Design of saccharide based organic binder for low-grade iron ore pelletization using atomistic simulations and machine learning methods

Inorganic binders like bentonite, used for pelletization of low-grade iron ore, generate iron ore slimes with comparatively high silica and alumina content necessitating extra steps for their removal during iron making process. This demands the usage of organic binders as full or partial replacement of bentonite for iron ore pelletization. In this work, adsorption of organic binders with saccharides skeleton and -H, -OH, -CH2OH and -CH2CH2OH as polar substituents, on goethite surface was studied using density functional theory, molecular dynamics and machine learning. It was observed that adsorption energy of binders on goethite surface had weak dependence on number of hydrogen bonds between them. With this favorable interaction in mind, a library containing 64 organic binders was constructed and adsorption energy of 30 of these binders was computed using molecular dynamics, followed by training of a linear regression model, which was then used to predict the adsorption energy of rest of the binders in the library. It was found that the introduction of -CH2CH2OH at R2 position resulted in statistically significant higher adsorption energy. Binder34 and Binder44 were identified as viable candidates for both goethite and hematite ore pelletization and adsorption of their n-mers on goethite and hematite surfaces was also quantified.

Migration characteristics of chlorine during pyrolysis of municipal solid waste pellets

The migration process of chlorine during municipal solid waste (MSW) pellets pyrolysis was studied in a fixed bed reactor. Distribution and speciation changes of chlorine at different pyrolysis temperatures were determined by ion chromatography (IC) and X-ray photoelectron spectroscopy (XPS) analyses. Results showed that chlorine was mainly distributed in pyrolysis char (42.36-65.29 %) and gas (26.66-35.03 %) after MSW pellets pyrolysis. With the temperature increasing, chlorine in char and tar was enriched due to the increase of chlorine release and the decrease of product yields, with chlorine concentration increasing to 3498 ppm and 1415 ppm at 800 °C, respectively. Results of chlorine forms analysis indicated that most of the organic-Cl in MSW was released into the volatiles during pyrolysis due to the dissociation of CCl. Inorganic-Cl became the dominant form of chlorine in char after pyrolysis, with the proportion increasing from 46.69 % (raw) to 61.22 % (500 °C), which also suggested that part of organic-Cl was converted into the inorganic-Cl. Notably, the proportions of inorganic-Cl decreased at >600 °C due to the migration of inorganic. In addition, the pyrolysis release behavior of chlorine was affected by the pore structure of char, which could be inhibited by the unprosperous pores in char, especially at low temperatures (<600 °C). These findings provided a reference for the chlorine regulation of MSW pyrolytic products.

Performance of cocultivation of Chlorella vulgaris and four different fungi in biogas slurry purification and biogas upgrading by induction of strigolactone (GR24) and endophytic bacteria

This study aimed to determine the best fungi to form the algal-bacterial-fungal symbionts and identify the optimal conditions for the synchronous processing of biogas slurry and biogas. Chlorella vulgaris (C. vulgaris) and endophytic bacteria (S395-2) isolated from it and four different fungi (Ganoderma lucidum, Pleurotus ostreatus, Pleurotus geesteranus, and Pleurotus corucopiae) were used to form different symbiotic systems. Four different concentrations of GR24 were added to systems to examine the growth characteristics, the content of chlorophyll a (CHL-a), the activity of carbonic anhydrase (CA), the photosynthetic performance, the removal of nutrients, and the biogas purification performance. The results suggested that the growth rate, CA, CHL-a content, and photosynthetic performance of the C. vulgaris-endophytic bacteria-Ganoderma lucidum symbionts were higher than the other three symbiotic systems when 10^-9 M GR24 was added. The highest nutrients/CO₂ removal efficiency 78.36 ± 6.98% for chemical oxygen demand (COD), 81.63 ± 7.35% for total nitrogen (TN), 84.05 ± 7.16% for total phosphorus (TP) and 65.18 ± 6.12% for CO₂ was obtained under the above optimal conditions. This approach will provide a theoretical basis for the selection and optimization of the algal-bacterial-fungal symbionts for biogas slurry and biogas purification.

