Achmad Roesyadi

Ultrasonic assisted biodiesel production of microalgae by direct transesterification

Microalgae are considered as the third generation source of biofuel and an excellent candidate for biofuel production to replace the fossil energy. The use of ultrasonic in producing biodiesel by direct transesterification of Nannochloropsis occulata using KOH as catalyst and methanol as a solvent was investigated. The following condition were determined as an optimum by experimental evaluates:: 1: 15 microalga to methanol (molar ratio); 3% catalyst concentration at temperature 40°C after 30 minute of ultrasonication. The highest yield of biodiesel produced was 30.3%. The main components of methyl ester from Nannochloropsis occulata were palmitic (C16 :0),, oleic (C18:1), stearic (C18;0), arahidic (C20:0) and myristic (C14:0). This stated that the application of ultrasounic for direct transesterificaiton of microalgae effectively reduced the reaction time compared to the reported values of conventional heating systems.

Formation of hydrocarbon compounds during the hydrocracking of non-edible vegetable oils with cobalt-nickel supported on hierarchical HZSM-5 catalyst

The hierarchical Co-Ni/HZSM-5 catalyst with hierarchical pore structure was prepared by desilication and incipient wetness impregnation. Hydrocracking of non-edible vegetable oils at temperature of 400 °C, 20±5 bar for 2 h was performed in the presence of this type of catalyst under hydrogen initial pressure in pressured batch reactor. Non-edible vegetable oils, such as Reutealis trisperma (Blanco) airy shaw (sunan candlenut) and Hevea brasiliensis (rubber seed) were chosen to study the effect of the degree of saturation and lateral chain length on hydrocarbon compounds obtained through hydrocracking. Cerbera manghas oil was also tested for comparison because the composition of fatty acid was different with the other oils The hydrocracking test indicated that liquid product produced has a similar hydrocarbon compounds with petroleum diesel. The most abundant hydrocarbon is pentadecane (n-C15) and heptadecane (n-C17). The high aromatic compounds were found in liquid product produced in hydrocracking of Sunan candlenut oil.

Production of carrageenan from seaweed (Eucheuma cottoni) with KOH treatment

Eucheuma Cottoni is one type of seaweed that is widely used. This seaweed contains carrageenan in the range of 61.5-67.5 % on a dry weight basis. Carrageenan is a hydrocolloid compound that consists of ester potassium, sodium, magnesium and potassium sulphate with copolymer 3.6-anhydrogalactose. This research is aimed to study the effect of the concentration of alkaline solution (KOH), temperature, time and the concentration of salt solution (KCl) on the yield and gel strength of carrageenan generated in the extraction process. The best process conditions such as the concentration of KOH, temperature and time were found to obtain the best quality of carrageenan in terms of gel strength quality. The research procedure consisted of the preparation of raw materials, KOH treatment, and the extraction process with water. In the KOH treatment, process consists of several variables i.e. the KOH concentration in range of 4-10%, treatment temperature from 60 to 90 °C, and treatment time from 60 to 150 minutes. In ...

Biodiesel Production Using Double-Promoted Catalyst CaO/KI/γ-Al2O3 in Batch Reactor with Refluxed Methanol

A benign process for biodiesel production has been developed using heterogeneous γ-alumina base as catalyst. This study was conducted using double-promoted catalyst CaO/KI/γ-Al2O3 to improve the activity of catalyst and this research was the first one which employs that kind of catalyst for biodiesel production. The preparation of the catalyst was conducted by precipitation and impregnation methods. The effects of reaction temperature, reaction time, and the ratio of oil to methanol on the yield of biodiesel were studied. The reactions were carried out in a batch-type reactor system which consists of three-neck glass flask with 1000-ml capacity equipped with reflux condenser and hot plate stirrer. Results showed that CaO/KI/γ-Al2O3 catalyst effectively increased the biodiesel yield about 1.5 times than that the single-promoted catalyst. The optimum condition for the production of biodiesel is as follows: the reaction temperature is 65 °C, the reaction time is 5 h, and the ratio of oil to methanol is 1:42. Under this optimum condition, the highest biodiesel yield of 95 % was obtained.