PEMBUATAN ETANOL DARI JAMBU METE DENGAN METODE FERMENTASI

Annacardium occidentale known as jambu mete are grown well in Indonesia. The fruit of jambu mete contains of 15.9 % carbohydrate that can be hydrolyzed to produce glucose, and then it is fermented into etanol using yeast (Saccharomyces Cerevisiae). Objectives of this research were to know how to make etanol from jambu mete’s fruit extract, to know relation between fermentation time and amount of yeast to etanol production, and to determine the highest amount of etanol between 5 to 10 days for each variation of amount of yeast. A thousand grams of jambu mete’s fruit were mixed with 1500 ml of aquadest to produce pasta solution. This solution was then fermented, with variation of fermentation time and the amount of yeast. After fermentation, the solution was then purified by distillation to obtain the higher compotition of etanol. Results of the research is the longer of fermentation time and the higher of amount of yeast the higher composition of etanol can be produced. The highest composition of etanol was obtained at 10 days of fermentation and 20 grams of yeast, it is about 3,2 grams of etanol/100 grams of jambu mete. Keyword : jambu mete, fermentation, Saccharomyces cerevisiae, distillatio

Kinetics of In-Situ Catalytic Pyrolysis of Rice Husk Pellets Using a Multi-Component Kinetics Model

Ash-based catalysts, as low-cost materials, are applicable in biomass pyrolysis and play a role in lowering the activation energy. This study enriched the insights of different method of catalyst addition into biomass in the catalytic pyrolysis. The addition of rice husk ash as a catalyst into rice husk pellets allows for better solid-solid contact between the biomass and the catalyst, since the common methods were only solid mixing. This research aimed to investigate the thermal characteristics and kinetics of the biomass components (hemicellulose, cellulose, lignin) in the in-situ catalytic pyrolysis of rice husk pellets with the addition of husk ash. The three-independent parallel reaction kinetics model was used to calculate the kinetics parameters based on thermogravimetric analysis conducted at 303-873 K with various heating rates (5, 10, 20 K/min) and ash addition ratios (10:0, 10:1, 10:2). The thermogram shows that the pyrolysis of rice husk pellets was divided into two stages. Stage 1, ranging from 510-650 K, represented the decomposition of hemicellulose and cellulose, occurring faster with high mass loss, while Stage 2, starting at around 650 K, represented lignin decomposition, occurring more slowly with low mass loss. The catalytic activity of the ash was only apparent at high temperatures, where cellulose and lignin decomposition were more dominant. Activation energy, as a representation of catalytic activity for each component, was not always lower in catalytic pyrolysis. However, the average activation energy decreased with increasing heating rates and ash addition ratios. The addition of the catalyst slowed the decomposition of hemicellulose but accelerated the decomposition of cellulose and lignin. Copyright © 2023 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

PRODUKSI PATI SORGUM TERMODIFIKASI DENGAN METODE ASETILASI

Sorgum merupakan salah satu tanaman yang bijinya mengandung karbohidrat cukup tinggi mencapai 73 %. Pati termodifikasi adalah pati yang mengalami perlakuan fisik ataupun kimia  secara terkendali sehingga mengubah satu atau lebih dari sifat asalnya. Dewasa ini metode yang banyak digunakan untuk memodifikasi pati adalah modifikasi dengan asam, modifikasi dengan enzim, modifikasi dengan oksidasi dan modifikasi ikatan silang. Modifikasi dengan asetilasi menghasilkan produk dengan swelling power, solubility dan viskositas yang lebih tinggi. Selain itu proses modifikasi dengan asetilasi membutuhkan biaya yang lebih rendah, sehingga lebih menguntungkan apabila digunakan pada industri pangan. Hasil penelitian menunjukkan % asetil dan DS pati sorgum termodifikasi menggunakan metode asetilasi mencapi 43% dan 2,79. Pati sorgum tanpa modifikasi diperoleh swelling power sebesar 0.67 sedangkan untuk pati sorgum termodifikasi sebesar 20,89. Pati sorgum terasetilasi memiliki solubility yang lebih tinggi yaitu sebesar 46,22% dibandingkan pati sorgum tanpa asetilasi yaitu sebesar 10,88%. Ketahanan pati terhadap suhu rendah (Freeze Thaw Stability) untuk pati sorgum yang dimodifikasi secara asetilasi yaitu 1,95% sedangkan untuk pati sorgum tanpa asetilasi sebesar 1,07%. Kata kunci : asetilasi, sorgum, termodifikas

