Application of recycled paper sludge and biomass materials in manufacture of green composite pallet

Rice straw, rice husk and paper sludge are by-products and industrial waste, and are beneficial resources as raw biomass materials used for manufacturing value-added composite products. We investigated the effect on selected mechanical properties of adding rice straw, rice husk and paper sludge to wood composites to replace wood particles for manufacturing green pallets. Results showed that increasing the contents of rice straw and rice husk dramatically decreased the mechanical strength of the composites. This is because the wax and silicate coating of these materials obstructed the strong bonding with UF resin. When 10 wt.% of wood particle was replaced with 10 wt.% of paper sludge, the wood–paper sludge composites showed similar mechanical properties to those of wood particle. Wood particle can be replaced by 10 wt.% of dried paper sludge in accordance with the minimum requirement recommended by standards in green pallet manufacturing.     

Biomass as the Renewable Energy Sources in Malaysia: An Overview

Past and current economic growths of Malaysia have been primarily energized by fossil fuels. Malaysia has very substantial potential for biomass energy utilization given its equatorial climate that is ideal for dense tropical forest growth and agricultural vegetation. There are five major sectors contributing wastes to biomass energy in Malaysia: forestry (wood products), rubber cultivation, cocoa cultivation, sugar cane cultivation and oil palm cultivation. Biomass in Malaysia contributes about 14% of the approximately 340 million barrel of oil equivalent (boe) of energy used every year. This paper provides an overview on the types of biomass being used, the research works on biomass conversion into energy and the present biomass energy projects in Malaysia.     

生物质环保能源产业链发展探讨

简述了生物质概念及生物质利用技术的概况,介绍了生物质(竹、木剩余物)气、炭、液、油四联产生物质能源利用产业链的发展思路,对生物质利用的市场应用及发展进行了分析预测。     

Biomass of Speckled Alder on an Air-Polluted Mountain Site and its Response to Fertilization

The article summarizes outcomes of a biomass study conducted in a young speckled alder plantation on a cold mountain site. At this location, the previously existing old forest was clear felled because of damage from air pollution, and present-day surface humus is in need of restoration. The intention of this study was to quantify the biomass and nutrients accumulated by alders and their components and assess whether the initial fertilization resulted in increased biomass production and nutrient accumulation in the biomass. Besides the control, two fertilized treatments were installed. In the surface treatment (SUT), the amendment was applied as a base dressing in small circles around trees. In the planting-hole treatment (PHT), the amendment was incorporated into soil inside the planting holes. Five growth seasons after planting and fertilization, six alders from each treatment were harvested including roots. Their biomass was quantified and analyzed for macroelements. The greatest pool of dry mass (DM) was branches in the control and stem wood in the fertilized treatments. The greatest pools of macroelements were leaves and branches. The most pronounced effects of fertilization were recorded in the DM and consequently in the absolute quantities of nutrients. The DM of an average tree in the control, SUT, and PHT was 85, 226, and 231 g, respectively. The absolute contents of nutrients per tree in the fertilized treatments showed the following increases, as compared with the control: (N) 2.5–2.6 times; (P) 1.6–2.4 times; (K) 1.8–2.1 times; and (Mg) 1.8–2.0 times, respectively. Speckled alder responded positively to fertilization.     

Co-composting of acid waste bentonites and their effects on soil properties and crop biomass

Acid waste bentonite is a byproduct from vegetable oil bleaching that is acidic (pH < 3.0) and hydrophobic. These materials are currently disposed of in landfills and could potentially have a negative impact on the effective function of microbes that are intolerant of acidic conditions. A study was undertaken using three different sources of acid waste bentonites, namely soybean oil bentonite (SB), palm oil bentonite (PB), and rice bran oil bentonite (RB). These materials were co-composted with rice husk, rice husk ash, and chicken litter to eliminate their acid reactivity and hydrophobic nature. The organic carbon (OC) content, pH, exchangeable cations, and cation exchange capacity (CEC) of the acid-activated bentonites increased significantly after the co-composting phase. In addition, the hydrophobic nature of these materials as measured using the water drop penetration time (WDPT) decreased from >10 800 s to 16 to 80 s after composting. Furthermore, these composted materials showed positive impacts on soil physical attributes including specific surface area, bulk density, and available water content for crop growth. Highly significant increases in maize biomass (Zea mays L.) production over two consecutive cropping cycles was observed in treatments receiving co-composted bentonite. The study clearly demonstrates the potential for converting an environmentally hazardous material into a high-quality soil conditioner using readily available agricultural byproducts. It is envisaged that the application of these composted acid waste bentonites to degraded soils will increase productivity and on-farm income, thus contributing toward food security and poverty alleviation.     

