Baked Foams Based on Cassava Starch Coated with Polyvinyl Alcohol with a Higher Degree of Hydrolysis

The aims of this work were to produce trays based on cassava starch, coated with polyvinyl alcohol (PVA) with a higher degree of hydrolysis (98%), and to study the effects of the coating on the mechanical and water sorption properties of the trays. Two types of PVA were tested: SELVOL? 325 (degree of polymerization?=?1000–1500) and SELVOL? 107 (degree of polymerization?=?350–650). A decrease in the water absorption capacity of 50% was observed when the coated samples were compared with the control sample after 30 min of immersion in water. It was observed in both coated samples a reduction of the initial rate of water adsorption sorption and a decrease in hydrophilicity compared with the control sample. Tensile strength and elongation were increased with application of the coatings. The use of the two types of PVA resulted in materials with similar mechanical and water sorption properties.     

Synthesis,Characterization and Environmental Applications of a New Bio-Composite Gelatin-Zr(IV) Phosphate

Gelatin-Zr(IV) phosphate composite (GT/ZPC) was synthesized by sol–gel method. Different techniques viz. Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray powdered diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used for the characterisation of GT/ZPC composite ion exchanger. The ion exchange capacity (IEC) of GT/ZPC was observed to be better (1.04 meq g^?1) than its inorganic counterpart (0.64 meq g^?1). The pH studies revealed the monofunctional nature of GT/ZPC with one inflection point. The distribution studies showed that the GT/ZPC was highly selective for Cd²⁺ as compare to other metal ions. The environmental applicability of ion exchanger has been analysed for binary separations of metal ions using column method. Cd²⁺ was effectively removed from synthetic mixture of metal ions (Zn²⁺, Pb²⁺, Ni²⁺, Co²⁺ and Cu²⁺).     

Physical separation,mechanical enrichment and recycling-oriented characterization of spent NiMH batteries

Nickel–metal hydride (NiMH) batteries contain high amount of industrial metals, especially iron, nickel, cobalt and rare earth elements. Although the battery waste is a considerable secondary source for metal and chemical industries, a recycling process requires a suitable pretreatment method before proceeding with recovery step to reclaim all valuable elements. In this study, AA- and AAA-type spent NiMH batteries were ground and then sieved for size measurement and classification. Chemical composition of the ground battery black mass and sorted six different size fractions were determined by an analytical technique. Crystal structures of the samples were analyzed by X-ray diffraction. Results show that after mechanical treatment, almost 87 wt% of the spent NiMH batteries are suitable for further recycling steps. Size classification by sieving enriched the iron content of the samples in the coarse fraction which is bigger than 0.25 mm. On the other hand, the amounts of nickel and rare earth elements increased by decreasing sample size, and concentrated in the finer fractions. Anode and cathode active materials that are hydrogen storage alloy and nickel hydroxide were mainly collected in finer size fraction of the battery black mass.     

Absorption characteristics of potassium carbonate-based solutions with rate promoters and corrosion inhibitors

In this research, absorbents for CO₂ capture were prepared by blending 30 wt% potassium carbonate, 3 wt% of a rate promoter, and 1 wt% of a corrosion inhibitor. Pipecolic acid, sarcosine, and diethanolamine were chosen as rate promoter candidates. Based on a rate promoter screening test for CO₂ loading capacity and absorption rate, pipecolic acid and sarcosine were selected to be used as rate promoters. 1,2,3-benzotriazole and ammonium thiocyanate were chosen as corrosion inhibitors, and they were mixed with a 30 wt% potassium carbonate-based absorbent mixture containing one of the rate promoters. The absorption rates for four absorbent solutions (30 wt% potassium carbonate?+?3 wt% pipecolic acid?+?1 wt% 1,2,3-benzotriazole, 30 wt% potassium carbonate?+?3 wt% pipecolic acid?+?1 wt% ammonium thiocyanate, 30 wt% potassium carbonate?+?3 wt% sarcosine?+?1 wt% 1,2,3-benzotriazole, and 30 wt% potassium carbonate?+?3 wt% sarcosine?+?1 wt% ammonium thiocyanate) were measured, tabulated, and graphically displayed. These types of absorbents can be used for capturing CO₂ under high temperature and pressure conditions, such as those found in coal-fired power plants.     