(B. Teknologi) Produksi Gas Sintesis Bersih Pengganti Bahan Bakar Minyak Melalui Gasifikasi Sekam Padi di Reaktor Fixed-Bed Multi-Tahap

Sebagian besar pasokan listrik Indonesia tergantung kepada BBM sehingga rentan terhadap harga dan ketersediaannya. Jadi, teknologi pembangkitan listrik dari sumber terbarukan menjadi suatu keniscayaan karena potensi biomassa Indonesia melimpah. Sebagai contoh adalah sekam padi yang merupakan hasil samping penggilingan gabah. Pemanfaatan sekam masih belum optimal, sehingga perlu pengembangan teknologi agar konversi sekam menjadi energi lebih optimal. Teknologi produksi gas sintesis melalui proses gasifikasi sekam menawarkan pilihan pemecahan masalah. Kinerja gasifikasi sekam yang menghasilkan gas sintesis bersih dapat ditingkatkan dengan proses gasifikasi di reaktor fixed-bed multi-tahap. Penggunaan reaktor ini menghasilkan gas sintesis dengan kandungan CO dan H2 tinggi. Selanjutnya gas sintesis berpotensi besar sebagai sumber bahan bakar alternatif handal untuk produksi listrik. Penelitian pada tahun ke-1 ini menghasilkan beberapa peralatan proses hasil pabrikasi rancangan alat yang terdiri dari: reaktor pembakaran dan pembangkit uap, reaktor pirolisa, serta reaktor gasifikasi dan siklon. Peralatan proses tersebut dilengkapi dengan alat ukur laju alir, tekanan dan suhu. Masing-masing alat sudah diuji-coba dengan berbagai variasi kondisi operasi proses. Hasil uji-coba reaktor pembakaran dan pembangkit uap dengan bahan bakar kayu sebanyak 12,6 kg/jam dapat menghasilkan uap jenuh bertekanan rendah (atmosferis) dengan laju 14,5 kg/jam. Diperlukan waktu kurang lebih 30 menit untuk menghasilkan uap jenuh tekanan rendah dari air umpan bersuhu 300C. Temperatur fluegas yang keluar dari alat ini dapat mencapai 1300C. Fluegas yang dihasilkan dari pembakaran biomassa diharapkan dapat digunakan sebagai fluida pemanas di reaktor pirolisa untuk menghasilkan arang sekam. Namun karena suhu fluegas masih terlalu rendah, maka belum dapat difungsikan sebagai fluida pemanas. Hasil percobaan secara terpisah proses pirolisa secara batch dengan metode pembakaran langsung menghasilkan 0,5 kg arang sekam tiap 1 kg sekam padi. Reaktor pirolisa hasil pabrikasi dapat beroperasi secara kontinyu dengan waktu tinggal sekam di dalam reaktor selama 7 menit dengan laju alir sekam 5 kg/jam. Hasil uji-coba reaktor gasifikasi sudah dapat menghasilkan gas produser dari arang sekam dengan kandungan CO tinggi. Pengoperasian reaktor gasifikasimasih secara batch dengan menggunakan udara sebagai medium penggasifikasi, dan diperoleh nilai Specific Gasification Rate (SGR) 332 kg/(m2.jam). Manfaat penelitian lebih lanjut diantaranya hasil kegiatan penelitian yang berupa peralatan proses dapat digunakan sebagai peralatan praktikum bagi mahasiswa. Sedangkan hasil penelitian yang berupa kajian kelilmuan dapat digunakan sebagai bagian materi kuliah Teknologi Biomassa bagi mahasiswa Strata-1 Teknik Kimia

Reducing Gasoline Specific Consumption in Dual-Fuel Electricity Generation by Using Combustible Gas from Rice Husk Gasification

223-228Using air gasification process, rice husk is attractive to be converted into combustible gas mixture which contains mainly CO, H2, and several hydrocarbon substances. The gas is possible for fueling gasoline engine generator to generate electricity in dual-fuel operation mode, while partially substitutes the gasoline consumption. Obviously, it will influence the generator’s performance. This research reports the gasoline consumption savings in dual-fuel operation of electricity generation at different electricity loads. The gas flowrate was limited with the engine vibration level. A small scale air-blown downdraft gasifier converted rice husk at maximum capacity of 1 kg/h to the gas. A 1 kWe gasoline engine generator was used for this operation. At electricity load of 0.92 kVA in dual-fuel operation, the saving of gasoline (L/kVAh) attained 20.9% and the thermal system energy efficiency was about 11%. In this case, the producer gas flow rate was 1.84 L/s-1 and Specific Gasification Rate(SGR) was 81.53 kg/(m2.h). The energy equivalent was 4.6 kg rice husk/L gasoline or 0.7 kg rice husk/kVAh

