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It is hard to develop biodiesel industry currently as a consequence of the rapid increase in the prices of animal and vegetable oil in recent years. Production of high-value bulk chemicals from biodiesel (fatty acid methyl esters) and its by-product of glycerol is an effective way to overcome the difficulties and to promote the steady development of biodiesel industry. However, the choice of target products and technologic routes for producing them should follow three principles: 1) biomass feedstocks are cheaper than petroleum products when they are used as raw materials, 2) process being developed is simple and environmentally-friendly, 3) the target products are in line with the market demands [1]. Production of fatty alcohols (FA) from fatty acid methyl esters (FAME) by hydrogenation under supercritical conditions is in line with these principles. The study on hydrogenation of FAME to FA using propane and carbon dioxide as solvents under supercritical conditions has been reported previously. But the reaction is carried out above 15.0 MPa [2-5], and such high operation pressure will seriously increase the capital and operating costs. It is thus clear that a low-pressure hydrogenation process for FAME conversion to FA under supercritical conditions can lead to reduction in the capital and operating costs of the process while the advantages of supercritical reactions are maintained, which can also lead to great social and economic benefits.

Organic sulfides in fuels have become one of the main sources of serious pollution. The desulfurization of fuels has become a frontier scientific topic demanding prompt solutions. Research shows that the emergence of ionic liquid analogues—deep eutectic solvents (DESs)—has provided a new opportunity for the deep extraction desulfurization of fuels because of their cheap and easily obtained raw materials, higher extraction desulfurization efficiencies, and simple and environmentally friendly synthesis process. In this study, some DESs were designed and synthesized. Choline chloride (ChCl), tetramethyl ammonium chloride (TMAC), and tetrabutyl ammonium chloride (TBAC) were chosen as typical hydrogen bond acceptors (HBA), and malonic acid (MA), glycerol (Gl), tetraethylene glycerol (TEG), ethylene glycol (EG), polyethylene glycol (PEG), and propionate (Pr) were chosen as hydrogen bond donors (HBD), from which a series of deep eutectic solvents were synthesized. Research shows that the above DESs can be used for the desulfurization of fuels successfully. Tetrabutyl ammonium chloride-based DESs possess the highest extraction efficiency. In optimal conditions, the extraction efficiency of TBAC/PEG can reach as high as 82.83% for one cycle, which is much higher than the traditional and functionalized ionic liquids (ILs). After five cycles, the extraction efficiency can reach up to 99.48%. In addition, sulfur content in fuels can be reduced to less than 8.5 ppm and deep desulfurization was realized. Finally, the extraction mechanism was investigated systematically with quantitative 1H NMR and FT-IR. The hydrogen bonds formed between DESs and benzothiophene (BT) account for the higher desulfurization efficiency. This study will provide new green solvents for the extraction desulfurization process of fuels.

Near‐surface lateral inhomogeneities can lead to large errors in the interpretation of magnetotelluric data by shifting the MT apparent resistivity sounding curve by a factor that is almost independent of frequency on a standard log (apparent resistivity versus log‐frequency). The amount of this parallel shift, commonly known as the MT static shift, cannot be determined directly from conventionally recorded MT data at a single site because the shift is caused by boundary charges which mainly affect the electric field.