Volume 8 Issue 2

Scientists have been devoting increased time and attention to the tops of trees. As made clear by results of their studies, the environment of the forest canopy is teeming with life. Perhaps because the crowns of trees are difficult for people to reach, and due to the micro-climates within them, they hold a rich and diverse collection of life forms. Advances in the use of ropes, ladders, and suspended walkways is now making it possible for humans to be more frequent visitors to these realms.

Although the use of ionic liquids (ILs) has provided a potentially effective technical tool to improve the lignocellulosic ethanol production process, the technology still is facing great challenges with respect to its efficiency and economic viability. This editorial gives a systematical analysis of the potential and limitations of lignocellulosic ethanol production using IL technology. The use of ILs establishes a new platform for fractionation of lignocellulosic biomass. The IL pretreatment of lignocellulosic biomass can greatly increase its saccharification rate and the fermentable sugar yield. Use of ILs can also intensify the ethanol fermentation process and improve ethanol separation efficiency from its fermentation broth. However, many technical difficulties still exist in reducing the process costs and alleviating the environmental and ecological effects. More research and financial support are needed to overcome these difficulties.

The integration of combinatorial green chemistry (CGC), a more benign approach to combinatorial chemistry, with environmental life cycle assessment (LCA) methodologies as an improved process development methodology is discussed. It is expected that the CGC approach will require less labor and result in more globally optimized assay results, leading to more optimized unit process design. The technique utilizes chemical assay stage information to rapidly predict globally optimized process conditions based on techno-economic and LCA indicators. A simplified kraft pulping case study of the application of CGC-LCA is demonstrated herein, but CGC analyses could be applied to virtually any chemical-based project development and implementation project.

The prevalence of smoking around the world is well known. During the smoking of cigarettes, various toxins in both the mainstream smoke and sidestream smoke are huge threats to people’s health. In this context, the reduction of toxic emissions is indeed a global concern. Engineering of cigarette-related components, including cigarette paper and tobacco, is important for mitigating the negative impacts of smoking. In the case of cigarette paper, such concepts as decreasing the amount of cellulosic fibers, use of burn-promoting additives, increasing the permeability of paper, and use of catalysts, adsorbents, and/or reductants, have been proposed in the literature. The commercialization of technologies for the engineering of cellulosic paper is expected to result in the production of “healthier” cigarettes. A possible blueprint is to tailor cigarette paper to help smokers to completely quit smoking.

Greenhouse carbon dioxide (CO2) enrichment from biomass residues was investigated using exhaust gas from the combustion of syngas produced by gasification. Near complete syngas combustion is essential to achieve CO2 levels which increase plant yields while maintaining a safe environment for workers. Wood pellets were supplied to a downdraft gasifier to produce syngas fed to a steel swirl burner. The preliminary results were encouraging and represented a first step toward a successful development of this technology. The burner required an equivalence ratio (the actual air to fuel ratio relative to the stoichiometric air to fuel requirements) of 2.6 for near complete combustion. Concentrations of sulphur dioxide (SO2) and ethylene (C2H4) emissions were either below critical concentrations or negligible. In 60% of the trials, carbon monoxide (CO) emissions were below ASHRAE standards for indoor air quality. However, the average nitrogen oxide (NOx) emission was 23.6 ppm, and it would need to be reduced below the 0.05 ppm to meet ASHRAE standards. Proposed improvements to the syngas burner design to lower NOx emissions and increase efficiency are: integration of a low swirl design, mesh catalysers, a higher quality refractory material, and a more efficient heat exchanger. Theoretically, combustion or gasification of biomass could provide more CO2 for greenhouse enrichment than propane or natural gas per unit of energy.

Hybrid composites are characterized by a variety of properties that are of interest to automotive applications, including strength, mechanical, and thermal properties. In this work, palm kernel shell-filled maleated polypropylene composites and palm kernel shell/nanosilica-filled maleated polypropylene hybrid composites were produced using a Brabender Internal Mixer. The results showed that the usage of the two types of filler in the PP matrix enhanced the tensile strength, elongation at break, and impact strength but reduced the tensile modulus of the PP composites. Thermal studies confirmed that the improved nucleating ability of the hybrid fillers contributed to the superb mechanical properties of the hybrid composites. A lower percentage of water absorption was observed in hybrid composites compared to the palm kernel shell/PP composite system.

The feasibility of co-producing activated carbon and bio-oil from rice stalk through molten salt pyrolysis is reported in this work. The results indicated that: (1) mixed ZnCl2-KCl molten salt could considerably improve the solid and liquid yield as well as the ratio of H2 and CH4 selectively (compared to the traditional ZnCl2 method), (2) an increase of pyrolysis temperature had the same impact on the yield as mixed molten salt, except for a decrease of the liquid yield, which may have a negative effect on the adsorption ability of activated carbon, and (3) the adsorption capability of activated carbon varied significantly with the activation temperature and, to a lesser degree, with the pyrolysis temperature. The conclusion can be drawn that pyrolysis in molten salt is a potential technology for agricultural residue utilization because of its capability of co-production, especially in activated carbon and bio-oil.

A simple strategy is reported for catalytic conversion of glucose to 5-hydroxymethylfurfural (HMF) over AlI3 in N,N-dimethylacetamide (DMAC). When the reaction was conducted in DMAC at 120°C for 15 min over AlI3 catalyst, HMF was obtained with a yield of 52%. The reaction course was monitored by 13C NMR spectroscopy and HPLC analysis. The results suggest that AlI3 catalyzes the three consecutive reactions consisting of mutarotation of α-glucopyranose to β-glucopyranose, isomerization of glucose to fructose, and dehydration of fructose to HMF.

In order to use oil palm trunks more effectively, a new method was investigated to estimate the weight-based ratio of vascular bundles (VB) to parenchyma tissue (PT) in study materials taken from oil palm trunks, by using near infrared (NIR) spectroscopy based on chemical analyses of the composition. The VB and PT were carefully separated by hand from oil palm trunks using a polarizing microscope to ensure purity, and then they were mixed at certain ratios. As the VB ratio was increased, extractives, lignin, hemicellulose, and starch contents decreased, while the alpha-cellulose content increased. By using NIR spectroscopy coupled with partial least squares regression analysis, we could predict the ratio of VB to PT with an accuracy of R2 = 0.99. Absorption peaks significantly affecting estimation were observed at 1929, 2104, 2276, and 2335 nm, which were assigned to the chemical compositions of cellulose and starch. The NIR absorbance is considered to reflect the ratio of VB to PT, according to the compositions of cellulose and starch in oil palm trunks.

Heat treatment effects on surface properties of wild cherry (Prunus avium) including surface roughness, glossiness, and color stability were evaluated. Samples were exposed to a temperature of 212 °C for 1.5 and 2.5 h. A stylus type profilometer, glossmeter, and spectrophotometer were employed to determine surface characteristics of heat-treated specimens. Glossiness and surface roughness values of the samples decreased with heat treatment compared to those of control specimens. The glossiness and values of surface roughness decreased for the samples with all treatment combinations. The samples had significant discoloration as a result of heat exposure. Color difference of the specimens increased as a result of all treatment schedules.