Search

The steel industries account for 6% of the world's CO2 emissions. The number of emissions will continue to increase as the steel industry in Indonesia grows. Generally, steel production uses blast furnaces which can produce large CO2 emissions. The blast furnace process emissions called blast furnace gas (BFG) contain 20.7% mol of CO2. The high CO2 content also causes the calorific value of the gas to be low, so the gas must be purified to increase its calorific value to be used for power generation. In addition, the steel industry also produces steel slag as waste with a high CaO content (45.2%) but with low economic value. To increase its economic value, CaO content can be used to absorb CO2 from BFG to produce Precipitated Calcium Carbonate (PCC). The use of PCC is very broad for various industrial needs, such as a filler in the paper industry which can increase paper brightness. Therefore, the "Precipitated Calcium Carbonate from Blast Furnace Gas and Steel Slag" plant is expected to be a solution to reduce CO2 emissions from the steel industry. BFG and steel slag as raw materials were obtained from PT. Krakatau Posco. The PCC production process consists of three main stages, namely: (1) Pre-Treatment Steel Slag; (2) Carbonation; and (3) Purification. In the pre-treatment stage, the pH-swing method was used to extract CaO with NH4Cl solvent using pH control. The use of NH4Cl solution is advantageous because it can be recycled. This process obtained a solution of CaCl2 and NH4OH, which was then reacted with CO2 from BFG in a bubble column reactor, resulting in a carbonation process. In the reactor, PCC (CaCO3) and several impurities are formed. The PCC solids formed will then be filtered, dried, and reduced in size so that the moisture content and size are under PCC specifications for the paper industry. Besides producing PCC, purified BFG will be recycled and used as fuel for power generation. The plant location is integrated with PT. Krakatau Posco in the industrial area, Cilegon, Banten, West Java, with a production capacity of 12,750 tons/year. From the results of the economic analysis, with the capital expenditure (capex) of about IDR 337 million and operational expenditure (OPEX) of about IDR 89 million: the payback period is about 6.35 years, and the break-even point (BEP) is 32.38%. [ABSTRACT FROM AUTHOR]

Institut Teknologi Bandung (ITB) - Jatinangor Campus is one of the higher educational institutions located at Jatinangor, Sumedang Regency, West Java Province. This campus has area for about 47 hectares. When this campus have fully active activity, it produces huge amount of compostable waste especially organic and leaves waste. Solving the compostable waste is a key to realize Zero Waste ITB-Jatinangor Campus. MASARO technology offers fast, reliable, and profitable composting method to overcome the compostable waste problem at ITB-Jatinangor Campus. This technology has been applied in several areas in Indonesia, such as Ciwastra, Babakan Sari Waste Processing Site (Bandung City), Sabah Balau Village (South Lampung Province), Institut Teknologi Sumatera (ITERA), Sukadana Village (Ciamis Regency), Gorontalo, and several other areas. It has waste processsing capacity up to 10 Tons/day. The MASARO technology not only produces solid and liquid compost with Standard Nasional Indonesia (SNI) quality, but also shortens the composting period (about 7-10 days). Compost composition at ITB-Jatinangor Campus have 50,8% C-Organic, 2,71% N-total, 0,33 P2O5-total, 1,96% K2O-total, and 18,75 of C/N ratio. In this paper, it will focus on explaining implementation of the MASARO technology starting with the installation of the MASARO Composting House – Rumah Kompos MASARO (RKM). It would describe also about composting process and lesson learned about how the MASARO technology could solve the problem of compostable waste at a big educational institution like ITB-Jatinangor Campus. [ABSTRACT FROM AUTHOR]