Alcohol IbM SME in Bekonang and Ngombakan Hamlets

Alcohol industries in Bekonang hamlet, district of Mojobalan and Ngombakan hamlet, district of Polokarto, Sukoharjo regency has been established since the colonial era and is home industries which generally produce low level (approximately 20-30%) alcohol (ethanol) which is often referred as “ciu”. The total amount of home industries in both districts is approximately 150 entrepreneurs. However, not all of those home industries produce low level ethanol, such as SME in the alcohol industry of ARTA TIRTA ABADI owned by Mr. Sabariyono (as first partner) and SME in the alcohol industry of NGUDI REJEKI owned by Mr. Parno (as second partner). Both partners are selected because the main products being marketed are no longer in the form of ciu, but in 90% leveled-ethanol for the necessities in the fields of medicine, cosmetics, tobacco industries, pharmacies and hospitals in Surakarta regency. The brand new product of ethanol gel is easily obtained from the dilution of 90% leveled alcohol. Based on the result of discussions and observations with several alcohol SMEs in Bekonang and Ngombakan hamlets, the problems in the field of Bussines Development and Finance Administration is found. The business development could not be done because of the stagnant market share due to the lack of products variety. On the other side, SME finance administration was not yet well-managed. The SME had not separated its business finance from its family finance. The business and family expenses was still mixed, therefore it was difficult to determine how much the actual profit earned by the SME revenue. The solution offered related to the problems encountered by the partners is the training of new products manufacturing in the form of solid alcohol (ethanol gel), the means to market new products, the application of Manual Accounting Information System, as well finance management Methods and the cost of goods manufacture accounting. The implementation methods of P2M covered: a) production of ethanol gel; b) production of accounting training’s module; c) market research, d) training: product’s manufacture, cost of goods manufacture accounting training, marketing training and market research socialization; e) assistance of manufacturing, products packaging and simple bookkeeping; and f) marketing. Technically, the production of ethanol gel did not encounter problems and it resulted in ready to use products. Simple accounting training modules for the necessity of SME was also being compiled. Market research on ethanol gel had been done directly towards a number of respondents from Army/Police, catering businesses, college students (nature-lover students and regiment). Based on the result of market research, the respondents asserted their interest to try to consume ethanol gel products. Products’ manufacturing, training, accounting training and marketing training had been conducted and attended by approximately 12 SME representatives. The training participants assessed the activities carried out as good and were able to support the business development owned. The assistance activities of products manufacturing, products packaging and simple accounting were done directly to Mitra SME. While in the term of marketing, SME was helped in brochures production and products promotion through social networks on the internet. SME was also helped in the products offers to prospective users, especially catering businesses and government agencies/ privates

Thermogravimetric Analysis and Kinetic Study on Catalytic Pyrolysis of Rice Husk Pellet using Its Ash as a Low-cost In-situ Catalyst

The thermogravimetric behaviors and the kinetic parameters of uncatalyzed and catalyzed pyrolysis processes of a mixture of powdered raw rice husk (RRH) and its ash (RHA) in the form of pellets were determined by thermogravimetric analysis at three different heating rates, i.e., 5, 10, and 20 K/min, from 303 to 873 K. This research aimed to prove that the rice husk ash has a catalytic effect on rice husk pyrolysis. To investigate the catalytic effect of RHA, rice husk pellets (RHP) with the weight ratio of RRH:ARH of 10:2 were used as the sample. Model-free methods, namely Friedman (FR), Kissinger-Akahira-Sunose (KAS), and Flynn-Wall-Ozawa (FWO), were used to calculate the apparent energy of activation (EA). The thermogravimetric analysis showed that the decomposition of RHP in a nitrogen atmosphere could be divided into three stages: drying stage (303-443 K), the rapid decomposition stage (443-703 K), and the slow decomposition stage (703-873 K). The weight loss percentages of each stage for both uncatalyzed and catalyzed pyrolysis of RHP were 2.4-5.7, 35.5-59.4, and 2.9-12.2, respectively. Using the FR, FWO, and KAS methods, the values of EA for the degrees of conversion (α) of 0.1 to 0.65 were in the range of 168-256 kJ/mol for the uncatalyzed pyrolysis and 97-204 kJ/mol for the catalyzed one. We found that the catalyzed pyrolysis led the EA to have values lower than those got by the uncatalyzed one. This phenomenon might prove that RHA has a catalytic effect on RHP pyrolysis by lowering the energy of activation. © 2022. The Authors

