Scenario analysis on abating industrial process greenhouse gas emissions from adipic acid production in China

Adipic acid is an important petrochemical product,and its production process emits a high concentration of greenhouse gas N_2 O.This paper aims to provide quantitative references for relevant authorities to formulate greenhouse gas control roadmaps.The forecasting method of this paper is consistent with the published national inventory in terms of caliber.Based on the N_2 O abatement technical parameters of adipic acid and the production trend,this paper combines the scenario analysis and provides a measurement of comprehensive N_2 O abatement effect of the entire industry in China.Four future scenarios are assumed.The baseline scenario(BAUS) is a frozen scenario.Three emission abatement scenarios(ANAS,SNAS,and ENAS) are assumed under different strength of abatement driving parameters.The results show that China's adipic acid production process can achieve increasingly significant N_2 O emission abatement effects.Compared to the baseline scenario,by 2030,the N_2 O emission abatements of the three emission abatement scenarios can reach 207-399 kt and the emission abatement ratios can reach 32.5%-62.6%.By 2050,the N_2 O emission abatements for the three emission abatement scenarios can reach 387-540 kt and the emission abatement ratios can reach 71.4%-99.6%.

Simulation of the Accumulation Process of Biogenic Gas Hydrates in the Shenhu Area of Northern South China Sea

Previous work has largely discussed the relations between sediment structures and accumulation of gas hydrates in the Shenhu area of South China Sea, but has not documented why the gas hydrates occurred at the seafloor topographic highs. Many gas hydrate exploration examples abroad also indicate that the saturation of gas hydrates was higher at seafloor topographic highs. This work aims to understand why gas hydrates accumulated at topographic highs and why their saturation is higher.

Characteristics and Microstructure of a Hypereutectic Al-Si Alloy Powder by Ultrasonic Gas Atomization Process

A hypereutectic Al-Si alloy powder was prepared by ultrasonic gas atomization process. The morphologies, microstructure and phase constituent of the alloy powder were studied. The results showed that powder of the alloy was very fine and its microstructure was mainly consisted of Si crystals plus intermetallic compound A19FeSi3, which were.very fine and uniformly distributed.

VISUAL OBSERBATION OF HCFC141b GAS HYDRATE FORMATION/DECOMPOSITION PROCESS OUTSIDE OF A TUBE

In order to design a kind of heat exchanger suitable to the indirect-touched gas hydrate cool storage vessel, a visual observation of HCFC141b gas hydrate formation/decomposition process was presented through a self-designed small-scale visualization apparatus of gas hydrate cool storage. Based on the shooted photos and recorded temperatures, the formation/decomposition process of HCFC141b are described, some characteristics are concluded, and some suggestions of designing heat exchanger are indicated according to the specific characteristics of HCFC141b gas hydrate formation/decomposition process.

Piston mechanism of interaction of non-linear geomechanical and physicochemical gas exchange and mass transfer processes in coal-bearing rocks

The article focuses on a theoretical and experimental framework for the quantification of interaction between nonlinear geomechnical and physicochemical processes in high-stress coal-bearing rock mass during mining under high seismic risk due to large-scale blasting and earthquakes,as well as because of structural and temperature effects.The tests were aimed to examine and study comprehensively the piston mechanism of gas exchange and mass transfer processes,revealed recently at the Institute of Mining,SB RAS,as well as to explain the fact that the earthquake-induced low-velocity(quasi-meter range)pendulum waves(velocity to 1 m/s and frequency of 0.5–5 Hz)could stimulate an increase in the gas content in coal mines.In order to perform laboratory investigation at the Institute of Mining SB RAS,special-purpose stand for analyzing gas exchange and mass transfer processes in coal-bearing geomaterials under various thermodynamic conditions(P,V,T)and gas composition was constructed in cooperation with the Institute of Semiconductors Physics SB RAS.Matching of air flow rate with compression pressures allowed to obtain relations showing that air flow rate increases at the uncertain time interval under the increasing of the compression pressure.The same measurements was carried out with another gases such as Hydrogen H_(2),Helium He,methane CH_(4),carbon dioxide CO_(2) and carbon oxide CO.The laboratory tests aimed to detailed investigation of the previously revealed“piston mechanism”of gas exchange and mass transfer processes in the coal specimens and their quantitative description in terms of theory of the pendulum waves were carried in the first time.Consequently,there are some arguments for the testing of the opportunity of quantitative description of the“piston mechanism”related to gas exchange and mass transfer processes in the scale of coal mines.It is relevant when pendulum waves induced by powerful earthquakes and technical blasting reaches the mine.