The use of steam pretreatment to enhance pellet durability and the enzyme-mediated hydrolysis of pellets to fermentable sugars

Although densified wood pellets are an attractive biomass feedstock for bioenergy and biofuels production, partly due to their ease of transport, their friability and hygroscopic nature (attraction of moisture) have proven problematic in terms of storage and handling. Pre-steaming the biomass was shown to reduce the need for size reduction, significantly increasing pellet durability by relocating the plant cell wall lignin to the fibre surface and consequently enhancing binding between particles. Although steam pretreatment has been shown to facilitate enzyme-mediated hydrolysis of biomass, by increasing cellulose accessibility, drying and pelletization partially impeded enzymatic hydrolysis. However, the incorporation of alkaline deacetylation or neutral sulfonation step prior to pre-steaming was shown to mitigate many of the negative effects of drying. Although drying and pelletization did not significantly impact the redistribution of lignin, a mild mechanical refining step was shown to further enhance the hydrolysis of the cellulose component of the pelletized biomass.

Spent mushroom substrate is capable of physisorption-chemisorption of CO2

No in-depth investigation exists on the feasibility of integrating hydrothermal carbonization (HTC) and pelletization into the process of making spent mushroom substrate (SMS), an agro-food residue from the commercial mushroom industry, into an adsorbent for post-combustion CO₂ removal. Therefore, this study analyzed if it could be possible for systematically converting low-pressure hydrochars of various SMSs into carbon-adsorbing mini-capsules. Sources of SMS included paddy straw and achiote capsule shell from Pleurotus ostreatus; eucalyptus sawdust and grassy straw from Lentinula edodes; and compost containing peat or soil as casing layer from Agaricus subrufescens. The eucalyptus sawdust and grassy straw from L. edodes outperformed the other biomaterials in adsorbing CO₂, and thus effectively encapsuled most of the gas, 8.25 mmol g^-1 and 8.10 mmol g^-1, respectively. They contained mostly hetero-atoms of O and N, requiring less unit energy to bind acidic molecules of CO₂ at the alkaline sites. The amount of unit energy the pore-filling process demanded at 25 °C was 12.65 kJ mol^-1, an attribute of self-sustaining and saleable physisorption. A negative 6.80 kJ mol^-1 free energy validated both spontaneity and exothermal of biocarbons at steady-state atmosphere. The major findings and innovations of our study support utilizing SMS as an adsorbent as a carbon capture, storage and utilization networking. Our insights into the physisorption-chemisorption on SMS are timely and relevant to help manage the re-use of SMS, and thus bring the global mushroom industry closer to environmental sustainability and toward a lower carbon society and circular economy.

Agricultural wastes co-densification: A solution for seasonal feedstock storage and anaerobic digestion performance improvement

Rice straw and pig manure pellets (RPP) and sorghum straw and pig manure pellets (SPP) were used to identify their competition as the flexible feedstock of anaerobic digestion with one-year indoor storage. The results indicated the effect of time on their characteristic was tiny during storage period, such as density, calorific value, total solid, volatile solid, ratio of carbon and nitrogen, and lignocellulosic components. Biogas yields of stored RPP and SPP were 8.8% and 26.7% lower than that of fresh pig manure (PM), and 45.4% and 56.1% higher than the sum of corresponding straw and PM digestion alone, respectively. Improvements in biodegradability were observed in co-densified biomass anaerobic digestion. Net biogas yield of RPP was 24.2% higher than that of rice straw, considering volatile matter loss and biogas yield decline during densification and storage stage. Priority of manure and supplement of co-densified biomass were proposed for feedstock supply on demand.

Effects of exogenous GR24 on biogas upgrading and nutrient removal by co-culturing microalgae with fungi under mixed LED light wavelengths

To realize the synchronous purification of raw biogas and biogas slurry, the algal-fungal symbiont pellets were cultivated by supplementing strigolactone (GR24) under different mixed LED light wavelengths. The optimal light intensity was proved to be red and blue in the ratio of 5:5. The symbionts treated with 10^-9 M GR24 had the highest growth rate and mean daily productivity. The extracellular carbonic anhydrase activity and the content of chlorophyll were also affected by GR24 concentrations and mixed light wavelengths. With the induction of 10^-9 M GR24, the maximum removal efficiency of chemical oxygen demand, total nitrogen, and total phosphorus reached 76.35 ± 6.87%, 78.77 ± 7.13% and 79.49 ± 7.43%, respectively. Besides, the CO₂ removal efficiency reached 59.32 ± 5.19% when the concentration of GR24 was 10^-7 M. This work will be beneficial for large-scale biogas slurry purification and biogas upgrading using co-cultivation of microalgae and fungi.

