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In this study the NOx reduction capability of reburning three biomasses (i.e., wood pellet, torrefied biomass, and empty fruit bunch) via 12 cases (i.e., four reburning ratios for every biomass) is investigated in a 1 MWth-scale pilot-scale furnace. These reburning cases are compared with 12 cofiring cases presented in the Part 1 paper on a consistent basis. It is found that, for every cost to purchase and prepare biomass, reburning technology provides significantly better NOx abatement performance than cofiring (up to 3.4 times). NOx reduction effectiveness as high as 4.9 could be achieved by reburning, which means the percent of NOx abatement could be 4.9 times higher than the percent of reburning ratio. It is found that the highest NOx reduction per thermal unit of biomass happens at the lowest reburning ratio, and increasing the reburning ratio leads to a reduction in NOx abatement effectiveness in an exponential decay manner. Unlike cofiring technology, reburning was found to have little dependence on the fuel characteristics, such as fuel ratio or fuel-N, when it comes to NOx abatement potential.

In dedicated wood pellet combustion and cofiring with coal in large pulverized fuel furnaces, poor grindability and low bulk density of biomass are important issues for lowering the unburned carbon...

In this work, we studied indium tin oxides (ITOs) modified with dendrimer-encapsulated Pt nanoparticles (Pt DENs) to develop efficient p-aminophenol (p-AP) redox cycling platforms. The ITO surfaces were modified via electro-oxidative grafting of the terminal amine groups of the dendrimers encapsulating catalytic Pt nanoparticles (i.e., Pt DENs). Compared to conventional ITO surfaces, the Pt DEN-modified ITOs showed highly enhanced electrochemical oxidation current of p-AP even at low potentials with no significant background oxidation current due to the catalytic activity of Pt nanoparticles, leading to high signal-to-background ratio for sensitive p-AP redox cycling. The enhanced p-AP redox cycling on the Pt DEN-modified ITOs led to ∼17.8 times higher sensitivity of the p-AP redox cycling than that obtained with conventional ITOs. In addition, the Pt DEN-modified ITOs were found to be suitable as platforms for the immobilization of oligonucleotides due to the globular structure of dendrimers, which have a high surface-to-volume ratio and multiple terminal functional groups, grafted on ITO surfaces. The DEN-modified ITOs could be further functionalized by the immobilization of single-strand DNA oligonucleotides with high surface density (i.e., (2.2 ± 0.4) × 1012 molecules/cm2), which is ∼4.4-fold higher than that on the surface of conventional ITOs.

We present the concept of a novel thermal power plant process in conjunction with low-temperature selective catalytic reduction (SCR). This process can be employed to achieve modern standards for NOx emissions and solve problems related to post-gas cleaning processes, such as thermal fatigue, catalyst damage, and an increase in differential pressure in the boiler. Therefore, this study is aimed at evaluating the performance of a novel flue-gas cleaning process for use in a thermal power plant, where a low-temperature SCR is implemented, along with the existing SCR. We developed a process model for a large-scale power plant, in which the thermal power plant was divided into a series of heat exchanger block models. The mass and energy balances were solved by considering the heat transfer interaction between the hot and cold sides to obtain the properties of each material flow. Using the process model, we performed a simulation of the new process. New optimal operating conditions were derived, and the effects that the new facilities have on the existing process were evaluated. The results show that the new process is feasible in terms of operating stability and cost, as well as showing an increase in the boiler thermal efficiency of up to 1.3%.

A field scrutiny related to livestock excretions in Yeongsan stream basin was performed in this study. This result was used to verify the accuracy of nationwide survey result (formal document) for pollution sources by comparing them, and a management plan of livestock excretions was also suggested based on their comparison in this study. The major differences between them were 17.7% in the number of stock farms, 39.6% in the population of milk cows and 41.6% in the treatment method of pig excretions. The biggest difference to the pig case, which is currently the most problem in livestock excretions treatment, could be because of the cause that most of the farmlands, including orchard grove, used as individual treatment site for excretions played role as a dump site to reduce the cost for consignment treatment. Meanwhile, the 67% of compost heaps was illegally left alone in field without the rain shelter and could flow in the stream if it is raining.

Recently, Korean coal-fired power plants have used sub-bituminous coals with moisture and volatile contents higher than design coal of those plants. This causes a decrease in the efficiency of boil...

