Oxygen-fuel combustion is a promising technology for CO2 emission reduction. The high-temperature entrained flow reactor and high-temperature drop tube furnace were used to analyses the formation and O2/CO2 combustion characteristics of real-environment coal char in high-temperature oxy-fuel conditions. It proposed “inflection point standard” of high-temperature flame method for the preparation of real-environmental oxy-fuel coal char according to the flame method. The results show that the ratios of C=O/C-O and C=O/Car increase in the coal char compared with the raw coals. The trend of C=O/Car in oxy-fuel condition is opposite to that in the inert atmosphere, due to the effect of high-concentration CO2. To achieve the burnout rate similar to air combustion for coal char, with the increase of coal rank, the O2 concentration should be enhanced. The optimal O2 concentration for the oxy-fuel combustion of JC anthracite is 30%, while that of other low-rank coals could be lower than 30%. The combustion characteristic of JC anthracite is with the highest sensitivity to temperature and O2 concentration. 相似文献
Air rate and froth depth are the most commonly adjusted levers in PGM flotation plants. The optimisation of these levers on each flotation cell has traditionally been done by varying either air rate at a fixed froth depth or vice versa. This approach does not consider the interaction relationship between air rate and froth depth and this effect on flotation performance.Factorial type experimental designs are best suited for investigating interaction effects between variables. This paper presents the use of a factorial type of experimental design being the (CCRD) Central Composite Rotatable Design for plant scale flotation optimisation of air and froth depth. The results obtained include three dimensional response surfaces and models of flotation response variables such as 4E PGM recovery and grade as a function of air rate and cell level. This paper illustrates the experimental methodology and discusses the results for normalised 4E PGM grade and recovery for a rougher cell treating a Platreef ore.These results indicate that interaction effects of air and froth depth are significant and are more pronounced at conditions of higher air and shallower froth depth. In addition, indices which are based on an optimisation objective such as grade multiplied by recovery and/or grade multiplied by recovery squared allows application of this technique as an optimisation tool. These indices can be used to determine an optimum operating range for air and level with the consideration of interaction effects. 相似文献
Thirty-nine purple non-sulfur bacteria (PNSB) were isolated from 162 environmental samples. These isolates of PNSB were tested for their ability to produce biohydrogen (Bio-H2) at 40 °C and only 14 isolates were noted to possess such ability, which were considered as thermotolerant photosynthetic Bio-H2 producing bacteria (tt-PHPB). Of 14 isolates of tt-PHPB, KKU-SN1/1 was observed to have the highest Bio-H2 productivity. Central composite design was employed to optimize the operating conditions for maximal Bio-H2 production by the strain KKU-SN1/1. Under optimal conditions (7.6 g/L malic acid, 11 g/L glutamic acid, pH 6.7, at 40 °C) the Bio-H2 production was increased by 68.28%. The purity of Bio-H2 produced was 92.22%, as suggested by gas chromatography (GC-TCD). Based on morphological characteristics and 16S rDNA sequence analysis, the strain KKU-SN1/1 was identified as Rhodopseudomonas pentothenatexigens, with 99.7% similarity. To our knowledge, this is the first report on Bio-H2 production by R. pentothenatexigens KKU-SN1/1. 相似文献
Following the dissolution of the Soviet Union, various gas pipeline projects have been proposed to diversify transit routes and export markets of the landlocked Central Asian states. To evaluate the pipeline project's impact on the players' bargaining power, I apply the cooperate game theory to a quantitative model of the Eurasian gas trade and quantify the bargaining power structure via the Shapley value. Due to ample production capacities in Central Asia, I observe little strategic interaction between the West and China. Thus, demand competition with China is not necessarily a disadvantage for the West, and the Turkmenistan–China pipeline does not affect the impact of the westbound projects aiming Europe and Turkey. For Turkmenistan, i.e., the main supplier in the region, a link via the Caspian Sea to Turkey is the most beneficial westbound option. Although the projects carrying gas from Azerbaijan and Turkmenistan to Europe enjoy the European Commission's political support, they yield marginal benefits to the European consumers. Thanks to its transit position, Turkey collects a large share of the benefits in the East–West gas trade. 相似文献