Thermogravimetric Analysis and Kinetic Study on Catalytic Pyrolysis of Rice Husk Pellet using Its Ash as a Low-cost In-situ Catalyst

The thermogravimetric behaviors and the kinetic parameters of uncatalyzed and catalyzed pyrolysis processes of a mixture of powdered raw rice husk (RRH) and its ash (RHA) in the form of pellets were determined by thermogravimetric analysis at three different heating rates, i.e., 5, 10, and 20 K/min, from 303 to 873 K. This research aimed to prove that the rice husk ash has a catalytic effect on rice husk pyrolysis. To investigate the catalytic effect of RHA, rice husk pellets (RHP) with the weight ratio of RRH:ARH of 10:2 were used as the sample. Model-free methods, namely Friedman (FR), Kissinger-Akahira-Sunose (KAS), and Flynn-Wall-Ozawa (FWO), were used to calculate the apparent energy of activation(EA). The thermogravimetric analysis showed that the decomposition of RHP in a nitrogen atmosphere could be divided into three stages: drying stage (303-443 K), the rapid decomposition stage (443-703 K), and the slow decomposition stage (703-873 K). The weight loss percentages of each stage for both uncatalyzed and catalyzed pyrolysis of RHP were 2.4-5.7%, 35.5-59.4%, and 2.9-12.2%, respectively. Using the FR, FWO, and KAS methods, the values of  for the degrees of conversion (a) of 0.1 to 0.65 were in the range of 168-256 kJ/mol for the uncatalyzed pyrolysis and 97-204 kJ/mol for the catalyzed one. We found that the catalyzed pyrolysis led the  to have values lower than those got by the uncatalyzed one. This phenomenon might prove that RHA has a catalytic effect on RHP pyrolysis by lowering the energy of activation

PEMURNIAN BIOGAS DARI GAS H2S MENGGUNAKAN KARBON AKTIF DARI BUAH MANGROVE

Biogas layak sebagai bahan bakar mesin pembakaran dalam (internal combustion engine) karena kandungan metana (CH4) yang dimiliki tinggi. Namun, kandungan H2S dalam biogas yang relatif tinggi dapat menyebabkan korosi pada peralatan proses dan berdampak negatif ke lingkungan. Salah satu metode yang dapat dilakukan untuk pemisahan H2S dari biogas adalah dengan adsorpsi menggunakan arang aktif. Penelitian ini dilakukan untuk mengetahui efektivitas pemurnian H2S dalam biogas menggunakan arang aktif dari buah mangrove, serta menentukan konstanta isoterm adsorpsi Freundlich dan Langmuir. Aktivasi adsorben menggunakan larutan KOH 0,5M dan ukuran adsorben pada -3+4 mesh dan -6+8 mesh. Rangkaian alat adsorpsi terdiri dari 3 alat utama yaitu kondenser, flow stabilizer, dan kolom adsorber. Laju alir biogas yang digunakan diatur sebesar 4 liter per menit (lpm) pada suhu ruang dengan tinggi tumpukan adsorben divariasikan pada 6 dan 8 cm. Dari hasil penelitian diperoleh daya adsorpsi maksimum sebesar 0,324 mg/gram dengan efisiensi penjerapan H2S mencapai 83,16% pada ukuran adsorben -6+8 mesh dan tinggi tumpukan 8 cm. Konstanta kesetimbangan adsorpsi H2S dengan metode Langmuir diperoleh sebesar -239,981 dan metode Freundlich sebesar 824,89. Berdasarkan nilai koefisien korelasi (R2), model isoterm Langmuir lebih sesuai untuk adsorpsi H2S dalam biogas dengan arang aktif dari ampas magrove. Kata kunci: Biogas, hidrogen sulfida, buah mangrove, karbon aktif, adsorpsi, adsorben