This paper deals with and oxy-fuel circulating fluidized bed (Oxy-CFB) power plant with air separate unit (ASU), CO2 compression and purification unit, and an indirect supercritical CO2 cycle. This novel power plant was designed and modeled by using Aspen Plus at commercial scale to investigate the possibility and the effect of recirculated flue gas conditions. The indirect S–CO2 oxy-CFB power plant had higher net efficiencies compared with oxy-CFB power plant with steam cycles because the phase of CO2 does not change during the operation. Also, the effect of the amount of water retained in flue gas stream generated at the CFB boiler on the overall net efficiency was analyzed. By decreasing the temperature of recirculated flue gas from 90 °C to 40 °C, water retained in flue gas decreased, and input O2 concentration in combustor increased from 34.7 to 38.5 vol%. When flue gas recirculation temperature was 40 °C, the boiler efficiency was 99.6%, and the overall net efficiency was 43.1%. Although approximately 20% of the total power is the power consumption of the ASU and CPU, high net efficiency was achieved in this novel power plant.

Here, we demonstrate surface functionalization of Au chips with 4-(carboxymethyl)aniline (CMA) and amine-terminated polyamidoamine (PAMAM) dendrimers for immobilization of antibodies on the Au surfaces. Use of the functionalization strategy led to high surface density of the immobilized antibodies on the Au chips. Specifically, we found that the functionalization of Au chips with CMA and amine-terminated 6 th generation PAMAM dendrimers allowed immobilization of immunoglobulin (IgG) antibodies with high surface density, which is 5 times higher than that obtained with Au surfaces functionalized with CMA and ethylenediamine.

This study investigated the reduction of primary tar vapor from biomass pyrolysis over a bed of hot char particles, focusing on the effect of different operating conditions and char properties. The char samples were prepared from wood, paddy straw, palm kernel shell, and activated carbon. The primary tar was produced from fir wood by pyrolysis at 500 °C and passed through a reactor filled with char particles with different lengths and temperatures. The tar cracking reactions became active above 700 °C, and the presence of hot char particles promoted more tar reduction compared with thermal cracking alone. The mass yield of the primary tar was reduced from 24.8% by pyrolysis to 13.7% by thermal cracking at 800 °C, and further to 7.7% by hot char particles in a reactor volume of 1.48 cm 3 /g wood . In terms of carbon yield, these values correspond to 32.1%, 19.9% and 11.8%, respectively. The tar with smaller molecular weights was quickly decomposed to gases, whereas the heavy tar was resistant to cracking, even when the reactor volume was increased to 6.90 cm 3 /g wood . The tar cracking behaviors were similar for four char types despite differences in microscopic surface areas, pore-size distributions, and inorganic contents. The results suggest that creating a tar-cracking zone using char particles situated between the pyrolysis and gasification zones could be helpful in converting the primary tar vapor in a downdraft fixed-bed gasifier, but the degree of conversion is not high enough to eliminate tar issues completely.

The fixed bed reaction of sewage sludge briquettes was investigated to evaluate the potential applications to gasification, combustion, or production of biochar as soil ameliorator. The reaction had two distinctive stages: ignition propagation and char oxidation. The ignition front of the sludge briquettes propagated at a lower speed, which significantly increased the stoichiometric ratio of overall combustion reaction and peak temperatures. The ignition front also had irregular shapes due to the channeling effects. During the char oxidation stage, the sludge ash agglomerated because of the slow reaction rate and increased CO2 formation. Because of low energy content in the product gas, the large briquettes were not favorable for syngas production. In addition, the low burning rates and ash agglomeration could cause problems in the operation of a grate-type furnace for combustion. However, the char accumulated above the ignition front had similar properties with that from pyrolysis under inert atmosphere. Therefore, the fixed bed reaction under partial oxidation conditions can be applied to produce biochar as soil ameliorator from the sludge briquettes without external heat supply.

