Antonius Indarto | Institut Teknologi Bandung (original) (raw)

Papers by Antonius Indarto

Water

Batik is a piece of woven cloth decorated with beautiful patterns and designs and has become a si... more Batik is a piece of woven cloth decorated with beautiful patterns and designs and has become a signature product of the Malay Archipelago, including Malaysia and Indonesia. Batik industry consumes a large volume of water and produces a large amount of wastewater during the boiling process and dyeing process, both for hand-drawn (batik lukis) and block-printed (batik cap) batik. The release of colored effluents that contain a large number of dyes and chemicals can harm the environment and become a human health concern, particularly in south east Asian countries. Therefore, treatments of batik effluent are very crucial and have caught a lot of attention from researchers. The color removal is a major challenge, especially from this industry, as up until now there is no single and cost-effective treatment that can effectively decolorize as well as treat the dye effluent. Since batik is part of the textile industry, most treatment methods have been adapted from textile effluent treatment...

Water

The Biological Sulfur Recovery Unit (BSRU) with Thiobacillus as biocatalysts is believed to be su... more The Biological Sulfur Recovery Unit (BSRU) with Thiobacillus as biocatalysts is believed to be suitable for handling soluble sulfur in wastewater. The purpose of this study is to evaluate the effect of nutrient (SO42−, PO43−, and Fe2+) concentration on BSRU performance, particularly on the conversion of sulfide to elemental sulfur. This study shows that the variation of SO42− concentration does not significantly affect the conversion process, while a small increment of PO43− (KH2PO4 1.7 g/L and K2HPO4 1.36 g/L) results in a higher yield of elemental sulfur production. Fe2+ also significantly affected the formation and conversion rate of elemental sulfur.

Jurnal Kejuruteraan

The emerging contaminants (ECs) is detected at trace concentration in the discharge of sewage tre... more The emerging contaminants (ECs) is detected at trace concentration in the discharge of sewage treatment plant (STP) to the water bodies indicate incomplete removal during the treatment process. The presence of the ECs in the water has a potential impact on the ecological and human health associated with long-term ingestion of the mixture ECs compounds, and this includes the development of resistance in pathogenic bacteria, aquatic toxicity, genotoxicity, and endocrine disruption. In this study, we investigate the presence of ECs and review the occurrence of mainly of four pharmaceutical active compounds belonging to the group of non-steroidal anti-inflammatory drugs (NSAIDs) in influent and effluent of the STP. The target analytes (ibuprofen (IBU), diclofenac (DIC), ketoprofen (KET), and naproxen (NAP)) are extracted from the wastewater using the solid-phase extraction (SPE) followed by the identification and quantification using gas chromatography-mass spectrometry (GC-MS). The GC-...

Molecules

The production of sustainable diesel without hydrogen addition remains a challenge for low-cost f... more The production of sustainable diesel without hydrogen addition remains a challenge for low-cost fuel production. In this work, the pyrolysis of unsaturated fatty acid (UFA) basic soaps was studied for the production sustainable diesel (bio-hydrocarbons). UFAs were obtained from palm fatty acids distillate (PFAD), which was purified by the fractional crystallization method. Metal hydroxides were used to make basic soap composed of a Ca, Mg, and Zn mixture with particular composition. The pyrolysis reactions were carried out in a batch reactor at atmospheric pressure and various temperatures from 375 to 475 °C. The liquid products were obtained with the best yield (58.35%) at 425 °C and yield of diesel fraction 53.4%. The fatty acids were not detected in the pyrolysis liquid product. The gas product consisted of carbon dioxide and methane. The liquid products were a mixture of hydrocarbon with carbon chains in the range of C7 and C20 containing n-alkane, alkene, and iso-alkane.

