The Effect of Temperature and Addition of Cao to Hydrogen Production From Pattukku Coal Char Gasification

Hydrogen is an environment-friendly fuel and has a high caloric value. Hydrogen as a molecule is not found in nature, but it is found in compounds with other elements. Besides catalytic steam reforming of natural gas, hydrogen can also be produced from thermochemical processes such as combustion, pyrolysis, and gasification. The process of gasification using steam as gasification agent can increase the yield of H2 in the gas products. The objectives of this research are to study the influence of temperature and the addition of CaO on H2 production. This research was conducted in an up-draft reactor for 60 minutes with three different temperatures; i.e. 600, 700, and 800 oC and ratio of CaO:char of 0 and 0.5. Based on this study, the rise of temperature will improve the yield of H2 and CO2 in the gas products. At gasification temperature of 800 oC, the yield of H2 and CO2 is maximum. Moreover, the addition of CaO can improve the char conversion and reduce the concentration of CO2 in the gas products

Evaluasi Waktu Start Up pada Proses Peruraian Limbah Stillage secara Anaerobik Menggunakan Reaktor Fluidized Bed Kontinyu dengan Zeolit sebagai Media Imobilisasi

Stillage is wastewater from the ethanol industry. Organic matter content in the stillage is quite high, so it can damage to the environment if disposed of directly into the environment. Stillage has great potential to produce biogas that can be converted into energy by anaerobic treatment process. One of the anaeobic digestion methods is the bacterial cell immobilization technique. One of the  reactor types using cell immobilization technique is Anaerobic Fluidizied Bed Reactor (AFBR). This study uses a set of AFBR reactor containing zeolite media with particle diameters of 0.5 - 0.8 mm and operated at a fluidization level (FL) 20% - 40% of the total effective volume of the reactor. This work studied the effect initial organic concentrations and time dring start up process on decomposition of stillage using AFBR. Scope of this work was evaluating AFBR performance  by comparing the matematical model simulation result with experimental data. The simulation results were used as standard, that described AFBR performance under ideal conditions. This esperiment was conducted for 57 days in two cycles with varied sCOD concentrations and was done in batch recirculation process. The experiment showed that initial organic concentration was affected start up process.  On high organic concentration, start up process failed, but the maximum concentrations limits have not  been determined yet. Experiment showed that charging  50.000 mg sCOD/L to the reactor have made the system failed due the organic shock loading and inhibiton by VFA. Optimum time of start up was determined in first cycle, with initial organic concentration 10.000 mg sCOD/L. Optimum time of start up is 7 until 10 days. If start up process was longer than 10 days, bacteria entered the decay phase due insufficiency of substrat. AFBR performance evaluation using mathematical approaches produced more objective and more accurate result, although there were several factor not evaluated in the mathematical model such as the inhibition effect. These results could be used as a reference for reactor performance optimization especially in addressing the problem of inhibitio

Evaluasi Waktu Start Up pada Proses Peruraian Limbah Stillage secara Anaerobik Menggunakan Reaktor Fluidized Bed Kontinyu dengan Zeolit sebagai Media Imobilisasi

Stillage is wastewater from the ethanol industry. Organic matter content in the stillage is quite high, so it can damage to the environment if disposed of directly into the environment. Stillage has great potential to produce biogas that can be converted into energy by anaerobic treatment process. One of the anaeobic digestion methods is the bacterial cell immobilization technique. One of the  reactor types using cell immobilization technique is Anaerobic Fluidizied Bed Reactor (AFBR). This study uses a set of AFBR reactor containing zeolite media with particle diameters of 0.5 - 0.8 mm and operated at a fluidization level (FL) 20% - 40% of the total effective volume of the reactor. This work studied the effect initial organic concentrations and time dring start up process on decomposition of stillage using AFBR. Scope of this work was evaluating AFBR performance  by comparing the matematical model simulation result with experimental data. The simulation results were used as standard, that described AFBR performance under ideal conditions. This esperiment was conducted for 57 days in two cycles with varied sCOD concentrations and was done in batch recirculation process. The experiment showed that initial organic concentration was affected start up process.  On high organic concentration, start up process failed, but the maximum concentrations limits have not  been determined yet. Experiment showed that charging  50.000 mg sCOD/L to the reactor have made the system failed due the organic shock loading and inhibiton by VFA. Optimum time of start up was determined in first cycle, with initial organic concentration 10.000 mg sCOD/L. Optimum time of start up is 7 until 10 days. If start up process was longer than 10 days, bacteria entered the decay phase due insufficiency of substrat. AFBR performance evaluation using mathematical approaches produced more objective and more accurate result, although there were several factor not evaluated in the mathematical model such as the inhibition effect. These results could be used as a reference for reactor performance optimization especially in addressing the problem of inhibitio

Evaluation of volatile fatty acids (VFAs) production in thermophilic and mesophilic anaerobic digestion of oil palm empty fruit bunch (OPEFB)

