Influence of Pretreatments on Sustainability of Bioethanol Production from Napier Grass

The influences of pretreatments and acid hydrolysis conditions in bioethanol production from Napier grass were investigated. The alkaline and acid pretreatments removed 6.63 % and 5.71 %  of lignin more than the untreated grass.  The recommended acid concentration in hydrolysis was 35% sulphuric acid for duration of 20 to 40 min. Fermentation of samples from acid and alkaline pretreatments for 48 h produced the highest ethanol concentration of 13 %v/v. However, when the sustainability was taken into account, these chemical pretreatments had higher cost and released more chemical to environments in comparison to steam pretreatments which produced slightly lower ethanol of 11 %v/v

Fractionation Of Proteins In Surimi Wastewater Using Membrane Filtration

Wastewater from surimi production consists of proteins and other valuable components. Proteins, caused the difficulty in wastewater treatment can be recovered by ultrafiltration and microfiltration and then can be partially purified by bulk crystallization. The results from SDS-PAGE study showed that the range of molecular weight of the soluble proteins was about 10-100 kDa. Ultrafiltration surimi wastewater using membrane with MWCO 100 and 300 kDa could not fractionate these proteins since most the proteins were retained in the retentate. Therefore these membrane can be used for protein concentration. Fractionation of protein from this waste was also studied by using microfiltration with the membrane at the pore size of 0.22 µm, 0.45 µm and 1 µm. The results from SDS-page showed that the protein profile in the retentate and permeate did not difference, indicating that these membranes also could not use for fractionation these types of proteins. These may be due to the narrow range of the molecular weight of these proteins

Clarification of sugar palm sap using a pilot scale microfiltration

It is known that microfiltration can be used for clarification and cold sterilization of beverage and drink products. In this study the sugar palm sap was clarified using a pilot scale of crossflow microfiltration system. The membrane used was tubular ceramic membrane (ZrO2-TiO2) with pore size 0.1 and 0.2 µm. The experiments were carried out with batch mode at constant crossflow velocity 3.5 m.s-1 and 50 °C. It was found that the turbidity and number of microorganism in the permeate for both membrane pore size were reduced greatly while total soluble solid did not significantly decreased. The permeate flux behavior and fouling were also investigated. The permeate flux decreased greatly with processing time due to membrane fouling. The irreversible fouling of both membrane pore size also increased greatly indicating that the irreversible fouling was a major cause of fouling

RECOVERY OF PROTEIN FROM MUNG BEAN STARCH PROCESSING WASTEWATER BY ROTATING ULTRAFILTRATION

Mung bean wastewater containing valuable protein is very potential to be recovered for reuse. In this study, rotary disk ultrafiltration was employed to recover this protein. The effects of transmembrane pressure (TMP) and membrane rotational speeds on process efficiency were studied and the optimum condition was chosen based on membrane permeate flux and protein retention. The results suggested that the use of TMP of 1.2 bar and rotating speed of 1,683 rpm under total recycle mode tended to achieve highest permeate flux (43 L/m3h) compared to those using lower TMP and rotating speeds. The permeate fluxes under total recycle mode and batch concentration mode tended to increase with processing time, indicating the effectiveness of rotating shear force. In addition, the effect of stabilization technique on process performance under batch concentration mode was also studied. However, the variable did not show positive impacts on permeate flux and protein retention improvement. The optimum condition to achieve volume concentration factor (VCF) of 5 was TMP of 1.2 bar and rotating speed of 1,403 rpm without stabilization. Under this condition, the average flux, protein retention and energy consumption were 42 L/m2h, 96% and 81 kWh/m3, respectively

Pillared cloisite 15A as an enhancement filler in polysulfone mixed matrix membranes for CO2/N2 and O2/N2 gas separation

The Cloisite 15A (C-15A), an organically modified montmorillonite clay, was further modified with iron (Fe) pillars. Mixed matrix membranes (MMMs) were fabricated by incorporating Fe pillared Cloisite 15A (P–C15A) at different loading percentage of 0.1–1.5 wt% within the polysulfone (PSf) matrix. Fabricated membranes were characterized using thermal studies (TGA and DSC) and scanning electron microscopy (SEM). The morphological studies of fabricated MMMs confirmed that the P–C15A was well embedded through the PSf matrix. To investigate the effect of P–C15A incorporation, MMMs were tested for their gas permeation behavior using pure CO2, N2, and O2 gases. The gas permeation of MMMs was increased with the increase in loading percentage of P–C15A, whereas the gas selectivity was maintained at par to that of neat PSf membrane until it diminished at 1.5 wt% percentage of P–C15A causing mineral agglomeration. PSf/P–C15A (1 wt%) MMMs exhibited 232% and 274% increase in CO2 and O2 gas permeability respectively, while showing minimal variation in the selectivity of O2/N2 and CO2/N2 compared to that of neat PSf membrane. Furthermore, the gas separation performance of neat and P–C15A incorporated MMMs were compared with the Robeson upper bound. The PSf/P–C15A (1 wt%) MMM shown to have CO2 permeability of 18.01 barrer with the CO2/N2 and O2/N2 gas pair selectivities of 4.95 and 18.34 respectively, which depicted closeness towards the Robeson upper bound