The electrochemical behavior of sodium tungsten bronze electrodes false(NaxWO3,normalwith x normalbetween 0.58 normaland 0.89false) has been examined in helium‐saturated 1N H2SO4 . Several techniques have been employed, e.g., steady‐state polarization, potentiodynamic scanning, galvanostatic charging, and open‐circuit decay of electrode potential. New data involving potential‐pH, rotating‐ disk, and thermogravimetric measurements on the sodium tungsten bronze electrode are also reported.The results indicate that the surface layer of a strongly anodized bronze electrode is depleted of sodium and its composition may approach WO3. On a strongly (cathodically) reduced NaxWO3 , formation of sodium‐hydrogen tungsten bronze false(NaxHzWO3false) is indicated. The reduction of a preoxidized (and hence sodium‐depleted) sodium tungsten bronze electrode produces hydrogen tungsten bronze HzWO3 .

Fast pyrolysis was used to convert waste biomass into bio-oil, which has a benefit of storage and transportation with the potential as a fossil oil substitute. Pakistani cotton stalk was pyrolyzed in a bench-scale bubbling fluidized bed reactor. The effect of reaction conditions such as temperature and feed size on the bio-oil, char and gas yields was investigated. The optimal pyrolysis temperature for the production of bio-oil was 490 • C which gave the maximum yield (36 wt%) of product at feed size of 1.0 mm. Bio-oil yield increased with the increase in temperature, while the yield of char decreased. The various properties of bio-oil attained under these pyrolysis conditions were defined. Chemical composition of bio-oil was determined using FTIR and GC-MS analysis, and major chemical compounds were phenols, carboxylic acids, ketones, aldehydes, furans and sugars.

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The yield and composition of pyrolysis products depend on the characteristics of feed stock and process operating parameters. Effect of particle size, reaction temperature and carrier gas fl ow rate on the yield of bio-oil from fast pyrolysis of Pakistani maize stalk was investigated. Pyrolysis experiments were performed at temperature range of 360-540°C, feed particle size of 1-2 mm and carrier gas fl ow rate of 7.0-13.0 m 3 /h (0.6-1.1 m/s superfi cial velocity). Bio-oil yield increased with the increase of temperature followed by a decreasing trend. The maximum yield of bio-oil obtained was 42 wt% at a temperature of 490°C with the particle size of around 1.0 mm and carrier gas fl ow rate of 11.0 m 3 /h (0.9 m/s superfi cial velocity). High temperatures resulted in the higher ratios of char and non-condensable gas.

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