Identifikasi Gugus Gula Pereduksi Mikroalga Arthrospira platensis Hasil Hidrolisis dengan Bantuan Gelombang Mikro

Menipisnya sumber bahan bakar fosil dan meningkatnya emisi karbon dioksida (CO2) telah mendorong kegiatan penelitian untuk menemukan sumber-sumber energi terbarukan. Bioetanol merupakan sumber energi yang ramah lingkungan dan memiliki prospek yang menjanjikan untuk mengurangi ketergantungan pada gasolin. Bioetanol dihasilkan dari proses fermentasi monosakarida. Bioetanol generasi pertama dan kedua berasal dari tanaman pangan, limbah pertanian, dan limbah perkebunan, sedangkan generasi ketiga dihasilkan dari mikroalga. Arthrospira platensis merupakan salah satu jenis mikroalga dengan kandungan karbohidrat yang tinggi. Penelitian ini bertujuan untuk menentukan kandungan gugus gula pereduksi yang merupakan monosakarida hasil hidrolisis dengan bantuan gelombang mikro. Sebanyak 10 g serbuk mikroalga ditambahkan ke dalam 100 mL larutan 0,3 M H2SO4. Proses hidrolisis dijalankan dalam sebuah reaktor microwave pada suhu 100 °C selama 90 menit. Selanjutnya hidrolisat yang diperoleh difermentasi dengan ragi Saccharomyces cerevisiae secara anaerob di dalam shaking water bath. Uji HPLC dilakukan untuk mengidentifikasi gugus-gugus gula pereduksi dalam hidrolisat, sedangkan uji GC dilakukan untuk menentukan konsentrasi bioetanol yang dihasilkan dari proses fermentasi. Sementara itu, kandungan padatan biochar sisa hidrolisis dianalisis menggunakan FTIR. Dari hasil pengujian HPLC diperoleh konsentrasi glukosa sebelum fermentasi sebesar 11,963 g/L dan setelah fermentasi sebesar 0,546 g/L atau sebanyak 95% glukosa terkonversi menjadi etanol. Selanjutnya hasil distilasi dari fermentasi hidrolisat diuji dengan GC dan diperoleh kadar etanol sebesar 0,39%

ZAT WARNA ALAMI BERBASIS LIMBAH SABUT KELAPA MUDA (COCO NUCIFERA) UNTUK PEWARNAAN KAIN BATIK

Sabut kelapa muda salah satu limbah sumber daya alam yang dapat dimanfaatkan sebagai zat warna alami karena memiliki senyawa aktif sebagai donor pembawa warna, ketersediaan limbah sabut kelapa muda khususnya dilingkungan para penjual es kelapa muda di Yogyakarta cukup tinggi dan selama ini belum dimanfaatkan dengan optimal. Tujuan penelitian ini ingin mengetahui arah warna dan kualitas warna yang dihasilkan dari ekstrak limbah sabut kelapa muda kulit hijau untuk pewarnaan pada kain batik. Metode penelitian ini eksperimen kualitatif dengan melakukan variasi konsentrasi rasio larutan ekstraksi 1:5 dan 1:10, variasi suhu ekstraksi 60  dan 100 , variasi waktu ekstraksi 2 jam dan 4 jam. Hasil penelitian diperoleh ekstrak sabut kelapa muda kulit hijau sangat baik sebagai zat warna alami untuk pewarnaan kain batik, nilai uji ketuaan warna K/S tertinggi 0,0355 dari perlakuan variasi rasio ekstraksi 1:5, suhu 60 ℃ dan waktu 4 jam, nilai uji ketahanan luntur warna pada pencucian 40 ℃ rata-rata 4-5 kategori baik, nilai uji beda warna L*,a*,b* dan hasil pengamatan visual pada pantone color warna yang dihasilkan brown cork dan cream tan yang mengandung unsur arah warna kemerahan dan kekuningan

An Investigation into the Effectiveness of Green Betel (Piper betle L.) Leaf Extract Hand Sanitizer

Green betel (Piper betle L.) leaf contains anti-thrush, anti-cough, astringent, and antiseptic chemicals such as saponins, flavonoids, polyphenols, and essential oils. Hand sanitizer can also be used as an antiseptic agent, which is a more practical option. The purpose of this study was to see how the composition of green betel leaf extract made by infusion affected its physical properties and bacterial inhibition. Hand sanitizer samples were made using different concentrations of green betel leaf extract (10 - 25 wt%) with and without the addition of tea tree essential oil. Sample testing included organoleptic tests, physical properties tests, and effectiveness tests on the growth of Escherichia coli bacteria. The results showed that the best composition was found to be at a concentration of 10 wt% green betel leaf extract without the addition of essential oil, with pH ranging from 5.2 to 5.8 and viscosities ranging from 1.32 to 1.99 cps, in the form of a watery gel and a clear yellow color. Meanwhile, hand sanitizer sensitivity testing revealed that none of the samples could inhibit the growth of Escherichia coli bacteria. This indicates that the concentration of green betel leaf extract in the sample is still insufficient to inhibit bacterial growth

Amino-acid-salt-based carbon dioxide capture: precipitation behavior of potassium sarcosine solution

This work studied the precipitation behavior of solids in the aqueous solution of potassium sarcosine (KSar) during the CO2 capture process with the concentration of 5m' (mol/kg solution). The effect of precipitation on the CO2 capture capabilities was also studied. The results showed that 5m' KSar gives a comparable result to MEA. The relatively high initial CO2 absorption efficiency combined with the positive effect of precipitation on CO2 absorption rate and CO2 capacity have made the 5m' KSar be a promising solvent for the CO2 capturing process with precipitation.publishedVersio

Amino-acid-salt-based carbon dioxide capture: precipitation behavior of potassium sarcosine solution

This work studied the precipitation behavior of solids in the aqueous solution of potassium sarcosine (KSar) during the CO2 capture process with the concentration of 5m' (mol/kg solution). The effect of precipitation on the CO2 capture capabilities was also studied. The results showed that 5m' KSar gives a comparable result to MEA. The relatively high initial CO2 absorption efficiency combined with the positive effect of precipitation on CO2 absorption rate and CO2 capacity have made the 5m' KSar be a promising solvent for the CO2 capturing process with precipitation

Selection and Characterization of New Absorbents for Carbon Dioxide Capture

Removal of acidic gases, in particular CO2, is an important industrial operation. Carbon dioxide is produced in large quantities by fossil–fuel–fired power plants, steel production, the production of petrochemicals, cement production, and natural gas purification. The global climate change, where CO2 is found to be a major contributor, is one of the most important and challenging environmental issues facing the world community. This has motivated intensive research on CO2 capture and storage. Carbon dioxide capture by an absorption process is one of the most common industrial technologies today. Recent economic studies (Desideri and Corbelli, 1998) indicate that the process will also remain competitive in the future. One of the key improvements under development is new, faster and more energy–efficient absorbents. A chemical to be used as a commercial absorbent must have high net cyclic capacity, high absorption rate for CO2, and good chemical stability. Alkanolamines are the most commonly used chemical absorbents for the removal of acidic gases today. In the first part of this thesis, an experimental screening of new absorbents for CO2 capture was performed by absorption of CO2 into both single absorbents and absorbent mixtures for amine–based and non–amine–based systems at 40 °C. From testing of ∼30 systems, it was found that an aqueous 30 mass % AEEA {2-(2-aminoethyl-amino ethanol} solution seems to be a potentially good absorbent for capturing CO2 from atmospheric flue gases. It offers high absorption rate combined with high absorption capacity. In addition to AEEA, MMEA (2-(methylamino)ethanol) also needs to be considered. It could have a good potential when used in contactors where the two phases are separated, like in membrane contactors, whereas indications from the study showed foaming tendencies that will make it difficult to use in ordinary towers. AEEA as the selected absorbent obtained from the screening tests was further investigated to determine its vapor–liquid equilibrium characteristics. The experimental and modeling study of the solubility of CO2 in aqueous AEEA is described in the second part of the thesis. From the VLE data, it is shown that AEEA does not only offer high absorption rate combined with high absorption capacity in terms of CO2 loading but also offers higher cyclic capacity and lower regeneration energy requirement for some cases studied compared to MEA. In addition, a VLE thermodynamic modeling of the aqueous AEEA solution was performed by use of a modified Deshmukh–Mather model (Deshmukh and Mather, 1981) as well as NMR analyses to determine the species distribution in the liquid phase as function of CO2 loading. A two–stage calculation was performed to model the VLE of the CO2–AEEA–H2O system. The first stage of the calculation was the regression of the parameters involved in the temperature dependency of the chemical equilibrium constants without binary interaction parameters taken into account. As seen from the results, the model provides a very good representation of the experimental data over a range of temperatures from 40 to 120 °C. The second regression of the VLE data was then performed to evaluate the binary interaction parameters i.e. the short–range terms in the Deshmukh–Mather model. However, only minor improvements in the overall fit were achieved. In the last part of the thesis, an experimental kinetic study of the CO2–AEEA–H2O system was performed using a string of disc contactor over a range of temperatures from 32 to 49 °C for various concentrations of AEEA. The reaction mechanism used for interpretation of the kinetics was the single step and termolecular mechanism approach proposed by Crooks and Donnellan (1989) and reviewed by da Silva and Svendsen (2004). The results showed that the observed pseudo–first order rate constant is in good agreement with the equation proposed for this mechanism. In addition, the physical properties, density and viscosity, have been measured to determine the physico–chemical parameters. The solubility of N2O in AEEA was also measured to estimate the solubility of CO2 in AEEA solution

