Gases

3 pages, 185 KiB

Open AccessEditorial

Helium: Sources, Applications, Supply, and Demand

by

Juan Sebastian Serra Leal

,

Jimena Incer-Valverde

and

Tatiana Morosuk

Gases 2023, 3(4), 181-183; https://doi.org/10.3390/gases3040013 - 06 Dec 2023

Viewed by 429

Abstract

Helium is an inert gas with no color or odor [...] Full article

16 pages, 3884 KiB

Open AccessArticle

Greenhouse Gas Conversion into Hydrocarbons and Oxygenates Using Low Temperature Barrier Discharge Plasma Combined with Zeolite Catalysts

by

Oleg V. Golubev

,

Dmitry E. Tsaplin

and

Anton L. Maximov

Gases 2023, 3(4), 165-180; https://doi.org/10.3390/gases3040012 - 05 Dec 2023

Viewed by 512

Abstract

Global warming occurs as a result of the build-up of greenhouse gases in the atmosphere, causing an increase in Earth’s average temperature. Two major greenhouse gases (CH₄ and CO₂) can be simultaneously converted into value-added chemicals and fuels thereby decreasing [...] Read more.

Global warming occurs as a result of the build-up of greenhouse gases in the atmosphere, causing an increase in Earth’s average temperature. Two major greenhouse gases (CH₄ and CO₂) can be simultaneously converted into value-added chemicals and fuels thereby decreasing their negative impact on the climate. In the present work, we used a plasma-catalytic approach for the conversion of methane and carbon dioxide into syngas, hydrocarbons, and oxygenates. For this purpose, CuCe zeolite-containing catalysts were prepared and characterized (low-temperature N₂ adsorption, XRF, XRD, CO₂-TPD, NH₃-TPD, TPR). The process of carbon dioxide methane reforming was conducted in a dielectric barrier discharge under atmospheric pressure and at low temperature (under 120 °C). It was found that under the studied conditions, the major byproducts of CH₄ reforming are CO, H₂, and C₂H₆ with the additional formation of methanol and acetone. The application of a ZSM-12 based catalyst was beneficial as the CH₄ conversion increased and the total concentration of liquid products was the highest, which is related to the acidic properties of the catalyst. Full article

(This article belongs to the Section Gas Emissions)

► Show Figures

Figure 1

7 pages, 238 KiB

Open AccessOpinion

Alternative Gaseous Fuels for Marine Vessels towards Zero-Carbon Emissions

by

Cherng-Yuan Lin

,

Pei-Chi Wu

and

Hsuan Yang

Gases 2023, 3(4), 158-164; https://doi.org/10.3390/gases3040011 - 17 Nov 2023

Viewed by 686

Abstract

The maritime industry is recognized as a major pollution source to the environment. The use of low- or zero-carbon marine alternative fuel is a promising measure to reduce emissions of greenhouse gases and toxic pollutants, leading to net-zero carbon emissions by 2050. Hydrogen [...] Read more.

The maritime industry is recognized as a major pollution source to the environment. The use of low- or zero-carbon marine alternative fuel is a promising measure to reduce emissions of greenhouse gases and toxic pollutants, leading to net-zero carbon emissions by 2050. Hydrogen (H₂), fuel cells particularly proton exchange membrane fuel cell (PEMFC), and ammonia (NH₃) are screened out to be the feasible marine gaseous alternative fuels. Green hydrogen can reduce the highest carbon emission, which might amount to 100% among those 5 types of hydrogen. The main hurdles to the development of H₂ as a marine alternative fuel include its robust and energy-consuming cryogenic storage system, highly explosive characteristics, economic transportation issues, etc. It is anticipated that fossil fuel used for 35% of vehicles such as marine vessels, automobiles, or airplanes will be replaced with hydrogen fuel in Europe by 2040. Combustible NH₃ can be either burned directly or blended with H₂ or CH₄ to form fuel mixtures. In addition, ammonia is an excellent H₂ carrier to facilitate its production, storage, transportation, and usage. The replacement of promising alternative fuels can move the marine industry toward decarbonization emissions by 2050. Full article

