Konversi Lumpur Aktif Menjadi Biodiesel dengan Proses Subkritis tanpa Katalis secara Insitu

Nowadays, biodiesel has been produced commercially for partial supporting energy demmand in Indonesia. However, high price feedstock and need of catalyst appear as the problem. In this research, activated sludge which is available as large scale waste and comprises significant ammount of lipid fraction (direct adsorption of industrial waste water and microbial lipid), was converted into biodiesel using subcritical process (without catalyst). The potential of the feedstock and process in producing biodiesel were studied. The optimum condition of the production is 215oC, 65 bar, and 5:1 of methanol to lipid mass ratio and the biodiesel meets the SNI-04-7182-2006 spesification

Extraction, identification and quantitative HPLC analysis of flavonoids from sarang semut (Myrmecodia pendan)

The objective of this study was to extract and determine total contents of phenolic and flavonoid compounds as well as to identify and quantify some flavonoids from sarang semut (Myrmecodia pendan). Water bath extraction at 55 °C was employed for extracting flavonoids from sarang semut. The effects of parameters such as extraction time, composition of solvent mixture and solvent to sample ratio on extraction were investigated. From (33) factorial design the optimum extracting parameters were determined as follows: extraction time, 4 h; ethanol/water composition, 80%; and solvent to sample ratio, 50 ml/g. Under these optimal conditions, a yield of 13.82% was obtained. The free radical scavenging activity (antioxidant activity) of the extract was evaluated using DPPH radical and it was found that the IC50 occurred at 96.21 ± 9.03 μg/ml of extract. The total phenol and flavonoid contents were determined using designed methods and found to be 330.61 ± 2.13 mg GAE/g and 63.28 ± 1.75 mg QE/g of dry extract, respectively. The extract obtained under optimum conditions was analyzed by HPLC and five flavonoid compounds were identified and quantified; they are kaempferol (13.767 mg/g), luteoline (0.005 mg/g), rutine (0.003 mg/g), quercetin (0.030 mg/g) and apigenin (4.700 mg/g) of dry extract

Preparation of nanoporous carbon microspheres by subcritical water carbonization and electrocapacitive study

In this work, sugar-derived carbon microspheres (CMSs) with diameters in the range of 5-10 μmand uniform nanopores were prepared using the subcritical water carbonization method, followed bymicrowave-assisted KOH activation. The carbonization was conducted at 3 MPa and moderate tempera-tures (150-170°C) in subcritical water, which is a green dehydrating agent. The formation of the CMSsfrom a sugar solution under subcritical water conditions followed a radical-catalysed emulsion polymer-ization mechanism. The specific surface area and pore volume of the CMSs were found to increase withincreasing the mass ratio of KOH over carbon up to 1:1. Electrocapacitive results showed that a sampleprepared at a KOH to carbon ratio of 1:1 and microwave irradiation level of 70% possessed the highestspecific capacitance (about 179.2 F/g) at a current density of 1 A/g and excellent cycling performance over1000 charging/discharging cycles without significantly loss in capacitance. The specific capacitance andcapacitive retention of this electrode are comparable to that of an electrode prepared from commercialYP-80F activated carbon