Purification of Biogas From Tofu Waste using Zeolite and Activated Carbon (AC) as Adsorbent

<p>Substitution of fossil fuel into alternative energy sources, such as biogas, needs to be applied to prevent various problems in the environment. Biogas purification can be an alternative technology to improve the quality of biogas, which increases the heat value by reducing CO2. Purification can be carried out by the adsorption method using solid adsorbents, for example natural zeolite and activated carbon. This study used 12 reactors from PVC, with 2 different diameters, 3 different mesh size (20,50,80) and was given both zeolite (A1-A3; B1-B3) and activated carbon (A4-A6; B4-B6). Biogas purification with the addition of zeolite has an optimal compound content in reactor A3 which has an increase in CH4 (63.63%) and decrease in CO2 composition (25.07%), which is better than other reactors. Meanwhile, the results of measurements of gas content on the addition of activated carbon showed optimal performance in reactor A6, which was increased to 76.86% for CH4 levels and CO2 levels dropped to 19.79%.</p>

Modification of Sulfonated Polyethersulfone Membrane as a Selective Adsorbent for Co(II) Ions

In the current study, a variety of sulfonated polyethersulfone (SPES)-based ion-exchange membranes were prepared and utilized as efficient and selective solid adsorbents for the detection of Co(II) ions in aquatic solutions. SPES membranes were treated with a variety of cations at a 2:1 ratio overnight. The produced materials were assessed via XRD, FT-IR, SEM, and TGA analyses. The structure of these materials was confirmed by FT-IR and XRD, which also confirmed the inclusion of Na+, NH4+, and amberlite on the SPES surface successfully. TGA analysis showed that the thermal stabilities of these materials were enhanced, and the order of stability was NH4-SPES > SPES > Na-SPES > A-SPES. Furthermore, the efficiency of these modified membranes for the determination and adsorption of a variety of metal ions was also examined by the ICP-OES analytical technique. A-SPES expressed a powerful efficiency of adsorption, and it showed an efficient as well as quantitative adsorption at pH = 6. Moreover, A-SPES displayed the highest adsorption capacity of 90.13 mg/g for Co(II) through the Langmuir adsorption isotherm.

Optimization Analysis of the Structural Design of NNBI Cryosorption Pumps

Cryosorption pumps create a vacuum by adsorbing gas at low temperature through porous solid adsorbents. The transmission probability of gas molecules and heat loads of cryosorption pumps are important factors affecting its performance. Herein, Molflow software based on the Monte Carlo principle is used to analyze the effects of the structural design of cryosorption pumps on transmission probability. The influence of structural design on radiation heat transfer is analyzed by ANSYS Steady-State Thermal software. This provides a reference for the design of a cryosorption pump to validate the prototype of a neutral beam injector for the China Engineering Fusion Experimental Reactor (CFETR).

Effective adsorption of direct Red 23 by sludge biochar-based adsorbent: adsorption kinetics, thermodynamics and mechanisms study

Using solid adsorbents, such as biochar, has been a potential practice to remove the pollutants from water bodies to render the water safer for potential usage. A potential application of sludge biochar-based adsorbent (SBA) obtained by pyrolysis with hydrothermal treatment was developed to adsorb Direct Red 23 (DR23) from wastewater. The results showed that the synthesized SBA (0.5 g/L) in the adsorption of DR23 at low concentration (&lt;20 mg/L), the DR23 were totally removed from the aqueous solution. PH had a limited effect on the adsorption, while an increase in temperature was shown to have a large enhancing effect. The adsorption kinetics were the best fit by the pseudo-second-order kinetic model, while the equilibrium data were best fitted by the Langmuir isotherm. A maximum saturation adsorption capacity of SBA of 111.98 mg/g was achieved. SBA could then be regenerated by pyrolysis, and after three cycles, SBA still retained the good adsorption ability of DR23, a removal rate exceeding 97% was achieved. Functional groups, pores, π-π bond, and electrostatic interactions are the key to the adsorption mechanisms. The results proved that SBA would be a promising material in the removal application of dyes in printing and dyeing wastewater.

Novel Systems and Membrane Technologies for Carbon Capture

Due to the global menace caused by carbon emissions from environmental, anthropogenic, and industrial processes, it has become expedient to consider the use of systems, with high trapping potentials for these carbon-based compounds. Several prior studies have considered the use of amines, activated carbon, and other solid adsorbents. Advances in carbon capture research have led to the use of ionic liquids, enzyme-based systems, microbial filters, membranes, and metal-organic frameworks in capturing CO2. Therefore, it is common knowledge that some of these systems have their lapses, which then informs the need to prioritize and optimize their synthetic routes for optimum efficiency. Some authors have also argued about the need to consider the use of hybrid systems, which offer several characteristics that in turn give synergistic effects/properties that are better compared to those of the individual components that make up the composites. For instance, some membranes are hydrophobic in nature, which makes them unsuitable for carbon capture operations; hence, it is necessary to consider modifying properties such as thermal stability, chemical stability, permeability, nature of the raw/starting material, thickness, durability, and surface area which can enhance the performance of these systems. In this review, previous and recent advances in carbon capture systems and sequestration technologies are discussed, while some recommendations and future prospects in innovative technologies are also highlighted.

MXene-supported stable adsorbents for superior CO2 capture

Polyamine-based solid adsorbents are promising candidates for CO2 capture, but long-term stability under practical regeneration conditions (100% CO2 at 120 ℃) remains the biggest hurdle. In this paper, we prepared...

INVESTIGATION OF EFFICIENCY OF NATURAL GAS DRYING BY ABSORPTION AND ADSORPTION METHODS

В статье проанализированы современные методы осушки природного газа для дальнейшей переработки его в метано-водородную смесь. Приведены результаты исследования абсорбционной и адсорбционной осушки природного газа жидкими реагентами (этиленгликолями) и твердыми адсорбентами (цеолитами и бентонитами). Показано, что природные бентонитовые глины обладают сравнительно небольшой адсорбционной активностью, их активация водными растворами Na2CО3 и H2SO4 способствует повышению адсорбционной активности, и их применение в комплексе с другими адсорбентами способствует значительному повышению процессов адсорбции. Авторами показана возможность и необходимость дальнейших исследований поиска эффективных методов активации бентонитовых глин. The article analyzes modern methods of drying natural gas for further processing it into a methane- hydrogen mixture. The results of studies of absorption and adsorption drying of natural gas with liquid reagents (ethylene glycols) and solid adsorbents (zeolites and bentonites) are presented. It is shown that natural bentonite clays have a relatively small adsorption activity, their activation with aqueous solutions of Na2CO3 and H2SO4 increases the adsorption activity, and their use in combination with other adsorbents contributes to a significant increase in the adsorption processes.The authors show the possibility and necessity of further research to find effective methods of activation of bentonite clays.