Removal of ammonium, phosphate, and sulfonamide antibiotics using alum sludge and low-grade charcoal pellets

Powder adsorbents perform well due to their large surface area but are difficult to use because of aggregation and channeling. In this study, pelletization of adsorbents was proposed as a solution to these operating problems. A three-component mixture was extruded into pellets and calcined under air or nitrogen conditions The pellet adsorbent removed 47, 71, 97, and 72% of ammonium, phosphate, sulfathiazole, and sulfamethoxazole, respectively. Bentonite improved greatly the strength of pellets, and a 10 wt% of bentonite was sufficient to maintain pellet shape and mass. No significant difference in individual adsorption and multi-pollutant adsorption was found. Pellet adsorbents with alum sludge, bentonite, and low-grade charcoal are low-cost materials that effectively remove multi-pollutants from the aqueous phase.

Pelletized adsorbent of alum sludge and bentonite for removal of arsenic

Powder adsorbents show an excellent adsorption capacity for arsenic(As) due to the large specific surface area. However, the performance of powder adsorbents decreases significantly by channeling in the adsorption bed, and the powder is released from the bed. Pelletization of power adsorbent can solve the problems, and bentonite was proposed as a binder to improve the strength. The adsorption capacity and lifetime of pelletized adsorbent were evaluated through a batch and column study. The addition of bentonite decreased adsorption capacity by 16% of pellet without bentonite, but improved compressive strength of adsorbent up to 3.6 times. In the batch test, the maximum adsorption capacity of pelletized adsorbent is 22.2 mg As/g, which is about 40% of powder adsorbent. However, in the column study, pellet adsorbent showed similar adsorption performance and lifetime to commercial and powder adsorbent. As a result, the pellet adsorbent using bentonite is a potential low-cost adsorbent to remove effectively As in the aqueous phase.

Removal and formation of perfluoroalkyl substances in Canadian sludge treatment systems - A mass balance approach

Poly- and per-fluoroalkyl substances (PFAS) are an emerging class of anthropogenic contaminants whose occurrence has raised concerns with the beneficial reuse of biosolids from wastewater treatment. This study evaluated the behavior of thirteen PFAS in nine Canadian sludge treatment systems including pelletization, alkaline stabilization, aerobic and anaerobic digestion processes. The composition of the overall PFAS-fluorine (ΣPFAS-F) loading in a system fed with only primary sludge was dominated by perfluorodecanoate (PFDA), whereas systems with blended primary and waste activated sludge feeds had a mix of short and long chain PFAS in raw sludges and treated biosolids. An increase in average ΣPFAS-F mass flow was observed through pelletization (19% formation) and alkaline stabilization (99% formation) processes indicating negative removal or contaminant formation. One of the two aerobic digestion systems and three of the five anaerobic digestion systems showed modest reductions (< 40% removal) in ΣPFAS-F loading. Long chain PFAS such as perfluorodecanoate (PFDA) and perfluorooctane sulfonate (PFOS) exhibited a wide variation in behavior ranging from substantial formation (> 75% formation) to modest removal (42% removal) in the surveyed systems while short chain perfluoropentanoate (PFPeA) mass flows increased through the three systems where they occurred. Overall, the contaminant mass balances revealed that there were significant changes in mass flows of the target PFAS through all kinds of sludge treatment systems. The results of this study on PFAS fate through sludge processing can inform future global PFAS risk management activities as well as sludge treatment considerations.

Post-processing of biochars to enhance plant growth responses: a review and meta-analysis

A number of processes for post-production treatment of "raw" biochars, including leaching, aeration, grinding or sieving to reduce particle size, and chemical or steam activation, have been suggested as means to enhance biochar effectiveness in agriculture, forestry, and environmental restoration. Here, I review studies on post-production processing methods and their effects on biochar physio-chemical properties and present a meta-analysis of plant growth and yield responses to post-processed vs. "raw" biochars. Data from 23 studies provide a total of 112 comparisons of responses to processed vs. unprocessed biochars, and 103 comparisons allowing assessment of effects relative to biochar particle size; additional 8 published studies involving 32 comparisons provide data on effects of biochar leachates. Overall, post-processed biochars resulted in significantly increased average plant growth responses 14% above those observed with unprocessed biochar. This overall effect was driven by plant growth responses to reduced biochar particle size, and heating/aeration treatments. The assessment of biochar effects by particle size indicates a peak at a particle size of 0.5-1.0 mm. Biochar leachate treatments showed very high heterogeneity among studies and no average growth benefit. I conclude that physiochemical post-processing of biochar offers substantial additional agronomic benefits compared to the use of unprocessed biochar. Further research on post-production treatments effects will be important for biochar utilization to maximize benefits to carbon sequestration and system productivity in agriculture, forestry, and environmental restoration.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s42773-021-00115-0.