14 pages, 6985 KiB

Open AccessArticle

Influence of Hydrogen on the Performance and Emissions Characteristics of a Spark Ignition Ammonia Direct Injection Engine

by

,

,

,

and

Gases 2023, 3(4), 144-157; https://doi.org/10.3390/gases3040010 - 16 Oct 2023

Viewed by 735

Abstract

Because ammonia is easier to store and transport over long distances than hydrogen, it is a promising research direction as a potential carrier for hydrogen. However, its low ignition and combustion rates pose challenges for running conventional ignition engines solely on ammonia fuel [...] Read more.

Because ammonia is easier to store and transport over long distances than hydrogen, it is a promising research direction as a potential carrier for hydrogen. However, its low ignition and combustion rates pose challenges for running conventional ignition engines solely on ammonia fuel over the entire operational range. In this study, we attempted to identify a stable engine combustion zone using a high-pressure direct injection of ammonia fuel into a 2.5 L spark ignition engine and examined the potential for extending the operational range by adding hydrogen. As it is difficult to secure combustion stability in a low-temperature atmosphere, the experiment was conducted in a sufficiently-warmed atmosphere (90 ± 2.5 °C), and the combustion, emission, and efficiency results under each operating condition were experimentally compared. At 1500 rpm, the addition of 10% hydrogen resulted in a notable 20.26% surge in the maximum torque, reaching 263.5 Nm, in contrast with the case where only ammonia fuel was used. Furthermore, combustion stability was ensured at a torque of 140 Nm by reducing the fuel and air flow rates. Full article

(This article belongs to the Special Issue Gas Emissions from Combustion Sources)

► Show Figures

Figure 1

8 pages, 2041 KiB

Open AccessCommunication

Effect of Mixing Technique on Physico-Chemical Characteristics of Blended Membranes for Gas Separation

by

Danial Qadir

,

Humbul Suleman

and

Faizan Ahmad

Gases 2023, 3(4), 136-143; https://doi.org/10.3390/gases3040009 - 26 Sep 2023

Viewed by 672

Abstract

Polymer blending has attracted considerable attention because of its ability to overcome the permeability–selectivity trade-off in gas separation applications. In this study, polysulfone (PSU)-modified cellulose acetate (CA) membranes were prepared using N-methyl-2-pyrrolidone (NMP) and tetrahydrofuran (THF) using a dry–wet phase inversion technique. [...] Read more.

Polymer blending has attracted considerable attention because of its ability to overcome the permeability–selectivity trade-off in gas separation applications. In this study, polysulfone (PSU)-modified cellulose acetate (CA) membranes were prepared using N-methyl-2-pyrrolidone (NMP) and tetrahydrofuran (THF) using a dry–wet phase inversion technique. The membranes were characterized using scanning electron microscopy (SEM) for morphological analysis, thermogravimetric analysis (TGA) for thermal stability, and Fourier transform infrared spectroscopy (FTIR) to identify the chemical changes on the surface of the membranes. Our analyses confirmed that the mixing method (the route chosen for preparing the casting solution for the blended membranes) significantly influences the morphological and thermal properties of the resultant membranes. The blended membranes exhibited a transition from a finger-like pore structure to a dense substructure in the presence of macrovoids. Similarly, thermal analysis confirmed the improved residual weight (up to 7%) and higher onset degradation temperature (up to 10 °C) of the synthesized membranes. Finally, spectral analysis confirmed that the blending of both polymers was physical only. Full article

(This article belongs to the Special Issue Membrane Processes for Decarbonisation)

► Show Figures

Graphical abstract

Journal Menu

Journal Browser

Gases, Volume 3, Issue 4 (December 2023) – 5 articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI