Yano Surya Pradana

Application of micro bubble generator as low cost and high efficient aerator for sustainable fresh water fish farming

This study aimed to apply a novel type of aerator called Micro Bubble Generator (MBG) for fresh water fish farming. The MBG was run based on the principle of venturi tube in which water was circulated through a narrowed channel so that air was sucked into the device and pushed by the flowing water to create micro-sized bubble. The MBG aerator was tested on the aquaculture of tilapia fish to be compared to conventional aerator (the bubbler currently used in aquaculture experiments) and control (container with no aeration). The population of 150 tilapia fish of the average initial length of 6.44 cm was tested in each container. The water quality parameters (COD, pH, and TAN) and fish growth parameters (length and weight) were observed for 68 days. The results highlighted the promising potential of MBG as affordable aerator to be applied in intensive aquaculture. Although the dissolved oxygen level did not differ significantly with the conventional aerator, MBG aerator indicated faster degradation of organic...

Application of Coconut-Shell Activated Carbon as Heterogeneous Solid Catalyst for Biodiesel Synthesis

Biodiesel is a bio-based fuel for diesel engine synthesized from renewable oils isolated from oil crops or animal. Biodiesel can be produced through transesterification where the process involves a catalyst and an alcohol. The most common catalyst for this process is homogeneous liquid catalyst. However, this catalyst system suffers from environmental problems. In order to eliminate the problem, we developed potassium loaded on coconut-shell activated carbon (K/AC) as heterogeneous solid catalyst which is easily regenerated, leading to more secure and more environmental friendly application. The purpose of the present work is to demonstrate the biodiesel synthesis from palm oil using K/AC catalyst in stirred tank reactor. Reaction variables such as methanol-oil molar ratio and temperature were optimized to reach the highest conversion for 4 hours reaction time. The highest reaction conversion, 26.98%, was obtained at methanol-oil molar ratio of 6:1 and reaction temperature of 60 °C. Furthermore, the value of collision factor, activation energy and standard enthalpy change of reaction obtained are 5.40 x 103 dm6.(mol.gcat.min)-1, 16.113 cal/mol and 5499.40 cal/mol, respectively.

Performance Evaluation of Household Pyrolytic Stove: Effect of Outer Air Holes Condition

Renewable energy is the future energy for the substitution of the depleting fossil fuels. In Indonesia, biomass is one of promising renewable energy due to its abundant availability. Biomass can be converted into energy by thermochemical process, such as pyrolysis. In the implementation, pyrolysis can be applied in household cookstove, called pyrolytic stove. Pyrolytic stove will be proposed for people still cooking over an open biomass fire. This paper studied the pyrolysis of Indonesian teak using household pyrolytic stove. The effect of outer air holes on the performance of household pyrolytic stove was investigated. The increasing of cross section area of outer air holes effected on the higher of biomass combustion releasing energy for pyrolysis and cooking. Furthermore, the optimum outer air holes condition in the stove was fully open with the minimum of char product and the maximum of energy recovered for cooking.

Study of cultivation and growth rate kinetic for mixed cultures of local microalgae as third generation (G-3) bioethanol feedstock in thin layer photobioreactor

The increasing use of fossil fuels causes the depletion in supply and contributes to climate change by GHG emissions into the atmosphere. Microalgae indicate as renewable and sustainable energy sources as they have a high potential for producing large amounts of biomass for third-generation biofuels (bioethanol and biodiesel) feedstock. However, there are several parameters which should be considered for microalgae cultivation, such as environmental conditions, medium composition and microalgae species. The aim of this research was to study cultivation of mixed microalgae cultures (Glagah consortium and Arthrospira maxima) in a thin layer photobioreactor. Farmpion medium, Bolds Basal Medium (BBM) and Thoriq Eko Arief (TEA) medium were investigated as cultivation medium for bioethanol feedstock for 7 days. The results showed that the highest dry weight concentration of microalgae was in Farmpion medium (0.35 mg/ml) and the highest carbohydrate concentration of microalgae was in BBM (0.14 mg/ml). Thus, the optimum medium of microalgae cultivation for bioethanol feedstock was BBM because of the highest carbohydrate-dry weight ratio (0.88). In addition, mathematical approach by using Contois model was used to find out the growth rate of microalgae cultivation in each medium.

Bio-Synthesis of Eicosapentaenoic Acid (EPA) from Palm Oil Mill Effluent Using Anaerobic Process

The supply of omega-3 fatty acids, which are EPA and DHA, was only 14.7% of the prospective demand calculated by using 500 mg/day/person as threshold limit for EPA and DHA consumption for a world population of 7.515 billion people. Alternative sources other than fish oil or seed-based-α linolenic acid (ALA) were necessary. Anaerobic digestion of palm oil mill effluent (POME) offered a new way for one of omega-3 fatty acids production, EPA. The digestion was conducted in anaerobic fluidized bed reactor supported by natural zeolite as the immobilization media. Process condition tried to be optimized was the pH level and the pre-treatment method (TSS filtration) before the digestion. Without any pre-treatment, the fatty acid profile produced after digestion contained considerable amount of polyunsaturated fatty acid with acidic condition provided higher EPA purity. On the other hand, pre-treatment led the digestion to produce saturated fatty acids with acidic condition provided very high purity of butyric acid as the product.