Interaction and thermal stability of carboxymethyl cellulose on α-Fe2O3(001) surface: ReaxFF molecular dynamics simulations study

Reactive (ReaxFF) molecular dynamic simulations were performed to elucidate the nature of interaction between hematite and carboxymethyl cellulose (CMC) considering effect of moisture and temperature. Simulations showed that the presence of moisture prohibited CMC to interact directly with hematite surface. However, the moisture helps to disperse CMC along the hematite surface thus maximizing the interaction. In dry condition, it was found that the negatively charged oxygen present in the functional groups and in CMC backbone (-CH2OCH2-) take part to form chemical bond with the positively charged surface Fe. The bonding interaction with polymer back bone is a new finding from this simulation. The binding energy estimated as -56.2 kcal/mol clearly indicates chemisorption with bond length ∼2.00 Å. Upon heating up the complex in presence of atmospheric oxygen it was observed that CMC decomposed at high temperature rather than desorbed from the surface. This study clearly shows that CMC is a suitable binder for iron ore pelletization and will pave the way for more rationale design of organic binders.

Co-hydrothermal carbonization of food waste with yard waste for solid biofuel production: Hydrochar characterization and its pelletization

In this study, Co-HTC of food waste with yard waste was conducted for biofuel pellets production, and also to understand any possible synergy between two feedstock types. The calorific value of blended raw feedstock was 13.5 MJ/kg which increased to 27.6 MJ/kg after Co-HTC at 220 °C for 1 h. Energy yield and fuel ratio calculated was 45% and 0.65 respectively. Hydrochar produced demonstrated a stable combustion profile as compared to reactive combustion profile for raw samples. The blend of food and yard waste hydrochar was easily pelletized, and its pellets showed improvement in mechanical properties as compared to pellets made from mono-substrate((food waste) hydrochar. Pellets produced from the blend of food and yard waste hydrochar showed higher energy (46.4 MJ/m³) and mass density (1679 kg/m³) as compare to the pellet produced from food waste hydrochar alone. Tensile strength obtained for the blended hydrochar pellet was 2.64 MPa while same for the pellets produced from food waste hydrochar alone was 1.30 MPa. In addition to improving hydrophobicity, soften lignin from yard waste also helped in binding the food waste hydrochar particles together within the pellets matrix during heated pelletization. The results presented in the study indicated that in the presence of all favorable conditions, there is a potential that approximately 11% of the global coal consumption could be replaced by the combustion of hydrochar produced from food and yard waste globally.

Experimental data on the properties of pelletization of palm kernel shell using sago starch and sodium acetate

Pellet mixed with 5 wt% and 10 wt% of binders was tested. The pelleting process was performed using a pellet mill operated at 100 °C and at 50 MPa. The physical and chemical characteristics including hardness, high heating value and proximate analysis of pellet produces were obtained using durometer and through thermographic analysis and the results were reported in this paper. Bulk and unit density were determined according to ASABE standard. The dataset presented here are the data of palm kernel shell pellet prepared using two types of binder; (1) sago starch and (2) sodium acetate. The pelletization of palm kernel shell aimed to increase the density and strength of the palm kernel shell pellet and consequently provide better thermal degradation characteristics.

A comparative study of the physical and chemical properties of pelletized HKUST-1, ZIF-8, ZIF-67 and UiO-66 powders

The physical and chemical properties of four metal organic frameworks were examined before and after the pelletization process with pressure (tablet) and binders (pellet) for their possible use in industrial or other commercial processes. Due to the uniqueness of their crystal structure, each MOF behaved differently under the same treatment. ZIF-8 proved to be very robust in the presence of binding materials (pellet) as well as after the application of pressure (tablet). The presence of water resulted in the reversible partial loss of their crystalline morphology in the case of HKUST-1 and UiO-66 (pellet). The crystal structure of ZIF-67 was irreversibly lost in the case of the pellet but it was well maintained under pressure (tablet).