This paper presents an analysis of the capability of production facilities, 5S workplace culture, and competencies in foundry industries in West Java, Indonesia. The objective is to identify the current condition of the foundry industries in West Java, Indonesia. The research was conducted by doing an analysis of why the capability of production facilities, 5S workplace culture and employee competencies had not met the expectation yet and then providing alternative solutions to the problems. The research methodology is a descriptive analysis, which is an analysis of three variables researched with approximately 200 respondents in surveys conducted in six foundry industries in West Java, Indonesia. The dimensions of production facilities that were researched are: melting equipment, pattern and core making equipment, mould making equipment, testing and quality control equipment, and finishing equipment. The dimensions of 5S workplace culture that were researched are: segregation, arrangement, cleaning, cleanliness, and discipline. The dimensions of competencies that were researched are: occupational health and safety (OHS), testing and inspection for casting, and operation melting furnace. The results show that the capability of production facilities, 5S workplace culture, and employee competencies are perceived to be fair up to good. Production facilities have average value of 3.2943 and standard deviation of 0,5452; the 5S work culture has average score of 3.5038 and standard deviation of 0.5725; competencies has average value of 3.5647 and standard deviation of 0.5796. The grouping of the capability of production facilities, 5S workplace culture, and competencies in each foundry industry FI-1, FI-2, FI-3, FI-4, FI-5, FI-6 comes under fair good up to good categories. However, if it is viewed in detail, there are still some dimensions that are not optimal and so improvement is needed. [ABSTRACT FROM AUTHOR]

Polyphenols play a pivotal role as representative metabolites of tea. Their presence can also determine the quality of tea and provide valuable benefits for human health. Little attention, however, has been paid to studying polyphenols such as catechin and EGCG at various processes of green tea and limited information is available related to this study in Indonesia. This study was focused on the determination of polyphenols content, antioxidant and antibacterial activities from Indonesian green tea, Camellia sinensis extracts, obtained from Gambung, West Java. The samples used were fresh leaves, dried leaves, and green tea powder from three plant clones, namely GMB-1, GMB-3, and GMB-7. Metabolites of tea were extracted using a hot water method at a temperature of 80 °C and incubated for 60 min. Antioxidant activity was measured using a 2,2-diphenyl-1-pycrylhidrazyl (DPPH) radical scavenging assay, while antibacterial activity was examined using a paper disk diffusion assay. The content of catechin and EGCG was measured by using HPLC. All samples showed strong antioxidant activity against DPPH free radicals, and the highest activity was reached by powder extract from GMB-3 clones. Furthermore, all extracts inhibited the growth of Gram-positive Micrococcus luteus, Bacillus subtilis, and Staphylococcus aureus. However, the extracts had no activity against Gram-negative Pseudomonas aeruginosa, Mycobacterium smegmatis, and Escherichia coli. This study revealed that all samples from three clones of C. sinensis contributed to the potent antioxidant and antibacterial properties of Gram-positive bacteria. The content of catechin and EGCG was influenced by green tea processing steps, which consist of steaming, CTC (Crush, Tear, Curl), drying and grinding. In conclusion, Indonesian green tea can be potentially used as a functional beverage or additive in food applications intended to convey health benefits. [ABSTRACT FROM AUTHOR]

This paper aims to design and manufacture a tool for measuring alcohol concentration using a Grove-HCHO sensor for Indonesian traditional food (fermented black sticky rice). In Subang, West Java, Indonesia, black sticky rice is fermented by yeast, so it will produce fermented food that contains alcohol. In the whole system, the HCHO sensor also uses as a formalin detector. This research used one sensor to measure two parameters, i.e., formalin and alcohol concentrations. Day by day fermented food increased its alcohol content. The sample of alcohol with various concentrations was made to be compared with the sensor reading. The samples were made with the dilution method from a higher concentration of alcohol. The sample value and raw data from sensor voltage were used to find the mathematical modeling. The model changed the sensor reading in an experiment to the alcohol concentration value automatically with a microprocessor in Arduino. The experiment results successfully present the sensor that can be measuring the alcohol concentration of fermented black sticky rice 4 days after fermenting process. [ABSTRACT FROM AUTHOR]