Papers by Keyword: Pretreatment

Abstract: Due to rapid growth in population and industrialization, worldwide ethanol demand is increasing continuously. The abundant sources of lignocellulosic biomass (LB) from agricultural wastes are attractive feed stocks to become a sustainable source for bioethanol production. There are many crucial engineering steps involved in the bioethanol production route especially on the pretreatment which comprises of chemical, mechanical and biological approaches. In this study we reviewed the various pretreatment involved in biofuel production. By considering the all steps required which may incur costs then influence the price of bioethanol an effective pretreatment technology is required for minimizing the cost and concurrently minimizing other problem especially environmental pollution caused by the pretreatment process. Therefore, a compact step combining all or some of the steps and with additional application of green technology with ionic liquid (IL) will be beneficial to the future direct production of liquefied biofuel with chemical-mechanical-biological based techniques starting from the pretreatment study which therefore lessen cost incurred and process time.

Abstract: Aiming at obtaining glucose, we studied the chemical pretreatment (NaOH + H₂SO₄) and the hydrolysis of sugarcane bagasse using as catalyst the acid-treated vermiculite clay. Samples of the bagasse before and after the treatment were characterized as to the fiber content and XRD. It has been found that the chemical pretreatment showed satisfactory results providing a decrease of 40% in the lignin content and of 43% in the hemicellulose content, regarding to the bagasse in natura. Catalytic tests in aqueous solution were performed at 200°C, to evaluate the use of vermiculite treated as a catalyst for the hydrolysis of sugarcane bagasse. The reaction product was filtered and the supernatant was analyzed by high performance liquid chromatography. A yield of 6.18% in glucose was achieved.

Abstract: Classical EPD has typically been conducted in organic solvent media. Many suitable solvents are volatile and highly flammable and this limits the industrial application of the technique on the basis of safety alone. Aqueous EPD may be seen as a safer method, but issues relating to electrolysis and surface energy phenomena become prominent and can create interferences and variability unless the substrate type and its preparation are compatible with the aqueous EPD chemistry and its deposition method. As EPD layers become thinner, factors such as substrate surface structure and wettability become more critical. Industrial processes utilising some principles of EPD for applying paint from water-based preparations are well established in the metal finishing sector. Consequently there is a significant body of practical experience available from this sector that can be of use in translating classical EPD from a solvent to an aqueous technique while avoiding interferences inherent in the use of water as the deposition medium. In this paper, substrate selection is discussed in relation to the electrolyte content of the system where phenomena such as dissolution and micro-arcing can occur. The initial wetting of the substrate must be considered prior to applying voltage. Surface preparation techniques and the methods of introducing the substrate into the EPD dispersion all can have an impact on the final result. Note: This paper is based on the authors’ personal and practical experience of industrial electrophoretic painting over more than 40 years. Only metal substrates are discussed because these have been almost exclusive in this sector during that time. Non-metal substrates such as conductive plastics, graphite and carbon fibre have also been coated with electrophoretic paints but this is not yet at any significant scale and so no general principles have been established

Abstract: Alkaliphilic cellulases-producer fungi were isolated from soil of limestone areas in Perlis. The potential strain was isolated by soil dilution plate method on enriched selective medium using CMC as substrate at different pH levels. Eleven isolates of different morphological colonies were screened using the hydrolysis capacity test by Gram’s iodine. Out of eleven colonies, five showed positive results as the hydrolysis zone formed. BK1 showed the highest hydrolysis capacity among all sample strains for every pH levels. Eventually, four strains were selected to be further explored as cellulolytic fungi for the production of alkaline cellulase in the future.

Abstract: The characteristics of raw pharmaceutical wastewater was as follows: COD_Cr 30000~32000 mg/L, BOD₅ 4050~4360 mg/L, B/C: 0.12~0.14, Fe-C micro-electrolysis with Fenton reagent was adopted to pretreat this wastewater. Through static experiments analysis, optimal parameters of iron-carbon microelectrolysis Fenton pretreatment process are listed as follows: raw water pH, iron-carbon mass ratio (i.e. 2:3), the mass of iron-carbon (i.e. 500 g/L) and reaction time (i.e. 2 h). The optimal operation conditions (i.e. H₂O₂ dosage is12 mg/L, pH is 3.5, reaction time is 80 min) of Fenton reagent oxidation were confirmed.