The correlation of physicochemical properties and combustion performance of hydrochar with fixed carbon index

Hydrothermal carbonization (HTC) is effective method for improving fuel properties of biomass. Investigating the relationship between the HTC severity and the physicochemical properties of hydrochar is beneficial for the large-scale utilization. The fixed carbon index (FCI) based on the hydrothermal carbonization severity is introduced to predict the physicochemical properties, pelletization and combustion performance of hydrochar. The results showed the relationship between decarbonization, dehydrogenation, deoxygenation and FCI fits exponential function. It was predicted that the hydrochar pellets with FCI = 0.15-0.45 possessed the highest bulk density (>1175 kg/m3), the lowest specific energy consumption (<16.07 kJ/kg) and the strongest radial compressive strength (>10.7Mpa). Moreover, the activation energy of hydrochar combustion in FCI (0.15-0.25) is higher (the maximum is 216 kJ/mol). The study provides based datas for predicting the fuel properties of hydrochar and obtains high quality solid fuel.

Improvement of corn stover fuel properties via hydrothermal carbonization combined with surfactant

BACKGROUND

Biomass fuel has been used to supply heat or crude materials in industry to replace the traditional fossil fuel which was one of the chief causes of climate warming. However, the large-scale utilization of biomass fuel was restricted due to the low density and high hydrophilicity of biomass, which causes the problem of transportation and storage. Therefore, pelletization of biomass was used to improve its fuel density. At present, the biomass pellet was widely used to supply heat, gas or electricity generation via gasification, which supplied clean and sustainable energy for industry. However, the energy consumption during pelletization and high hydrophilicity of pellets were still the problem for the large-scale application of biomass pellet. In this study, hydrothermal carbonization and surfactant played the role of permeation, adsorption and wetting in the solution, which was expected to improve the fuel properties and pelletization effectivity of corn stover.

RESULTS

In the article, surfactant (PEG400, Span80, SDBS) was chosen to be combined with wet torrefaction to overcome the drawbacks and improve the pelletization and combustion properties of Corn stover (CS). Especially, hydrothermal carbonization (HTC) combined with surfactant improves the yield of solid products and reduces the ash content of solid product, which was beneficial for reducing the ashes of furnace during gasification. Meanwhile, surfactant promotes the formation of pseudo-lignin and the absorption for oil with low O and high C during HTC, which improves the energy density of solid product. Furthermore, the oil in solid product plays the role of lubricant and binder, which reduces the negative effect of high energy consumption, low bulk density and weak pellets strength caused by HTC during pelletization. HTC combined with surfactant improved the hydrophobicity of pellet as well as grindability due to the modification of solid product. Moreover, surfactant combined with HTC improved the combustion characteristic of solid product such as ignition and burning temperature as well as kinetic parameters due to the bio-oil absorbed and the improvement of surface and porosity.

CONCLUSIONS

The study supplied a new, less-energy intensive and effective method to improve the pelletization and combustion properties of corn stover via hydrothermal carbonization combined with surfactant, and provided a promising alternative fuel from corn stover .

Co-pelletization of microalgae and fungi for efficient nutrient purification and biogas upgrading

The fungi-assisted microalgae pellets were cultivated to simultaneously purify biogas slurry and biogas. Results demonstrated that the optimized culture conditions for the pellets were at the shaking speed of 160 rpm, initial inoculum concentration of 1.0 × 10⁶ spores L^-1 for microalgal cells, fungi/algae ratio of 1:10, mixed medium/simulated biogas slurry ratio of 3:7 incubated at a light intensity of 200 μmol m^-2 s^-1. Moreover, biogas slurry purification and biogas upgrading were successfully achieved by co-cultivation of fungi-assisted microalgae pellets at mixed light wavelength of red:blue of 5:5. The highest removal efficiency of COD, TN, TP and CO₂ were 92.17 ± 5.28%, 89.83 ± 4.36%, 90.31 ± 4.69% and 74.26 ± 3.14%, respectively. These results will provide a theoretical foundation for large-scale biogas slurry purification and biogas upgrading using fungi-assisted microalgal pellets.

