Society's increasing demand for transportation fuels has assured a viable future for the development of renewable fuels. Although first-generation biofuels are dependent on starches, sugars and vegetable oils, the need to generate higher volumes of biofuels at lower cost has shifted the research focus to cellulosic ethanol. The utilization of lignocellulosics for the sustainable manufacturing of biofuels is critically dependent on the chemical constituents of the starting biomass and the desired fuel properties. This review examines the major chemical constituents of biomass and the recent advances in their conversion to biofuels, with a special emphasis on the forest residues and woody-energy crops to bioethanol. © 2007 Society of Chemical Industry and John Wiley & Sons, Ltd

The new forestry biofuels sector

Role of water, acetic acid and chloride on corrosion and pitting behaviour of carbon steel in fuel-grade ethanol

The history of dynamic straining in stress corrosion cracking studies and the evolution of the slow strain rate test (SSRT) are reviewed. Smooth and notched specimens; the importance of strain rate, electrode potential, and other environmental factors; the evaluation of test results; and comparisons to other techniques are addressed. The SSRT’s application in research for oil and gas sour service, buried natural gas pipelines, ethanol transportation, nuclear power, low pressure turbines, and mechanism studies is summarized and its usage by material, industry, and geographic region quantified. Standard test procedures are compared and improvements suggested. The more recent use of cyclic loading is discussed and areas for future study proposed.

The Slow Strain Rate Stress Corrosion Cracking Test—A 50 Year Retrospective

The present invention relates to a method of producing silver films having large nanoparticles caused by cracking during anaerobic annealing to provide surfaces that exhibit increased metal enhanced fluorescence. Preferably the annealing process is conducted on a silver film having a thickness from about 14 to 17 nm for about an hour at a temperature of approximately 190° C. to about 210° C. resulting in the conversion of the just-continuous films into large particulate films, not readily assessable by other chemical deposition techniques.

Conversion of just-continuous metallic films to large particulate substrates for metal-enhanced fluorescence

An integrated Raman spectroscopy and laser-induced breakdown spectroscopy (LIBS) instrument is a valuable geoanalytical tool for future planetary missions to Mars, Venus, and elsewhere. The ChemCam instrument operating on the Mars Curiosity rover includes a remote LIBS instrument. An integrated Raman-LIBS spectrometer (RLS) based on the ChemCam architecture could be used as a reconnaissance tool for other contact instruments as well as a primary science instrument capable of quantitative mineralogical and geochemical analyses. Replacing one of the ChemCam spectrometers with a miniature transmission spectrometer enables a Raman spectroscopy mineralogical analysis to be performed, complementing the LIBS chemical analysis while retaining an overall architecture resembling ChemCam. A prototype transmission spectrometer was used to record Raman spectra under both Martian and Venus conditions. Two different high-pressure and high-temperature cells were used to collect the Raman and LIBS spectra to simulate surface conditions on Venus. The resulting LIBS spectra were used to generate a limited partial least squares Venus calibration model for the major elements. These experiments demonstrate the utility and feasibility of a combined RLS instrument.

Planetary Geochemical Investigations Using Raman and Laser-Induced Breakdown Spectroscopy

This paper presents the results of a study on the effects of water, acetic acid (CH3COOH), oxygen, corrosion inhibitor, chloride, methanol (CH3OH), denaturant, and corrosion product on the stress corrosion cracking (SCC) of steel in ethanol (C2H5OH). The factor that was found to have the greatest effect on causing SCC was corrosion potential, as influenced by oxygen. The lower critical potential for SCC ranges from 25 mV vs. saturated calomel electrode (SCE) to 300 mVSCE, depending on the presence of chloride and methanol as impurities. Galvanic contact with precorroded steel appeared to exacerbate SCC by increasing the corrosion potential. Within the fuel ethanol specification limits, chloride had a less significant effect than oxygen. SCC was intergranular when the chloride concentration in ethanol (both laboratory and field samples) was low (less than 1 ppm) and it was transgranular when the chloride concentration was high (32 mg/L). A denaturant, a corrosion inhibitor, and acidity, within the...

Stress Corrosion Cracking of Carbon Steel in Ethanol

Raman spectroscopy has been identified as a potentially useful tool to collect evidence of past or present life on extraterrestrial bodies. However, it is limited by its inherently low signal strength. In this investigation, laboratory tests were conducted using surface-enhanced Raman spectroscopy (SERS) in an "inverted" mode to detect the presence of organic compounds that may be similar to possible biomarkers present on Mars. SERS was used to overcome the inherently low signal intensity of Raman spectroscopy and was an effective method for detecting small concentrations of organic compounds on a number of surfaces. For small organic molecules, dissolution of the molecule to be analyzed in a suitable solvent and depositing it on a prepared SERS substrate for analysis is possible. However, for larger molecules, an "inverted" SERS (iSERS) technique was shown to be effective. In iSERS, nanoparticles of silver or gold were deposited on the mineral substrate/organic compound to be analyzed. Benzotriazole, benzoic acid, and phthalic acid were used as test organic analogs and the iSERS technique was able to detect femtomole levels of the analytes. The interference from various mineral substrates was also examined. Different methods of depositing silver particles were evaluated, including ion beam-assisted vapor deposition and deposition from aqueous colloidal suspensions.

Development of a Surface-Enhanced Raman Technique for Biomarker Studies on Mars

Cpc Performance In Occluded Sites

Embedded Coating Degradation Sensors For Monitoring Performance Of Temporary Coatings

Polarization and Mott-Schottky experiments were performed on alloy 625 samples previously exposed to 1.2 MeV gamma radiation at dose rates up to 1 Mrad/hour. While the breakdown potential is dependent on dose rate, the repassivation potential is not. These residual effects of the radiation exposure were not observed on samples exposed to the field in an air environment. At the highest dose rate, trapped holes at the surface at potentials above the repassivation potential result in a significant reduction in the crevice corrosion nucleation time.

Kendra T. Price

Papers

Stress Corrosion Cracking of Carbon Steel in Ethanol

Development of a Surface-Enhanced Raman Technique for Biomarker Studies on Mars

Cpc Performance In Occluded Sites

Embedded Coating Degradation Sensors For Monitoring Performance Of Temporary Coatings

Electrochemical and Mott-Schottky Behaviour of the Oxide Films on 1625 Exposed to Gamma Radiation