Valorisation of Biowastes for the Production of Green Materials Using Chemical Methods

With crude oil reserves dwindling, the hunt for a sustainable alternative feedstock for fuels and materials for our society continues to expand. The biorefinery concept has enjoyed both a surge in popularity and also vocal opposition to the idea of diverting food-grade land and crops for this purpose. The idea of using the inevitable wastes arising from biomass processing, particularly farming and food production, is, therefore, gaining more attention as the feedstock for the biorefinery. For the three main components of biomass—carbohydrates, lipids, and proteins—there are long-established processes for using some of these by-products. However, the recent advances in chemical technologies are expanding both the feedstocks available for processing and the products that be obtained. Herein, this review presents some of the more recent developments in processing these molecules for green materials, as well as case studies that bring these technologies and materials together into final products for applied usage

of essential oils of Origanum onites

Superheated water extraction (SWE) at various temperatures (100, 125, 150 and 175degreesC), steam distillation, and Soxhlet extraction were compared in the extraction of essential oils from two samples of the plant Origanum onites, one cultivated, the other wild. C18 solid-phase extraction was used to elute the essential oils from the SWE aqueous extract. The compositions of the extracted essential oils obtained from all three methods were then characterized by comprehensive GCxGC/time-of-flight mass spectrometry (TOF/MS). The highest essential oil yields were obtained by using SWE at 150degreesC with a flow rate of 2 mL min(-1) and a pressure of 60 bar for 30 min: these were 3.76 and 4.11% for wild and cultivated O. onites samples, respectively, expressed as a percentage of 100 g of dry (leaf) matter. The yields obtained using SWE at 150degreesC were slightly higher than those from conventional methods. Steam distillation was performed for 3 h, and Soxhlet extraction was completed in 12 h. The major compounds found were borneol, terpinen-4-ol and carvacrol.C1 Univ Pamukkale, Fac Sci & Arts, Dept Chem, TR-20017 Denizli, Turkey

Superheated water extraction of fragrance compounds from Rosa canina

Floral oil of Rosa canina was isolated using superheated water extraction (SWE). The effects of different temperatures (50 degreesC, 100 degreesC and 150 degreesC) and pressures (25, 50 and 75 bar) on the recovery of fragrance compounds were investigated. The components of rose oil were removed from the aqueous extract by C18 solid phase extraction. Qualification and quantification were carried out by fast gas chromatography-time of flight/mass spectroscopy (GC-TOF/MS) and gas chromatography-flame ionization detection (GC-FID), respectively. SWE of rose petal oils shows a highest extraction efficiency at 100 degreesC, 2 ml/min flow rate and 50 bar pressure for 2 h. The SWE-based method is quicker, more environmentally friendly and more efficient than the Soxhlet extraction method. Copyright (C) 2004 John Wiley Sons, Ltd.C1 Univ Pamukkale, Fac Sci & Arts, Dept Chem, TR-20017 Denizli, Turkey.Univ Leeds, Sch Chem, Leeds LS2 9JT, W Yorkshire, England

supercritical fluid extraction

Supercritical fluid extraction (SFE) is currently being investigated as a possible technique in the production of high quality mesophase pitch from coal tar and petroleum pitches. Mesophase pitch is used to make high technology products, such as carbon fibre. The conventional production of mesophase pitch initially involves the removal of low molecular weight species from coal tar and petroleum pitches. The remaining residue is then transformed into a mesophase pitch through a polymerisation process. The aim of this study involves the extraction of light molecular weight species using SFE. Both petroleum and coal tar pitch contain complex aromatic molecules with an average molecular weight of 200 to 800, whereas mesophase pitch has a molecular weight range of about 1200 to 1300. Toluene, heptane, pentane and methanol were added to CO2 as modifiers at temperatures between 80 and 200degreesC and at pressures of 200 to 400 atm. The effect of the temperature and pressure on extraction yield was found to be less than that of modifier addition and the results showed that the extraction Yields were 19% and 33% from the petroleum and coal tar pitches respectively

Extraction Using GCxGC-TOF/MS

Superheated water extraction was used to extract essential oils from leaves and grains of Origanum onites. The effect of different sample collection dates on the amount and composition of extracted essential oils was investigated. C-18 solid phase extraction was used to elute the essential oils from the aqueous extract. The volatile components were characterized by comprehensive (two dimensional) gas chromatography with time of flight mass spectrometry (TOF/MS). The O. onites samples were collected on three different dates (15 June 2006, 25 June 2006, 05 July 2006). The extraction yields from O. onites leaves were 2.88 %, 3.06 % and 3.97 %; and from O. onites grains 3.63 %, 4.22 % and 4.57 %, respectively from each collection date. The main component found in all samples was carvacrol. The later collection dates gave better essential oil recovery from both leaves and grains

Superheated water extraction, steam distillation and Soxhlet extraction of essential oils of Origanum onites.

