There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Biomass is an important feedstock for the renewable production of fuels, chemicals, and energy. As of 2005, over 3% of the total energy consumption in the United States was supplied by biomass, and it recently surpassed hydroelectric energy as the largest domestic source of renewable energy. Similarly, the European Union received 66.1% of its renewable energy from biomass, which thus surpassed the total combined contribution from hydropower, wind power, geothermal energy, and solar power. In addition to energy, the production of chemicals from biomass is also essential; indeed, the only renewable source of liquid transportation fuels is currently obtained from biomass.

The Catalytic Valorization of Lignin for the Production of Renewable Chemicals

Renewable Resources Robert-Jan van Putten,†,‡ Jan C. van der Waal,† Ed de Jong,*,† Carolus B. Rasrendra,‡,⊥ Hero J. Heeres,*,‡ and Johannes G. de Vries* †Avantium Chemicals, Zekeringstraat 29, 1014 BV Amsterdam, the Netherlands ‡Department of Chemical Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands DSM Innovative Synthesis BV, P.O. Box 18, 6160 MD Geleen, the Netherlands Department of Chemical Engineering, Institut Teknologi Bandung, Ganesha 10, Bandung 40132, Indonesia

Hydroxymethylfurfural, A Versatile Platform Chemical Made from Renewable Resources

This critical review provides a survey illustrated by recent references of different strategies to achieve a sustainable conversion of biomass to bioproducts. Because of the huge number of chemical products that can be potentially manufactured, a selection of starting materials and targeted chemicals has been done. Also, thermochemical conversion processes such as biomass pyrolysis or gasification as well as the synthesis of biofuels were not considered. The synthesis of chemicals by conversion of platform molecules obtained by depolymerisation and fermentation of biopolymers is presently the most widely envisioned approach. Successful catalytic conversion of these building blocks into intermediates, specialties and fine chemicals will be examined. However, the platform molecule value chain is in competition with well-optimised, cost-effective synthesis routes from fossil resources to produce chemicals that have already a market. The literature covering alternative value chains whereby biopolymers are converted in one or few steps to functional materials will be analysed. This approach which does not require the use of isolated, pure chemicals is well adapted to produce high tonnage products, such as paper additives, paints, resins, foams, surfactants, lubricants, and plasticisers. Another objective of the review was to examine critically the green character of conversion processes because using renewables as raw materials does not exempt from abiding by green chemistry principles (368 references).

Conversion of biomass to selected chemical products

Various novel techniques including ultrasound-assisted extraction, microwave-assisted extraction, supercritical fluid extraction, and accelerated solvent extraction have been developed for the extraction of nutraceuticals from plants in order to shorten the extraction time, decrease the solvent consumption, increase the extraction yield, and enhance the quality of extracts. A critical review was conducted to introduce and compare the conventional Soxhlet extraction and the new alternative methods used for the extraction of nutraceuticals from plants. The practical issues of each extraction method were discussed. Potential uses of those methods for the extraction of nutraceuticals from plant materials was finally summarized.

Recent advances in extraction of nutraceuticals from plants

The objective is to develop an approximate model for diffusion problems by the parabolic profile approximation for particles with inert cores, where only outer shell region of a particle is available for diffusion. The overall mass transfer coefficient that appears in the approximate rate equation involves the effect of the inert core as the well as external film mass transfer . The validity of the model is evaluated by comparison with numerical solution of rigorous models. The model is compared with the extreme cases, i.e., uniform spherical particles and slab geometry

