Synthesis of lignin-based resin and fabrication of sustainable transparent wood based on bio-recycling concept.

Transparent wood (TW) has attracted much attention in the field of energy saving building structural materials because of its high light transmittance, good thermal insulation performance and good toughness. However, the polymeric resins used in the present study to impregnate lignin-based wood templates are usually derived from petroleum-based chemical resources, which pose a fatal threat to human beings both in terms of consuming large amounts of resources and causing environmental pollution problems. It is therefore important to develop alternatives to petroleum-derived chemicals in renewable natural resources. Here, we report a green and sustainable TW production process based on the bio-recycling concept. Lignin-based sustainable resin (LSR) was prepared from waste lignin produced during delignification by polymerization of guaiacol. At the same time, according to FT-IR and NMR data analysis combined with previous studies, the synthesis mechanism of LSR was proposed, and this result provided a reference for bio-based resins made from biomass materials. The prepared lignin-based sustainable transparent wood (LSTW) has good light transmittance and good dimensional stability. In addition, the LSTW also shows good thermal insulation and indoor temperature regulation capabilities compared with the common glass.

Ball-milling as effective and economical process for biodiesel production under Kraft lignin activated carbon stabilized potassium carbonate.

Biodiesel is a typical renewable energy and the previous transesterification processes for biodiesel production mainly focus on thermocatalytic methods. In this paper, the ball-milling process was investigated into the biodiesel production under Kraft lignin activated carbon stabilized K2CO3. Biodiesel yield increased to 66 % after only 5 min and reached 100 % within 25 min under optimal ball-milling conditions (0.5 g of the catalyst; methanol/oil molar ratio 18:1; 195 g of ball-mill beads; 1400 rpm; 25 °C). The power demand between the thermocatalytic method and the ball-milling method was also compared. Based on the computation, the ball-milling method has lower power demand than the traditional method (38 vs 201 kWh·mol-1). Therefore, the ball-milling method is an effective and economical process for biodiesel production.

Hydrogen-induced high-temperature segregation in palladium silver membranes.

Higher operation temperatures benefit H2 permeability and selectivity of metal membranes and they are interesting for e.g. water gas shift and steam reforming in membrane reactors. Hence the behaviour of PdAg-ceramic composite membranes has been investigated between 823 K and 923 K. The H2 flux of membranes with less than 10 µm thick alloy layers decreased continuously with time during operation under H2 at 873 K and above. This was accompanied by a steady increase of the activation energy for H2 permeation and the growth of Ag-depleted crystallites on the membrane surface. All phenomena could be reversed through annealing under N2 at 923 K. The textural and permeability changes are consistent with a segregation mechanism starting with metal sublimation from hydrogenated PdAg layers and subsequent metal resublimation. This implies an enhancement of the yet unknown metal activities in PdAg hydride phases over metallic PdAg alloys. Ramifications for application of thin-layered, supported PdAg membranes for H2 separation above 823 K are discussed.