A SUPPLEMENT TO THE PAPERS CONVERGENCE OF THE LAX-FRIEDRICHS SCHEME FOR ISENTROPIC GAS DYNAMICS (Ⅱ)-(Ⅲ)

In the papers (Ⅱ)—(Ⅲ), we studied the global existence of the solutions for the isentropic equation of gas dynamics

Preparation of HCl Gas Sorbent from Paper Sludge

Paper sludge (PS) is generated as an industrial waste during the manufacture of recycled paper products, and amounts discharged globally are increasing annually. On the other hands, hydrogen chloride (HCl) is an acidic pollutant that is present in the flue gases of most municipal and hazardous waste incinerators. In this study, the removal of hydrogen chloride gas using the product from paper sludge at high temperatures (700oC) using a fixed-bed flow-type reactor was investigated. PS can be granulated with distilled water using granulators, and the particle shapes can be kept after calcination and alkali reaction. Calcined PS and the product after alkali reaction of calcined PS have amorphous phases and katoite (Ca3Al2(SiO4)(OH)8) phase, respectively, and both of these indicate HCl removal ability at high temperature (700oC). The product from calcined PS via alkali reaction has higher HCl fixation ability (78 mg/g) than calcined PS. Removal experiments for HCl gas showed that the removal process followed pseudo-second-order kinetics rather than pseudo-first-order kinetics. These results suggested that the product particles with HCl gas removal ability at high temperature can be prepared from PS using calcination and alkali reaction.

Upgrading of Yi'an gas coal by low temperature pyrolysis under different atmospheres

The quality of Yi＇an gas coal before and after low temperature upgrading under either a N2 or H2 atmosphere was examined by thermogravimetric and infrared analyses. The effect of upgrading on the prepared coke quality was analyzed. The results show that the carboxyl and phenolic hydroxyls in the coal molecular structure are removed after upgrading by low temperature pyrolysis under either N2 or Hz atmospheres. This improves coal caking properties to a certain extent. The upgrading effect under a Hz atmosphere is remarkably better than the effect observed after upgrading under N2. Compared to coke obtained from raw coal, the compressiveand micro-strength of the cokes obtained from upgraded coal are greatly improved. The effect on coke reactivity with CO2 is not significant. The best upgrading temperature for Yi＇an gas coal under either a N2 or H2 atmosphere is 250 or 275 ℃ respectively.

Economic feasibility and efficiency enhancement approaches for in situ upgrading of low-maturity organic-rich shale from an energy consumption ratio perspective

The technical feasibility of in situ upgrading technology to develop the enormous oil and gas resource potential in low-maturity shale is widely acknowledged.However,because of the large quantities of energy required to heat shale,its economic feasibility is still a matter of debate and has yet to be convincingly demonstrated quantitatively.Based on the energy conservation law,the energy acquisition of oil and gas generation and the energy consumption of organic matter cracking,shale heat-absorption,and surrounding rock heat dissipation during in situ heating were evaluated in this study.The energy consumption ratios for different conditions were determined,and the factors that influence them were analyzed.The results show that the energy consumption ratio increases rapidly with increasing total organic carbon(TOC)content.For oil-prone shales,the TOC content corresponding to an energy consumption ratio of 3 is approximately 4.2%.This indicates that shale with a high TOC content can be expected to reduce the project cost through large-scale operation,making the energy consumption ratio after consideration of the project cost greater than 1.In situ heating and upgrading technology can achieve economic benefits.The main methods for improving the economic feasibility by analyzing factors that influence the energy consumption ratio include the following:(1)exploring technologies that efficiently heat shale but reduce the heat dissipation of surrounding rocks,(2)exploring technologies for efficient transformation of organic matter into oil and gas,i.e.,exploring technologies with catalytic effects,or the capability to reduce in situ heating time,and(3)establishing a horizontal well deployment technology that comprehensively considers the energy consumption ratio,time cost,and engineering cost.