Abstract: According to the requirement of aircraft fuel quality property calculation, this paper studied pretreatment methods for tank CATIA model. Firstly, extract outside surfaces of wing skins, start and end wing ribs, front and back spars and then joint them to create a complete closed surface by additional repairing surfaces gap. Secondly, inside the closed surface, bool operation is utlized to remove actual bodies of fuel tank structures and internal accessories from the model of fuel tank. Direct accurate calculation of fuel quality property in CATIA environment is then achieved. Finally,simulation is carried out with an real aircraft fuel tank, comparison between simulation results and test data shows that relative error of pretreated fuel tank volume model is less than 1%, which satisfies engineering requirements.

Abstract: The paper discussed the extraction process of rubusoside from Rubus suavissimus using a new technique named cellulase pretreatment approach. First, the parameters of cellulose which generate the optimized condition for the extraction of rubusoside from Rubus suavissimus were identified. Under the most optimal condition, the extraction efficiency is maximal. The parameters include pH value,temperature and enzyme-substrate ratio. Second, single factor experiment and an orthogonal test then could be conducted to obtain the optimized condition for the extraction process with the assistances of cellulose. The parameters under the optimized condition were determined as following: ethanol as solvent, 1.2% cellulose, 40°C, pH 4.8 and duration 25 minutes. The result shows that the extraction efficiency of rubusoside is 10.81%.

Abstract: Azithromycin wastewater has high ammonia, high COD and high salt content characteristics. By ammonia stripping-Fenton oxidation pretreatment of azithromycin wastewater, the effect is obvious. The optimum technological conditions are determined by experiments, the effluent COD can be reduced to 5000mg/L or less, the total removal of up to 85.6%. After pretreatment of wastewater, the BOD₅/COD value was increased from 0.12 to 0.38, and the biodegradability of the wastewater was improved.

Abstract: In this paper, authors made contrast with the three finite element methods in analysis accuracy and usability .Those are all based on the structural analysis of mining excavator arm. The first fem is using UG solid modeling capabilities to create model .The finite element model is generated by UG_ANSYS, including setting the loads of material properties and boundary conditions ,also loading work. The process is called preprocessing completely .Then export a“. inp” file,after that, imported that file directly into ANSYS software for solving. The second one is to import solid mode created in UG into ANSYS software directly ,then take pretreatment and solution accordingly.The last one is using UG modeling and UG NX NASTRAN (the finite element analysis function) for structure analysis. It is concluded that using UG completely pretreatment of ANSYS analysis method and UG NX NASTRAN method feel more convenient to operate it with the high analyze accuracy,with the two methods , designers can modify mining mechanical arm weak positions more easily.In turns,they can improve the designing level of physical prototyping.

Abstract: Fe/Cu bimetallic process was developed as a new industrial wastewater pretreatment method. It was difficult for an industrial park wastewater treatment plant in Shanghai to treat the wastewater with many refractory pollutants and match the improved discharge standards. The plant needed renovation and adopted Fe/Cu process as a core pretreatment technology. 60,000 tons of wastewater is treated in the plant every day and the average removal rate of COD, BOD, total phosphorous (TP) and color was 73%, 77%, 55% and 48% respectively before renovation. After renovation, the average removal rate of COD, BOD, total phosphorous (TP) and color was reached to 86%, 93%, 76% and 85%, respectively. The engineering practice shows that the removal rate of COD, color and TP in Fe/Cu tank reached 29.7%, 60% and 53.6%. The continuous operating data in two years shows that Fe/Cu process can effectively improve the biodegradability of wastewater and enhanced the subsequent biological treatment. The successful engineering practice indicts that the slag dropping quickly effectively avoid agglomeration and clogging of the Fe/Cu filler and the operating cost is very low.