High temperature deformation behavior and processing map of hot isostatically pressed Ti-47.5Al-2Cr-2Nb-0.2W-0.2B alloy using gas atomization powders

The hot compressive deformation behavior of hot isostatically pressed Ti-47.5Al-2Cr-2Nb-0.2W-0.2B alloy using gas atomization powders was systematically investigated and the processing map was obtained in the temperature range of 1323-1473 Kand strain rate range of 0.001-0.5s^（-1）.The calculated activation energy in the above variational ranges of temperature and strain rate possesses a low activation energy value of approximately 365.6kJ/mol based on the constitutive relationship models developed with the Arrhenius-type constitutive model respectively considering the strain rate and deformation temperature.The hot working flow behavior during the deformation process was analyzed combined with the microstructural evolution.Meanwhile,the processing maps during the deformation process were established based on the dynamic material model and Prasad instability criterion under different deformation conditions.Finally,the optimal hot processing window of this alloy corresponding to the wide temperature range of 1353-1453 Kand the low strain rate of 0.001-0.1s^（-1） was obtained.

Novel approaches for the prediction of density of glycol solutions

Two new approaches for the accurate prediction of densities of the commonly used glycol solutions in the gasprocessing industry are presented in the article. The first approach is based on developing a simple-to-use polynomial correlation for an appropriate prediction of density of glycol solutions as a function of temperature and weight percent of glycols in water, where the obtained results show very good agreement with the reported experimental data. The second approach, however, is based on the artificial neural networks （ANN） methodology, wherein the results demonstrate the ability of the introduced method to predict reasonably accurate densities of glycols under operating conditions. Comparisons of the two novel approaches indicated that the simple-to-use correlation appears to be superior owing to its simplicity and clear numerical background, wherein the relevant coefficients can be retuned if new and more accurate data are available in the future. The average deviation of the new proposed polynomial correlation results from reported data is 0.64 kg/m^3 whereas the average deviation of artificial neural networks （ANN） methodology from reported data is 1.1 kg/m^3.

Comparative Study on Processing Property Between CWW CO_2 Gas Shielded Welding and SAW

Cable welding wire（CWW）CO2gas shielded welding is an innovative process arc welding with high efficiency,high quality and low consumption,in which cable wire is used as consumable electrode.CWW CO2gas shielded welding and submerged arc welding（SAW）are used for contrast studies on processing property of high strength steel A36used in ship structure.The results show that the shapes of weld seam,using CWW CO2gas shielded welding and SAW,are good and no weld defect such as air hole,flaw,slag inclusion,incomplete fusion,lack of penetration and so on are found in the weld seam.Because the rotating of arc during CWW CO2gas shielded welding process has a strong stirring effect on molten pool,the grain in the heat affected zone（HAZ）of the joints,using CWW CO2 gas shielded welding,is small.Tensile failure positions of joints by CWW CO2gas shielded welding and SAW are all in the base metal,but tensile strength of CWW CO2gas shielded welding joint is higher than that of SAW joint by an average of 2.3%.The average impact energy of HAZ,using CWW CO2gas shielded welding and SAW,is almost equal,but the average impact energy of the weld seam using CWW CO2gas shielded welding is increased by 6%,and the average impact energy of the fusion line is increased by 7%.The 180°bending tests for the joints of CWW CO2 gas shielded welding and SAW are all qualified,and the joints hardness is all less than HV 355,but hardness of CWW CO2gas shielded welding wire welding joint near the fusion line is obviously lower.It can be concluded that the properties of CWW CO2gas shielded welding are better than those of the SAW joint,and CWW CO2gas shielded welding is suitable for welding high strength steel A36used in ship structure.