Balancing the energy demand by a resource circulation project in Daejeon,Korea

Demand for sustainable renewable energy is on an increase worldwide, whereas the supply is limited. This paper analyses the feasibility of generating electricity and supplying the surplus steam to Daeduk Industrial Complex, by incinerating the combustible municipal waste generated in Daejeon Metropolitan City. The economic feasibility of surplus biogas generated from the anaerobic digestion of food waste and food waste leachate has been analysed. This study estimated resource circulation facility to supply 23,200 m³/day of biogas generated to Daejeon Combined Heat and Power plant. By 2023, it is expected to supply 25.7 tons of steam per hour all year round. The additional steam demand in Daeduk Industrial Complex is estimated as 101,537 tons/year. Surplus biogas will be supplied through an additional 960-m new installation. The cost of biogas is estimated at 30% of the unit biogas production cost. Daejeon Combined Heat and Power plant expects to make 60% additional profit, and Daeduk Industrial Complex and the communities nearby expect to achieve 10% cost savings. It also reduces the dependence of energy on fossil fuels, contributes to national environmental energy policy in reduction in greenhouse gases, creates competitiveness in local business and reduces corporate tax and generates revenue.     

Gasification characteristics of biomass for tar removal by secondary oxidant injection

Gasification experiments for sawdust were conducted using a fixed bed reactor at 900 °C by varying the secondary oxidant injection ratio to determine the optimal conditions for tar removal along with the enhancement of gasification efficiency. Secondary oxidant was injected as an oxidant at the top zone of the gasifier in varying ratios of 10–30% of the total amount of oxidant. This method was based on the primary method of tar removal and gasification efficiency improvement by thermal cracking of tar. Various gasification performance parameters were evaluated and tar content was estimated by measuring the fluctuation of weight of the activated carbon filter. The results showed that the concentration of tar in the producer gas decreased by injecting the secondary oxidant, even though syngas yield decreased. The recycling potential of the char produced in the gasification experiments was also assessed with the purpose of utilizing char as an adsorbent by determining its surface area and pore volume. The results demonstrated that the char produced from the gasification experiment had similar quality to that of the activated carbon used in this experiment.     

Production of natural and recycled aggregates: the environmental impacts of energy consumption and CO<Subscript>2</Subscript> emissions

Natural aggregates (NA) are crushed and processed in crushing plants after the extraction stage in quarries. In the present study, the aggregates are divided into three scenarios, depending on the production methods. The first scenario considers the production of NA, the second scenario deals with the production of recycled aggregates (RA) with respect to construction and demolition waste, and the third scenario, which is a hybrid scenario, handles the combination of NA and RA by assuming a 50% mixing percentage. In this research, we assess the environmental impacts on the production of aggregates via each scenario, using life cycle assessment; in addition, energy consumption and CO₂ emissions are considered as the environmental variables. We conclude that Iran’s current policy with an annual energy consumption of 1.48 million tons of oil equivalent (toe) can have a footprint of 2.88 million tons of CO₂ eq emissions per year (the first scenario). Achieving 30 and 36% reduction in annual energy consumption and CO₂ emissions, respectively, by the third scenario compared to the first scenario indicates the destructive effect of the first scenario from the environmental outlook.     

Mechanical Properties of Layered Laminated Woven Bamboo <Emphasis Type="Italic">Gigantochloa Scortechinii</Emphasis>/Epoxy Composites

This study investigated the application of bamboo as a natural composite, in which its potential as a composite material had been examined for 2–6 layers. In precise, the woven bamboo (BW) formed the culm fiber composite with an average of 0.5 mm thickness and 5.0 mm width strip. In addition, this study looked into a specific type of bamboo species known as Gigantochloa Scortechinii (Buluh Semantan), which can be found in Malaysia. This laminated plain BW, which had been reinforced with epoxy (EP), was developed by applying the hand lay-up technique. After that, the specimens were characterized via mechanical analyses, for instance, tensile, flexural, hardness, and impact tests. As a result, the 2-layer BW had displayed rather excellent results chiefly due to the incorporation of epoxy composite, although this is exceptional hardness value.     

Improvement of Impact Toughness of Biodegradable Poly(butylene succinate) by Melt Blending with Sustainable Biobased Glycerol Elastomers

Poly(butylene succinate) (PBS) was melt blended with glycerol based polyesters (PGS) synthesized from pure and technical glycerol aiming to improve the impact strength of PBS. It was found that after addition of 30 wt% PGS to PBS its impact strength was significantly increased by 344% (from 31.9 to 110 J/m) and its elongation at break was maintained at 220%. Infrared spectra of the blends showed the presence of hydroxyl groups from the PGS phase suggesting that hydrogen bonding between the phases could be responsible for a good stress transfer and an efficient toughening in the PBS/PGS blends. Scanning electron microscopy imaging showed a good dispersion of PGS phase into PBS with a PGS particle size of 10 μm and less and no agglomeration. Addition of PGS to PBS was shown to be an effective strategy for improvement of PBS impact resistance without serious detrimental effects on its thermal and rheological properties.