Performance and Economic Analysis of Mulberry Paper Handmade Dryer by Using Downdraft Gasifier

The mulberry paper handmade dryer uses downdraft gasifier, which is a continuous hot air dryer. The downdraft gasifier uses charcoal or wood chip as fuel to produce the producer gas for a dryer heat source. Two steps operation of a dryer as follows： The frst was to reduce mulberry paper pulp moisture by an air vacuum pump; the second was a continuous hot air drying process. The optimum condition drying, the capacity of dryer, the fuel consumption, the drying constant （k） and economics analysis were investigated. It was found that the first step could be to reduce mulberry paper pulp moisture content about 25% and the suitable condition drying was 80 ~C drying temperature, 0.04 kg/s air mass flow rate and 0.29 m/min chain conveyor speed, respectively. The capacity of this dryer was 20 sheets per hour. The quality of mulberry paper product was very good （based on the standard of mulberry paper community 41/2546） and the fuel consumption rate was 5 kg/h （charcoal）. The drying constant was about 0.532933-0.541367 min~ and the drying constant was a function of drying temperature （T）, air mass flow rate （F） and conveyor speed （10 as equation of k（T, F, V） = 0.567494 ＋ 0.000422T- 1.40588F- 0.000205 V （R2 = 0.9254） and the breakeven point of dryer was 0.79 years.

Recent advances on the membrane processes for CO_2 separation

Membrane separation technology has popularized rapidly and attracts much interest in gas industry as a promising sort of newly chemical separation unit operation. In this paper, recent advances on membrane processes for CO_2 separation are reviewed. The researches indicate that the optimization of operating process designs could improve the separation performance, reduce the energy consumption and decrease the cost of membrane separation systems. With the improvement of membrane materials recently,membrane processes are beginning to be competitive enough for CO_2 separation, especially for postcombustion CO_2 capture, biogas upgrading and natural gas carbon dioxide removal, compared with the traditional separation methods. We summarize the needs and most promising research directions for membrane processes for CO_2 separation in current and future membrane applications. As the time goes by, novel membrane materials developed according to the requirement proposed by process optimization with increased selectivity and/or permeance will accelerate the industrialization of membrane process in the near future. Based on the data collected in a pilot scale test, more effort could be made on the optimization of membrane separation processes. This work would open up a new horizon for CO_2 separation/Capture on Carbon Capture Utilization and Storage(CCUS).

Improved properties of carbon fiber paper as electrode for fuel cell by coating pyrocarbon via CVD method

The fabrication of a pyrocarbon coated carbon paper and its application to the gas diffusion lay(GDL) of proton exchange membrane(PEM) fuel cell were described.This carbon paper was fabricated by using conventional carbon paper as the precursor,and coating it with pyrocarbon by pyrolyzing propylene via the chemical vapor deposition(CVD) method.For comparison,conventional carbon paper composites were also prepared by using PAN-based carbon fiber felt as the precursor followed by impregnation with resin,molding and heat-treatment.SEM characterization indicates that pyrocarbon is uniformly deposited on the surface of the fiber in the pyrocarbon coated carbon paper and made the fibers of carbon felt bind more tightly.In contrast,there are cracks in matrix and debonding of fibers due to carbonization shrinkage in the conventional carbon paper.Property measurements show that the former has much better conductivity and gas permeability than the latter.In addition,current density-voltage performance tests also reveal that the pyrocarbon coating can improve the properties of carbon paper used for electrode materials of fuel cell.

Discussion of the indexes of nonoutburst coal seam upgrade and its corresponding critical values

In view of the measurement difficulties of indexes recommended by the 50Items Experience of Coal Mine Gas Prevention in the process of the nonoutburst coalseam upgrade, this paper took the No.8 coal seam of Huainan Mining Group as research object. Discussed the suitability of indexes and corresponding critical values, putforward method in determining the indexes and its critical values by analysis and investigation of the gas geological condition and the-spot tracking near position where anoutburst occurred combined with laboratory experiment, and established the indexesand its critical values of nonoutburst coal seam upgrade in No.8 coal seam of HuainanMining Group. The results show that it is suitable to take gas content and tectonic softcoal thickness easily to gain in routine production as primary upgrade indexes that itscritical values are 7.5 m^3/t and 0.8 m, respectively. In addition, takefvalue and Ap valueas auxiliary indexes.

Gas flow and filter ventilation of an unlit cigarette: model building,numerical solution and experimental validation

Understanding the fundamcntal relationship betwecn gas dilution rate of a cigarette and key cigarette design parameters is important in the overall control of smoke yield.In this work,an equation was derived to express the total gas dilution with the cigarette rod length,cigarette paper air permeability,and the filter ventilation level.The relationship was validated using experimental results.The accuracy of the developed model was dependent on the regression method used,i.e.,linear or a nonlinear.The expression provides a quantitative description of the interactions between filter ventilation level,cigarette length,cigarette circumference and cigarette paper air permeability and the total air dilution at the cigarette's mouth end.

