Eco-friendly fermentation module for maximization of hydrogen harvesting from fatty restaurant waste diluted with grey water

Valorization of fatty restaurant waste (RW) is an economically and environmentally promising approach due to the enriched high biodegradable organic content of this substrate. However, the lipid fraction has an adverse impact on the hydrogen fermentation process. Thus, three staged hybrid reactors (HR1, HR2 and HR3) connected in series were investigated for lipid degradation and H₂ harvesting from the codigestion of fatty RW and grey water. A hydrogen harvesting volume of 0.3 ± 0.02 L/L.d., was recorded in HR1, and lower values of 0.22 ± 0.1 and 0.11 ± 0.06 LH₂/L.d were obtained in HR2 and HR3, respectively. The phyla Actinobacteria (6.4%), Bacteroidetes (10.9%), Chloroflexi (45.1), and Proteobacteria (22.4%), which degrade carbohydrates, lipids and proteins, were dominant in HR1 and highly reduced in HR2 and HR3. Nevertheless, the abundance of the phylum Firmicutes was 16.6% in HR1 and increased to 21.7% in HR3. Staging of the anaerobic digesters highly distributed the hydrolytic and acetogenic syntrophic microbes, creating a unique fermentation medium for H₂ harvesting from RW diluted with grey water.     

AZ31B镁合金磷化工艺研究

应用Tafel极化曲线分析方法,对在不同磷化时间及不同磷化温度条件下磷化的AZ31B镁合金的防腐性能进行了研究,此外还研究了磷化膜的存在对AZ31B镁合金表面环氧涂层防腐性能的影响.研究结果表明:磷化时间及磷化温度对AZ31B镁合金磷化膜的防腐性能有较大影响,其最佳磷化时间为5min,最佳磷化温度为50℃.在最佳条件下,磷化膜的腐蚀电流密度最小,腐蚀电位明显正移,且极化电阻最大.此外,磷化膜的存在使环氧涂层在AZ31B镁合金表面的腐蚀电流密度下降了3个数量级,腐蚀电位正向移动了588mV,即磷化膜可提高环氧涂层在AZ31B镁合金表面的防腐性能.     

Modelling of methane sorption enhanced reforming for blue hydrogen production in an adiabatic fixed bed reactor: unravelling the role of the reactor's thermal behavior

Methane sorption enhanced reforming (SER) is investigated in this work as a promising route for blue H₂ production. A 1-D dynamic heterogeneous model is developed to evaluate the thermal behavior of a fixed bed reactor under adiabatic conditions. The heterogeneous model allows to decouple the feed gas temperature from the initial solid one in order to investigate the behavior of the reforming step in a temperature swing reforming/regeneration process. The effects of the feed gas temperature, the initial bed temperature, and the bed thermal capacity are studied by evaluating the global impact of each parameter through a set of key performance indices (CH₄ conversion, H₂ yield and purity, carbon capture ratio) calculated as integrals over the duration of the reforming step. The results highlight the minor effect of the initial bed temperature on the process performances showing the potential of minimizing the extent of a cooling step between regeneration and reforming stages. Besides, due to the endothermic nature of the methane sorption enhanced reforming process at high temperatures, thermal energy must be provided to the SER process to achieve high CH₄ conversion and high carbon capture ratio. This can be made either in the form of high feed temperature or by utilizing the energy stored in the bed benefiting from the bed thermal capacity.