after continuous heating was applied for a sufficiently long time, the residual mass was reduced to almost zero eventually.

Study on thermal stability and thermal decomposition mechanism of 1-((cyano-1-methylethyl) azo) formamide

1-((Cyano-1-methylethyl) azo) formamide (CABN) is an azo initiator that has the inherent property of being decomposed at high temperatures with considerable amounts of heat generated. The thermal hazard of CABN is the main consideration in the occurrence of serious accidents. In this study, differential scanning calorimetry (DSC) was used to obtain the heat flow profiles and thermodynamic parameters of pure and impure CABN at various heating rates. The gaseous products and decomposition residues corresponding to each mass loss stage of CABN were judged by a thermogravimetry-mass spectrometer (TG-MS) and infrared spectrometer (IR). The optimal thermal decomposition reaction path of CABN was simulated and determined by the Gaussian software. The Materials Studio software was used to simulate the front-line orbits and energy gaps of CABN and its mixture to determine the influence of impurities on the thermal stability of CABN. Above results showed that the addition of the impurities caused an increased thermal decomposition risk of CABN. N2, CO, CO2, CH4N2O, 2-aminoisobutyronitrile, and isobutyronitrile were the potential products as a result of the thermal decomposition of CABN. The results of this study are expected to provide the fundamentals for safely handling CABN in preparation, production, transportation, and storage purposes.

Mechanical and microscopic properties of fly ash phosphoric acid-based geopolymer paste: A comprehensive study

Fly ash (FA) is a common industrial by-product, which is usually used as raw materials of alkali-activated geopolymer or cement additive. However, there are few studies on phosphoric acid-based geopolymer cement synthesized with FA. In this study, FA phosphoric acid-based geopolymer (FAPG) was prepared by using low-calcium FA as raw material and phosphoric acid (PA) as reactant at room temperature. Microscopic properties and geopolymerization mechanism were studied by X-ray diffraction, scanning electron microscopy, mercury intrusion porosimetry, nuclear magnetic resonance instrument and Fourier transform infrared spectroscopy. The hydration characteristics were studied by isothermal calorimetry, and the thermal properties were explored by thermogravimetric analysis. Additionally, the setting time, compressive strength, pH and electrical conductivity of FAPG were measured. The results indicated that room-temperature cured FAPG paste activated with 50% PA and 0.3 liquid–solid mass ratio (L/S) yielded a maximum compressive strength during 0–90 days of curing. As curing time increased, the strength increased for FAPG with 50% PA, but increased at first and then scarcely increased for other FAPG pastes. The compressive strength decreased with L/S increasing. As curing time increased, the pH increased and electrical conductivity decreased. The initial and final setting time, and fluidity decreased with increasing PA concentration but increased with L/S increasing. The FAPG paste was a composite structure composed of crystalline and amorphous phase. The crystalline phase was composed of Brushite, Monetite and Berlinite, and the amorphous phase was composed of -Al-O-P-, -Si-O-P- and Si-O-Al-O-P- units. The average pore diameter of FAPG ranged from 37.38 to 64.44 nm. Heating to 1200 °C, FAPG paste presented four stages of mass loss. The total hydration heat increased with PA concentration increasing.

A comprehensive evaluation on pyrolysis behavior, kinetics, and primary volatile formation pathways of rice husk for application to catalytic valorization

Catalytic fast pyrolysis is a prospective and effective route to produce value-added products from rice husk (RH). Understanding the volatile compositions and its formation pathways as well as kinetics during RH pyrolysis is crucial and fundamental to regulate the quality of the target products since catalysts interact directly with primary volatiles. In this study, two pyrolysis coupled real-time volatile monitoring techniques (TG-FTIR and Py-GC/TOF-MS) were employed to conduct comprehensive experiments for RH. The results showed that RH presented three mass loss and gaseous product evolution stages in the temperature range of 200 to 330 °C, 330 to 390 °C, and 390 to 600 °C, respectively. After speculating the formation pathways of the 24 main volatile species, it was indicated that 2,3-dihydro-benzofuran was the major product for hemicellulose, while 2-methoxy-4-(1-propenyl)-phenol was potentially a key active intermediate and very unstable during pyrolysis of lignin constituent in RH. In addition, pyrolysis of RH could be divided into two kinetic stages at cut-off point of 25% conversion. The first kinetic stage obeyed three-dimensional (D3) diffusion model and Ea was within 140–170 kJ/mol. In the secondary kinetic stage, Ea raised gradually to about 200 kJ/mol and pyrolysis reactions followed the second-order reaction model.

Thermal oxidation and heterogeneous combustion of AlH3 and Al: A comparative study

Aluminum hydride (AlH3) is currently receiving considerable attention due to its potential to replace aluminum (Al) as a new metal fuel in solid propellants. In this study, simultaneous thermogravimetric analysis and differential scanning calorimetry and a laser ignition testing system were used to investigate the thermal oxidation and combustion characteristics of AlH3 and Al. The combustion residues were then analyzed using a scanning electron microscope. Results show that the thermal oxidation processes of both AlH3 and Al contain a mass loss stage and two mass gain stages. After dehydrogenation, AlH3 exhibits a stepwise oxidation behavior that is similar to that of a similar sized Al, but has a much higher mass gain. The combustion process of Al can be divided into three stages, which correspond to the combustion of dispersed Al particles, formation of Al agglomerate and combustion of Al agglomerate, respectively. The combustion flame of AlH3 is significantly different from that of Al, but their microscopic combustion behaviors are very similar. A unique flame delamination phenomenon exists in the early stage of AlH3 flame development. AlH3 has shorter ignition delay times and a larger combustion intensity than Al. The release and combustion of hydrogen changes the combustion environment of the remaining AlH3 particles, leading to the appearance of an OH characteristic peak and increasing the production path of AlO. The morphology of combustion residues shows that the dehydrogenation of AlH3 starts from the particle surface and then gradually expands towards its interior.