Filter paper-templated preparation of ZnO thin films and examination of their gas-sensing properties

ZnO thin films prepared by using quantitative filter paper as a template and Zn（CH3CO2）2.2H2O ethanol precursor solution were characterized by scanning electron microscopy （SEM） and X-ray diffraction （XRD）. The effects of sample calcination temperature, precursor concentration and filter paper types were studied, and the growth process was investigated by infra-red （IR） spectroscopy and thermogravimettic analysis/differential thermal analysis （TGA/DTA）. The results show that samples soaked in a 1.5 mol/L Zn（CH3 CO2）2.2H2O ethanol solution and calcined at 600 ℃ yield ZnO films of uniform particle size, approximately 30, 40 and 50 nm. for fast-, medium- and slow-speed filter papers, respectively. The formaldehyde gas sensing properties of the ZnO nanoparticles were tested, showing that the material prepared from fast-speed filter paper has a higher response to 120-205 ppm formaldehyde at 400 ℃ than that prepared from medium- or slow-sneed paper, which depends on the narticle size.

Ceria in halogen chemistry

Halogen chemistry constitutes an essential part in the industrial production of polymers and gains increasing attention as an attractive strategy to activate light alkanes that constitute natural gas. CeO2-based catalysts offer an exciting potential for advances in hydrogen halide recovery that enables a high efficiency of halogen-based processes for activation of small molecules. This review provides an overview of recently developed ceria-based catalysts in the context of polymer industry(polyvinyl chloride, polyurethanes, and polycarbonates) and activation of light hydrocarbons for natural gas upgrading. In addition, mechanistic insight and the challenges of ceria catalysts are provided, aiding the design of future catalytic materials and applications.

Analyzing the energy intensity and greenhouse gas emission of Canadian oil sands crude upgrading through process modeling and simulation

This paper presents an evaluation of the energy intensity and related greenhouse gas/CO2 emissions of integrated oil sands crude upgrading processes. Two major oil sands crude upgrading schemes currently used in Canadian oil sands operations were investigated： cokingbased and hydroconversion-based. The analysis, which was based on a robust process model of the entire process, was constructed in Aspen HYSYS and calibrated with representative data. Simulations were conducted for the two upgrading schemes in order to generate a detailed inventory of the required energy and utility inputs： process fuel, steam, hydrogen and power. It was concluded that while hydroconversion-based scheme yields considerably higher amount of synthetic crude oil （SCO） than the cokerbased scheme （94 wt-% vs. 76 wt-%）, it consumes more energy and is therefore more CO2-intensive （413.2kg CO2/m3sco vs. 216.4kg CO2/m^3sco）. This substantial difference results from the large amount of hydrogen consumed in the ebullated-bed hydroconverter in the hydroconversion-based scheme, as hydrogen production through conventional methane steam reforming is highly energy-intensive and therefore the major source of CO2 emission. Further simulations indicated that optimization of hydroconverter operating variables had only a minor effect on the overall CO2 emission due to the complex trade-off effect between energy inputs.

双碳视角下绿色产业政策对造纸产业转型升级影响研究

围绕双碳目标,通过研究绿色产业政策与造纸产业发展的相关关系,探究了绿色产业政策对造纸产业转型升级的影响机理,并以京津冀及周边地区为例进行实证分析。得出如下结论:绿色产业政策有利于造纸产业的发展;“碳排放权交易”对造纸企业转型升级有一定程度的促进作用,而“碳排放权交易”“环境保护税”和“排污许可证”等对造纸企业转型升级具有一定的抑制作用。为促进我国造纸业高质量发展和实现双碳目标,政府应继续加大绿色政策扶持力度,大力推广清洁生产工艺和技术,引导企业积极开展节能减排改造活动,同时制定企业环境行为准则并加强对企业环境的责任落实与监督。

基于大数据视域下造纸工业废水控制软件系统升级改造研究

造纸业对水的需求整体较大,在造纸的过程中所生成的废水涉及到各类杂质,如颜料、纤维等,若是无法及时进行相应处理,则会对周围环境带来显著影响。基于大数据技术,成功开发造纸废水远程监控系统,对原有的废水控制系统进行升级。升级之后的系统使用微信小程序用作上位机,而下位机则使用了STM32芯片,借助于WIFI模块、云服务器等,将现场运行的动态参量传递至微信小程序,可对设备进行远程监控。系统在运行之后,具有较高的实时性,同时反应也具有较高的灵敏度,可以对造纸厂的废水排放进行远程监控。

