gas composition
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2022 ◽  
Vol 13 (1) ◽  
Xiaoqin Si ◽  
Rui Lu ◽  
Zhitong Zhao ◽  
Xiaofeng Yang ◽  
Feng Wang ◽  

AbstractNatural gas is one of the foremost basic energy sources on earth. Although biological process appears as promising valorization routes to transfer biomass to sustainable methane, the recalcitrance of lignocellulosic biomass is the major limitation for the production of mixing gas to meet the natural gas composition of pipeline transportation. Here we develop a catalytic-drive approach to directly transfer solid biomass to bio-natural gas which can be suitable for the current infrastructure. A catalyst with Ni2Al3 alloy phase enables nearly complete conversion of various agricultural and forestry residues, the total carbon yield of gas products reaches up to 93% after several hours at relative low-temperature (300 degrees Celsius). And the catalyst shows powerful processing capability for the production of natural gas during thirty cycles. A low-carbon footprint is estimated by a preliminary life cycle assessment, especially for the low hydrogen pressure and non-fossil hydrogen, and technical economic analysis predicts that this process is an economically competitive production process.

Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 485
Wenjiu Cai ◽  
Xin Huang ◽  
Hailong Lu

Studies revealed that gas hydrate cages, especially small cages, are incompletely filled with guest gas molecules, primarily associated with pressure and gas composition. The ratio of hydrate cages occupied by guest molecules, defined as cage occupancy, is a critical parameter to estimate the resource amount of a natural gas hydrate reservoir and evaluate the storage capacity of methane or hydrogen hydrate as an energy storage medium and carbon dioxide hydrate as a carbon sequestration matrix. As the result, methods have been developed to investigate the cage occupancy of gas hydrate. In this review, several instrument methods widely applied for gas hydrate analysis are introduced, including Raman, NMR, XRD, neutron diffraction, and the approaches to estimate cage occupancy are summarized.

2022 ◽  
Vol 1 (2) ◽  
pp. 49-53
Angga Yunis Prasetya ◽  
Darmanto Darmanto ◽  
Muhammad Dzulfikar

Nitriding has been carried out using plasma nitriding techniques for surface treatment of Titanium as a biomaterial component. The purpose of this study was to determine the effect of plasma nitriding on surface hardness that occurs in titanium. The material used is Titanium Alloy (Ti-6Al-4V) Grade 5 which is processed by plasma nitriding by varying nitrogen (N2) and argon (Ar) gases of (100% N2/0% Ar), (95% N2/5% Ar), (90% N2/10% Ar), (85% N2/15% Ar), (80% N2/20% Ar), and (75% N2/25% Ar), and temperature 400ºC, time 5 hours and a pressure of 1.6 bar. The test results show that the optimum hardness is found in the gas composition with a ratio of 95% N2: 5% Ar. Obtained a hardness of 371 HV/VHN or an increase of 159% of the raw material with hardness value of 143 HV/VHN

2022 ◽  
Vol 2152 (1) ◽  
pp. 012052
Chen Yang

Abstract Carbon nanomaterials are becoming new materials which can be used in many fields including transistors, sensors, displays, hydrogen storage, capacitors, catalyst supporters and so on. PECVD is an important method for producing carbon nanomaterials. However, it remains a challenge to control the final production of the PECVD process. This paper tries to figure out the gas factors influencing the growth of different carbon nanomaterials. This paper begins with a brief introduction of PECVD and the growth regime of carbon nanowalls and carbon nanotubes. It discusses how the Argon, carbon source, hydrogen and other gas affect the growth of CNMs. The paper ends with a discussion on the practical influence of confirming the function of each gas.

I. I. Mukhamatdinov ◽  
E. E. Giniyatullina ◽  
R. E. Mukhamatdinova ◽  
O. V. Slavkina ◽  

The article examines the aquathermolysis process of high viscosity oil from Strelovskoe field developed by RITEK LLC using steam injection. Laboratory modeling of non-catalytic and catalytic aquathermolysis in a high-pressure reactor was performed. Laboratory tests have demonstrated the high efficiency of the iron-based oil-soluble catalyst developed at Kazan Federal University in the destruction reactions of resinous asphaltenes. Samples of the initial oil as well as products of non-catalytic and catalytic aquathermolysis in the presence of iron tallate and the solvent Asphalt-Resin-Paraffin Deposits were studied at temperatures of 200, 250 and 300°C for 24 hours. In addition, the gas composition of the oil aquathermolysis products and the viscosity-temperature characteristics of the oil samples were determined. The studies have shown that catalytic aquathermolysis has a significant effect on the changes in the composition and properties of oil from the Strelovskoe field. It was found that the presence of a catalyst contributes to decarboxylation reactions, increases the degree of desulfurization and decreases the viscosity of oil samples. Keywords: high-viscosity oil; aquathermolysis; catalyst precursor; steam thermal treatment; viscosity.

