scholarly journals Achieving the Carbon-Neutral Production of Magnesia and Silica Products Using a HCl-Based Process in Serpentine Feedstock

2021 ◽  
Vol 5 (1) ◽  
pp. 19
Author(s):  
David Konlechner ◽  
Gregor Kappacher
Keyword(s):  
High Purity ◽  
Energy Demand ◽  
Raw Materials ◽  
Synthetic Fuel ◽  
Heating Source ◽  
Neutral Process ◽  
Carbon Neutral

Magnesia is mainly produced from carbonate sources (magnesite (MgCO3)), and seawater brines (MgCl2). The calcination of magnesite and the precipitation of brine using quicklime (CaO) are processes that have significant CO2 footprints, even before considering the burning of hydrocarbons required to meet the energy demand. There are also significant amounts of silica-based magnesia raw materials available worldwide, such as serpentine, dunite, and olivine. It is possible to produce synthetic MgO of high purity using a HCl-based process. HCl can be fully recycled and reused. If a carbon-neutral heating source such as electricity, synthetic fuel, or plasma is used for the pyrohydrolysis process, the result is the production of MgO via a carbon-neutral process.

Preparation of High-Purity Ultrafine α-Al2O3 by Solid-State Reaction at Room Temperature

2008 ◽  
Vol 368-372 ◽  
pp. 683-685
Author(s):  
Cheng Wei Hao ◽  
Bo Lin Wu ◽  
Ji Yan Li
Keyword(s):  
Solid State ◽  
High Purity ◽  
Solid State Reaction ◽  
Room Temperature ◽  
Raw Materials ◽  
Phase Particle ◽  
Phase Transformation Temperature ◽  
Particle Size And Morphology ◽  
Size And Morphology ◽  
Α Al2o3

Ammonium aluminium carbonate hydroxide (AACH), with a small quantity of γ-AlOOH, was synthesized through solid-state reaction at room temperature using AlCl3·6H2O and NH4HCO3 as raw materials and polyethylene glycol (PEG-10000) as the dispersant. After calcined at 1100°C for 1.5h, α-Al2O3 powders with primary particle sizes of 20~30nm were obtained. The crystal phase, particle size and morphology of the high-purity ultrafine α-Al2O3 were characterized. The results showed that a small quantity of γ-AlOOH in the AACH decomposed and formed crystal seeds. The presence of crystal seeds reduced the nucleation activation energy and therefore reduced the phase transformation temperature.

Sol-Gel Synthesis and Characterization of Ultrafine ZrSiO4 Powder

2014 ◽  
Vol 906 ◽  
pp. 66-71
Author(s):  
Zhen Quan Li ◽  
Qiang Zhen ◽  
Ya Li Wang
Keyword(s):  
Wavelength Range ◽  
High Purity ◽  
Raw Materials ◽  
Formation Rate ◽  
Sol Gel ◽  
Molar Ratio ◽  
Sem And Tem ◽  
Homogeneous Product ◽  
Sol Gel Synthesis ◽  
Calcined Temperature

High purity ZrSiO4 powder were synthesized using Si (C2H5O)4 and ZrOCl2·8H2O as raw materials by the sol-gel method, LiCl was added as mineralizer to promote crystallization of zircon. The influences of molar ratio of Zr:Si, calcined time and calcined temperature on the synthesis of ZrSiO4 powder were investigated. XRD, SEM and TEM were used to characterize the powders. It was found that when the molar ratio of Zr:Si was 1:1.2, the calcined temperature was 1600°C and the calcined time was 4h, the high purity ZrSiO4 ultrafine powder was obtained. The ZrSiO4 formation began at 1300°C and when the gel was calcined at 1600°Cfor 4 h, the formation rate of ZrSiO4 was up to 95%. SEM and TEM studies reveal a homogeneous product with particle sizes on the order of 0.1-1μm. The IR emissivity of ultrafine ZrSiO4 is 0.892 at the whole wavelength range, and that is up to 0.951 at the wavelength range of 8-14 μm.

PLZT:Nd3+ Ceramics for Photonic Applications

2012 ◽  
Vol 82 ◽  
pp. 32-37 ◽  
Author(s):  
Malgorzata Plonska ◽  
Wojciech A. Pisarski ◽  
Beata Wodecka-Dus ◽  
Lukasz Cienki
Keyword(s):  
Optical Properties ◽  
High Purity ◽  
Raw Materials ◽  
Ceramic Materials ◽  
Ceramic Powders ◽  
Pressing Method ◽  
All Ceramic ◽  
Neodymium Concentration ◽  
Sintering Conditions ◽  
Dielectric And Optical Properties

In the present work the influence of neodymium concentration (0-1at-%) and sintering conditions on 8/65/35 PLZT:Nd3+ ceramics were studied. All ceramic powders were synthesized by MOM technique from high purity raw materials (>99,9%), and subsequently sintered by free sintering and hot uniaxial pressing method. To analyze the powders and ceramics more the XRD, EDS SEM, and ferroelectric measurements were performed. Optical spectra were examined for all prepared samples, and their optical properties were analyzed using reflectance, excitation and luminescence measurements. The study gives a detailed account of the relationships between doping and preparing conditions on the basic physical and dielectric and optical properties of obtained ceramic materials.

Research on Purification Technology of Ultra-Large Flake Graphite Based on Alkali-Acid Method

2021 ◽  
Vol 1036 ◽  
pp. 104-113
Author(s):  
Hong Fei Guo ◽  
Bao Chao ◽  
Zeng Qi Zhao ◽  
Ding Nan
Keyword(s):  
Carbon Content ◽  
High Purity ◽  
Raw Materials ◽  
Acid Leaching ◽  
Flake Graphite ◽  
Fixed Carbon ◽  
Fusion Temperature ◽  
Acid Method ◽  
Fixed Carbon Content ◽  
Flake Structure

Graphite is a strategically scarce resource, and the preparation of high-purity graphite is the prerequisite and basis for the application of graphite. In order to determine the optimal purification technology parameters of an ultra-large flake graphite mine pneumatic separation ore with a fixed carbon content of 77.69%, a particle size of mainly 10 to 40 mesh, and main impurities of calcium carbonate, iron oxide and silica , two additional experiments of acid method and alkali method were added on the basis of alkali-acid method, to investigate the purification effect of different technological processes and acid leaching times on graphite raw materials, as well as to analyze the retention extent of different methods and alkali fusion temperature on graphite ultra-large flake structure. The results show that all three methods can increase the fixed carbon content of graphite to above 99%. However, compared with the acid method and the alkali method, the alkali-acid method can obtain high-purity graphite while also better protecting the graphite's ultra-large flake structure. The optimal fusion temperature is 400 °C, the optimal acid leaching time is 30% sulfuric acid thrice and 5% hydrofluoric acid once. After purification, the fixed carbon content of the product exceeds 99.97%.

scholarly journals Ethanol production using vegetable peels medium and the effective role of cellulolytic bacterial (Bacillus subtilis) pre-treatment

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 271
Author(s):  
Salman Khan Promon ◽  
Wasif Kamal ◽  
Shafkat Shamim Rahman ◽  
M. Mahboob Hossain ◽  
Naiyyum Choudhury
Keyword(s):  
Bacillus Subtilis ◽  
Ethanol Production ◽  
Energy Demand ◽  
Biochemical Characterization ◽  
Raw Materials ◽  
Maximum Yield ◽  
Clean Energy ◽  
Raw Material ◽  
Cellulolytic Bacteria ◽  
Alcohol Production

Background: The requirement of an alternative clean energy source is increasing with the elevating energy demand of modern age. Bioethanol is considered as an excellent candidate to satiate this demand.Methods:Yeast isolates were used for the production of bioethanol using cellulosic vegetable wastes as substrate. Efficient bioconversion of lignocellulosic biomass into ethanol was achieved by the action of cellulolytic bacteria (Bacillus subtilis).  After proper isolation, identification and characterization of stress tolerances (thermo-, ethanol-, pH-, osmo- & sugar tolerance), optimization of physiochemical parameters for ethanol production by the yeast isolates was assessed. Very inexpensive and easily available raw materials (vegetable peels) were used as fermentation media. Fermentation was optimized with respect to temperature, reducing sugar concentration and pH.Results:It was observed that temperatures of 30°C and pH 6.0 were optimum for fermentation with a maximum yield of ethanol. The results indicated an overall increase in yields upon the pretreatment ofBacillus subtilis; maximum ethanol percentages for isolate SC1 obtained after 48-hour incubation under pretreated substrate was 14.17% in contrast to untreated media which yielded 6.21% after the same period. Isolate with the highest ethanol production capability was identified as members of the ethanol-producingSaccharomycesspecies after stress tolerance studies and biochemical characterization using Analytical Profile Index (API) ® 20C AUX and nitrate broth test. Introduction ofBacillus subtilisincreased the alcohol production rate from the fermentation of cellulosic materials.Conclusions:The study suggested that the kitchen waste can serve as an excellent raw material in ethanol fermentation.

