White Pellets Research Articles

Performance Analysis of Mobile Vertical Burner Using Various Types of Biomass Pellets

The high availability of biomass waste in the agricultural sector as an energy source promises sustainable energy for drying agriculture product. The low efficiency of air heating of biomass burners due to their separate design from the heat exchanger. This study aims to analyse the effect of various types of biomass pellets on the performance of a mobile vertical burner according to the air heating system efficiency and carbon emission production. This experiment used biomass waste from tea plantations as raw material for the pellets. There are three variations of biomass pellets used in this study: black pellet (A), mixed pellet (B), and white pellet (C). An analysis for the efficiency of the air heating system is conducted at six different heating process levels. The analysis showed that the mobile vertical burner machine can provide up to 1,028 CFM with a temperature of 89.9°C. The highest air heating efficiency is achieved using black pellet [80.6%], followed by mixed pellet [75.2%], and white pellet [71.4%]. Carbon monoxide gas emission production from this machine ranges from 33,6-114,8 ppm. These results indicate that black pellets have the potential to improve air heating efficiency with low gas emission production.

Assessment of the pharmaceutical quality of various brands of omeprazole capsules

Introduction: Omeprazole is a first-line therapy drug for the treatment of peptic ulcer disease. The availability of numerous generic brands in the market raises doubts about their quality. Purpose: This study aimed to assess the pharmaceutical quality of various brands of omeprazole capsules marketed in three states of southern Nigeria. Methods: Organoleptic and physicochemical properties of ten (10) generic brands of omeprazole capsules were assessed according to official and unofficial standards. Quality assurance tests such as weight uniformity, disintegration time and drug content assay were carried out. The dissolution test was done in a double dissolution medium consisting of 0.1 N HCl for 1.0 h and phosphate buffer pH 6.8 for 2.0 h. Results: Capsules tested were suitably packaged with shells containing evenly coloured white pellets. All capsules were slightly soluble in water, sparingly soluble in ethanol and readily dissolved in alkaline medium. The 10 brands tested met the British Pharmacopeia (BP) specification for weight uniformity. All capsules had drug content within 90 - 110% and an average disintegration time of less than 15 min. All brands retained the drug in acid medium for 1 hour but released more than 75% within 40 min in phosphate buffer pH 6.8. Conclusion: Brands of omeprazole capsules passed Pharmacopeia tests, exhibited similar in vitro drug release profiles and may therefore be used interchangeably for the treatment of peptic ulcer. The study also showed that almost all brands of omeprazole capsules available in Nigeria are imported, hence the need arises for regular post-clinical analysis of imported drugs. Keywords: Omeprazole, generic brands, quality, analysis

Evolution of biomass particles during pelletization process

Pulverizing is an essential unit operation in co-firing biomass with coal. Pulverizers are only compatible with pellet forms of fibrous biomass materials and crush them down to their original forming particle sizes. That is why the data on the size distribution of the particles forming a biomass pellet is crucial to achieving optimum combustion conditions. The current study determines the internal particle size distribution of pellets after wet disintegration, following ISO 17830 standard, and aims to suggest improvements to the mentioned standard based on new measured evidence. Experiments were carried out on white wood pellets (no bark) and brown wood pellets containing bark at four water temperatures: 20, 40, 60, and 95 °C, with or without stirring. The particle size distribution of the pre-pelletizer wood particles was also measured and compared with particles in the formed pellets. Ambient water temperature of 20 °C was found to be adequate for the complete disintegration of pellets, and no mechanical stirring was required. About 30% of particles in the disintegrated pellets were 0.5–1.0 mm. Pelletization changes the particle size distribution to smaller particles. The disintegrated bark pellets contained more fines than white pellets.