Calculation of vibrational energy transition rates in acoustic relaxation processes for excitable gas molecules

To research the correlation between vibrational energy transition rates and acoustic relaxation processes in excitable gases, the vibrational relaxation theory provided by Tanczos [J. Chem. Phy3. 25, 439 （1956）] is applied to calculate the energy transition rates of Vibrational- Vibrational （V-V） and Vibrational-Translational （V-T） energy transfer in gas mixtures. The results of calculation for the multi-relaxation processes in various gas mixtures, consisting of carbon dioxide, methane, chlorine, nitrogen, and oxygen at room temperature, demonstrate that the acoustic energy stagnated in every vibrational mode is coupled with each other through V-V energy exchanges. The vibrational excitation energy will relax through the V-T de-excitation path of the lowest mode because of its fastest V-T transition rate, resulting in that only one absorption peak can be measured for most of excitable gas mixtures. Thus, an effective model is provided to analyze how the vibrational energy transition rates affect the characteristics of acoustic relaxation processes and acoustic propagation in excitable gas mixtures.

Important mesoscale phenomena in gas phase fluidized bed ethylene polymerization

Gas phase fluidized bed processes have been widely applied to polyethylene production.In these processes,the flow,mass transfer,and reaction rate on the microscale and macroscale are strongly coupled because of the multiphase and multiscale nature of the fluidization system.Understanding mesoscale phenomena is therefore essential to the quantitative translation of the knowledge obtained from the microscale to the macroscale.This paper reviews the development of ethylene polymerization gas phase processes while focussing on studies regarding mesoscale phenomena.These include experimental characterizations,mathematical modelling and control strategies.Trends and future developments in this field are also discussed.

Effect of Gas Bubbling Filtration Treatment on Microporosity Variation in A356 Aluminium Alloy

In the present study, the contribution of the gas bubbling filtration （GBF） process to the microporosity variation, microstructural characteristics and tensile properties of A356 aluminium alloy was investigated. The test specimens were fabricated through gravity casting in terms of the process variables： the degassing time, the impeller rotation and the aperture size of gas inlet hole. The density measurement and scanning electron microscope fractography analyses were conducted to evaluate the variation of the volumetric porosity and fractographic porosity with the GBF process, respec- tively. The fractographic porosity of the specimens can be minimised under specific GBF conditions in terms of the buoyant velocity and the absorbing capacity of gas bubbles, the inclusion of oxide films, whereas the volumetric porosity can be wholly reduced on the lapse of degassing time. The ultimate tensile strength （UTS） and elongation at optimal conditions were improved to approximately 30 MPa and 1.5% compared with no GBF treatment. Even though an extension of the degassing time and/or excessive stirring action of the melt may induce the inclusion of bifilm oxides and the increase of fractographic porosity, the tensile properties of over-treated specimens were maintained to a level which is similar to those that did not undergo GBF treatment due to the grain refinement accompanying with the GBF process. In addition, the defect susceptibility of UTS and elongation to microporosity variation could be remarkably improved at an optimal GBF condition.

Recent advances in thermochemical conversion of woody biomass for production of green hydrogen and CO_(2)capture:A review

Hydrogen as a clean energy carrier has attracted great interests world-wide for substitution of fossil fuels and for abatement of the climate change concerns.However,green hydrogen from renewable resources is less than 0.1%at present in the world hydrogen production and this is largely from water electrolysis which is beneficial only when renewable electricity is used.Hydrogen production from diverse renewable resources is desirable.This review presents recent advances in hydrogen production from woody biomass through biomass steam gasification,producer gas processing and H_(2)/CO_(2)separation.The producer gas processing includes steam-methane reforming(SMR)and water-gas shift(WGS)reactions to convert CH_(4)and CO in the producer gas to H_(2)and CO_(2).The H_(2)storage discussed using liquid carrier through hydrogenation is also discussed.The CO_(2)capture prior to the SMR is investigated to enhance H_(2)yield in the SMR and the WGS reactions.