Palm oil is one of the leading global commodities, and Indonesia is one of the largest palm oil producers in the world. One of the solid wastes generated from oil palm industrial activities is oil palm empty fruit bunches (OPEFB). The annual accumulation of OPEFB in Indonesia is 126,317.54 tons/year, and it increases with increasing palm oil production. The cellulosic content of OPEFB is a potential substrate for anaerobic digestion to produce volatile fatty acids (VFAs). This study used chemical pretreatment (NaOH 8% w/V) for OPEFB delignification before the anaerobic digestion for VFAs production. Digested cow manure (DCM) was used as the inoculum. Process optimization of producing VFAs is challenging because VFAs act as intermediate products in the metabolic pathway of anaerobic digestion. In general, the temperature can affect the activity of hydrolytic and acidogenic facultative microorganisms. It increases the hydrolysis rate of organic polymers to more soluble forms and improves the performance of anaerobic reactors for the formation of VFAs. This study examines the effect of temperature on the anaerobic digestion process of OPEFB for VFAs production in a batch reactor. The temperature varied in mesophilic (29 oC) and thermophilic (55 oC) conditions. This study showed that anaerobic digestion in the thermophilic conditions produces almost thrice VFAs compared to the mesophilic process. The highest accumulation of VFAs in both reactors occurred on the seventh day, i.e., 3311.57 ± 89 mg.L-1 at ORP-163 ± 16 mV in the thermophilic reactor and 1307 ± 42 mg.L-1 at ORP-224 ± 32 mV in the mesophilic reactor. Acetic acid was the dominant VFA in each reactor. The VFA production in thermophilic reactor (RT) reached 59% of the stoichiometric potential. Although the thermophilic condition improves the VFA yield compared to the mesophilic condition, further study is still needed to increase the VFA production from OPEFB

Characteristic of oil palm empty fruit bunch after ethanolorganosolv pretreatment catalyzed by acid

The increasing growth of palm oil industry results in an increase in the accumulation of waste generated from the industry, such as oil palm empty fruit bunches (OPEFB). OPEFB is a good source of renewable raw materials if a pretreatment process can overcome the recalcitrance of OPEFB and allows the fractionation of all carbohydrates and lignin. In this work, the effectiveness of organosolv pretreatment to deconstruct OPEFB and to recover high purity of lignin and glucan was studied. The pretreatment experiments were carried out at 210 °C for 90 minutes with a solid to liquid ratio of 1/10. Ethanol 50% (v/v) was used as solvent. The effect of H2SO4 0.07% (w/w) as catalyst was also studied. The results showed that organosolv pretreatment with the addition of acid increased the purity of glucan and lignin by 36 and 5%, respectively. A total of 65% lignin was recovered, which was 3.6 times higher than lignin from pretreatment without acid catalyst. After organosolv pretreatment with an acid catalyst, the crystallinity index (CRI) decreased by 54%, while the decrease in CRI was only 14.4% after pretreatment without an acid catalyst. The water retention value of the pretreated OPEFB with acid catalyst increased by 8%. It can be concluded that organosolv pretreatment using ethanol as a solvent with the addition of acid catalyst succeeded in fractionating OPEFB with high purity and reducing recalcitrant OPEFB

Eksplorasi Produksi Biohidrogen dari Fraksi Organik Sampah Rumah Tangga dengan Penambahan Zat Aditif N,P dan K

Fraksi organik sampah rumah tangga adalah salah satu potensi sumber energi terbarukan melalui konversi menjadi metana dan hidrogen. Dengan pengaturan pH yang tepat, proses anaerob dapat menghasilkan metana atau hidrogen. Penelitian ini bertujuan mempelajari peningkatan produksi biohidrogen dari fraksi organik sampah rumah tangga dengan penambahan zat aditif berupa pupuk NPK. Pupuk NPK berfungsi sebagai penyempurnaan nutrisi bagi mikroba anaerob. Ketersediaan bahan organik pada substrat untuk mikroba anaerob direpresentasikan dengan VS (volatile solid) dan inokulum yang digunakan berupa kotoran sapi. Pupuk NPK ditambahkan ke dalam 440 mL substrat dengan variasi dosis 5,840 g (R1); 7,280 g (R2); dan 8,745 g (R3). Penelitian ini dijalankan dalam reaktor batch selama 30 hari pada suhu ruangan. Analisis yang dilakukan mencakup analisis kandungan gas menggunakan GC (Gas Chromatography) serta analisis sampel campuran yang meliputi VS (volatile solid), TS (total solid), dan pH. Hasil penelitan menunjukkan bahwa penambahan zat aditif berupa pupuk NPK dengan jumlah terukur berpengaruh positif dalam meningkatkan produksi gas hidrogen dari sampah organik rumah tangga. Selain itu, nilai pH merupakan faktor yang penting dalam proses anaerob ini. Pada pH 4 produk gas yang dihasilkan didominasi oleh H2 dan CO2. Rasio C/N yang menghasikan gas terbanyak adalah 20:1