Effects of the addition of RPF and woody biomass on PM emissions during co-firing with coal

Two Cl-free refuse plastic and paper fuels (RPFs) produced by hydrothermal treatment with Ca(OH)2, as well as two biomasses, were co-fired with bituminous coal in a lab-scale drop tube furnace (DTF). The results indicate that the addition of biomass and RPF partially reduced the emission of SO2, which can readily cause corrosion, deposition and pollution. For the biomass co-firing, the particulate matter (PM) emissions from the black pellet (BP) series were 5.0% higher than those from the white pellet (WP) series because more sticky particles were formed with the increment of Ca-Al-Si and K-Al-Si, which absorbed alkali vapor and fine grains in the gas bulk to inhibit the PM emissions. For RPF, the major origins of sticky particles turned into Ca-Al-Si and Ca-K-Al-Si, the proportion of which was dramatically higher than that from the biomass, resulting in a stiffer suppression of PM formation. In general, the promotion of Ca from additives conversely restrained its transformation into PMs during both biomass and RPF co-firing. It can be concluded that the co-firing of RPF with bituminous coal provides an alternative approach to simultaneously control the emissions of greenhouse gases, gaseous pollutants and PM while remediating plastic waste.

Occurrence and contents of trace metals and rare earth elements on plastic pellets.

We determined the occurrence of pellets (2-5mm) and their composition in terms of trace metals and rare earth elements (REE) on nine sandy beaches of the coast of Bahia, northeastern Brazil. We compared the occurrence of pellets between oceanic and sheltered beaches and the effect of fluvial contribution on the occurrence of these microplastics. The number of pellets found was surprisingly low (i.e., max 45 pellets per m2 in an oceanic beach without fluvial river inputs). Thus, the studied beaches exhibited a very low pollution index. Concentrations of ∑REE in pellets varied between 0.36 and 1.74mgkg-1 and were ~5-fold higher in white/transparent pellets than in brown pellets. The sum of trace metals (i.e., Fe, Cd, Cu, Ni, Pb, and Zn) was also highest in the white pellets (357±12mgkg-1). Plastic pellets are a potentially important vector of REE exposition to biota.

The blessed handful of light: genesis and message of the Yezidi berat

ABSTRACT The article is devoted to berat, the sacred object of the Yezidi religion. It is a pearl-shaped white pellet made in the holy Iraqi valley of Lalish from the local dust mixed with several ingredients. For the Yezidis, berat constitutes a physical testimony of their connection with the holiest place on earth and at the same time the link with the location that, according to their cosmogonic myth, has been created by God in the heavens and then descended as the first place on earth. The objective of the article is to analyse this sacred object, describe its preparation, discuss its symbolism, and its use in Yezidi religious rituals. Such an approach allows the author to conclude the article with a hypothesis about the origin of the berat and its connection with similar Muslim and Christian objects (turba, hnana, Malka), and early Islamic legend about the creation of primordial Muhammad from a handful of light resembling a pearl. The study, which is the first monograph on berat, is based mainly on the author’s own field research in Iraq, Georgia and Turkey, Yezidi oral tradition and source texts.

Microplastics in sediments from the littoral zone of the north Tunisian coast (Mediterranean Sea)

The distribution of microplastics (MPs) was investigated in the sediments of five sampling sites from the northern Tunisian coast during June 2017. MPs were categorized according to type, colour and size. Representative MPs from the five sites were isolated for polymer identification using Fourier Transformed Infrared Spectroscopy in attenuated total reflectance mode (FTIR-ATR). Results showed that MPs were recovered, from all sediment samples, indicating for the first time, their extensive distribution in Tunisian coast. Concentrations varied from 141.20 ± 25.98 to 461.25 ± 29.74 items kg−1 dry weight. Fibres, fragments, Styrofoam®, pellets and films were the types registered in this study. With the exception of Menzel Bourguiba (MB), fibres significantly outnumbered plastic particles followed by fragments, Styrofoam®, films and pellets. The predominant colours are as follows: black > clear > white > red > blue > green for fibres, blue > white > clear > red > green > yellow > black for fragments, blue > white > black > clear for films while only white pellets and Styrofoam® were found. MPs particles ranged from 0.1 to 5 mm in length. A total of three polymer types were identified, polyethylene (PE), polypropylene (PP) and polystyrene (PS). Except for industrial pellets, the presence of MPs is likely due to the degradation of marine plastic debris accumulating in each site. This work provides original data of the presence of MPs in coastal sediments from Northern Tunisian coast.