Agrochemicals Detection, Treatment and Remediation

Abstract The rise of global population has resulted in an impressive growth in food production, w... more Abstract The rise of global population has resulted in an impressive growth in food production, which has been attributed to the overly increased use of agrochemicals such as pesticides and fertilizers. However, unthoughtful use of agrochemicals also leads to deterioration of environmental quality and pose severe threats to terrestrial and aquatic ecosystems. Even though persistent and harmful chemicals have been phased out and replaced by less persistent and biodegradable chemicals, legacy residues from the past and recent residues are still a painful challenge to solve. In this chapter the advances of nanotechnology and their application for remediations of agrochemicals are discussed. Depending on the decontamination process, these techniques have been classified into two categories: reactive and adsorptive treatments. This review covers the utilization of various nanomaterials including metal- and metal-based silica, carbonaceous, and polymeric nanomaterials for remediation techniques. Besides, ecotoxicological concerns associated to the application of nanomaterials in the environment is also included.

Jurnal Teknik Kimia Indonesia, Jul 1, 2021

Jurnal Teknik Kimia Indonesia, 2018

The formation of first aromatic ring was suggested to be a crucial step of the PAHs and soot grow... more The formation of first aromatic ring was suggested to be a crucial step of the PAHs and soot growth mechanism. In general, four-, five-, six-, or seven-membered ring molecules could be formed by the addition reaction of two hydrocarbon molecules resulted from many different pathways. Small hydrocarbon molecules with numerous concentrations during combustion/pyrolysis are suspected to play an important role. Propargyl radical (•C3H3) and butadiene (C4H2) have been chosen as the initial reactants in this discussion, since they are found at relatively high concentrations in flame experiments to examine the above particular reaction. Following initial addition mechanisms, their adduct intermediate can form a ring molecule and undergo subsequent rearrangement. All possible molecular structures were considered and the viability of each channel was assessed through a “RRKM + master equation” kinetic study. This study is an attemp and example to develop and apply molecular computational met...

IOP Conference Series: Materials Science and Engineering, 2021

Turpentine is a potential non-wood product from pine tree forest in Indonesia. Turpentine has a w... more Turpentine is a potential non-wood product from pine tree forest in Indonesia. Turpentine has a wide application in industry mainly as solvent. Isomerization of turpentine is an attractive route to obtain a higher value fine chemical such as cineole. Acid catalyst is often used for this purpose and screening of numerous combination of acid catalysts is often challenging. Therefore, an investigation of isomerization operating condition is important. The aim of present work is to investigate the influence of several acids ratios, and residence time. The raw turpentine was obtained from PT Perhutani Anugerah Kimia (PAK) Trenggalek, East Java. Here, we have investigated the influence of raw turpentine to acid catalyst ratios as well as residence time using central composite design (CCD) of 22 factorial design. In this work, the strong acid catalysts used is hydrochloric acid (HCl) and the weak acid catalysts is formic acid (HCOOH). The result from GC-MS analyses showed that isomerizatio...

Agrochemicals Detection, Treatment and Remediation, 2020

Abstract Phosphate as an essential compound in every plantation is largely produced in the form o... more Abstract Phosphate as an essential compound in every plantation is largely produced in the form of fertilizer. Despite its usefulness, phosphate discharge into water body in excessive amount causes eutrophication that leads to ecosystem disturbances. Aside from the aforementioned negative effect, phosphate itself is deemed as an unsustainable resource. Thus its recovery has attained considerable attention from both academician and industrial societies. In this book chapter, simultaneous phosphate recovery by converting it into some type of salts that constitute either calcium and fluorine ions is being considered. In addition, the effect of Ca and F ions removal to phosphate conversion into struvite (magnesium ammonium phosphate hexahydrate) as a valorized by product is deeply considered. This salt formation and crystallization are reported to be well affected by both Ca and F ions. Since both aforementioned ions are reported as potent inhibitors for struvite crystallization, their removal can potentially reduce the settling time of struvite and eventually capital and operation costs.

The topic on conversion and utilization of methane were important issues both in chemical industr... more The topic on conversion and utilization of methane were important issues both in chemical industry and environmental purposes. Several technologies including plasma-insisted techniques have been proposed to improve the process involving the activation of methane. The direct conversion of methane to methanol in the presence of energetic species, i.e. ion, radical, electron, and excited molecules, has attracted many experts'' attention in recent years. In this book, the concepts and some applications of plasma to synthesize methanol from methane were briefly discussed. The book contains some recent and important scientific reports in direct conversion of methane to methanol with and without catalyst support.

