Transport properties of a binary mixture of CO_2-N_2 from the pair potential energy functions based on a semi-empirical inversion method

The potential energy snrface of a CO2-N2 mixture is determined by using an inversion method, together with a new collision integral correlation [J. Phys. Chem. R@ Data 19 1179 （1990）]. With the new invert potential, the transport properties of CO2-N2 mixture are presented in a temperature range front 273.15 K to 3273.15 K at low density by employing the Chapman-Enskog scheme and the Wang Chang-Uhlenbeck de Boer theory, consisting of a viscosity coefficient, a thermal conductivity coefficient, a binary diffusion coefficient, and a thermal diffusion factor. The accuracy of the predicted results is estimated to be 2% for viscosity, 5% for thermal conductivity, and 10% for binary diffusion coefficient.

Assessment of CH4 and C 2 surface emissions from Polesgo’s landfill(Ouagadougou, Burkina Faso) based on static chamber method

Methane (CH4) and carbon dioxide (C02) surface emissions from Polesgo's landfill (Ouagadougou, Burkina Faso) were measured using the static chamber technique in 2017 and 2018. The Polesgo's landfill was composed of four zones: Phase I, II, Phase III, and SP. The surface of Phase I was fully covered and its conditions are better for surface emission measurements. As results concerning the Phase I zone, the geospatial means flux rates of CH4 (657 mg m-2 h l in 2017 and 1210 mg m 2 h_, in 2018, respectively) are measured higher than the tolerable value reported in literature. The emitted CH4 or C 02 have permitted to locate higher surface emissions which are related to the cover state. The calculated gas collection efficiency (27.4% in 2017 and 23.0% in 2018) is low compared to those reported for landfills integrating landfill gas (LFG) extraction system. The carbon footprint calculations (24,966 tC02-eq 2017 and 40,025 tC02-eq in 2018, respectively) shown that Polesgo's landfill is a significant source of greenhouse gases (GHG) and its important potential for organic recovery can contribute to reduce the carbon footprint.

Preparation and Application of the Sol–Gel Combustion Synthesis-Made CaO/CaZrO_3 Sorbent for Cyclic CO_2 Capture Through the Severe Calcination Condition

Calcium looping method has been considered as one of the efficient options to capture C02 in the combustion Ilue gas. CaO-based sorbent is the basis for application of calcium looping and should be subjected to the severe calcination condition so as to obtain the concentrated C02 stream. In this research, CaO/CaZrO3 sorbents were synthesized using the sol-gel combustion synthesis （SGCS） method with urea as fuel. The cyclic reaction performance of the synthesized sorbents was evaluated on a lab-scaled reactor system through calcination at 950 ℃ in a pure C02 atmosphere and carbonation at 650 ℃ in the 15% （by volume） C02. The mass ratio of CaO to CaZr03 as 8：2 （designated as CasZr2） was screened as the best option among all the synthesized CaO sorbents for its high CO2 capture capacity and carbonation conversion at the initial cycle. And then a gradual decay in the C02 capture capacity was observed at the following 10 successive cycles, but hereafter stabilized throughout the later cycles. Furthermore, structural evolution of the carbonated CasZr2 over the looping cycles was investigated. With increasing looping cycles, the pore peak and mean grain size of the carbonated CasZr2 sorbent shifted to the bigger direction but both the surface area （SA） ratio and surface fractal dimension Ds decreased. Finally, morphological transformation of the carbonated CasZr2 was observed. Agglomeration and edge rounding of the newly formed CaC03 grains were found as aggravated at the cyclic carbonation stage. As a result, carbonation of CasZr2 with C02 was observed only confined to the external active CaO by the fast formation of the CaC03 shell outside, which occluded the further carbonation of the unreacted CaO inside. Therefore, enough attention should be paid to the carbonation stage and more effective activation measures should be explored to ensure the unreacted active CaO fully carbonatPd river the extended Ioonin cycles.

日本甲烷水合物开发现状与进展

世界陆地和深海甲烷水合物（MH）合计原始储量为2×10·6m3。日本周边已确认的MH储量为6x101Zm3以上。目前．美国和日本的MH开发计划均以砂质层中的MH为主要开发对象。2001年7月日本“MH开发研讨委员会”提出了“日本MH开发计划”，并组建了MH21研究企业集团实施从基础研究到商业化生产的开发计划。计划的第一阶段（2001～2008年度）实施基础研究，调查东部南海海沟的资源量。第二阶段（2009～2015年度）目标为：选择日本近海资源场地，实施世界首次减压法的生产试验；为商业规模生产配备机器设备、拟定操作程序并研究其经济性；验证环境影响监控设备等。第三阶段（2016～2018年度）实现商业化的技术开发。日本2008年度完成了第一个阶段的任务。推荐减压法适用于日本周边海域的MH天然气生产。第二阶段和第三阶段相当于技术的发展成长期。2018年以后转向商业化开发阶段后，民营企业将成为主体，承担技术、经济、环境方面的风险。美国进行了注入CO2的MH天然气生产现场实验。印度、韩国和我国也开始MH研究开发工作。

Research on desorption and regeneration of simulated decarbonization solution in the process of CO_2 capture using ammonia method

Study on desorption and regeneration of simulated decarbonization solution using ammonia method for CO2 capture was car- fled out in order to understand the feature of regeneration of decarbonization solution. The mechanisms about solution desorp- tion after decarbonization were introduced briefly. Under the atmospheric pressure and in the presence of nitrogen carrier gas, several effects related to desorption of simulated decarbonization solution were analyzed, such as temperature, solution con- centration, pH, loading capacity, etc. The results showed that the CO2 desorption percentage increased with the increases of temperature, solution concentration and loading capacity, but CO2 desorption percentage increased with the increasing of pH and then decreased.