Papers by Keyword: Pretreatment

Abstract: The air-conditioning/cotton blended fiber was pretreatment to investigate the effects of the sodium hydroxide, hydrogen peroxide, scouring agent, tea saponin, oil removing agent, the processing temperature and the processing time on the fabric. The values of capillary, strength, whiteness were got after single factor tests. The results showed that the best pretreatment process was at 90°C, tea saponin 4g/L,oil removing agent 3g/L and the processing time 30min.Through this process, the strength of the fiber was 165cN, the whiteness was 71.2% and the capillary is 10cm.Tea saponin is a main factor only second to temperature.

Abstract: Sewage sludge is difficult to degrade in anaerobic digestion systems and pretreatments have been shown to speed up the hydrolysis stage. In this paper sludge anaerobic digestion experiments with peracetic acid as a pretreatment were carried out and the effects of acid pretreatment using peracetic acid on subsequent digestion were investigated. It has been proved that this treatment effectively leads to a solubilisation of organic material and thus leads to a increase of soluble chemical oxygen demand (SCOD) and volatile fatty acids (VFA) concentration. Besides, the SV of sludge was reduced and the settling characteristics of sludge were improved. But high dosage of peracetic acid lead to a decrease in biogas production and the proper dosage was 20 g/kg DS. It can be concluded that sludge anaerobic digestion with peracetic acid pretreatment is an effective method for biomass material transformation.

Abstract: Despite of the fact that the first and the second generation biomass feedstock are attractive options for the biofuel production, these production schemes are considered unsustainable. As the demand for renewable energy grows exponentially, the practicability of the production of these energy carriers becomes tentative and limited since large arable croplands in tropical and tempe-rate regions are required for their cultivation. Moreover, the conversion processes (i.e. thermo-chemical and bio-chemical) associated with the second generation biomass feedstock are far more complex and sophisticated because of the recalcitrant nature of cellulosic biomass. The biofuels, thus, derived are not cost-competitive with existing petroleum derived fuels. In future, the integra-tion of various biochemical and bioprocessing technologies will be supporting the establishment of biomass energy programs. This paper is an attempt to review the potential of microalgal biodiesel in comparison to the first and the second generation biomass feedstock and its global prospects. Keywords : microalgae biomass, pretreatment, biofuels, clean energy

Abstract: In order to find out the appropriate kinetic model for biomass pyrolysis, pyrolysis experiments of four samples (untreated biomass, HCl-washed, 3%KCl-treated and 10% KCl-treated) of sweet sorghum bagasse were performed by Thermogravimetry (TG) separately at different heating rates. The pyrolysis data was processed by the methods of Ozawa、Coats-Redfern integration and Achar-Brindley-Sharp differential, and the kinetic parameters were calculated. The results showed that the activation energy from deduced mechanism functions is more approach to the Ozawa’s than that from tentative mechanism functions, and the deduced mechanism functions can more realistically reflect the dynamic process four samples of sweet sorghum bagasse pyrolysis.

Abstract: To discuss the effect of NaOH pretreatment technology for biogas production and methane (CH₄) content enhancement during the anaerobic digestion of rice straw waste, a self-designed laboratory-scale continuous anaerobic biogas digester was used in this study. Anaerobic biogas slurry, NaOH pretreatment and anaerobic digestion were evaluated for biogas production from rice straw. The results showed that the peak value of biogas production was attained on the 16^th day by using 6% NaOH pretreatment on rice straw. However, the highest CH₄ content was 60.8% on the 24^th day for the 4% NaOH-treated rice straw. The cumulative biogas production of 6% NaOH pretreatment was the highest, about 18 720 mL, which was followed by 8% NaOH (15 057 mL), 4% NaOH (12 103 mL), and 2% NaOH (10 754 mL).

Abstract: The concentration of ammonia nitrogen in a slaughterhouse wastewater sample was determined using Nessler's reagent spectrophotometry with four different pretreatment approaches. Comparison of the results shows that the concentrations increased in the following order: coagulation sedimentation < boric acid absorption < filtration < acidifying filtration. Boric acid absorption method is more favorable, and standard curve method (SCM) should be considered superior to standard addition method (SAM) in the present research.

Abstract: The microwave pretreatment of pineapple peel for ethanol production was optimized by RSM (Response surface methodology). Three variables, which were studied, were peel to water ratio (100-160 g/L), microwave power (90-900 watt) and time (5-20 min). The optimal condition for reducing sugar production was 132 g/L peel to water ratio, 90 watt for 12 min that provide the 10.4 g/L of highest content. For total sugar production was 160 g/L ratio, 90 watt for 20 min that gave the optimum content of 579.9 g/L. This microwave pretreatment without a reagent could achieve the satisfied sugar content for ethanol fermentation that led to save time and energy consumption.

Abstract: Since spectral curves were obtained by experiment, on the basis of the fully use of the waveform characters, a new method for spectral matching pretreatment has been proposed in this paper. Corresponding to the spectral curve, we can accurately get the spectral absorption curve of the number of bands, it can effectively suppress the effects of the noise according to the times of fitting the points. Besides, it can also prominent the peak point of the material. This method can have an effective influence on the initial period of spectral match and detailed resolution; some numerical simulations have been made to test the validity and capability of the proposed method.

Abstract: This study took three factors three levels orthogonal experiment scheme and chose PAM as the coagulant, pretreated a pharmaceutical factory wastewater by chemical coagulation method, and the results indicated: when coagulant dosage was 50 mg/L, pH was 5 and mixing time was 20 minutes, the removal efficiency of SO₄^2- and COD could be 39.0% and 72.5% respectively. The water quality could meet the requirements of the subsequent treatment processes.

Abstract: A novel process of electroless Ni-P plating on magnesium-lithium alloy is discussed in this paper, by which nickel ions are provided by basic nickel carbonate and a new pretreatment method is introduced to obtain good quality coating. The corrosion behavior of magnesium-lithium alloy without or with coating was compared and the bonding strength of the electroless Ni-P coating to the matrix surface was also measured. The results showed that the process of electroless Ni-P plating can be easily achieved on the intermediate layer and a compact Ni-P coating without flaws is formed synchronously. The thickness of Ni-P coating is above 20 μm and its phosphorus content is about 10.501wt.%. The corrosion potential of magnesium-lithium alloy coated by Ni-P increases obviously (-0.315V) during the anodic polarization in 3.5 wt. % NaCl solution and this phenomenon indicates that an effective protection has been formed for the alloy. It was proved that the Ni-P coating adheres on magnesium-lithium alloy surface tightly through the file test and cross cut test.