Jurnal Teknik Kimia Indonesia, 2021

Abstrak. Dalam rangka meningkatkan komoditas susu di Indonesia, pemerintah menargetkan sapi perah... more Abstrak. Dalam rangka meningkatkan komoditas susu di Indonesia, pemerintah menargetkan sapi perah lokal harus mampu menyuplai 41% produksi susu dalam negeri pada 2022. Salah satu cara untuk menaikkan produksi susu sapi adalah memberikan suplemen pakan berupa sabun kalsium. Sabun kalsium telah banyak digunakan di luar negeri, namun tidak di Indonesia, untuk menaikkan produksi susu sekaligus fertilitas ruminansia. Sabun kalsium dapat dibuat melalui reaksi fusi termodifikasi antara Palm Fatty Acid Distillate (PFAD) sebagai sumber asam lemak bebas dengan sumber kalsium. Penelitian ini mengevaluasi pengaruh jenis PFAD terhadap kualitas produk sabun kalsium. PFAD yang digunakan berasal dari beberapa industri pengolahan kelapa sawit di Indonesia, yaitu Kabupaten Sidoarjo, Kabupaten Bekasi, Kota Bekasi, dan Kabupaten Pelalawan dengan rentang angka asam 195–221 mg KOH/g sampel. Produk sabun kalsium yang dihasilkan kemudian dianalisis nilai angka asam untuk menguantifikasi kualitasnya. Keempa...

Indo. J. Chem. Res., 2020

Acetylene and polyyne are intermediates in the formation of Polycyclic Aromatic Hydrocarbons (PAH... more Acetylene and polyyne are intermediates in the formation of Polycyclic Aromatic Hydrocarbons (PAHs) and soot in combustion or pyrolysis. PAH formation from acetylene is known as the most adopted pathway because it has a low reaction energy. Another mechanism for the formation of PAH is a mechanism that involves polyyne or known as a radical pathway, proposed by Krestinin. This pathway involves the reaction of alkyne + alkenes which results in the addition of radical sites to the molecular structure. In this study, the two reaction mechanisms will be compared. Electronic features and energy requirements of the reaction process will be evaluated using molecular computational studies based on electron density (DFT). In combustion conditions (high temperature), the formation of radical sites requires relatively little energy, with a range of 2-5 kcal/mol. This is very different when compared to the energy profile for the same reaction at room temperature. From this study, it can be conc...

Current Physical Chemistry, 2018

International Journal of Ambient Energy, 2017

ABSTRACT Devolatilisation is the release of volatile compounds from coal matrix by thermal decomp... more ABSTRACT Devolatilisation is the release of volatile compounds from coal matrix by thermal decomposition. During coal devolatilisation, fragmentation could occur due to pressure build-up of accumulated volatiles. A fragmentation model is necessary to ensure the safe operation of coal combustion and optimum process condition. In this study, the refinement of fragmentation model of coal devolatilisation was done. In order to obtain a comprehensive model, a fluidised bed combustion experiment was conducted using two Indonesian coals (Musi Banyuasin and Berau) and the results were then compared with the model simulation. Using a coal diameter of 0.8–17 mm at a combustion temperature of 850°C, it shows that the fragmentation probability and number of fragments could be affected by the coal particle diameter, convective pore diameter, and porosity. Predictions made by the developed model were close to the experimental fragmentation data, with an error range of less than 5.1%.

IOP Conference Series: Materials Science and Engineering, 2016

IOP Conference Series: Materials Science and Engineering, 2020

One of the problems that commonly found in petroleum industry is related to the evaporation of cr... more One of the problems that commonly found in petroleum industry is related to the evaporation of crude oil during storage. Hence the purpose of this study is to find lower-cost method to reduce crude oil evaporation. The method has the same principle as floating roof tank, but instead of surface covered by metal, low-density chemical substances, i.e., polyurethane foam and ethylene vinyl acetate foam (EVA mat), was used to cover the surface of crude oil. In comparison with EVA mat, polyurethane foam gave lower percentage of reduced crude oil evaporation. Increasing the thickness of the additive to 3 cm was found to be the best parameter to reduce the evaporation of crude oil. At temperatures of 40, 45, and 50°C, 3 cm thickness of polyurethane foam was able to reduce the evaporation of crude oil by 81.6 - 91.7%, 75.9 - 87.3%, and 74.2% - 86.6%, respectively. At temperatures of 40, 45, and 50°C, 3 cm thickness of EVA mat can reduce the evaporation of crude oil by 68.6 - 78.1%, 56.8 - 60...

