Based on the practice of magnesium production in China,a quantitative evaluation of the environment impact was carried out according to the theory and framework of life cycle assessment (LCA) study.The major gaseous pollutants including CO2,SO2,NOx,CH4,HF and particulates were calculated.The accumulative environmental performances of different energy use strategies and the characterization results,including abiotic depletion potential (ADP),global warming potential (GWP),acidification potential (AP) and human-toxicity potential (HTP) were compared.The results show that the direct emission of fuel combustion in the process is the major contributor to the pollutants emission of magnesium production.Global warming potential and acidification potential make the main contribution to the accumulative environmental impact.The different fuel use strategies in the practice of magnesium production cause much different impacts on the environmental performance.The accumulative environmental impact of coal burned directly is the highest,and that of producer-gas comes to the next,while that of coke-oven gas is the lowest....
Large quantity of fine Ti(C,N) particles, 15-30 nm in size, were observed in low carbon hot strips added to a small amount of Ti and produced by CSP process. The results showed that the precipitation of Ti(C,N) mostly took place during soaking and hot rolling,which is significantly different from that in the conventional production. These fine Ti carbonitride particles could be very effective on the austenite grain refinement by hindering grain growth of recrystallized austenite. Their precipitation behavior was discussed and compared with that of the steels produced in the conventional production....
Expanded granular sludge bed (EGSB) reactor and bioaugmentation were employed to investigate biohydrogen production with molasses wastewater. The start-up experiments consisted of two stages. In the first stage (0～24d) seeded with activated sludge, the butyric acid type-fermentation formed when the initial expanding rate, organic loading rate (OLR), the initial redox potential (ORP) and hydraulic retention time (HRT) were 10%, 10.0 kg COD/(m3·d), - 215 mV and 6.7 h, respectively. At the beginning of the second stage on day 25, the novel hydrogen-producing fermentative bacterial strain B49 (AF481148 in EMBL) were inoculated into the reactor under the condition of OLR 16. 0 kg COD/(m3·d), ORP and HRT about - 139 mV and 6.7 h, respectively, and then the reaction system transformed to ethanol-type fermentation gradually with the increase in OLR. When OLR, ORP and HRT were about 94.3 kg COD/(m3·d), -250 mV and 1.7 h, respectively, the system achieved the maximum hydrogen-producing rate of 282.6 mL H2/L reactor· h and hydrogen percentage of 51%～53% in the biogas....
A hierarchical closed-loop production control scheme integrating scheduling, control and performance evaluation is discussed. Firstly, the production process is divided into two main hierarchies: the lower level is the physical operation level and the upper one is the management level. Secondly, the schedule template for the management level and the activity template for the physical operation level are constructed separately, the tasks in the schedule have the ability to make partial decisions, and the performance parameters are introduced into activity template. Thirdly, the two levels use different model representations: stochastic process algebra for the management level whose output is the control commands and stochastic Petri net for the physical operation level which is the execution of the control commands. Then, the integration of the two levels is the control commands mapping into the lower physical operations and the responses feeding back to the upper decision-making that are defined by some transition functions. Under the proposed scheme, the production process control of a flexible assembly is exemplified. It is concluded that the process control model has partial ability to make decision on-line for uncertain and dynamic environments and facilitates reasoning about the behaviors of the process control, and performance evaluation can be done online for real-time scheduling to ensure the global optimization....
The entropy production rate of stationary minimal diffusion processes with smooth coefficients is calculated. As a byproduct, the continuity of paths of the minimal diffusion processes is discussed, and that the point at infinity is absorbing is proved....
Value analysis of grain production influencing factors is a complex decision problem. This paper introduced a modified Analytic Hierarchy Process （AHP） accumulation factor, namely Solving Weight by AHP＇s Accumulation Factor Sequence Evaluating Data. We used the arithmetical average to replace the expert marking, so that the possible decision mistakes by the subjective judgments could be avoided. We computed the case with this method, which obtained attribute value of 17 influencing factors of the potential food production in Heilongjiang Province, and the result of which was reasonable...