Peruraian Anaerobik Termofilik Limbah Vinasse : Pengaruh Zeolit Alam Teraktivasi Asam dan Basa terhadap Performa Proses

Vinasse merupakan limbah produksi bioetanol dengan kadar chemical oxygen demand (COD) tinggi dan dapat diolah melalui Peruraian anaerobik untuk menghasilkan biogas. Optimasi proses dapat dilakukan pada kondisi termofilik (55°C) dengan penambahan zeolit alam terkativasi. Penelitian ini bertujuan untuk menginvestigasi efek zeolit alam terkativasi asam dan basa terhadap performa proses Peruraian anaerobik termofilik vinasse. Proses aktivasi zeolit alam diawali dengan perendaman selama 24 jam pada larutan asam klorida (HCl) 3 M atau natrium hidroksida (NaOH) 3 M, dilanjutkan pengeringan dan kalsinasi. Selanjutnya zeolit alam tanpa aktivasi (NZ), teraktivasi asam (NZA), dan teraktivasi basa (NZB) ditambahkan pada proses Peruraian anaerobik termofilik limbah vinasse secara batch dengan inokulum digested vinasse yang diperoleh dari reaktor skala laboratorium. Hasil penelitian menunjukkan bahwa penambahan NZB mempercepat puncak produksi gas metana (hari ke9) dibanding NZ (hari ke-12), sedangkan pada NZA tidak terdapat produksi gas metana. Hal ini disebabkan oleh perbedaan pH cairan. Penambahan NZB menyebabkan pH berada pada kisaran nilai optimum sedangkan NZA menyebabkan hasil sebaliknya. Hasil methane yield NZB juga menunjukkan hasil lebih tinggi yakni 84.37 mL-CH4/g-sCOD removal dibanding NZ 73.94 dan NZA 0.07. Oleh karena itu, direkomendasikan penambahan zeolite teraktivasi basa untuk meningkatkan performa process Peruraian anaerobik termofilik limbah vinasse

Recovery of high purity lignin and digestible cellulose from oil palm empty fruit bunch using low acid-catalyzed organosolv pretreatment

The lignocellulosic residue from the palm oil industry, oil palm empty fruit bunch (OPEFB), represents a challenge to both producing industries and environment due to its disposal diffculties. Alternatively, OPEFB can be used for the production of valuable products if pretreatment methods, which overcome OPEFB recalcitrance and allow tailored valorization of all its carbohydrates and lignin, are developed. Specifically, high-value applications for lignin, to increase its contribution to the feasibility of lignocellulosic biorefineries, demand high-purity fractions. In this study, acid-catalyzed organosolv using ethanol as a solvent was used for the recovery of high-purity lignin and digestible cellulose. Factors including catalyst type and its concentration, temperature, retention time, and solid-to-liquid (S/L) ratio were found to influence lignin purity and recovery. At the best conditions (0.07% H2SO4, 210 °C, 90 min, and S/L ratio of 1:10), a lignin purity and recovery of 70.6 ± 4.9% and 64.94 ± 1.09%, respectively, were obtained in addition to the glucan-rich fraction. The glucan-rich fraction showed 94.06 ± 4.71% digestibility within 18 h at an enzyme loading of 30 filter paper units (FPU)/g glucan. Therefore, ethanol organosolv can be used for fractionating OPEFB into three high-quality fractions (glucan, lignin, and hemicellulosic compounds) for further tailored biorefining using low acid concentrations. Especially, the use of ethanol opens the possibility for integration of 1st and 2nd generation ethanol benefiting from the separation of high-purity lignin. © 2020 by the authors

Production of edible fungal (Rhizopus delemar CBS 145940) biomass from organosolv-pretreated oil palm empty fruit bunch (OPEFB) in submerged fermentation

Accumulation of oil palm empty fruit bunches (OPEFB) from palm oil industry poses challenges for the disposal process, which leads to environmental damage. For this reason, valorization of OPEFB fractions to produce edible fungal biomass was carried out in this research. The fungus was Rhizopus delemar CBS 145940, which is an edible fungus, Indonesian indigenous, and is favorable for the production of several end products. Organosolv pretreatment was first conducted on OPEFB using ethanol (50%) as the solvent. Enzymatic hydrolysis was then performed using Cellic® Ctec3 on the pretreated-OPEFB fractions. Hydrolyzates from cellulose-rich fraction, slurry (a mixture of cellulose-rich fraction and hemicellulose-rich fraction), and hemicellulose-rich fraction were used as the cultivation media for fungal growth. The corresponding yield of fungal biomass from each medium was 0.62 ± 0.07 g/g glucose; 0.41 ± 0.02; and 0.61 ± 0.13 g/g fermentable sugars, respectively. These results showed that Rhizopus delemar CBS 145940 could be grown in all the hydrolyzates from the OPEFB fractions. Nevertheless, in order to obtain higher fungal biomass, supplementation of nutrition was needed. © 2020 Institute of Physics Publishing