新媒体背景下制浆造纸专业协同育人教育模式应用研究

新媒体络技术的不断发展以及中国轻化工产业的改革与升级,培养具有扎实专业技能以及综合能力较强的人才已成为轻化工产业结构转型升级中的重要环节。在制浆造纸专业基础上,对协同教育与互动教学的概念进行解读;总结高校内制浆造纸专业在德育教育中存在的问题;分析制浆造纸专业德育课互动教学优势特征并提出协同教育模式下制浆造纸专业教学方式;旨在为我国造纸行业培养大批高素质综合型人才。

高质量新动能下造纸业绿色低碳发展路径研究

绿色低碳发展已成为“十四五”时期推动经济高质量发展的重要引擎,对造纸业转型升级和可持续发展具有重要意义。基于此,拟在分析绿色低碳发展对造纸业重要意义的基础上,剖析造纸行业在原料选择、生产工艺、能源利用、污染治理等方面存在的突出问题,并围绕清洁生产、循环经济、智能制造等维度,就推进造纸行业绿色低碳发展、加快绿色转型升级进行系统探索,以期为造纸企业在新发展理念指引下谋划长远发展、实现高质量发展贡献绵薄之力。

基于数字经济的造纸产业转型升级路径研究

数字经济是指以信息和通信技术为基础,以数据为核心,以创新为驱动,以互联网为载体,以网络效应为特征的经济形态。数字经济的发展对各行各业都有着深远的影响,其中包括了传统的造纸产业。数字经济对传统造纸产业转型升级的直接驱动效应是沿着产业链数字化转型和产业链合理空间布局展开的,并形成造纸产业空间结构的完整思路体系框架。基于此,从数字转型与各省份造纸产业链空间布局两个方面阐述数字经济影响下,传统造纸产业经济转型升级的有效路径,以突破造纸产业发展困境。

绿色可循环视角下传统造纸企业绿色价值链创新管理研究

面对越来越严格的节能减排和污染防治要求,传统造纸企业正面临着绿色产品设计、绿色制造、绿色消费和绿色回收等经营革新的挑战。绿色价值链创新管理、低碳循环经济发展是实现传统造纸企业经济重塑与蓬勃发展的必经之路。对此,简述了绿色价值链的涵义,分析了传统造纸产业绿色循环经济发展现状,探究了传统造纸企业实施绿色价值链创新管理的必要性和意义,并基于绿色可循环视角提出传统造纸企业绿色价值链创新管理策略,以期推动传统造纸企业的转型升级和绿色可持续发展。具体体现在:调整原料与能源结构、创新绿色包装、改进绿色营销和绿色价值链风险识别与防范。

Review on cryogenic technologies for CO_(2) removal from natural gas

CO_(2) in natural gas(NG)is prone to condense directly from gas to solid or solidify from liquid to solid at low temperatures due to its high triple point and boiling temperature,which can cause a block of equipment.Meanwhile,CO_(2) will also affect the calorific value of NG.Based on the above reasons,CO_(2) must be removed during the NG liquefaction process.Compared with conventional methods,cryogenic technologies for CO_(2) removal from NG have attracted wide attention due to their nonpolluting and low-cost advantages.Its integration with NG liquefaction can make rational use of the cold energy and realize the purification of NG and the production of byproduct liquid CO_(2).In this paper,the phase behavior of the CH_(4)-CO_(2) binary mixture is summarized,which provides a basis for the process design of cryogenic CO_(2) removal from NG.Then,the detailed techniques of design and optimization for cryogenic CO_(2) removal in recent years are summarized,including the gas-liquid phase change technique and the gas-solid phase change technique.Finally,several improvements for further development of the cryogenic CO_(2) removal process are proposed.The removal process in combination with the phase change and the traditional techniques with renewable energy will be the broad prospect for future development.

智能化视角下中国造纸产业高质量发展路径规划研究

智能化时代的到来给我国造纸产业带来了巨大的转型升级机遇与挑战。为获得智能化时代下中国造纸产业高质量发展的宏观路径与微观策略,从中国造纸产业发展现状及当前面临的发展问题入手进行分析,总结了智能化时代的到来给中国造纸产业造成的影响,分析了智能化视角下中国造纸产业高质量发展的路径规划原则,从做好战略规划、强化协同创新、避免增加额外负担、重视人才培养等角度对智能化视角下中国造纸产业高质量发展路径进行了具体规划。