Superheated water extraction (SWE) at various temperatures (100, 125, 150 and 175 degrees C), steam distillation, and Soxhlet extraction were compared in the extraction of essential oils from two samples of the plant Origanum onites, one cultivated, the other wild. C18 solid-phase extraction was used to elute the essential oils from the SWE aqueous extract. The compositions of the extracted essential oils obtained from all three methods were then characterized by comprehensive GCxGC/time-of-flight mass spectrometry (TOF/MS). The highest essential oil yields were obtained by using SWE at 150 degrees C with a flow rate of 2 mL min(-1) and a pressure of 60 bar for 30 min: these were 3.76 and 4.11% for wild and cultivated O. onites samples, respectively, expressed as a percentage of 100 g of dry (leaf) matter. The yields obtained using SWE at 150 degrees C were slightly higher than those from conventional methods. Steam distillation was performed for 3 h, and Soxhlet extraction was completed in 12 h. The major compounds found were borneol, terpinen-4-ol and carvacrol

supercritical fluid extraction

Supercritical fluid extraction (SFE) is currently being investigated as a possible technique in the production of high quality mesophase pitch from coal tar and petroleum pitches. Mesophase pitch is used to make high technology products, such as carbon fibre. The conventional production of mesophase pitch initially involves the removal of low molecular weight species from coal tar and petroleum pitches. The remaining residue is then transformed into a mesophase pitch through a polymerisation process. The aim of this study involves the extraction of light molecular weight species using SFE. Both petroleum and coal tar pitch contain complex aromatic molecules with an average molecular weight of 200 to 800, whereas mesophase pitch has a molecular weight range of about 1200 to 1300. Toluene, heptane, pentane and methanol were added to CO2 as modifiers at temperatures between 80 and 200degreesC and at pressures of 200 to 400 atm. The effect of the temperature and pressure on extraction yield was found to be less than that of modifier addition and the results showed that the extraction Yields were 19% and 33% from the petroleum and coal tar pitches respectively

Determination of Teucrium chamaedrys volatiles by using direct thermal desorption-comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry.

The direct qualification and quantification of the volatile components of Teucrium chamaedrys was studied using a direct thermal desorption (DTD) technique with comprehensive two-dimensional (2D) gas chromatography-time-of-flight mass spectrometry (GC x GC-TOF/MS). The GC x GC separation chromatographically resolved hundreds of components within this sample, and with the separation coupled with TOF/MS for detection, high probability identifications were made for 68 compounds. The quantitative results were determined through the use of internal standards and the desorption of differing amounts of raw material in the injector. The highest yield of volatile compounds (0.39%, w/w) was obtained at 150 degrees C thermal desorption temperature using 1.0mg of dried sample placed in a glass injector liner when studied over the range 1.0-7.0mg. Lowest yield of 0.33% (w/w) was found for the largest sample size of 7.0mg. Relative standard deviation (RSD) for 10 replicates at each size sample were in the range 3.9-21.6%. The major compounds identified were beta-pinene, germacrene D, alpha-pinene, alpha-farnesene, alpha-gurjunene, gamma-elemene and gamma-cadinene. All identified compounds were quantified using total ion chromatogram (TIC) peak areas. DTD is a promising method for quantitative analysis of complex mixtures, and in particular for quantitative analysis of plant samples, which can yield data without the traditional obligation for costly and time-consuming extraction techniques

Analysis of Eucalyptus camaldulensis Volatiles from Turkey Using D-GC-MS

The direct analyses of the volatile organic components of 30 Eucalyptus camaldulensis fruit samples, obtained from the Antalya, Aegean and Cukurova regions in Turkey, was studied using a direct thermal desorption (DTD) technique coupled with gas chromatography mass spectrometry (GC-MS). It was found that the E. camaldulensis samples yielded a similar chemical composition. However, some of the compounds were only seen in one region, such as thymol in the Aegean region, ocimen and cis-sabinene hydrate in the Antalya region and nerolidol and pentacosane in the Cukurova region. A total of 68 components were identified from 30 samples. The main compounds found in the volatiles were: ledene (0-23.08 %), aromadendrene (0.59-42.31 %), alloaromadendrene (0-24.14%), globulol (0-19.97%) and isolongifolen (0-50.04 %). However, some of the quantities of the main compounds differed between samples. DTD with GC-MS is a good method for analysis of complex mixtures, and in particular for plant samples, which can yield data without the traditional obligation for costly and time consuming extraction techniques