Indo. J. Chem. Res., 2019

The Rate Determining Step (RDS) in adsorption proses plays a key role in order to understand the ... more The Rate Determining Step (RDS) in adsorption proses plays a key role in order to understand the correct adsoption mechanism. In this experiment, a simple method used for distinguishing the RDS of liquid adsorption on solid adsorben was studied by an experiment based on Shrinking-Core Diffusion-based Model (SCM). RDS determination was done by comparing experimental data of two SCM Models: (1) Pore-Surface Model Diffusion (PSDM) and (2) Film-Pore Diffusion Model (FPDM). The adsorption of methylene blue by activated carbon obtained from Jatropha curcas L. was used as a case study. The result of experiment by three variated parameters: initial concentration (C0), pH, and type of adsorben shows that PSDM has more accuration compared to FPDM in representating the characterstic of mass transport of metil red adsorption on activated carbon.

Frontiers in Energy, 2013

ABSTRACT Energy is of great importance in human life because of its benefits as the main resource... more ABSTRACT Energy is of great importance in human life because of its benefits as the main resource for human activity. According to International Energy Agency (IEA), energy demands are expected to continue increasing until 2030. Because energy demand will never decrease, it is necessary to develop modern technology, such as nanobased technology, in order to obtain a more effective and efficient process to produce more energy. The application of nano technology or nano material in the field of energy, which involves lithium-ion battery, fuel cell, light emitting diode (LED), ultra-capacitor, and solar cell (including Grätzel cell), is a hot topic in many scientific researches. Unfortunately, its current development is hampered by the expensive cost of production compared to conventional technologies. Therefore, priority should be given to nano technology in the energy sector order to obtain higher efficiency, lower production cost, and easier in its application.

Water

Batik is a piece of woven cloth decorated with beautiful patterns and designs and has become a si... more Batik is a piece of woven cloth decorated with beautiful patterns and designs and has become a signature product of the Malay Archipelago, including Malaysia and Indonesia. Batik industry consumes a large volume of water and produces a large amount of wastewater during the boiling process and dyeing process, both for hand-drawn (batik lukis) and block-printed (batik cap) batik. The release of colored effluents that contain a large number of dyes and chemicals can harm the environment and become a human health concern, particularly in south east Asian countries. Therefore, treatments of batik effluent are very crucial and have caught a lot of attention from researchers. The color removal is a major challenge, especially from this industry, as up until now there is no single and cost-effective treatment that can effectively decolorize as well as treat the dye effluent. Since batik is part of the textile industry, most treatment methods have been adapted from textile effluent treatment...

Water

The Biological Sulfur Recovery Unit (BSRU) with Thiobacillus as biocatalysts is believed to be su... more The Biological Sulfur Recovery Unit (BSRU) with Thiobacillus as biocatalysts is believed to be suitable for handling soluble sulfur in wastewater. The purpose of this study is to evaluate the effect of nutrient (SO42−, PO43−, and Fe2+) concentration on BSRU performance, particularly on the conversion of sulfide to elemental sulfur. This study shows that the variation of SO42− concentration does not significantly affect the conversion process, while a small increment of PO43− (KH2PO4 1.7 g/L and K2HPO4 1.36 g/L) results in a higher yield of elemental sulfur production. Fe2+ also significantly affected the formation and conversion rate of elemental sulfur.