Chitin extraction by biological way, using the lactobacilli Lactobacillus helveticus, is a non-polluting method and offers the opportunity to preserve the exceptional qualities of chitin and its derivatives. However, the major disadvantage of the fermentative way is the low efficiency of demineralization and deproteinization. The aim of our study is to improve the yield of extraction. 相似文献
This work was to correlate physical properties with adhesion properties of soy protein‐based adhesives. By building such a correlation, the adhesion properties can be predicted by measuring physical properties of soy protein‐based adhesives. In this context, three important physical properties, viscosity, tacky force, and water resistance, were selected to correlate with adhesion strength of enzymatically modified soy protein‐based adhesives (ESP). Response surface methodology, specifically central composite design, was used with three independent variables to prepare ESP: trypsin concentration (X1), incubation time (X2), and glutaraldehyde (GA) concentration (X3). The three physical properties measured were all greatly affected by our three independent variables with significance at the 95 % confidence level. The responses were then correlated with the adhesion properties of ESP. In conclusion, viscosity can be used to predict the dry adhesion strength of ESP based on the coefficient of determination (R2) of 0.8558. In addition, tacky force and water resistance can be used to represent wet adhesion strength of ESP based on R2 of 0.7082 and 0.6930, respectively (P < 0.05). This work preliminarily identified the significant physical properties that can predict the adhesion strength of the ESP system crosslinked with GA, but the results need to be further confirmed by another protein modification system to give a generic conclusion. 相似文献
Palm oil biodiesel (POB) is characterized by a very high cold soak filtration time (CSFT), which places the acceptability of this biofuel at risk. Therefore, the effect of four adsorbents, namely diatomaceous earth, natural silicate (NS), neutral bleaching earth (NBE), and acid activated bleaching earth (AABE), at two levels of addition (1 and 5 wt%) or two temperatures (25 and 110 °C) on the precipitate content and CSFT of POB was investigated. The impact on total glycerin content, moisture content, and oxidative stability was also examined. All treatments significantly decreased the precipitate content, total glycerin content, and moisture content, but only treatments with NS, NBE, and AABE at 5 wt% and 25 °C achieved acceptable filterability. The OSI value was also decreased; however, it remained above the ASTM limit. Operational conditions of treatment with AABE were further optimized in a two‐factor, five‐level center composite design. The combination of 0.65 wt% AABE and 10 min at 25 °C decreased CSFT to below the ASTM limit. Lower adsorbent concentrations could be effective down to 0.44 wt%, given a corresponding increase in the contact time up to 30 min. 相似文献
Objective: For better treatment of circadian cardiovascular events, a novel Propranolol hydrochloride (PNH) delayed-release osmotic pump capsule was developed.
Methods: The capsule body was designed of asymmetric membrane and the capsule cap was made impermeable. The physical characteristics of capsule body walls and membrane permeability were compared among different coating solutions.
Results: The formulation with the glycerin and diethyl phthalate (DEP) ratio of 5:4 appeared to be the best. The lag time and subsequent drug release were investigated through assembling the capsule body with capsule caps of different length. WSR N-10 was chosen as the suspending for its moderate expanding capacity. The influence of factors (WSR N-10 content, NaCl content and capsule cap length) on the responses (lag time and drug release rate) was evaluated using central composite design-response surface methodology. A second-order polynomial equation was fitted to the data and actual response values were in good accordance with the predicted ones. The optimized formulation displayed complete drug delivery, zero-order release rate with 4-h lag time. The results of in vivo pharmacokinetics in beagle dogs clearly suggested the controlled and sustained release of PNH from the system and that the relative bioavailability of this preparation was about 1.023 comparing the marketed preparation.
Conclusions: These results indicate that by the adjustment of capsule cap length, PNH could be developed as a novel pulsatile and controlled drug delivery system. 相似文献