Experiments and modeling of the torrefaction of white wood fuel pellets

The main purpose of this study was to find the optimal conditions for thermal treatment of white wood pellets. Other goals of this study were to compare torrefied and white pellets and to model the treatment process. Three types of pellets acquired from different manufacturing companies in the pellet market, representing distinct wood species, were torrefied at different temperatures of 160, 180, 200, and 220 °C, for 1, 2, and 3 h. After thermal treatment, the properties of the treated pellets were determined, including their mass loss, calorific value, ash content, and shear strength, and compared with those of the non-torrefied pellets. The calorific value increase was modeled based on the thermal degradation of hemicellulose and cellulose of the pellets and the correlation between the calorific value and mass loss. It was concluded that torrefied pellets have an increase in calorific value up to 22%, because of hemicelluloses degradation.

Analysis of pellet coating uniformity using a computer scanner

A fast method for pellet coating uniformity analysis, using a commercial computer scanner was developed. The analysis of the individual particle coating thicknesses was based on using a transparent orange colored coating layer deposited on white pellet cores. Besides the analysis of the coating thickness the information of pellet size and shape was obtained as well. Particle size dependent coating thickness and particle size independent coating variability was calculated by combining the information of coating thickness and pellet size. Decoupling coating thickness variation sources is unique to presented method. For each coating experiment around 10000 pellets were analyzed, giving results with a high statistical confidence. Proposed method was employed for the performance evaluation of classical Wurster and swirl enhanced Wurster coater operated at different gap settings and air flow rates.

Hydrothermal Carbonization of Deciduous Biomass (<i>Alnus incana</i>) and Pelletization Prospects

Thermal treatment of biomass has been attracting attention for a decade or so, especially torrefaction. However, for the past few years, wet pyrolysis, also known as hydrothermal carbonization (HTC), has been getting some attention. Hydrothermal carbonization is a thermal treatment of biomass in the presence of water in a temperature range of 180°C - 260°C. This method of treating biomass has some benefits which others do not, such as it can handle extremely wet biomass. However, treating biomass may not be enough for practical use. It may need to be transported and stored. Thus, this study explored the idea of pelletizing the HTC biomass. The mechanical strength of the HTC pellets was found to be 93%, whereas, higher heating value (HHV) (dry basis) was found to be 4% higher than the corresponding white pellets. The initial results with some limited parameters indicated that it would be possible to pelletize without binder. However, extensive research on energy balance and economic assessment would be necessary to achieve economic feasibility.

Integrating Torrefaction in the Wood Pellet Industry: A Critical Review

As an established bioenergy industry, the global wood pellet sector is ideally positioned to adopt biomass torrefaction technologies. In this review, potential benefits and challenges of integrating torrefaction within the pellet industry are reviewed and the required technological interventions to enable this integration are analyzed. It is apparent that integration would accelerate the commercialization of biomass torrefaction and benefit the wood pellet industry, torrefaction developers, as well as coal-based utilities. Torrefied pellets are expected to have distinct applications in power generation and help coal-based utilities to reduce their emission levels and comply with increasingly stringent regulations. Co-firing coal with black pellets requires little-to-no retrofit of the existing power plant and, therefore, can offer a low-cost solution. Two potential pathways, in either an upstream or downstream configuration, for retrofitting torrefaction within a white pellet facility are assessed. A succ...

Use of linear programming to ‐optimize the social, −environmental, and economic impacts of using woody feedstocks for pellet and ‐torrefied pellet production

AbstractLinear programming was used to optimize the economic, environmental, and social impacts of forest biomass used for bioenergy production. Sixteen scenarios (combinations of feedstocks, products, markets, and end use) were studied. Two feedstocks (roundwood and wood residues), two densified bioenergy products (white pellet, torrefied pellet), two markets (domestic, international), and two end uses (power generation, district heating) were evaluated. The social, environmental, and economic sustainability attributes were quantified and monetized using peer‐reviewed literature to analyze the trade‐offs. Using the economic criteria alone, the model showed that the best solution was use of 70% roundwood and 30% forest residue feedstock to produce torrefied pellets (TP) sold for district heating in the EU. The model predicts $5.4 million annual profit which is driven by the use of lower cost forest residue feedstocks, and relatively higher prices for the heating market in the EU. Inclusion of all three sustainability attributes led to a different optimized solution. TP produced from roundwood and sold to the EU market for heating was the optimum, due to the social benefits derived from increased local income to landowners and reduced shipping costs. It also had added benefits of reductions in emissions across the transportation system on an energy basis. TP consistently had higher social benefits than WP due to the need for more biomass per unit of final product, and providing more local jobs and income from feedstock production. The increasing costs of carbon emissions increased the environmental benefits of TP compared to WP or coal. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd

Moving torrefaction towards market introduction – Technical improvements and economic-environmental assessment along the overall torrefaction supply chain through the SECTOR project

The large-scale implementation of bioenergy demands solid biofuels which can be transported, stored and used efficiently. Torrefaction as a form of pyrolysis converts biomass into biofuels with according improved properties such as energy density, grindability and hydrophobicity. Several initiatives advanced this development. The first pilot-scale and demonstration plants displayed the maturity and potential of the technology.The European research project SECTOR intended to shorten the time-to-market. Within the project 158 Mg of biomass were torrefied through different technologies (rotary drum, toroidal reactor, moving bed). Their production led to process optimization of combined torrefaction-densification steps for various feedstocks through analysing changes in structure and composition. The torrefied pellets and briquettes were subjected to logistic tests (handling and storage) as well as to tests in small- and large-scale end-uses. This led to further improvement of the torrefied product meeting logistics/end-use requirements, e.g. durability, grindability, hydrophobicity, biodegradation and energy density. Durability exceeds now 95%.With these test results also international standards of advanced solid biofuels were initiated (ISO standards) as a prerequisite for global trade of torrefied material. Accompanying economic and environmental assessment identified a broad range of scenarios in which torrefied biomass perform better in these areas than traditional solid biofuels (e.g. white pellets), depending e.g. on feedstock, plant size, transport distances, integration of torrefaction in existing industries and end use. The implementation of industrial plants is the next step for the technology development. Different end user markets within and outside Europe can open opportunities here.

Microplastic resin pellets on an urban tropical beach in Colombia.

Microplastics are a problem in oceans worldwide. The current situation in Latin America is not well known. This paper reports, for the first time, the presence of microplastics on an urban Caribbean beach in Cartagena, Colombia. Pellet samples were collected from a tourist beach over a 5-month period covering both dry and rainy seasons. Pellets were classified by color and their surface analyzed by stereomicroscopy, and some were characterized by infrared spectroscopy. The most abundant pellets were white, presenting virgin surfaces, with few signs of oxidation. This is congruent with a short residence time in the marine environment and primary sources possibly located nearby. The frequency of white pellets did not change with sampling period. Surface features identified in the pellets included cracks, material loss, erosion, adhesion, granulation, color change, and glazed surfaces. Reticulated granular pellets exhibited the greatest degradation, easily generating submicroplastics. Sample composition was mostly polyethylene, followed by polypropylene. This pollution problem must be addressed by responsible authorities to avoid pellet deposition in oceans and on beaches around the world.

Fuel Properties of Woody Pellets in Domestic Markets of Korea

This study investigated physical properties and combustion gas characteristics for 8 types of wood pellets (4 domestic and 4 imported products) distributed in the domestic market. Results showed that most pellet types were first-grade pellets in the wood pellet quality standards in Korea with the exception of 3 pellet types from K company (second-grade in mechanical durability), G company (off-grade in nitrogen content) and P company (second-grade in ash percentage). Mixed pellets which contained more lignin and sap content were higher in mechanical durability (%) than that of white pellets. From the combustion gas analysis results, NOx emitted from all pellets combustion was at acceptable levels for national emission standard of the Clean Air Conservation Act except for pellets from G company. In addition, CO levels from all types of wood pellets were acceptable except for pellets from D company and domestic pellets were higher CO levels than imported pellets. These results indicate the higher CO levels in domestic pellets due to the usage of forest thinning materials including logging debris which usually had the high content of bark.

Triboelectric charging behavior of wood particles during pellet handling processes

Electrostatic charges accumulated on wood particles through triboelectrification during their transportation and handling processes can cause hazardous electrical discharge which may further trigger dust explosion. In this work, tribo-charging behavior of different kinds of wood particles was investigated by a vibrating plate charging method. It was found that reduction in the work function difference between contact bodies might contribute to the reduction of tribo-charge generation, while the reduction of electrical resistivity of wood pellets could effectively accelerate the charge dissipation. As the particle size decreases, accumulated charges increase significantly. In contrast, higher moisture content of wood particles leads to lower charge accumulation due to an accelerated charge dissipation rate. Tribo-charging behaviors of white pellets, torrefied pellet, steam treated pellets and dark pellets have also been investigated. Compared to the white pellets, they all have shown a reduction on charge accumulation to some extent. However, results suggested that all of them have nearly equivalent tribo-charge density as coal and wheat grains used as references in this study.