Features of the Thermolysis of Li, Na, and Cd Maleates

Processes of the multi-stage decomposition of maleic acid and Li, Na, and Cd maleates in an inert atmosphere are studied via thermal analysis with synchronous analysis of the composition of the released gases. Reaction mechanisms are proposed according to the data on the mass loss stages determined via thermal analysis, gaseous products, and the final solid decomposition products. It is shown that when heated to 700°C, Li and Na carbonates incorporated into the porous carbon matrix are the final products. Above 350°C, cadmium is reduced from oxide to metal and evaporates to form a porous carbon residue as the only product of thermolysis. All carbon products are X-ray amorphous. Maleic acid decomposes completely into gaseous products in the range of 133–239°C. The maleate ion is more stable in the structure of lithium maleate than in free maleic acid, and Na and Cd cations reduce its stability.

Experimental investigation on using ionic liquid to control spontaneous combustion of lignite

Coal spontaneous combustion (CSC) has become a safety topic and has been widely debated. This study investigated the inhibiting effect on CSC by using a series of novel ionic liquids (ILs) as chemical inhibitors. The microstructure and thermokinetic characters were observed and evaluated by Fourier transform infrared spectroscopy and synchronous thermal analyser. The results indicated that ILs could destroy reactive groups on relatively active coal surfaces, such as OH, aliphatic CH, and O-containing groups. However, as aromatic CH is the main chain of coal molecule, damaging it is difficult. Different anions and cations found in ILs exhibited different abilities for destroying the groups on the surface of coal molecules. The damage was caused by the properties of anions and cations by affecting the chain length, number of chains of the anion and cations, and electronegativity strength. The changes in microstructure increased the physical adsorption capacity of inhibitive coal samples during low-temperature oxidation, which changed the characteristic temperature points. In stages of water evaporation and desorption mass loss (stage 2) and the thermal decomposition (stage 3), the apparent activation energy of coal samples increased. The kinetic characteristics of the obstructed coal sample were predicted using the Flynn–Wall–Ozawa method. The development ability was delayed and the risk level was reduced of CSC in stages 2 and 3. Therefore, ILs should be utilised at relatively low-temperatures (<230.0 °C) to control CSC.

Pyrolysis performance of peat moss: A simultaneous in-situ thermal analysis and bench-scale experimental study

Peat moss in drained peatlands has become a non-negligible source of greenhouse gases (GHG) emission. Pyrolysis is a potential technique to convert carbon-emitting peat moss to carbon-storage materials. This work investigates the behavior of peat moss pyrolysis by a combined in-situ thermal analysis and bench-scale pyrolysis experiment methodology. The simultaneous thermal analyzer, which provides the simultaneous TG/DTA analysis, was employed to reveal the thermal decomposition behavior of peat moss. The samples were heated up to 900 °C with different heating rates of 10, 15, and 20 °C/min. Thereafter, pyrolysis experiments with peak temperatures of 450, 500, 550 and 600 °C were performed in a bench-scale pyrolyzer. It was found that there are four main stages and two micro stages of mass loss during peat moss pyrolysis from room temperature to 900 °C. Also, kinetic parameters were calculated based on the results of TG and DTG by the Kissinger-Akahira-Sunose (KAS) method and the Coats-Redfern (CR) method. In the bench-scale pyrolysis experiments, four phases, i.e., char, tar, aqueous phase, and gas, were obtained and characterized. The carbon distribution and the GHG emission from peat moss pyrolysis were determined.

Valorization of Soybean Molasses as Fermentation Substrate for the Production of Microbial Exocellular β-Glucan

Soybean molasses was studied for the first time as a raw material for the fermentative production of (1 → 6)-β-d-glucan (lasiodiplodan) by Lasiodiplodia theobromae MMPI fungus. The work included characterization of soybean molasses, assessment of cultivation medium and nutritional supplementation, saccharification, fermentation of unhydrolyzed and hydrolyzed molasses, and characterization of lasiodiplodan. Crude soybean molasses showed high concentrations of monosaccharides (glucose: 13.26 g/L, galactose: 9.53 g/L and fructose: 1.99 g/L) and oligosaccharides (sucrose: 74.51 g/L, raffinose: 96.58 g/L, and stachyose: 114.02 g/L). Clarification of molasses promoted reduction of 60% of the total phenolic contents, and showed high-nutritional quality not requiring medium supplementation for fungal growth and lasiodiplodan production. Lasiodiplodia theobromae was able to assimilate the sugars from molasses (YC: 98.25%), including the oligosaccharides, thus no need for prior acid-hydrolysis for saccharification. Maximum production (1.06 g/L), yield (0.13 g/g) and volumetric productivity of lasiodiplodan (0.01 g/L h) were verified in fermentations using unhydrolyzed molasses. Both lasiodiplodan samples demonstrated high thermal stability, and presented three stages of mass-loss; the first at 150 oC, followed by two events between 250 and 525 °C. FT-IR spectra showed characteristic signs of lasiodiplodan including bands at 1060 and 1600 cm−1 corresponding to symmetrical stretching of C–O–C (characteristic group of sugars) and glucose ring vibration, respectively.