Performance of oil palm kernel shell gasification using a medium-scale downdraft gasifier

This article focused on the performance of oil palm kernel shell (PKS) gasification using a medium-scale downdraft gasifier with a feedstock capacity of 500 kg at a temperature range of 399–700°C and at a feed rate of 177 kg/h. This article is important for evaluating the reliability of PKS gasification for commercial power generation activities from biomass. The process performance was evaluated based on the syngas calorific value (CV), syngas flow rate, and its cold gas efficiency (CGE). The syngas flow rates and CVs were measured using a gas flow meter and a gas analyzer in real time. The data obtained were then analyzed to evaluate the performance of the process. The results showed that the CGE of the process was moderately high (51%) at 681°C, with a high syngas CV (4.45–4.89 MJ/Nm³) which was ideal for gas engine applications. The PKS gasification performance increased when the reactor temperature increased. Projections were made for the CGE and the syngas CV for the PKS gasification with increased reactor temperatures and it was found that these values could be increased up to 80% and 5.2 MJ/Nm^3, respectively at a reactor temperature of 900°C. In addition, the estimated power that could be generated was about 600 kW_e at a maximum operation of 500 kg/h of feed rate. Based on the analysis, a medium-scale PKS gasification is observed to be a promising process for power generation from biomass due to the favorable performance of the process.     

The Evaluation of Mesoporous Materials as Catalyst in Fast Pyrolysis of Wheat Straw

In this study, wheat straw was chosen as a biomass sample and the fast pyrolysis of this sample was carried out with or without catalyst at different conditions in a well-swept fixed-bed reactor. Experiments were carried out in a well-swept tubular fixed-bed reactor with a heating rate of 300°C/min, between pyrolysis temperature ranges 300–800°C in the nitrogen atmosphere. The results indicated that a maximum oil yield of 31.9% was obtained at a pyrolysis temperature of 500°C in non-catalytic procedure. Siliceous and Al-MCM-41 materials were evaluated as potential catalysts in the pyrolysis experiments. Mesoporous materials have large pore dimensions with strong acid sites. These acidic sites catalyze some reactions in pyrolysis. The product yields and the quality of bio-oil were influenced with using MCM-41 materials. The bio-oil yield was reduced, whereas the gas yield increased with using a catalyst in the experiments. An increase in the fractions of pure phenol, alkyl phenols, alkenes+alkanes, carbonyls, aromatic, and cyclic compounds and a decrease in the fractions of methoxy phenols, acids+esters, furans, and alcohols were observed in the presence of Al-MCM-41 material. According to all results, the use of Al-MCM-41 materials as catalyst in the pyrolysis can be suggested to obtain both quality fuels and valuable chemicals.     

Effect of pH and alum dosage on the efficiency of microalgae harvesting via flocculation technique

Microalgae biomass is well known as a potential sustainable product for bio-based industry, which has reported encountering numerous difficulties during biomass harvesting and recovering. This study examined the effect of pH (5–12) and alum dosage (30–180 mg/L) for microalgae Botryococcus sp. harvested via flocculation technique. The optimum pH condition for Botryococcus sp. harvesting was measured to be 9.2, and the alum dosage was 100 mg/L. Both optimum values successfully harvested up to 95% microalgae biomass. This study revealed that flocculation efficiencies for alum are highly dependent on the range of pH and coagulant dosage that were applied during the process. Use of flocculation technique with alum as a coagulant represents a convenient technique for Botryococcus sp. biomass harvesting and is recommended for use in both small- and large-scale biomass industries.     