Low rank coals are more reactive at low temperatures than high rank coals, which leads to spontaneous combustion if not controlled. Due to the increased use of low rank coals, preventing spontaneous combustion during storage and size reduction has become an important issue in power plants. The present study evaluates the low-temperature reactivity for various coals in terms of their rank and country of origin. The experimental method determined the temperature and its gradient for coals in a small fixed bed at the point surpassing that of input oxygen, which were defined as the crossing-point temperature (CPT) and slope (CPS), respectively. Combining the two parameters, a low-temperature reactivity index (LTR index) was proposed. The method tested 17 coals collected from a power plant that yielded CPTs ranging between 168–190 °C and CPSs between 0.862–1.228 °C/min. The LTR index for the coals was calculated to be 0.696 to 1.542. The LTR index was positively correlated with the moisture content and volatile matter/fixed carbon (VM/FC) ratio, and inversely correlated with the ash content. The ignition temperature, measured by thermogravimetric tests, also exhibited a positive relationship with the LTR index. However, no single property of coal was sufficiently correlated with the self-heating propensity for all the coals tested, illustrating the complex mechanisms involved.

The selective permeation of organic solvents and water through graphene oxide (GO) membranes has been demonstrated. Water was found to permeate through GO membranes faster than various alcohols. The permeation rates of ethanol, 1-propanol and 2-propanol (IPA) are about 80 times lower than that of water. Taking advantage of the differences in the permeation rates, we separated water from the alcohols and obtained alcohols with high purity. For ethanol and 1-propanol, binary solutions of the alcohol and water were filtered efficiently to produce alcohols with concentration of about 97%. However, the selectivity of the filtration of methanol is significantly lower than those of the other alcohols. To understand the mechanism we followed the structural changes in the GO membranes by X-ray diffraction analysis. From the X-ray diffraction results we speculate that the selectivity of the permeation of water and alcohols is closely related to the molecular sizes of the solvents and their polarity. In order to demonstrate the potential applications of this process for the selective removal of water from aqueous organic mixtures, we performed the separation of water from a bio-oil containing 73% of water. The majority of the water was filtered out resulting in a higher purity bio-oil.

Among many uses of rice straw, application of its biochar from pyrolysis to the soil is receiving greater interest for increased crop productivity and sequestration of CO2. This study investigated slow pyrolysis of rice straw at 300-700°C to characterize the yields and detailed composition of the biochar, bio-oil and non-condensable gases. Biochar was analyzed for pH, microscopic surface area and pore volume distribution. Although the mass yield for the organic fraction was only about 25% above 500°C, biochar was the primary product of pyrolysis containing 40% of energy and 45% of carbon from the straw. The utilization of by-products (bio-oil and gases) as energy resources was essential, since the sum of energy yield was about 60%. The gases could be burned to produce the heat for an auto-thermal pyrolysis process, but the heat balance was significantly influenced by the moisture content of the raw material.

This study investigated producing biochar from Geodae-Uksae 1 for soil applications to sequestrate carbon from the atmosphere and improve the productivity of crops. Using a lab-scale packed bed reactor, pyrolysis products of Geodae-Uksae 1 were produced over a temperature range of 300-700°C with a heating rate of 10°C/min. Pyrolysis at 500°C was found appropriate for biochar production considering the properties of char and the amount of heat required. It yielded biochar of 27.2wt.% that contained approximately 48% carbon in the raw biomass. The surface area of the biochar rapidly increased to 181m(2)/g. Large cylindrical pores with diameters of 5-40μm developed within the biochar due to the vascular cell structure of the parent biomass. The byproducts (bio-oil and gases) were also analyzed for use as fuel.

We report a method to tailor chemically converted graphenes (CCGs) using a water-soluble pyrene derivative (1) with a zwitterionic arm, and the feasibility of the tailored CCGs to sensitive electrochemiluminescence (ECL)-based analyses. The compound 1 serves the dual purpose of improving the dispersion of the CCGs in aqueous solutions and further tailoring the catalytic activity of the CCGs with dendrimer-encapsulated catalytic nanoparticles. As a model system, we conjugated dendrimer-encapsulated Pt nanoparticles to the 1-functionalized CCGs on indium tin oxide (ITO) electrodes. The resulting ITOs exhibited significantly increased ECL emission of the luminol/H2O2 ECL system; i.e. two orders-of-magnitude enhancement in the ECL compared to that obtained from bare ITOs, which allowed a ca. 154 times more sensitive ECL-based analysis of cholesterol using the modified ITOs compared with the use of bare ITOs.