This paper deals with a comparative research between two processes of granulation,namely mini-pelletized sintering (MPS) and hybrid pelletized sintering (HPS),focusing on aspects such as the balling effect,production,quality,and mineralography and metallurgical performance of sinter.The results indicate that both methods can result in a satisfying capability in balling effect and metallurgical performance of sinter,qualified to meet the plant production requirements,but when the granulation time and granulating moisture are set to around 6 minutes and 7.0％ respectively,MPS is better than HPS....
Production of ursolic acid, the anti-hepatitis effective composition from natural plant,Sambucus chinensis Lindl.was carried out and the scale-up preparation technology was studied.Extraction of the herb Sambucus chinensis Lindl.was extracted in reflux with 7 volume times of refluxing ethanol at 80℃ for 1 h for two times.The extract was purified with a selt-made specific impurity remover "YCXY-1" to yield ursolic acid of high purity.A new "Extraction/Gelation" technology for the production of ursolic acid was developed. The specific impurity remover "YCXY-1" showed high effectiveness in purification. The purity of the mass-produced ursolic acid was up to 99.8%. The chemical structure of the product was confirmed by the physicochemical constants and spectroscopic identification. The production of high-purity ursolic acid was optimized with natural plant as raw material and with only ethanol as extracting solvent. The difficulties such as isolation and impurity removal were addressed effectively. The novel technology is reasonable, convenient, practical, low-cost, high-yield, suitable for mass production....
La2O2CO3 was prepared by calcination of La2 (CO3)3 in the air.Catalysts Ni-Fe/La2O2CO3 with different mole ratios of Ni to Fe,Ni/La2O2CO3 and Fe/La2O2CO3 were prepared by impregnation method.The catalytic properties were evaluated on steam reforming of ethanol (SRE) from 300 to 700 ℃ under atmospheric pressure and the samples were characterized by Brunauer-Emmett-Teller method (BET),X-ray diffraction (XRD) and temperature programmed reduction (TPR).The results showed that Ni-Fe bimetallic catalysts exhibited higher activities than single metallic catalysts,which was attributed to the co-existence of well dispersed Ni,Fe and LaFeyNi1 yO3.It was found that the catalyst Ni-Fe/La2O2CO3 containing 10 wt.％ Ni and 3 wt.％-5 wt.％ Fe showed the best performance,the conversion of ethanol was 100％,the selectivity of H2 was higher than 90％,and the selectivity of CO was lower than 1.5％ at 400 ℃....
A technology to achieve stable and high ammonia nitrogen removal rates for corn distillery wastewater (ethanol fuel production) treatment has been designed.The characteristics of nitrifying bacteria entrapped in a waterborne polyurethane (WPU) gel carrier were evaluated after acclimation.In the acclimation period,nitrification rates of WPU-immobilized nitrobacteria were monitored and polymerase chain reaction (PCR) was also carried out to investigate the change in ammonium-oxidizing bacteria.The results showed that the pellet nitrification rates increased from 21 to 228 mg-N/(L-pellet-hr) and the quantity of the ammonia oxidation bacteria increased substantially during the acclimation.A continuous ammonia removal experiment with the anaerobic pond effluent of a distillery wastewater system was conducted with immobilized nitrifying bacteria for 30 days using an 80 L airlift reactor with pellets at a fill ratio of 15％ (V/V).Under the conditions of 75 mg/L influent ammonia,hydraulic retention time (HRT) of 3.7-5,6 hr,and dissolved oxygen (DO) of 4 mg/L,the effluent ammonia concentration was lower than 10 mg/L and the ammonia removal efficiency was 90％.While the highest ammonia removal rate,162 mg-N/(L-pellet-hr),was observed when the HRT was 1.3 hr....
The partial oxidation of ethanol to hydrogen was investigated over Ni/Fe/La catalysts prepared by the co-precipitation method. The effects of introduction of La promoter and the reaction temperature on the catalytic performance were studied. It was found that the introduction of La into Ni/Fe catalysts is helpful to increase the selectivity to hydrogen and the stability of the catalysts. The results of XRD and XPS characterization show that the structure of the catalyst was changed during the reaction. The existence of LaFeO3 species is possibly the main reason of the increase of the catalyst stability....