Jurnal Kejuruteraan

The emerging contaminants (ECs) is detected at trace concentration in the discharge of sewage tre... more The emerging contaminants (ECs) is detected at trace concentration in the discharge of sewage treatment plant (STP) to the water bodies indicate incomplete removal during the treatment process. The presence of the ECs in the water has a potential impact on the ecological and human health associated with long-term ingestion of the mixture ECs compounds, and this includes the development of resistance in pathogenic bacteria, aquatic toxicity, genotoxicity, and endocrine disruption. In this study, we investigate the presence of ECs and review the occurrence of mainly of four pharmaceutical active compounds belonging to the group of non-steroidal anti-inflammatory drugs (NSAIDs) in influent and effluent of the STP. The target analytes (ibuprofen (IBU), diclofenac (DIC), ketoprofen (KET), and naproxen (NAP)) are extracted from the wastewater using the solid-phase extraction (SPE) followed by the identification and quantification using gas chromatography-mass spectrometry (GC-MS). The GC-...

Molecules

The production of sustainable diesel without hydrogen addition remains a challenge for low-cost f... more The production of sustainable diesel without hydrogen addition remains a challenge for low-cost fuel production. In this work, the pyrolysis of unsaturated fatty acid (UFA) basic soaps was studied for the production sustainable diesel (bio-hydrocarbons). UFAs were obtained from palm fatty acids distillate (PFAD), which was purified by the fractional crystallization method. Metal hydroxides were used to make basic soap composed of a Ca, Mg, and Zn mixture with particular composition. The pyrolysis reactions were carried out in a batch reactor at atmospheric pressure and various temperatures from 375 to 475 °C. The liquid products were obtained with the best yield (58.35%) at 425 °C and yield of diesel fraction 53.4%. The fatty acids were not detected in the pyrolysis liquid product. The gas product consisted of carbon dioxide and methane. The liquid products were a mixture of hydrocarbon with carbon chains in the range of C7 and C20 containing n-alkane, alkene, and iso-alkane.

Agrochemicals Detection, Treatment and Remediation

Abstract The rise of global population has resulted in an impressive growth in food production, w... more Abstract The rise of global population has resulted in an impressive growth in food production, which has been attributed to the overly increased use of agrochemicals such as pesticides and fertilizers. However, unthoughtful use of agrochemicals also leads to deterioration of environmental quality and pose severe threats to terrestrial and aquatic ecosystems. Even though persistent and harmful chemicals have been phased out and replaced by less persistent and biodegradable chemicals, legacy residues from the past and recent residues are still a painful challenge to solve. In this chapter the advances of nanotechnology and their application for remediations of agrochemicals are discussed. Depending on the decontamination process, these techniques have been classified into two categories: reactive and adsorptive treatments. This review covers the utilization of various nanomaterials including metal- and metal-based silica, carbonaceous, and polymeric nanomaterials for remediation techniques. Besides, ecotoxicological concerns associated to the application of nanomaterials in the environment is also included.

Jurnal Teknik Kimia Indonesia, Jul 1, 2021

Jurnal Teknik Kimia Indonesia, 2018

The formation of first aromatic ring was suggested to be a crucial step of the PAHs and soot grow... more The formation of first aromatic ring was suggested to be a crucial step of the PAHs and soot growth mechanism. In general, four-, five-, six-, or seven-membered ring molecules could be formed by the addition reaction of two hydrocarbon molecules resulted from many different pathways. Small hydrocarbon molecules with numerous concentrations during combustion/pyrolysis are suspected to play an important role. Propargyl radical (•C3H3) and butadiene (C4H2) have been chosen as the initial reactants in this discussion, since they are found at relatively high concentrations in flame experiments to examine the above particular reaction. Following initial addition mechanisms, their adduct intermediate can form a ring molecule and undergo subsequent rearrangement. All possible molecular structures were considered and the viability of each channel was assessed through a “RRKM + master equation” kinetic study. This study is an attemp and example to develop and apply molecular computational met...

IOP Conference Series: Materials Science and Engineering, 2021

Turpentine is a potential non-wood product from pine tree forest in Indonesia. Turpentine has a w... more Turpentine is a potential non-wood product from pine tree forest in Indonesia. Turpentine has a wide application in industry mainly as solvent. Isomerization of turpentine is an attractive route to obtain a higher value fine chemical such as cineole. Acid catalyst is often used for this purpose and screening of numerous combination of acid catalysts is often challenging. Therefore, an investigation of isomerization operating condition is important. The aim of present work is to investigate the influence of several acids ratios, and residence time. The raw turpentine was obtained from PT Perhutani Anugerah Kimia (PAK) Trenggalek, East Java. Here, we have investigated the influence of raw turpentine to acid catalyst ratios as well as residence time using central composite design (CCD) of 22 factorial design. In this work, the strong acid catalysts used is hydrochloric acid (HCl) and the weak acid catalysts is formic acid (HCOOH). The result from GC-MS analyses showed that isomerizatio...