Co-hydrothermal carbonization of food waste-woody biomass blend towards biofuel pellets production

Co-hydrothermal carbonization of food waste-woody biomass blend was conducted to enhance the pelletization and hydrochar-fuel properties. The hydrochar was characterized by proximate, elemental analysis and HHVs, whilst energy consumption of pelletization, tensile strength, and combustion characteristics of hydrochar pellets were evaluated. Results showed that food waste (FW) blended with 0-50% mainly decreased H/C of hydrochar, while blend ratio from 75% to 100% mainly decreased O/C. When FW blended from 0% to 75%, the energy consumption for hydrochar palletization decreased about 12-17 J, whereas tensile strength of pellets increased about 2.4-5.5 MPa by formation of solid bridge when woody biomass (WS) ratio was increased. The hydrochar pellets from high ratio FW had decreased ignition temperature and maximum weight loss rate with wider temperature range, indicating the increased flammability and moderate combustion. These findings demonstrate that HTC of food waste-woody biomass blend was suitable for pelletization towards solid biofuel production.

The pelletization and combustion properties of torrefied Camellia shell via dry and hydrothermal torrefaction: A comparative evaluation

The torrefaction performance and properties of torrefied CS (Camellia shell) bio-char obtained via dry and hydrothermal torrefaction have been compared as well as pyrolysis and combustion properties. And making of torrefied pellets and their properties such as pellet density, Meyer hardness, and energy consumption are also investigated. The results showed that dry torrefied bio-char had higher energy and density at 220 °C and decreased significantly with temperature, while hydrothermally prepared bio-char had stable energy and mass yield with temperature. The coalification status of hydrothermally bio-char is similar to that of sub-bituminous coal. The pellet formed from dry terrified bio-char via quart tube in 220 °C with high pellet density (1048 kg/m³) and low energy consumption (17.6 KJ/kg) in spite of low the Meyer hardness (6.8 N/mm²). As for the process kinetics, the activation energy via dry torrefection with auger showed lower activation energy 43.26 KJ/mol as well as lowest ignition temperature (290 °C), compared to hydrothermal torrefaction.

Steam torrefaction of Eucalyptus globulus for producing black pellets: A pilot-scale experience

Steam torrefaction of Eucalyptus globulus was performed at temperatures between 245°C and 265°C in a 100kg/h pilot plant. Torrefied biomass was then pelletized in a 300kg/h unit and the pellets were subject to durability, density and combustion tests. The structural changes measured with FTIR were studied along with the combustion behavior of the materials. Compositional analysis showed that increasing the torrefaction temperature reduced both hemicellulose fraction and overall mass yield (MY). Furthermore, there was a linear relationship between the energy yield (EY) and mass yield (EY=[1.04-0.9(1-MY)]) for these samples. The ignition and comprehensive indexes confirmed that the stability of the torrefied biomass in a combustion environment was higher than for untreated biomass. Finally, pellets showed high durability (98%), and had an energy density (13-14GJ/m³), which is comparable to low-rank coals.

Integral recycling of municipal solid waste incineration (MSWI) bottom ash fines (0-2mm) and industrial powder wastes by cold-bonding pelletization

The cold-bonding pelletizing technique is applied in this study as an integrated method to recycle municipal solid waste incineration (MSWI) bottom ash fines (BAF, 0-2mm) and several other industrial powder wastes. Artificial lightweight aggregates are produced successfully based on the combination of these solid wastes, and the properties of these artificial aggregates are investigated and then compared with others' results reported in literature. Additionally, methods for improving the aggregate properties are suggested, and the corresponding experimental results show that increasing the BAF amount, higher binder content and addition of polypropylene fibres can improve the pellet properties (bulk density, crushing resistance, etc.). The mechanisms regarding to the improvement of the pellet properties are discussed. Furthermore, the leaching behaviours of contaminants from the produced aggregates are investigated and compared with Dutch environmental legislation. The application of these produced artificial lightweight aggregates are proposed according to their properties.

Formulation and Optimization of Lansoprazole Pellets Using Factorial Design Prepared by Extrusion-Spheronization Technique Using Carboxymethyl Tamarind Kernel Powder

BACKGROUND

In the present study, Lansoprazole pellets were prepared employing a novel excipient Carboxymethyl tamarind kernel powder (CMTKP) using extrusion-spheronization technique. Various research studies including patents have been carried out on this polymer. Pellet formulation was optimized for formulation parameters (concentration of microcrystalline cellulose, CMTKP, croscarmellose sodium and isopropyl alcohol).

METHODS

Process parameters (speed and duration of spheronization) were optimized using factorial design. The pellets were evaluated for yield, bulk and tapped density, particle size, hardness, drug content, disintegration time and drug release.

RESULTS

The optimized batch showed 93.53% yield, 0.307 kg/cm2 hardness, 2.15 mm average particle size, 292 sec disintegration time and 90.46% drug content.

CONCLUSION

Drug release of the optimized batch (2F7) and marketed formulation (LANZOL cap) was found to be 82.33% and 80.07%, respectively. An accelerated study indicated that optimized formulation was stable.

Risk assessment of heavy metals from combustion of pelletized municipal sewage sludge

Fly ash and slag are important by-products obtained from combustion of municipal sewage sludge (MSS) after pelletization. The quantitative environmental impact assessment of heavy metals in fly ash and slag, compared to MSS, were performed in accordance with bioavailability and eco-toxicity, geo-accumulation index (GAI), risk assessment code (RAC), and potential ecological risk index (PERI). The results demonstrated that not only direct but also long-term bioavailability and eco-toxicity of heavy metals in fly ash and slag decreased except direct bioavailability and eco-toxicity of Pb in fly ash. The GAI demonstrated that combustion significantly weakened (P < 0.05) the pollution levels of heavy metals. PERI indicated that all risks attributed to heavy metals were significantly lowered (P < 0.05) from 777.07 (very high risk) in MSS to 288.72 (moderate risk) and 64.55 (low risk) in fly ash and slag, respectively. In terms of the RAC, seven heavy metals had low even no risk to the environments after combustion besides As in slag. The environmental risk of heavy metals in fly ash and slag was decreased compared with MSS. However, the results of PERI showed that fly ash had a moderate risk.

The densification of bio-char: Effect of pyrolysis temperature on the qualities of pellets

The densification of bio-chars pyrolyzed at different temperatures were investigated to elucidate the effect of temperature on the properties of bio-char pellets and determine the bonding mechanism of pellets. Optimized process conditions were obtained with 128MPa compressive pressure and 35% water addition content. Results showed that both the volume density and compressive strength of bio-char pellets initially decreased and subsequently increased, while the energy consumption increased first and then decreased, with the increase of pyrolysis temperature. The moisture adsorption of bio-char pellets was noticeably lower than raw woody shavings but had elevated than the corresponding char particles. Hydrophilic functional groups, particle size and binder were the main factors that contributed to the cementation of bio-char particles at different temperatures. The result indicated that pyrolysis of woody shavings at 550-650°C and followed by densification was suitable to form bio-char pellets for application as renewable biofuels.

Improved compaction of dried tannery wastewater sludge

We quantitatively studied the advantages of improving the compaction of a powder waste by several techniques, including its pelletization. The goal is increasing the mass storage capacity in a given storage volume, and reducing the permeability of air and moisture, that may trigger exothermic spontaneous reactions in organic waste, particularly as powders. The study is based on dried sludges from a wastewater treatment, mainly from tanneries, but the indications are valid and useful for any waste in the form of powder, suitable to pelletization. Measurements of bulk density have been carried out at the industrial and laboratory scale, using different packing procedures, amenable to industrial processes. Waste as powder, pellets and their mixtures have been considered. The bulk density of waste as powder increases from 0.64 t/m(3) (simply poured) to 0.74 t/m(3) (tapped) and finally to 0.82 t/m(3) by a suitable, yet simple, packing procedure that we called dispersion filling, with a net gain of 28% in the compaction by simply modifying the collection procedure. Pelletization increases compaction by definition, but the packing of pellets is relatively coarse. Some increase in bulk density of pellets can be achieved by tapping; vibration and dispersion filling are not efficient with pellets. Mixtures of powder and pellets is the optimal packing policy. The best compaction result was achieved by controlled vibration of a 30/70 wt% mixture of powders and pellets, leading to a final bulk density of 1t/m(3), i.e. an improvement of compaction by more than 54% with respect to simply poured powders, but also larger than 35% compared to just pellets. That means increasing the mass storage capacity by a factor of 1.56. Interestingly, vibration can be the most or the least effective procedure to improve compaction of mixtures, depending on characteristics of vibration. The optimal packing (30/70 wt% powders/pellets) proved to effectively mitigate the onset of smouldering, leading to self-heating, according to standard tests, whereas the pure pelletization totally removes the self-heating hazard.

Chemical speciation, mobility and phyto-accessibility of heavy metals in fly ash and slag from combustion of pelletized municipal sewage sludge

Combustion of pelletized municipal sewage sludge (MSS) can generate pestilent byproducts: fly ash and slag. Comparisons of heavy metal sequential extraction results among MSS, fly ash and slag showed that after combustion, the bioavailable heavy metal fractions (acid soluble/exchangeable, reducible and oxidizable fractions) were mostly transformed into the very stable heavy metal fractions (residual fractions). On the other hand, the results of toxicity characteristic leaching procedure (TCLP), diethylenetriamine pentaacetic acid and HCl extraction (phyto-accessibility assessment) demonstrated that the mobility and toxicity of heavy metals were greatly reduced. The direct and long-term bioavailability and eco-toxicity of heavy metals in fly ash and slag were relieved, which implied that combustion of pelletized MSS could be a promising and completely safe disposal technology for MSS treatment.

Physicochemical and thermal characterization of nonedible oilseed residual waste as sustainable solid biofuel

The present study aims to investigate the potential of nonedible oilseed Jatropha (Jatropha curcas) and Karanja (Pongamia pinnata) defatted residual biomasses (whole seed, kernel, and hull), as solid biofuel. These biomasses showed good carbon contents (39.8-44.5%), whereas, fewer amounts were observed for sulfur (0.15-0.90%), chlorine (0.64-1.76%), nitrogen (0.9-7.2%) and ash contents (4.0-8.7%). Their volatile matter (60.23-81.6%) and calorific values (17.68-19.98 MJ/kg) were found to be comparable to coal. FT-IR and chemical analyses supported the presence of good amount of cellulose, hemicellulose and lower lignin. The pellets prepared without any additional binder, showed better compaction ratio, bulk density and compressive strength. XRF analysis carried out for determination of slagging-fouling indices, suggested their ash deposition tendencies in boilers, which can be overcome significantly with the optimization of the blower operations and control of ash depositions. Thus, overall various chemical, physical properties, thermal decomposition, surface morphological studies and their high biofuel reactivity indicated that residual biomasses of Jatropha and Karanja seeds have high potential to be utilized as a solid biofuel.

Effect of pelleting process variables on physical properties and sugar yields of ammonia fiber expansion pretreated corn stover

Pelletization process variables, including grind size (4, 6mm), die speed (40, 50, 60 Hz), and preheating (none, 70°C), were evaluated to understand their effect on pellet quality attributes and sugar yields of ammonia fiber expansion (AFEX) pretreated biomass. The bulk density of the pelletized AFEX corn stover was three to six times greater compared to untreated and AFEX-treated corn stover. Also, the durability of the pelletized AFEX corn stover was>97.5% for all pelletization conditions studied except for preheated pellets. Die speed had no effect on enzymatic hydrolysis sugar yields of pellets. Pellets produced with preheating or a larger grind size (6mm) had similar or lower sugar yields. Pellets generated with 4mm AFEX-treated corn stover, a 60Hz die speed, and no preheating resulted in pellets with similar or greater density, durability, and sugar yields compared to other pelletization conditions.

Formulation and evaluation of olanzapine matrix pellets for controlled release

BACKGROUND AND THE PURPOSE OF THE STUDY

Olanzapine is an antipsychotic used in treatment of schizophrenia. This research was carried out to design oral controlled release matrix pellets of water insoluble drug Olanzapine (OZ), using blend of Sodium Alginate (SA) and Glyceryl Palmito-Stearate (GPS) as matrix polymers, micro crystalline cellulose (MCC) as spheronizer enhancer and Sodium Lauryl Sulphate (SLS) as pore forming agent.

METHODS

OZ formulations were developed by the pelletization technique by drug loaded pellets and characterized with regard to the drug content, size distribution, Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction study (XRD). Stability studies were carried out on the optimized formulation for a period of 90 days at 40±2 °C and 75±5% relative humidity.

RESULTS AND MAJOR CONCLUSION

The drug content was in the range of 93.34-98.12%. The mean particle size of the drug loaded pellets was in the range 1024 to 1087µm. SEM photographs and calculated sphericity factor confirmed that the prepared formulations were spherical in nature. The compatibility between drug and polymers in the drug loaded pellets was confirmed by DSC and FTIR studies. Stability studies indicated that pellets are stable. XRD patterns revealed the crystalline nature of the pure OZ. Loose surface crystal study indicated that crystalline OZ is present in all formulations and more clear in formulation F5. Drug release was controlled for more than 24 hrs and mechanism of the drug release followed by Fickian diffusion. It may be concluded that F5 is an ideal formulation for once a day administration.