Selection and characterization of phase-change solvent for carbon dioxide capture: precipitating system

Characterization of a precipitating solvent for CO2 capture was performed. Aqueous solution of 5m’ potassium salt of sarcosine (KSar) that was precipitated at CO2 loading of 0.52 was selected. The equilibrium solubility of CO2 in the solution was measured over a range of temperatures from 40 to 120 °C. The SOFT model was implemented to predict the vapor-liquid-solid equilibrium (VLSE) data for the CO2-KSar-H2O system. The vapor pressures of the solution were measured at temperatures between 53 and 130 °C. The heat of absorption was also measured at 40 °C. In addition, the heat of absorption of CO2 in the solution was estimated from the VLSE data by use of the Gibbs- Helmholtz equation and was able to predict well the precipitation occurred in the system.publishedVersio

Selection and characterization of phase-change solvent for carbon dioxide capture: precipitating system

Characterization of a precipitating solvent for CO2 capture was performed. Aqueous solution of 5m’ potassium salt of sarcosine (KSar) that was precipitated at CO2 loading of 0.52 was selected. The equilibrium solubility of CO2 in the solution was measured over a range of temperatures from 40 to 120 °C. The SOFT model was implemented to predict the vapor-liquid-solid equilibrium (VLSE) data for the CO2-KSar-H2O system. The vapor pressures of the solution were measured at temperatures between 53 and 130 °C. The heat of absorption was also measured at 40 °C. In addition, the heat of absorption of CO2 in the solution was estimated from the VLSE data by use of the Gibbs- Helmholtz equation and was able to predict well the precipitation occurred in the system

Economic analysis and environmental assessment of aluminum debris power generator for deployment to communal-scale disaster areas

The potential use of aluminum debris as an energy source and carrier has been recently highlighted in the research. An aluminum debris power generator is a promising system that can be deployed in the aftermath of various types of disasters and provide portable electricity. Such a power generator produces electricity while simultaneously handling aluminum debris in disaster areas. We assess the economic and environmental performance of the aluminum debris power generator deployed to communal-scale disaster areas to determine its feasibility. The economic analysis indicates that aluminum debris power generators have a higher net present cost and levelized cost of energy than diesel generators, which are currently used for emergency power generation. However, aluminum debris power generators can improve their economic feasibility when the valuable boehmite by-product is considered. The aluminum debris power generator outperforms the diesel generator for the environmental impact on climate change. The life cycle assessment indicates that the primary source of the environmental impact comes from generator manufacturing. Our results suggest that recycling valuable materials and redesigning manufacture to reduce the use of critical materials can improve the profile of environmental impacts and provide economic benefits for aluminum debris power generators. Future research should be conducted to devise an ecosystem facilitating the sustainability of this type of generator