Agrochemicals Detection, Treatment and Remediation, 2020

Abstract Phosphate as an essential compound in every plantation is largely produced in the form o... more Abstract Phosphate as an essential compound in every plantation is largely produced in the form of fertilizer. Despite its usefulness, phosphate discharge into water body in excessive amount causes eutrophication that leads to ecosystem disturbances. Aside from the aforementioned negative effect, phosphate itself is deemed as an unsustainable resource. Thus its recovery has attained considerable attention from both academician and industrial societies. In this book chapter, simultaneous phosphate recovery by converting it into some type of salts that constitute either calcium and fluorine ions is being considered. In addition, the effect of Ca and F ions removal to phosphate conversion into struvite (magnesium ammonium phosphate hexahydrate) as a valorized by product is deeply considered. This salt formation and crystallization are reported to be well affected by both Ca and F ions. Since both aforementioned ions are reported as potent inhibitors for struvite crystallization, their removal can potentially reduce the settling time of struvite and eventually capital and operation costs.

The topic on conversion and utilization of methane were important issues both in chemical industr... more The topic on conversion and utilization of methane were important issues both in chemical industry and environmental purposes. Several technologies including plasma-insisted techniques have been proposed to improve the process involving the activation of methane. The direct conversion of methane to methanol in the presence of energetic species, i.e. ion, radical, electron, and excited molecules, has attracted many experts'' attention in recent years. In this book, the concepts and some applications of plasma to synthesize methanol from methane were briefly discussed. The book contains some recent and important scientific reports in direct conversion of methane to methanol with and without catalyst support.

Jurnal Teknik Kimia Indonesia, 2021

Abstrak. Dalam rangka meningkatkan komoditas susu di Indonesia, pemerintah menargetkan sapi perah... more Abstrak. Dalam rangka meningkatkan komoditas susu di Indonesia, pemerintah menargetkan sapi perah lokal harus mampu menyuplai 41% produksi susu dalam negeri pada 2022. Salah satu cara untuk menaikkan produksi susu sapi adalah memberikan suplemen pakan berupa sabun kalsium. Sabun kalsium telah banyak digunakan di luar negeri, namun tidak di Indonesia, untuk menaikkan produksi susu sekaligus fertilitas ruminansia. Sabun kalsium dapat dibuat melalui reaksi fusi termodifikasi antara Palm Fatty Acid Distillate (PFAD) sebagai sumber asam lemak bebas dengan sumber kalsium. Penelitian ini mengevaluasi pengaruh jenis PFAD terhadap kualitas produk sabun kalsium. PFAD yang digunakan berasal dari beberapa industri pengolahan kelapa sawit di Indonesia, yaitu Kabupaten Sidoarjo, Kabupaten Bekasi, Kota Bekasi, dan Kabupaten Pelalawan dengan rentang angka asam 195–221 mg KOH/g sampel. Produk sabun kalsium yang dihasilkan kemudian dianalisis nilai angka asam untuk menguantifikasi kualitasnya. Keempa...

Indo. J. Chem. Res., 2020

Acetylene and polyyne are intermediates in the formation of Polycyclic Aromatic Hydrocarbons (PAH... more Acetylene and polyyne are intermediates in the formation of Polycyclic Aromatic Hydrocarbons (PAHs) and soot in combustion or pyrolysis. PAH formation from acetylene is known as the most adopted pathway because it has a low reaction energy. Another mechanism for the formation of PAH is a mechanism that involves polyyne or known as a radical pathway, proposed by Krestinin. This pathway involves the reaction of alkyne + alkenes which results in the addition of radical sites to the molecular structure. In this study, the two reaction mechanisms will be compared. Electronic features and energy requirements of the reaction process will be evaluated using molecular computational studies based on electron density (DFT). In combustion conditions (high temperature), the formation of radical sites requires relatively little energy, with a range of 2-5 kcal/mol. This is very different when compared to the energy profile for the same reaction at room temperature. From this study, it can be conc...

