Size reduction of high- and low-moisture corn stalks by linear knife grid system

High- and low-moisture corn stalks were tested using a linear knife grid size reduction device developed for first-stage size reduction. The device was used in conjunction with a universal test machine that quantified shearing stress and energy characteristics for forcing a bed of corn stalks through a grid of sharp knives. No published engineering performance data for corn stover with similar devices are available to optimize performance; however, commercial knife grid systems exist for forage size reduction. From the force–displacement data, mean and maximum ultimate shear stresses, cumulative and peak mass-based cutting energies for corn stalks, and mean new surface area-based cutting energies were determined from 4–5 refill runs at two moisture contents (78.8% and 11.3% wet basis), three knife grid spacings (25.4, 50.8, and 101.6 mm), and three bed depths (50.8, 101.6, and 152.4 mm). In general, the results indicated that peak failure load, ultimate shear stress, and cutting energy values varied directly with bed depth and inversely with knife grid spacing. Mean separation analysis established that high- and low-moisture conditions and bed depths ≥ 101.6 mm did not differ significantly (P < 0.05) for ultimate stress and cutting energy values, but knife grid spacing were significantly different. Linear knife grid cutting energy requirements for both moisture conditions of corn stalks were much smaller than reported cutting energy requirements. Ultimate shear stress and cutting energy results of this research should aid the engineering design of commercial scale linear knife gird size reduction equipment for various biomass feedstocks.     

The potential of electricity imports to meet future electricity requirements in India

As resources of electricity generation in India are not sufficient, this paper analyses the potential of electricity import from neighboring countries to meet the future electricity requirements of India. Based on the data of electricity generation, consumption, and future generation potential, we work out projected electricity generation/ demand of India and its neighboring countries by 2050 to identify the possibility of India’s cross-border electricity trading with its neighboring countries, more particularly the electricity import potential.     

Flexible,hard, and tough biobased polyurethane thermosets from renewable materials: glycerol and 10-undecenoic acid

The main theme of this work is to develop 100% biobased low viscous polyols from renewable resources. An epoxide compound (UA-GLY-E) was synthesized through esterification of glycerol and 10-undecenoic acid preceded by peroxidation. For the first time, UA-GLY-E was utilized as a building block in the generation of low viscous polyols and polyurethanes therefrom. The biobased polyols were synthesized by epoxide ring opening of UA-GLY-E with different nucleophiles, namely glycerol, water, and methanol. The advantage of these biobased polyols is their low viscosity and at the same time high functionality. These biobased polyols were further converted into poly(urethane–urea) coatings by reacting with methylene diphenyl diisocyanate. The impact of peripheral structural change in the polyols on the properties of polyols and their polyurethane coatings was studied. Flexible, hard, and tough thermosets have been prepared successfully from the same epoxy compound by altering the peripheral moiety in the polyol structure. Biobased polyurethanes prepared from glycerol and water-based polyols have shown better crosslinking density over the methanol-based polyol. Moreover, these biobased polyurethane films have shown good thermal stability, mechanical strength, and chemical resistance as well.