Wood pellet is a densified fuel with homogeneous physical properties suitable for use at various scales in domestic and industrial furnaces. A wood pellet stove is a small-scale furnace for domestic heat production that can replace conventional oil or gas boilers. Since the fuel properties of wood pellet are very different from those of oil or gas, the design of a wood pellet stove requires profound understanding of solid fuel combustion as well as of gas flow mixing and reactions. Due to limitations on the height of an installed furnace (~1 m), poor design of the furnace, air supply, fume extraction, or the heat exchanger may lead to excessive CO emissions or low energy efficiency. This study evaluated the design of an existing wood pellet stove with 30,000 kcal/h capacity, using experimental and computational techniques in order to optimize the furnace design. The results show that it is critical to minimize unused furnace volume and to enhance gaseous mixing for reduced CO emissions while maintaining sufficiently high temperatures for fast oxidation.

An evacuated tubular solar collector was fabricated from acrylics for improved resistance to shattering. A plasmatron was employed to apply a thin gas-barrier coating to the surfaces of the plastic tube to prevent/alleviate gas infiltration. Experiments were conducted to investigate the effect of vacuum level on the performance of the non-glass vacuum-tube solar collector. Inserted in the evacuated tube was a finned heat pipe for solar energy collection and heat transfer to a water tank. Time variations of temperatures on the heat pipe surface and in the water tank were recorded and analyzed for different degrees of vacuum in the collector. The steady-state temperature of the non-glass collector was compared to that of a commercial glass vacuum-tube collector to assess the feasibility of the use of evacuated plastic tubes for solar energy collection. A simple analytical model was also developed to assist in understanding and analyzing the transient behavior and heat losses of the vacuum-tube solar collector.

Application of biochar from biomass pyrolysis to soil is gaining greater interest; this can ameliorate the soil quality, reduce fertilizer consumption, and sequestrate carbon. This study compares the characteristics of biochar produced by slow pyrolysis at 500°C for agricultural residues: sugarcane bagasse, cocopeat, paddy straw, palm kernel shell (PKS) and umbrella tree. In the biochar yield, the influence of the inert and lignin contents was significant. The wood stem, bagasse and paddy straw had biochar yields of 24-28 wt.% from the organic fraction while cocopeat had 46 wt.%. The carbon content of biochar ranged from 84 wt.% to 89 wt.%, which corresponded to 43-63% of carbon in the biomass. The biochar from wood stem and bagasse had well-developed pores of various sizes with large surface areas. Although the surface area was significant, PKS biochar had dense matrix with few large pores. The elemental composition and pH of biochars were also compared.

We report the readout stability improvement results of super-resolution near field structure (Super-RENS) write-once read-many (WORM) disk at a blue laser optical system. (Laser wavelength 405nm, numerical aperture 0.85) By using diffusion barrier structure (GeSbTe sandwiched by GeN) and high transition temperature recording material (BaTiO3), material diffusion of phase change layer and recording mark degradation were greatly improved during high power (Pr=2.0mW) readout process up to 1X105 times.

A super-resolution near-field structure (super-RENS) read-only-memory disc with an In–Sb thin film as a super-resolution active layer corresponding to a 50 Gbyte capacity per layer was fabricated. The carrier-to-noise ratio at a pit length of 75 nm exceeded 40 dB and a bit error rate (bER) of the order of 10-5 satisfying the 3.0×10-4 criterion was obtained. To the best of our knowledge, this is the first report on the successful and seamless playback performance of a high-definition video content from the super-RENS disc at a data transfer rate of either 36 or 72 Mbps. The bER results of fixed and adaptive partial response maximum likelihood detections are described.

Superresolution (SR) phenomena due to Ge2Sb2Te5 films were examined by combined analysis of the transmission electron microscopy (TEM) microstructures of the laser-irradiated films and the results from dynamic and static tests using blue lasers. A new finding was made that comprises a complementary case of the classical SR readout by Ge2Sb2Te5 film; an amorphous band instead of a closed aperture of melt in the crystalline background forms behind a moving laser but still produces a high SR signal. A complete carrier-to-noise-ratio curve of a SR-read-only memory employing Ge2Sb2Te5 may be derived from a nonlinear optical effect, specifically thermally assisted saturable absorption.