Current Physical Chemistry, 2018

International Journal of Ambient Energy, 2017

ABSTRACT Devolatilisation is the release of volatile compounds from coal matrix by thermal decomp... more ABSTRACT Devolatilisation is the release of volatile compounds from coal matrix by thermal decomposition. During coal devolatilisation, fragmentation could occur due to pressure build-up of accumulated volatiles. A fragmentation model is necessary to ensure the safe operation of coal combustion and optimum process condition. In this study, the refinement of fragmentation model of coal devolatilisation was done. In order to obtain a comprehensive model, a fluidised bed combustion experiment was conducted using two Indonesian coals (Musi Banyuasin and Berau) and the results were then compared with the model simulation. Using a coal diameter of 0.8–17 mm at a combustion temperature of 850°C, it shows that the fragmentation probability and number of fragments could be affected by the coal particle diameter, convective pore diameter, and porosity. Predictions made by the developed model were close to the experimental fragmentation data, with an error range of less than 5.1%.

IOP Conference Series: Materials Science and Engineering, 2016

IOP Conference Series: Materials Science and Engineering, 2020

One of the problems that commonly found in petroleum industry is related to the evaporation of cr... more One of the problems that commonly found in petroleum industry is related to the evaporation of crude oil during storage. Hence the purpose of this study is to find lower-cost method to reduce crude oil evaporation. The method has the same principle as floating roof tank, but instead of surface covered by metal, low-density chemical substances, i.e., polyurethane foam and ethylene vinyl acetate foam (EVA mat), was used to cover the surface of crude oil. In comparison with EVA mat, polyurethane foam gave lower percentage of reduced crude oil evaporation. Increasing the thickness of the additive to 3 cm was found to be the best parameter to reduce the evaporation of crude oil. At temperatures of 40, 45, and 50°C, 3 cm thickness of polyurethane foam was able to reduce the evaporation of crude oil by 81.6 - 91.7%, 75.9 - 87.3%, and 74.2% - 86.6%, respectively. At temperatures of 40, 45, and 50°C, 3 cm thickness of EVA mat can reduce the evaporation of crude oil by 68.6 - 78.1%, 56.8 - 60...

Indo. J. Chem. Res., 2019

The Rate Determining Step (RDS) in adsorption proses plays a key role in order to understand the ... more The Rate Determining Step (RDS) in adsorption proses plays a key role in order to understand the correct adsoption mechanism. In this experiment, a simple method used for distinguishing the RDS of liquid adsorption on solid adsorben was studied by an experiment based on Shrinking-Core Diffusion-based Model (SCM). RDS determination was done by comparing experimental data of two SCM Models: (1) Pore-Surface Model Diffusion (PSDM) and (2) Film-Pore Diffusion Model (FPDM). The adsorption of methylene blue by activated carbon obtained from Jatropha curcas L. was used as a case study. The result of experiment by three variated parameters: initial concentration (C0), pH, and type of adsorben shows that PSDM has more accuration compared to FPDM in representating the characterstic of mass transport of metil red adsorption on activated carbon.

Frontiers in Energy, 2013

ABSTRACT Energy is of great importance in human life because of its benefits as the main resource... more ABSTRACT Energy is of great importance in human life because of its benefits as the main resource for human activity. According to International Energy Agency (IEA), energy demands are expected to continue increasing until 2030. Because energy demand will never decrease, it is necessary to develop modern technology, such as nanobased technology, in order to obtain a more effective and efficient process to produce more energy. The application of nano technology or nano material in the field of energy, which involves lithium-ion battery, fuel cell, light emitting diode (LED), ultra-capacitor, and solar cell (including Grätzel cell), is a hot topic in many scientific researches. Unfortunately, its current development is hampered by the expensive cost of production compared to conventional technologies. Therefore, priority should be given to nano technology in the energy sector order to obtain higher efficiency, lower production cost, and easier in its application.