Comparing carbon substrates for denitrification of subsurface drainage water

Nitrate in water from tile drained corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] fields in the U.S. Midwest contributes to nitrate contamination of surface waters. Denitrification-based biofilters are a promising strategy for reducing nitrate concentrations, but these systems require an external carbon supply to sustain denitrification. The ability of four organic materials to serve as carbon substrates for denitrification biofilters was evaluated in this laboratory study. Wood chips, wood chips amended with soybean oil, cornstalks, and cardboard fibers were mixed with subsoil (oxidized till) and incubated anaerobically for 180 d. Periodically, 15NO3-N was added to maintain nitrate N concentrations between 10 and 100 mg L-1. All of the materials stimulated NO3-N removal and the degree of removal from highest to lowest was: cornstalks, cardboard fibers, wood chips with oil, and wood chips alone. Analysis of 15N showed that immobilization and dissimilatory nitrate reduction to ammonium accounted for <4% of NO3-N removal in all treatments, therefore denitrification was the dominant NO3-N removal process. Cardboard fibers, wood chips and oil, and wood chips alone did not support as much denitrification as cornstalks, but their rates of NO3-N removal were steady and would probably continue longer than cornstalks. The addition of soybean oil to wood chips significantly increased denitrification over wood chips alone.     

Studies on the Drying Characteristics of Zingiber Officinale Under Open Sun and Solar Biomass (Hybrid) Drying

Drying characteristics of Zingiber officinale (Ginger) under the open sun and direct type natural convection solar biomass (hybrid) drying were studied. It has been observed that under open sun drying conditions, the drying rate depends on the product thickness and climatic conditions. The results have been drawn for both the summer (April-May, 2004) and winter (November-January, 2003–04) months of Delhi, in India. In the hybrid drier, the ginger, with a thickness of 0.008 m, dried in 33 hours in comparison to 96 hours in open-sun drying. The overall drying efficiency of the hybrid drier was found to be 18% and 13% under summer and winter climatic conditions respectively. The loss of volatile oil content of the ginger is less in hybrid drier in comparison to open sun drying. It was found that the average drying air temperature of 60°C with average air velocity of 0.6m/sec was sufficient for the drying of ginger in the hybrid drier. Ginger quality after drying is better and drying time is less in the hybrid drier in comparison to open-sun drying. The hybrid drier is a simple device, which can be manufactured with locally available materials and can be used for drying of other spices, vegetables and fruits etc.     

Clam shell catalyst for continuous production of biodiesel

Continuous flow transesterification of waste frying oil (WFO) with methanol for the biodiesel production was tested in a laboratory scale jacketed reactive distillation (RD) unit packed with clam shell based CaO as solid catalyst. The physiochemical properties of the clam shell catalysts were characterized by X-ray Diffraction (XRD), Brunauer–Emmett–Teller (BET), Scanning Electron Microscopy (SEM), and Energy Dispersive Atomic X-ray Spectrometry (EDAX). The effects of the reactant flow rate, methanol-to-oil ratio, and catalyst bed height were studied to obtain the maximum methyl ester conversion. Reboiler temperature of 65°C was maintained throughout the process for product purification and the system reached the steady state at 7 hr. The experimental results revealed that the jacketed RD system packed with clam shell based CaO showed high catalytic activity for continuous production of biodiesel and a maximum methyl ester conversion of 94.41% was obtained at a reactant flow rate of 0.2 mL/min, methanol/oil ratio of 6:1, and catalyst bed height of 180 mm.     

Effects of Bioengineered Streambank Stabilization on Bank Habitat and Macroinvertebrates in Urban Streams

Non-structural streambank stabilization, or bioengineering, is a common stream restoration practice used to slow streambank erosion, but its ecological effects have rarely been assessed. We surveyed bank habitat and sampled bank macroinvertebrates at four bioengineered sites, an unrestored site, and a comparatively less-impacted reference site in the urban Peachtree-Nancy Creek catchment in Atlanta, GA, USA. The amount of organic bank habitat (wood and roots) was much higher at the reference site and three of the bioengineered sites than at the unrestored site or the other bioengineered site, where a very different bioengineering technique was used (“joint planting”). At all sites, we saw a high abundance of pollution-tolerant taxa, especially chironomids and oligochaetes, and a low richness and diversity of the bank macroinvertebrate community. Total biomass, insect biomass, and non-chironomid insect biomass were highest at the reference site and two of the bioengineered sites (p < 0.05). Higher biomass and abundance were found on organic habitats (wood and roots) versus inorganic habitats (mud, sand, and rock) across all sites. Percent organic bank habitat at each site proved to be strongly positively correlated with many factors, including taxon richness, total biomass, and shredder biomass. These results suggest that bioengineered bank stabilization can have positive effects on bank habitat and macroinvertebrate communities in urban streams, but it cannot completely mitigate the impacts of urbanization.     