2021 ◽  
Vol 9 (4) ◽  
pp. 87-94
A. E. Osadchinskiy ◽  
I. S. Pavlov ◽  
S. V. Kotov

Introduction. In healthy men, a significant increase in pO2 in the cavernous tissue occurs during episodes of nocturnal erections. This process ensures sufficient oxygenation and high-pressure substances such as prostaglandin-E1 and nitric oxide. These substances suppress the expression of transforming growth factor β1, thereby preventing collagen synthesis and the development of cavernous fibrosis. In patients undergoing nerve-sparing radical prostatectomy, nocturnal erections are absent, hypoxia inhibits the production of PGE-i, and neuropraxia inhibits NO. Thus, cavernous fibrosis develops through the production of pro-apoptotic and profibrotic factors, resulting in persistent erectile dysfunction. The importance of a vacuum in penile rehabilitation for the prevention of penile cavernous hypoxia is not fully understood. This is due to the deficiency of data on the gas composition of cavernous blood when a vacuum-induced erection is achieved.Purpose of the study. To investigate the cavernous blood at the time of vacuum-induced erection, to analyze the obtained results with the International Index of Erectile Function score and with the values of penile hemodynamics.Materials and methods. The study included i5 patients with prostate cancer and preserved sexual function. The average age of all men was 57.87 ±4.36 years. All patients underwent a preoperative comprehensive assessment of erectile function: International Index of Erectile Function questionnaire, dynamic duplex penile ultrasound. Immediately prior to the surgery, penile blood was collected at the time of achieving a vacuum-induced erection. The gas composition and oxygenation were assessed using the values of the partial oxygen pressure, carbon dioxide and saturation in accordance with the approved standards to differentiate arterial and venous blood. Statistical data processing was carried out using the PASW Statistics 22 software (IBM SPSS, IBM Corp., Chicago, IL, USA)Results. All patients were divided into 3 groups depending on the gas composition and oxygen level of the cavernous blood. Group I included 4 (26.6%) patients with a predominance of arterial blood, group II — 4 patients (26.6%) with venous blood and group III — 7 patients (46.6%) with a mixed composition of cavernous blood. The average International Index of Erectile Function score in group I was 23.5 [2i.0; 25.0], in group II — 22.0 [2i.0; 24.0] and in group III — 24.0 [i9.0; 25.0]. Peak systolic velocity (cm/s) in group I was 40.i [35.i; 45.2], in group II — 35.9 [29.5; 50.2], in group III — 32.5 [32.5; 34.4]. End-diastolic velocity (cm/s) in group I was 2.52 [0.55; i0.5], in group II — 8.3 [2.9; i0.8], in group III — 7.5 [7.5; 9.0]. Resistive index in group I was 0.87 [0.77; 0.98], in group II — 0.75 [0.63; 0.94], in group III — 0.75 [0.73; 0.75].Conclusions. Vacuum prophylaxis may be the method of choice for penile rehabilitation in patients after nerve-sparing radical prostateectomy, especially in the early postoperative period during neuropraxia. The use of vacuum devices should be prescribed to patients with preserved veno-occlusive mechanism, which should be confirmed by dynamic duplex penile ultrasound.

Fermentation ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 318
Pavel Hrnčiřík

This paper focuses on the design of soft sensors for on-line monitoring of the biotechnological process of biopolymer production, in which biopolymers are accumulated in bacteria as an intracellular energy storage material. The proposed soft sensors for on-line estimation of the biopolymer concentration represent an interesting alternative to the traditional off-line analytical techniques of limited applicability for real-time process control. Due to the complexity of biochemical reactions, which make it difficult to create reasonably complex first-principle mathematical models, a data-driven approach to the design of soft sensors has been chosen in the presented study. Thus, regression methods were used in this design, including multivariate statistical methods (PLS, PCR). This approach enabled the creation of soft sensors using historical process data from fed-batch cultivations of the Pseudomonas putida KT2442 strain used for the production of medium-chain-length polyhydroxyalkanoates (mcl-PHAs). Specifically, data from on-line measurements of off-gas composition analysis and culture medium capacitance were used as input to the soft sensors. The resulting soft sensors allow not only on-line estimation of the biopolymer concentration, but also the concentration of the cell biomass of the production bacterial culture. For most of these soft sensors, the estimation error did not exceed 5% of the measurement range. In addition, soft sensors based on capacitance measurement were able to accurately detect the end of the production phase. This study thus offers an innovative and practically relevant contribution to the field of monitoring of bioprocesses used for the production of medium-chain-length biopolymers.

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