Formamide‐based RNA Isolation at Above ZeroTemperatures from High Starch Cassava Tubers

Cassava (Manihot esculenta) tubers are a main source of carbohydrate for a large percentage of people in the tropics. However, obtaining RNA from such high starch tubers proves problematic because gelation occurs during standard isolation procedures. In preliminary studies, formamide was used to homogenise tubers at room temperature and no gelation was observed. To develop a simple, reproducible formamide-based procedure for RNA isolation from high starch tissues without the initial use of liquid nitrogen or lyophilisation. A second objective was to determine the impact of storage of formamide homogenates at 4°C on RNA integrity. Tubers were homogenised in 100% formamide at room temperature and stored for 1, 4 or 7 days at 4°C. Homogenates were centrifuged at 14000 × g for 10 min and RNA recovered from the supernatants by isopropanol precipitation followed by dissolution in guanidinium buffer. Protein was removed by standard phenol-chloroform-isoamyl alcohol extraction and RNA recovered by isopropanol precipitation. For immediate RNA isolation, formamide homogenates can be processed without incubation at 4°C. In formamide homogenates a non-gelatinous white pellet was observed which was identified as starch by Lugol's staining. Intact RNA was observed by agarose gel electrophoresis. The RNA was successfully used in downstream RT-PCR reactions. Formamide maintained the integrity of the RNA during tissue processing at 25 ± 2°C and storage at 4°C. This room temperature formamide-based RNA isolation procedure met the criteria of simplicity, low-cost, reproducibility and addressed gelation problems associated with high starch tissues.

Changes in Cell Structure, Morphology and Activity of Streptomyces venezuelae during the Growth, Shocking and Jadomycin Production Stages

Streptomyces venezuelae have the ability to synthesize a group of novel benzoxazolophenanthridine antibiotics called jadomycin. The aim of the study was to investigate the changes in activity, cell structure and morphology of Streptomyces venezuelae while subjected to different environmental conditions during the growth, ethanol shocking, and jadomycin production stages. The activity of S. venezuelae was measured using the triphenyl tetrazolium chloride (TTC) technique while the microbial population was measured using the optical density and plate count techniques. Samples from each stage were viewed under the scanning electron microscope (SEM) and transmission electron microscope (TEM). The specific TF yield was calculated by dividing the TF yield by the number of cells. The specific TF yield remained constant at 2.44 x 10-8(μmol/CFU) during the growth period in nutrient rich medium and decreased to 0.25 x 10-8 μmol/CFU and 0.28 x 10-8 μmol/CFU during the acclimatization to the nutrient deprived-amino acid rich production medium and after shocking and then increased to 3.67 x 10-8 μmol/CFU during jadomycin production. The ethanol shock did not cause 100% of the cells to change their morphology. Remarkable changes were observed in the morphology and structure (cell diameter, vacuoles present and septation/sporulation) of S. venezuelae during the four consecutive stages (growth, acclimatization, shocking and jadomycin production). The elemental analysis provided information for verifying jadomycin B purity (97.86%). However, it was not possible to detect jadomycin B within cells. It is probable that jadomycin was produced outside the cells by extracellular enzymes as opposed to intracellularly by the uptake of isoleucine and glucose. The white pellets (cells), obtained by centrifugation of production medium, supports the idea that jadomycin B is produced outside the cells as jadomycin is highly coloured compound. It is also possible that the cells were highly efficient at excreting the secondary metabolites. These hypotheses need further investigation.

RNA Methods: RNA Extraction from Plasma

RNA Methods: RNA Extraction from Plasma

A novel HPLC method reveals that precipitation of 2′-deoxyadenosine 5′-monophosphate with lithium perchlorate/acetone leads to base depurination

A novel HPLC method reveals that precipitation of 2′-deoxyadenosine 5′-monophosphate with lithium perchlorate/acetone leads to base depurination