Immobilization of ß-1,3-xylanase on pitch-based hyper-crosslinked polymers loaded with Ni2+ for algal biomass manipulation.

ß-1,3-xylanase plays an important role in the conversion of algal biomass into renewable chemical commodities and functional xylooligosaccharides. Efficient immobilization of the target enzymes that could integrate the separation, purification, and immobilization in one-step may have great potentials. The cheap and easily obtained pitch was adopted as the raw material to prepare the hyper-cross-linked polymers with the specific surface areas of 560 m2/g and the Ni2+ loading about 80 mg/g. As a carrier, it could immobilize and purify the ß-1,3-xylanases directly from the crude cell debris with the activity recovery of (80.66 ± 0.87) %. The half-life of the immobilized ß-1,3-xylanases was 50 min at 50 °C, which was significantly longer than the free ones with only 14 min. The immobilized ß-1,3-xylanases could retain 65 % of the activity after stored at 30 ℃ for 80 h, they could also retain 87 % of the original activity after 15 cycles of reuse. In terms of potential applications in the manipulation of algae Caulerpa lentillifera, the immobilized ß-1,3-xylanases could release 30 % more reducing sugar in 85 h. The method proposed here is promising for algal biomass manipulation because of its low cost, stable storage, convenient recycling and excellent reusability.

Preparation of Porous Carbon Materials Derived from Hyper-Cross-Linked Asphalt/Coal Tar and Their High Desulfurization Performance.

The development of simple and highly effective desulfurization technology is attracting more and more interest in both industrial and academic fields. Here, a new family of precursors was prepared based on hyper-cross-linked asphalt and coal tar building blocks. Thanks to the preintroduced porous structure, the precursors were converted into carbons with high surface area and large micropore volume via a uniform carbonization process. The synergistic effects of high surface area, abundant microporous structure, and the introduced polar functional groups endow the carbon materials with high desulfurization performance. The results of repeated experiments show that the adsorption capacities of five carbonized samples are higher than 40 mg S g-1, and the theoretical maximum adsorption capacity reaches 44.7 mg S g-1. Particularly, the adsorption equilibrium of all the carbonized samples can be reached in 5 min. Moreover, the recycle adsorption performance was also studied. Toluene exhibits the best elution effect among three eluents (iso-octane, para-xylene, and toluene) and the adsorption capacity remains 89% of the initial adsorption capacity after two adsorption-desorption cycles. It is believed that both innocent treatment of byproducts from petroleum industry and their high-value application for deep desulfurization in liquid hydrocarbon fuels benefit environmental protection and sustainable development.

Enhanced CO2 capture by reducing cation-anion interactions in hydroxyl-pyridine anion-based ionic liquids.

In this work, an efficient strategy for improving CO2 capture based on anion-functionalized ionic liquids (ILs) by reducing cation-anion interactions in ILs was reported. The influence of the cationic species on CO2 absorption was investigated using 2-hydroxyl pyridium anions ([2-Op]) as a probe. CO2 capture experiments indicated that the CO2 absorption capacity in [2-Op] anion-based ILs varied from 0.94 to 1.69 mol CO2 per mol IL at 30 °C and 1 atm. Spectroscopic analysis and quantum chemical calculations suggested that the increase of the CO2 absorption capacity may be ascribed to the reduction of the strength of cation-anion interactions in ILs, and stronger cation-anion interactions would make one CO2 site in the [2-Op] anion inactive. Furthermore, the effect of the cation unit on the anion was evidenced by FT-IR spectra, implying that strong interactions between ions may lead to the decrease of the IR absorption wavenumber of hydroxy pyridium and work against CO2 capture. Following this strategy, it was finally found that [Ph-C8eim][2-Op] (Ph-C8eim = 1-N-ethyl-3-N-octyl-2-phenylimidazolium) with weaker cation-anion interactions exhibited a significant increase in the CO2 uptake capacity, and extremely high capacities of 1.69 and 1.83 mol CO2 per mol IL could be achieved at 30 and 20 °C, respectively. The study presented here would be helpful for further designing novel and effective ILs for advancing CO2 capturing performance.