scholarly journals Analysis of the Plasma Recycling Process of Radioactive Waste

2019 ◽  
pp. 23-29
Author(s):  
M. Semerak ◽  
S. Lys ◽  
T. Kovalenko
Keyword(s):  
Radioactive Waste ◽  
Silicon Oxide ◽  
Raw Materials ◽  
Shaft Furnace ◽  
Plasma Heating ◽  
Plasma Processing ◽  
Radioactive Wastes ◽  
Heating Source ◽  
Long Term Storage ◽  
Plasmochemical Reactor

The possibility of the plasma processing of low-level or intermediatelevel radioactive wastes in the reactor equipped with arc plasmatrons is shown. The reactor design for the plasma processing of the radioactive wastes that allows promoting the efficiency of the plasma processing of the radioactive wastes (RAW) by the increasing of the speed and the intensity of the plasma pyrolysis is proposed. The various methods for RAW preparation, dosage and supply into the plasmochemical reactor have been investigated. The waste which is supplied to the reactor can be in various aggregate states (solid, liquid or gaseous) depending on which different kinds of preparation, dosage, and supply of RAW materials to the plasmochemical reactor are used. The solid waste must be ground for increasing of the phase separation surface. The degree of grinding of the wastes depends on their further reprocessing. The reactor allows processing of the mixed-type radioactive waste, which includes both combustible and non-combustible components. The wastes can be packed or ground up. The selected technological regimes should provide temperature from 1500 °C in the melting chamber to 250 °C in the upper part in the pyrogas exit zone to prevent the flow-out of volatile compounds of a series of radionuclides and heavy metals from the furnace and to process the waste and merge slag melt without adding of fluxes. The fused slag is a basaltiform monolith, where the content of aluminum oxide reaches 28%; silicon oxide up to 56%; sodium oxide from 2.5 to 11 %. The resulting radioactive slag is extremely resistant to the chemical influence. The pyrogas produced in the shaft furnace will have a heating value of about 5 MJ/nm3. This allows, after initial heating by plasmatron, maintaining the required temperature in the combustion chamber due to the heat released during combustion of the pyrogas, when the plasma heating source is switched off, and burning the resin and soot effectively. It is proved that the plasma technology for RAW reprocessing allows a significant reduction in waste volumes and waste placement for long-term storage with the most efficient use of storage facilities.

scholarly journals A Feasibility Study of Cellulosic Isobutanol Production—Process Simulation and Economic Analysis

Processes ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 667 ◽  
Author(s):  
Avraam Roussos ◽  
Nikiforos Misailidis ◽  
Alexandros Koulouris ◽  
Francesco Zimbardi ◽  
Demetri Petrides
Keyword(s):  
Energy Demand ◽  
Production Cost ◽  
Fossil Fuels ◽  
Raw Materials ◽  
Downstream Processing ◽  
Economic Feasibility ◽  
Unit Production Cost ◽  
Product Titer ◽  
Product Removal ◽  
The Cost

Renewable liquid biofuels for transportation have recently attracted enormous global attention due to their potential to provide a sustainable alternative to fossil fuels. In recent years, the attention has shifted from first-generation bioethanol to the production of higher molecular weight alcohols, such as biobutanol, from cellulosic feedstocks. The economic feasibility of such processes depends on several parameters such as the cost of raw materials, the fermentation performance and the energy demand for the pretreatment of biomass and downstream processing. In this work, two conceptual process scenarios for isobutanol production, one with and one without integrated product removal from the fermentor by vacuum stripping, were developed and evaluated using SuperPro Designer®. In agreement with previous publications, it was concluded that the fermentation titer is a crucial parameter for the economic competitiveness of the process as it is closely related to the energy requirements for product purification. In the first scenario where the product titer was 22 g/L, the energy demand for downstream processing was 15.8 MJ/L isobutanol and the unit production cost of isobutanol was $2.24/L. The integrated product removal by vacuum stripping implemented in the second scenario was assumed to improve the isobutanol titer to 50 g/L. In this case, the energy demand for the product removal (electricity) and downstream processing were 1.8 MJ/L isobutanol and 10 MJ/L isobutanol, respectively, and the unit production cost was reduced to $1.42/L. The uncertainty associated with the choice of modeling and economic parameters was investigated by Monte Carlo simulation sensitivity analysis.

scholarly journals A Facile and Low-Cost Method to Produce Ultrapure 99.99999% Gallium

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2308 ◽  
Author(s):  
Kefeng Pan ◽  
Ying Li ◽  
Jiawei Zhang ◽  
Qing Zhao
Keyword(s):  
Liquid Phase ◽  
High Purity ◽  
Raw Materials ◽  
Low Cost ◽  
Crystallization Rate ◽  
Segregation Coefficient ◽  
Crystal Direction ◽  
Partial Recrystallization ◽  
Removal Ratio ◽  
Critical Raw Materials

