No abstract

Preliminary study of activated carbon from water chestnut (Eleocharis dulcis) has been done. The water chestnut plants, which were taken from Barito Kuala regency, South Kalimantan, were carbonized at 400 °C. The carbonized time were varied in 1 and 2 hours. Then the carbons were activated by KOH and H2SO4 solutions. The activated time were also varied in 1 and 2 hours. The physical-chemical properties of water chestnut charcoal, such as water content, ash content, volatile and fixed carbon values, before and after activated, were characterized. The results showed that the water content, ash content, volatile and fixed carbon values of activated carbon were in the range of 5.63-12.17%; 10.95-17.22%, 41.78-56.18% and 34.66-45.05%, respectively.

This research made three kinds of briquettes from various biomass waste, including alaban wood charcoal and rubber seed shells mixed with coal bottom ash and coal fly ash. The purpose of the study was to obtain the characteristics and quality of briquette combustion. Making briquettes is by drying, grinding, and sifting raw materials then mixed with adhesive, printing and drying. Briquettes were made with variations in composition and pressure and the particle size of the material passing through the 50 and 250 mesh sieves. Briquettes produced from alaban wood charcoal and coal bottom ash, or fly ash, obtained more bottom ash or fly ash composition characteristics. The moisture content and calorific value would be lower while the ash content was higher. While the initial ignition time, the combustion duration is getting longer, but the burning rate would decrease. Briquettes made from rubber seed shells and coal bottom ash obtained variations in composition and pressure that affect the characteristics and quality of combustion. The higher the rubber seed shell composition and pressure, the lower the water and ash content, but the calorific value increased.

Moisture content, ash content and heating value have been measured on briquettes which were made from a mixture of halaban charcoal and coal bottom ash with variations in pressures and form factor. Factors that influence the characteristics of briquettes were powder fineness and pressure. And so both materials were made in the form of powder on a 250 mesh sieve and pressure variations (150, 200, 250, 300, and 350) kg / cm2. The composition of the mixture of halaban charcoal and coal bottom ash was with a ratio of 90%: 10%, while 5% of starch adhesive was added. Briquettes were made in the form of solid cylinders and hollow cylinders. From the measurements, the moisture content, ash content and heating value of solid cylinder briquettes were yielded 3.831-5.892%, 7.178-10.507% and 5,607.467-5,732.033 cal/g, respectively. While for hollow cylinder briquettes were 4.564-5.621%, 8.688-11.191% and 5,620.833-5,685.100 cal/g. All briquette samples meet Indonesian national standards requirements for moisture content and heating value, but not all briquette samples meet the requirements for ash content. Higher pressure gave lower water and ash content, but higher heating value. Based on the results, it is recommended that the pressure given in making the briquette was 200 kg/cm2. This is based on consideration of the highest heating value obtained when the pressure was 200 kg / cm2.

In this study, the combustion properties of briquette from halaban charcoal, bottom ash and fly ash has been carried out. For briquetting, the halaban charcoal and bottom ash was mixed in different composition, 100%: 0%, 90%: 10%, 80%: 20% and 70%: 30%. While for halaban charcoal and fly ash the composition ratio were 100%: 0%, 90%: 10%, 80%: 20%. The combustion properties of briquettes, the initial ignition time, duration of combustion and ignition rate, would be investigated. The results were 1.32-2.22 minutes,74-84 minutes and 0.22-0.34 g / minute, respectively. The data shows that the initial ignition time and duration of combustion would be longer while the burning rate would be faster when bottom ash and/or fly ash composition were increased.