Chlorophyll is one of the most used coloring materials derived from green leaves and other parts of almost all green plants. It contains several components that are beneficial to health: vitamins, antioxidants, antibacterial, anti-inflammatory; hence, chlorophyll is a nutraceutical. Chlorophyll has been developed by extracting green plants, for instance, katuk leaves (Sauropus androgynous). A review of various chlorophyll extraction methods from natural ingredients was done to obtain the most suitable katuk leaves. Preliminary experiments had been carried out to develop the chlorophyll stability of katuk leaves on the influence of temperature, pH, and storage time. The chlorophyll content of katuk leaves decreased at high temperatures. Extraction using supercritical/subcritical CO2 can extract components selectively so that it is suitable for extraction applications for products that are not heat resistant. Meanwhile, carbon dioxide (CO2) as a supercritical/subcritical solvent has several advantages, including producing an inert gas that is non-toxic, non-flammable, and cheap. Under normal gas conditions, it is straightforward to separate CO2 and dissolved components without heating and producing extracts free of solvents. The most suitable chlorophyll extraction method of katuk leaves was supercritical/subcritical CO2 extraction because it could prevent chlorophyll degradation.

Indonesia memiliki lahan mangrove seluas 4,255 juta ha, termasuk yang terluas di dunia. Salah satu species yang banyak tumbuh di lahan mangrove adalah Rhizophora mucronata. Potensi tanaman mangrove di Bontang sebagai bahan baku pewarna alami cukup memadai. Luas tanam 2.935 ha menempati luasan sekitar 70% dari lahan yang tersedia. Luasan tersebut, terdapat sekitar 3 juta pohon jenis ini bila dianggap jarak tanam 2 m x 2 m, dengan anggapan bahwa  setiap tahun satu batang pohon spesies ini menghasilkan 50 kg buah dan  50% buah tersebut dipergunakan untuk pembibitan maka masih tersedia sebanyak 75.000 ton buah sebagai bahan baku pewarna alami. Apabila perolehan proses ini sebesar 5% maka berpotensi diperoleh pewarna alami sebanyak 3.750 ton. Pada penelitian ini pengambilan zat warna alami dari buah mangrove spesies Rhizopora mucronata dilakukan dengan proses ekstraksi menggunakan pelarut air pada perbandingan massa bahan terhadap pelarut 1 : 10, suhu 100 °C selama 60 menit. Zat  warna  tersebut kemudian dipekatkan dengan proses evaporasi hingga volume tinggal 30%. Selanjutnya ekstrak dimanfaatkan untuk pewarnaan pada kain batik. Pada penelitian ini dipelajari pengaruh jumlah pencelupan : 5 kali, 7 kali, dan 10 kali terhadap hasil pewarnaan pada kain. Selain itu dipelajari juga pengaruh larutan fixer terhadap hasil pewarnaan pada kain. Larutan fixeryang digunakan pada percobaan ini yaitu tawas, kapur tohor dan tunjung. Untuk kain yang dicelupkan pada fixer tawas, memberikan warna yang lebih muda. Pencelupan zat warna dengan fixer kapur tohor memberikan warna coklat, sesuai warna asli ekstrak buah mangrove dan fixer dengan tunjung memberikan warna kehitaman.

<p><strong><em>Abstract:</em></strong><strong><em> </em></strong><em>Gas purification from the content of H₂S using  Fe-EDTA (Iron Chelated Solution) gave  several advantages. The advantages were  the absorbent solution can be regenerated that means  a cheap operation cost,  the separated sulfur was a solid that is easy to handle and is save to be disposal to environment. This research was done by simulation and experimental. The simulation step was done by mathematical model arrangement representing the absorption process in packed column through mass transfer arrangement such as mass transfer equations and chemical reaction. The experimental step was done with the making of Fe-EDTA solution from FeCl₂ and EDTA. Then Fe-EDTA solution was flown in counter current packed column that was contacted with H₂S in the methane gas. By comparing gas composition result of experiment and simulation, the value of mass transfer coefficient in gas phase ( k_Aga), mass transfer coefficient in liquid phase (k_Ala) and the reaction rate constant ( k) were found. The values of mass transfer coefficient in liquid phase (k_Ala) were lower than values of mass transfer coefficient in gas phase (k_Aga) and the reaction rate constant (k). It meant that H₂S absorption  process using Fe-EDTA absorbent solution was determined by mass transfer process in liquid phase. The higher flow rate of absorbent, the higher value of mass transfer coefficient in liquid phase. </em><em>The smaller packing diameter, the higher value of mass transfer coefficient in liquid phase.From analysis of dimension, the relation of dimensionless number between Sherwood number and flow rate of absorbent, packing diameter was</em><strong></strong></p><p> <strong><em>Keywords:</em></strong><strong><em> </em></strong><em>chemical reaction, Fe-EDTA, H₂S absorption, mass transfer</em></p>