As one of the critical raw materials, very pure gallium is important for the semiconductor and photoelectric industry. Unfortunately, refining gallium to obtain a purity that exceeds 99.99999% is very difficult. In this paper, a new, facile and efficient continuous partial recrystallization method to prepare gallium of high purity is investigated. Impurity concentrations, segregation coefficients, and the purification effect were measured. The results indicated that the contaminating elements accumulated in the liquid phase along the crystal direction. The order of the removal ratio was Cu > Mg > Pb > Cr > Zn > Fe. This corresponded to the order of the experimentally obtained segregation coefficients for each impurity: Cu < Mg < Pb < Cr < Zn < Fe. The segregation coefficient of the impurities depended strongly on the crystallization rate. All observed impurity concentrations were substantially reduced, and the purity of the gallium obtained after our refinement exceeded 99.99999%.

scholarly journals Pellet Production from Woody and Non-Woody Feedstocks: A Review on Biomass Quality Evaluation

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2937 ◽  
Author(s):  
Rodolfo Picchio ◽  
Francesco Latterini ◽  
Rachele Venanzi ◽  
Walter Stefanoni ◽  
Alessandro Suardi ◽  
...  
Keyword(s):  
Energy Demand ◽  
Quality Evaluation ◽  
Current Knowledge ◽  
Raw Materials ◽  
Applied Pressure ◽  
Sustainable Use ◽  
Quality Analysis ◽  
Future Research ◽  
Pellet Quality ◽  
Pellet Production

Forest and agricultural biomass are important sources of renewable and sustainable fuel for energy production. Their increasing consumption is mainly related to the increase in global energy demand and fossil fuel prices but also to the limited availability of petroleum and the lower environmental impact of these biomass compared with other non-renewable fuels. In particular, the pellet sector has seen important developments in terms of both production and the number of installed transformation plants. In addition, pellet production from non-woody biomass is increasing in importance. One of the fundamental aspects for the correct and sustainable use of a biofuel is evaluation of its quality. This is even more important when dealing with pellet production, considering the broad spectrum of possible raw materials for pelletizing. Considering the significant number of papers dealing with pellet quality evaluation and improvement in the last decade, this review aims to give the reader an overall view of the most current knowledge about this large and interesting topic. We focused on pellets of agricultural and forestry origin and analyzed papers regarding the specific topic of pellet quality evaluation and improvement from the last five years (2016–2020). In particular, the review findings are presented in the following order: the influence of different agro-forest management systems on pellet quality; analysis of pellets from pure feedstocks (no blending or binders); the influence of blending and binders on pellet quality; and the influence of pre and post treatments. Finally, a brief discussion about actual research lacks in this topic and the possibilities for future research are presented. It is important to underline that the present review is focused on the influence of the biomass characteristics on pellet quality. The effects of the process parameters (die temperature, applied pressure, holding time) on pellet features are not considered in this review, because that is another very large topic deserving a dedicated paper.

scholarly journals Life Cycle Environmental Impacts and Energy Demand of Craft Mezcal in Mexico

2020 ◽  
Vol 12 (19) ◽  
pp. 8242
Author(s):  
Jazmín Maciel Martínez ◽  
Eduardo Baltierra-Trejo ◽  
Paul Taboada-González ◽  
Quetzalli Aguilar-Virgen ◽  
Liliana Marquez-Benavides
Keyword(s):  
Life Cycle ◽  
Environmental Impact ◽  
Life Cycle Analysis ◽  
Energy Demand ◽  
Functional Unit ◽  
Raw Materials ◽  
White Wine ◽  
Mexican Culture ◽  
Analysis Methodology ◽  
Potential Environmental Impact

Agave distillates, such as tequila and mezcal, are alcoholic spirits representative of Mexican culture. In recent years, the demand for mezcal has increased, and with it the requirement for raw materials, bringing with it a series of difficulties. The objective of this study was to evaluate the potential environmental impact and energy demand of the production of young craft mezcal from an endemic agave (Agave cupreata) found in the central and southern Pacific area of Mexico. The potential environmental impact of the mezcal studied was obtained through the life cycle analysis methodology using a midpoint approach by the ReCiPe method to calculate the potential environmental impact with SimaPro software (version 8.2.3.0., PRé Sustainability, Amersfoort, The Netherlands). The functional unit is a young craft mezcal bottle of 750 mL with 46% Vol. Alc. The stage of highest contribution to the environmental impact of mezcal was the manufacturing/processing, contributing 59.6% of them. The energy demand of the craft mezcal resulted in 163.8 MJ/bottle of 7.5 dl. The kg CO2eq in mezcal (1.7) is higher than beer (0.63) or white wine (1.01), but lower than whisky (2.25) or pisco (3.62). These findings could allow the search for alternatives for the development of sustainable production.

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