Co-processing of bio-oil and petroleum-derived feed in a fluid catalytic cracking process of a refinery is considered to be one of the most potential bio-liquid fuel preparation technologies. The detailed qualitative and quantitative analysis of the oxygenates in the co-cracking products facilitates optimization of the subsequent processing. In this study, an in-depth characterization of trace oxygenates from home-made co-processing liquid products in a fluid catalytic cracking (FCC) pilot plant unit at different bio-oil water-soluble phase (BOWS)/vacuum gas oil (VGO) mass blending ratios (0/100, 10/90, 20/80) at different reaction temperature (500 and 525 °C) was performed with quantitative and qualitative comprehensive two-dimensional gas chromatography–mass spectrometry (GC × GC–MS). An internal standard method with the internal standard 1,1,3,3-tetramethoxypropane was used to quantify trace oxygenates, which was selected from the qualitative analysis of the co-processing liquid products. The results showed that the contents of phenols and benzofurans in the liquid products from co-processing were low and the addition of BOWS was beneficial to improve the co-processing conversion, reduce the coke yield, but reduce the gas products and gasoline yield. The deoxygenation of catalytic cracking for oxygenates also weakened with the increase of bio-oil addition. The increase of reaction temperature can strengthen the deoxygenation of catalytic cracking, but the excessively high temperature can strengthen the thermal cracking reaction and reduce the gasoline yield.
Due to its potential environmental hazards and the importance of valuable metal supply, the recycling of spent lithium-ion batteries (LIBs) has attracted widespread attention. The hydrometallurgical process for recycling spent lithium-ion batteries faces the problem of excessive acid consumption and the need for different redox additives to improve the leaching rate of major metals which will result in issues such as resource waste and secondary pollution. In this study, using LFP and NCM as raw materials, the inherent oxidation/reduction characteristics between them were utilized to achieve leaching rates of over 99 % for Ni, Mn, Li, and over 95 % for Co, without the addition of any redox additives under near stoichiometric sulfuric acid . The leaching kinetics and reaction mechanism of different metals indicate that LFP rapidly dissolves in the sulfuric acid solution, with the released Fe 2+ acting as a reducing agent. The subsequent slower reaction between Fe 2+ and NCM becomes the rate-controlling step. Afterwards, the leachate regulated by solution control can be further used to prepare Ni-Co-Mn hydroxide precursors and lithium carbonate after the formation of FePO 4 . This method effectively reduces chemical consumption, mitigates environmental footprint , and achieves highly economical recovery of metals from spent lithium-ion batteries.
Sun Xiaolei,Li Qiao,Shen Jinyou,Han Weiqing,Li Jiansheng,Sun Xiuyun
In this study, we report the co-treatment of municipal solid waste incineration fly ash and high arsenic-containing wastewater. The appropriate liquid-solid ratio for co-treatment and the feasibility of co-treatment with 5000 mg/L arsenic in wastewater were investigated, as well as the risk of heavy metals leaching from the co-treated products in the actual leachate. Further, a new index for assessing the risk of heavy metals releasing into the environment was proposed. The results demonstrated that the optimal liquid-solid ratio was 10 mL/ 20 g, considering that it allowed the maximum co-treatment amount of wastewater and would not affect the subsequent disposal of co-treated products in landfills. In the presence of 5000 mg/L arsenic in wastewater, the chemical speciation distribution and leaching toxicity of As, Cr, Cu, and Pb in the co-treated products would not change significantly. The leaching results of co-treated products in actual leachate indicated that the co-treated products can favor the stabilization of As, Cr, and Pb in leachate. The migration and transformation index value of Cu suggested the risk of Cu releasing in a leachate scenario. Through co-treatment, wastewater can be completely absorbed into the fly ash without the need for further treatment, featuring significant economic and environmental benefits. Graphical Abstract
危险品化学品经营许可证（带存储）