Biomass use in chemical and mechanical pulping with biomass-based energy supply

The pulp and paper industry is energy intensive and consumes large amounts of wood. Biomass is a limited resource and its efficient use is therefore important. In this study, the total amount of biomass used for pulp and for energy is estimated for the production of several woodfree (containing only chemical pulp) and mechanical (containing mechanical pulp) printing paper products, under Swedish conditions. Chemical pulp mills today are largely self-sufficient in energy while mechanical pulp mills depend on large amounts of external electricity. Technically, all energy used in pulp- and papermaking can be biomass based. Here, we assume that all energy used, including external electricity and motor fuels, is based on forest biomass. The whole cradle-to-gate chain is included in the analyses. The results indicate that the total amount of biomass required per tonne paper is slightly lower for woodfree than for mechanical paper. For the biomass use per paper area, the paper grammage is decisive. If the grammage can be lowered by increasing the proportion of mechanical pulp, this may lower the biomass use per paper area, despite the higher biomass use per unit mass in mechanical paper. In the production of woodfree paper, energy recovery from residues in the mill accounts for most of the biomass use, while external electricity production accounts for the largest part for mechanical paper. Motor fuel production accounts for 5–7% of the biomass use. The biomass contained in the final paper product is 21–42% of the total biomass use, indicating that waste paper recovery is important. The biomass use was found to be about 15–17% lower for modelled, modern mills compared with mills representative of today's average technology.     

Limnological effects of wood ash application to the subcatchments of boreal,humic lakes

To assess environmental risks of wood ash, limnological effects of ash application to the drainage basins of two small, humic lakes and one reference lake in southern Finland were examined in this three-year study. Treated areas corresponded to 12 and 19% of the total catchment and the amount of wood ash added was 6400 kg ha(-1). Immediate effects of wood ash on lake water were investigated in three tank experiments each lasting 1.5 wk. In tank experiments, addition of wood ash increased pH, alkalinity, conductivity, and Ca and P concentrations of humic lake water, while growth of phytoplankton decreased. After wood ash application to the subcatchments, pH, alkalinity, conductivity, and concentrations of K+, SO4(2-), and Cl- slightly increased, both in inflowing waters and in the lakes, but no increased leaching of Ca, N, or P from the treated subcatchments occurred. Phytoplankton biomass increased in both experimental lakes in comparison with the reference lake. In the lake with 19% application rate to the catchment, zooplankton biomass also increased. The results indicate that, over the short term, a small-scale ash treatment to a forested drainage basin will not necessarily cause significant changes in the water quality of boreal humic lakes, but at higher application rates, changes in water chemistry and biology are more evident.     

Evaluating the efficacy of wood shreds for mitigating erosion

An erosion control product made by shredding on-site woody materials was evaluated for mitigating erosion through a series of rainfall simulations. Tests were conducted on bare soil and soil with 30, 50, and 70% cover on a coarse and a fine-grained soil. Results indicated that the wood product known as wood shreds reduced runoff and soil loss from both soil types. Erosion mitigation ranged from 60 to nearly 100% depending on the soil type and amount of concentrated flow and wood shred cover. Wood shreds appear to be a viable alternative to agricultural straw. A wood shred cover of 50% appears optimal, but the appropriate coverage rate will depend on the amount of expected concentrated flow and soil type.     

Uptake and distribution of iodine in rice plants

Rice (Oryza sativa L.) plants were cultivated in an experimental field and separated at harvest into different components, including polished rice, rice bran, hull, straw, and root. The contents of iodine in these components and the soil were determined by inductively coupled plasma-mass spectrometry and radiochemical neutron activation analysis, respectively. Iodine content varied by more than three orders of magnitude among the plant components. Mean concentration of iodine in the entire plants was 20 mg kg(-1) dry weight, and the concentration of iodine in the surface soil (0-20 cm depth) was 48 mg kg(-1). The highest concentration of iodine (53 mg kg(-1) dry weight) was measured in root and the lowest concentration (0.034 mg kg(-1) dry weight) in polished rice. While the edible component (polished rice) accounted for 32% of the total dry weight, it contained only 0.055% of iodine found in the entire rice plants. Atmospheric gaseous iodine (5.9 ng m(-3)) was estimated to contribute <0.2% of the total iodine content in the biomass of rice plants; therefore nearly all of the iodine in the rice plants was a result of the uptake of iodine from the soil. The content of iodine in the aboveground part of rice plants was 16 mg kg(-1) dry weight and the percentage of iodine transferred per cropping from the soil into the aboveground biomass corresponded to 0.27% (20 mg m(-2)) of the upper soil layer content.     

Application of response surface methodology for the optimization of biodiesel production from yellow mustard (Sinapis alba L.) seed oil

In the present study, response surface methodology (RSM) involving central composite design (CCD) was applied to optimize the reaction parameters of biodiesel production from yellow mustard (Sinapis alba L.) seed oil during the single-step transesterification process. A total of 30 experiments were designed and performed to determine under the effects of variables on the biodiesel yield such as methanol to oil molar ratio (2:1–10:1), catalyst concentration (0.2–1.0 wt.% NaOH), reaction temperature (50–70°C), and reaction time (30–90 min). The second order polynomial model was used to predict the biodiesel yield and coefficient of determination (R²) was found to be at 0.9818. The optimum biodiesel yield was calculated as 96.695% from the model with the following reaction conditions: 7.41:1 of methanol to oil molar ratio, 0.63 wt. % NaOH of catalyst concentration, 61.84°C of reaction temperature, and 62.12 min of reaction time. It is seen that the regression model results were in agreement with the experimental data. The results showed that RSM is a suitable statistical technique for optimizing the reaction parameters in the transesterification process in order to maximize the biodiesel yield.     

Social trends of the people of the region of Eastern Macedonia and Thrace-Greece: about the potential of using biofuels from forest products residues

In the framework of enquiry of biomass usage possibilities in our country, a research was made through the whole Eastern Macedonia region, related to disposal possibilities from the production conveyors and usage possibilities from the region’s residents and businessmen, of biofuels that come from mechanical wood treatment residues and from the residues of agricultural production, in wooden form, known with the term wood pellets or wood briquettes. From the present study, it came to light that there is an intense interest for direct personal usage and application of biomass for the residents or occupational spaces heating. The necessary biomass quantity for the entire region’s households is estimated up to 205,520 t. From the biomass usage as a combustible material, a 680 €/year and household about, is made. The potential investments that will be made to the region seem to have a very short depreciation, but a business plan and a marketing plan syntax are considered as necessary for the result’s maximisation.     

农作物废料对海洋溢油吸附研究

根据海上围油栏围油原理,使用小型围油设备模拟出在围油栏除油后海上剩余溢油的质量M。收集稻壳、小米壳、小麦壳3种农作物废料作为吸油材料,室温下分别测出3种吸油材料对质量为M的溢油的饱和吸附时间。在吸附平衡的条件下,利用紫外分光光度计分别测出3种吸油材料吸附海水表面M质量溢油后的平衡吸附浓度ce。根据物理吸附理论,由平衡吸附浓度ce和平衡吸附量qe分别得出3种材料的Freundlich吸附等温式,从Freundlich吸附等温式比较了3种农作物废料的吸油性能。结果表明:稻壳的吸油性能最佳。     

Bio-Hydrogen Synthesis from Wastewater by Anaerobic Fermentation Using Microflora

Biological hydrogen production was investigated using biomass in palm oil mill effluent (POME) and artificial wastewater containing 10g glucose under anaerobic fermentation in a batch process. Activated POME sludge and different types of composts were collected as sources of inocula for the study. The anaerobic microflora was found to yield significant amounts of hydrogen. The experimental results show that the gas composition contained hydrogen (66–68%) and carbon dioxide (32–34%). Through out the study, methane gas was not observed in the evolved gas. The hydrogen production was accompanied with the formation of acetate and butyrate. Furthermore, the cumulative hydrogen data were fitted to a simple model developed from Gompertz Equation, where the lag phase time, hydrogen production potential and hydrogen production rate at various conditions were quantitatively estimated.