Background: The production of D-lactic acid (D-LA) from non-detoxified corn stover hydrolysate is hindered by substrate-mediated inhibition and low cell utilization times. In this study, we developed a novel temperature-sensitive hydrogel, F127-IEA, for efficient D-LA production using a cell-recycle batch fermentation process.Results: F127-IEA exhibited a porous structure with an average pore size of approximately 1 μm, facilitating the formation of stable Lactobacillus bulgaricus clusters within the gel matrix. It also maintains excellent mechanical properties. It also maintains excellent mechanical properties. F127-IEA immobilized Lactobacillus bulgaricus T15 (F127-IEA-T15) can be used in cell-recycle fermentation for over 150 days from glucose and 50 days from corn stover hydrolysate, achieving high production rates of D-LA from glucose (2.71 ± 0.85 g/L h) and corn stover hydrolysate (1.29 ± 0.39 g/L h). F127-IEA-T15 enhanced D-LA production by adsorbing and blocking toxic substances present in corn stover hydrolysate that are detrimental to cellular activity.Conclusions: The newly developed hydrogels in this study provide a robust platform for large-scale extraction of D-LA from non-detoxified corn stover.
Sun Yanan,Lv Zhengxian,Sun Zhiwei,Wu Chuanxiang,Ji Zhongyin,You Jinmao
A simple, sensitive, and selective high-performance liquid chromatography (HPLC) method using 9-(2-iodoethyl)acridone (IEA) as a novel fluorescence derivatizing agent for the simultaneous determination of six thiophenols has been developed. An efficient Pb 2+ -modified OASIS-MCX cartridge was used and could get good recoveries. IEA was successfully used to label thiophenols with high sensitivity and excellent selectivity. The effects of different solvents, pH, and surfactants on fluorescence properties of derivatives were investigated. To obtain the best labeling efficiency, derivatizing parameters including pH value, temperature, and concentration of IEA, as well as types of catalysts were also evaluated in detail. Under the optimal conditions, the separation could be achieved within 12 min with limits of detection (LODs) in the range of 0.6–5.8 μg L −1 and relative standard deviations (RSDs) < 3.9 %. This is the first time that IEA was applied to the analysis of thiophenols, and the established method has been successfully applied to the trace level detection of thiophenols in industrial wastewater samples.
Recently, worldwide, the attention being paid to hydrogen and its derivatives as alternative carbon-free (or low-carbon) options for the electricity sector, the transport sector, and the industry sector has increased. Several projects in the field of low-emission hydrogen production (particularly electrolysis-based green hydrogen) have either been constructed or analyzed for their feasibility. Despite the great ambitions announced by some nations with respect to becoming hubs for hydrogen production and export, some quantification of the levels at which hydrogen and its derived products are expected to penetrate the global energy system and its various demand sectors would be useful in order to judge the practicality and likelihood of these ambitions and future targets. The current study aims to summarize some of the expectations of the level at which hydrogen and its derivatives could spread into the global economy, under two possible future scenarios. The first future scenario corresponds to a business-as-usual (BAU) pathway, where the world proceeds with the same existing policies and targets related to emissions and low-carbon energy transition. This forms a lower bound for the level of the role of hydrogen and its penetration into the global energy system. The second future scenario corresponds to an emission-conscious pathway, where governments cooperate to implement the changes necessary to decarbonize the economy by 2050 in order to achieve net-zero emissions of carbon dioxide (carbon neutrality), and thus limit the rise in the global mean surface temperature to 1.5 °C by 2100 (compared to pre-industrial periods). This forms an upper bound for the level of the role of hydrogen and its penetration into the global energy system. The study utilizes the latest release of the annual comprehensive report WEO (World Energy Outlook—edition year 2023, the 26th edition) of the IEA (International Energy Agency), as well as the latest release of the annual comprehensive report WETO (World Energy Transitions Outlook—edition year 2023, the third edition) of the IRENA (International Renewable Energy Agency). For the IEA-WEO report, the business-as-usual situation is STEPS (Stated “Energy” Policies Scenario), and the emissions-conscious situation is NZE (Net-Zero Emissions by 2050). For the IRENA-WETO report, the business-as-usual situation is the PES (Planned Energy Scenario), and the emissions-conscious situation is the 1.5°C scenario. Through the results presented here, it becomes possible to infer a realistic range for the production and utilization of hydrogen and its derivatives in 2030 and 2050. In addition, the study enables the divergence between the models used in WEO and WETO to be estimated, by identifying the different predictions for similar variables under similar conditions. The study covers miscellaneous variables related to energy and emissions other than hydrogen, which are helpful in establishing a good view of how the world may look in 2030 and 2050. Some barriers (such as the uncompetitive levelized cost of electrolysis-based green hydrogen) and drivers (such as the German H2Global initiative) for the hydrogen economy are also discussed. The study finds that the large-scale utilization of hydrogen or its derivatives as a source of energy is highly uncertain, and it may be reached slowly, given more than two decades to mature. Despite this, electrolysis-based green hydrogen is expected to dominate the global hydrogen economy, with the annual global production of electrolysis-based green hydrogen expected to increase from 0 million tonnes in 2021 to between 22 million tonnes and 327 million tonnes (with electrolyzer capacity exceeding 5 terawatts) in 2050, depending on the commitment of policymakers toward decarbonization and energy transitions.
危险品化学品经营许可证（带存储）