Approximations of Diffusion Processes for a Particle with Inert Core

Temperature and pressure effects of supercritical carbon dioxide (SCCO2) on the extraction of carotenoids and seed oil from rosehip fruits have been studied. Supercritical fluid extraction (SFE) has shown much potential skills for the isolation of organic compounds from various samples. SFE minimizes sample handling, provides fairly clean extracts, expedites sample preparation and reduces the use and disposal of environmentally aggressive solvents. SCCO2 is by far the fluid most commonly used in SFE. This is due to its non-toxicity, non-flammability, having low cost, ease of removal from the extracted ma- terials and having low critical temperature and pressure (31.1 o C and 7.4 MPa, respectively). Fruits and seeds of rosehip fruits were pretreated prior to extraction processes. Extraction was carried out at various pressures (15 - 45 MPa) and temperatures (40 - 80 o C). The yield of total carotenoids and seed oil ex- tracted from fruits and seeds of rosehip were found to be 1.43 - 5.02% and 4 - 15.8%, respectively. As detected by high-performance liquid chromatography (HPLC) methods, the carotenoids extracted from rosehip peel contained lycopene, β-carotene and xanthophylls. Lycopene, β-carotene and xanthophylls content in the extract were 7 - 84.9%, 0.93 - 6.0% and 0.002 - 0.13%, respectively. The total carotenoids and seed oil extracted, and carotenoids content in the extracts were significantly affected by SCCO2 con- dition. Fatty acids in the seed oil extracted were determined by gas chromatography - flame ionization detector (GC-FID) after esterification. No significant effects of SCCO2 condition were observed on the fatty acid composition of the extracts.

Effect of Supercritical Carbon Dioxide Condition on Extraction of Carotenoids and Seed Oil from Rosehip Fruits

Nano-structured Material Fabrication using Pulsed Laser Ablation in Supercritical CO2

Antioxidant compounds from mangosteen pericarps have been extracted with low-transition-temperature mixture (LTTM) assisted hydrothermal method Extracted antioxidant compounds were determined as xanthone and total phenolic compounds The effects of temperature, concentration of LTTM, and sonication pretreatment on the recovery of xanthone and total phenolic compounds were investigated Extraction were carried out in a batch extractor at various temperatures (120 – 160°C), concentrations of LTTM (01 – 03 mg/mL), and sonication pretreatments (0 – 10 min) LTTM used for extraction was consisted of citric acid as hydrogen bond donor and alanine as hydrogen bond acceptor Xanthone and total phenolic compounds were analyzed by spectrophotometer In order to determine the effect of extraction condition on the antioxidant efficiency of the extract, the antioxidant efficiency of extract were analyzed by DPPH assay method Based on the result, the recovery of xanthone increased as increasing temperature and concentration of LTTM Inversely, the recovery of total phenolic compounds decreased as increasing temperature The sonication pretreatment had significantly effect on the recovery of both xanthone and total phenolic compounds, however the optimum condition of sonication pretreatment was at 5 min The antioxidant efficiency of the extract was affected by the extraction condition, and the highest antioxidant efficiency was 1395 obtained at temperature of 120°C, LTTM concentration of 03 mg/mL, and sonication time of 5 minAntioxidant compounds from mangosteen pericarps have been extracted with low-transition-temperature mixture (LTTM) assisted hydrothermal method Extracted antioxidant compounds were determined as xanthone and total phenolic compounds The effects of temperature, concentration of LTTM, and sonication pretreatment on the recovery of xanthone and total phenolic compounds were investigated Extraction were carried out in a batch extractor at various temperatures (120 – 160°C), concentrations of LTTM (01 – 03 mg/mL), and sonication pretreatments (0 – 10 min) LTTM used for extraction was consisted of citric acid as hydrogen bond donor and alanine as hydrogen bond acceptor Xanthone and total phenolic compounds were analyzed by spectrophotometer In order to determine the effect of extraction condition on the antioxidant efficiency of the extract, the antioxidant efficiency of extract were analyzed by DPPH assay method Based on the result, the recovery of xanthone increased as increasing temperature and conc

Motonobu Goto

Papers

Approximations of Diffusion Processes for a Particle with Inert Core

Effect of Supercritical Carbon Dioxide Condition on Extraction of Carotenoids and Seed Oil from Rosehip Fruits

Nano-structured Material Fabrication using Pulsed Laser Ablation in Supercritical CO2

Hydrothermal extraction of antioxidant compounds from mangosteen pericarp with low-transition-temperature mixture and sonication pretreatment

Comparison of decomposition rate in supercritical water oxidation of various wastes