Depolymerization of concentrated sulfuric acid hydrolysis lignin to high-yield aromatic monomers in basic sub- and supercritical fluids

Hidajat, Marcel Jonathan,Riaz, Asim,Park, Jaeyong,Insyani, Rizki,Verma, Deepak,Kim, Jaehoon Elsevier 2017 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.317 No.-

<P><B>Abstract</B></P> <P>Conversion of lignin into high-yield aromatic monomers is investigated using base-catalyzed depolymerization (BCD) in sub- and supercritical fluids. The effects of the base catalysts (NaOH, KOH, and Na<SUB>2</SUB>CO<SUB>3</SUB>), reaction media (subcritical water (subH<SUB>2</SUB>O) and supercritical methanol (scMeOH)), and type of lignin (concentrated sulfuric acid hydrolysis lignin (CSAHL) and Kraft lignin (KL)) on the lignin conversion and product yields (gas, bio-oil, solid residue, and aromatic monomers) are explored to understand dominant factors determining the aromatic monomer yield. Treatment of KL lignin in subH<SUB>2</SUB>O-NaOH at 330°C for 30min results in a high monomeric yield of 21.5wt%. Under identical reaction conditions, a low amount of CSAHL (17.9wt%) is converted to aromatic monomers; the low yield results from the resistant nature of CSAHL. In scMeOH, the monomeric yields are much lower (3.3–7.8wt%), and the solid residue yields are much higher (about 26–31wt%) than those obtained from subH<SUB>2</SUB>O (monomeric yields, 6.2–17.9wt%; solid-residue yields, 16–17wt%). The most abundant monomers produced in the subH<SUB>2</SUB>O-basic media are catechols and their alkylated and alkoxylated derivatives, while those produced in the scMeOH-basic media are methoxylated benzene and toluene species because of the unique <I>O</I>-alkylation ability of scMeOH.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Concentrated sulfuric acid hydrolysis lignin (CSAHL) depolymerized in base catalysts. </LI> <LI> CSAHL is harder to depolymerize than Kraft lignin (KL). </LI> <LI> The aromatic monomer yields from CSAHL was 17.9wt% and that from KL was 21.5wt%. </LI> <LI> Subcritical water preferred to form guaiacols and catechols. </LI> <LI> Supercritical methanol preferred to form methoxylated benzene and toluene. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A two-step approach for producing oxygen-free aromatics from lignin using formic acid as a hydrogen source

Hidajat, Marcel Jonathan,Riaz, Asim,Kim, Jaehoon Elsevier 2018 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.348 No.-

<P><B>Abstract</B></P> <P>A high-calorific-value oil with a high amount of oxygen-free aromatics was produced from highly recalcitrant concentrated-sulfuric-acid-hydrolysis lignin (CSAHL) using a two-step approach. In the first step, lignin-derived bio-oil (LBO) was produced by the liquefaction of CSAHL in a mixture of supercritical ethanol and formic acid. In the second step, hydrodeoxygenation (HDO) of the LBO over sulfided CoMo/γ-Al<SUB>2</SUB>O<SUB>3</SUB> (CoMoS<SUB>x</SUB>/γ-Al<SUB>2</SUB>O<SUB>3</SUB>), Pd/Al<SUB>2</SUB>O<SUB>3</SUB>, and Ru/γ-Al<SUB>2</SUB>O<SUB>3</SUB> catalysts was performed to produce upgraded LBO. Although the yield of the LBO was high (70 wt%), its calorific value and the yield of monoaromatics (mainly oxygenated guaiacol- and syringol-type molecules) were low (27.2 MJ kg<SUP>−1</SUP> and 4 wt% (based on CSAHL), respectively). The LBO was separated from the ethanol and used as a feed for HDO in formic acid, which acts as an <I>in-situ</I> hydrogen donating agent. HDO of the LBO over CoMoS<SUB>x</SUB>/γ-Al<SUB>2</SUB>O<SUB>3</SUB> at 350 °C for 4 h produced oxygen-free aromatics, such as alkylated benzenes, indanes, and tetralins, with the high yield of 6.8 wt% (based on CSAHL). The degree of deoxygenation was high (>90%) and the upgraded LBO exhibited a high calorific value (>40 MJ kg<SUP>−1</SUP>). The effects of different HDO parameters, including catalyst loading, amount of formic acid, reaction time, catalyst type, and solvent type were assessed to gain insight into the LBO deoxygenation mechanisms.</P> <P><B>Highlights</B></P> <P> <UL> <LI> High-yield deoxygenated aromatics (6.8 wt%) were produced from lignin. </LI> <LI> First, lignin-derived bio-oil (LBO) with 40 wt% O content produced in scEtOH-HCOOH. </LI> <LI> Second, hydrodeoxygenation of LBO over CoMoS<SUB>x</SUB>/γ-Al<SUB>2</SUB>O<SUB>3</SUB> resulted in >40 MJ kg<SUP>−1</SUP> oil. </LI> <LI> The upgraded bio-oil mainly consists of alkylated benzenes, indanes, and tetralins. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Measuring Bitcoin Literacy in Indonesia

HIDAJAT, Taofik,KRISTANTO, Rudi Suryo,OCTRINA, Fajra Korea Distribution Science Association 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.3

The purpose of this research is to discuss the concept of measuring cryptocurrency literacy, especially Bitcoin. This research uses a qualitative approach. The data source comes from a literature review on cryptocurrency and opinions from Bitcoin academics, traders, and investors. Data collection was conducted through desk evaluations and interviews to determine what attributes should be considered for assessing Bitcoin literacy. The results of a literature review reinforced by discussion show that eight attributes can be used to assess basic level Bitcoin literacy, namely Bitcoin supply, regulatory guarantees, transaction recording, the role of third parties, treatment of transfer transactions, initial coin offerings, the smallest Bitcoin unit, and conversion with another currency. These eight attributes can be used to measure Bitcoin literacy through various questions with the choice of true, false, and do not know answers. This research is essential because there is no method to measure Bitcoin literacy. This research can be a measuring tool that becomes a reference or standard in assessing or measuring Bitcoin literacy. This study's results provide benefits to the development of science in the form of a tool that can be used to assess Bitcoin literacy and become a standard in assessing a person's level of understanding of Bitcoin.

The Effect of Synthetic Phonics on the Development of Reading Skills in L1 and L2

Lanny Hidajat,Yosephine Susanto,Angeline Iskandar 아시아영어교육학회 2017 The Journal of Asia TEFL Vol.14 No.3

This research investigated the effect of using synthetic phonics for teaching Indonesian young learners to read in English and Indonesian. Since English orthography is very different from Indonesian orthography, the use of synthetic phonics for teaching Indonesian young EFL learners to read in English potentially affects the development of their skills to read in Indonesian. To verify this assumption, the researchers analyzed the development of the skills for decoding English and Indonesian sounds represented by ‘a’, ‘u’, and ‘o’ within five months in K-2 students from two kindergartens. In one kindergarten, the teacher used synthetic phonics to teach English. In the other, the teacher used the MIKids program. The results of this research indicate that the synthetic phonics method might be less effective when it is used for teaching reading in English in Indonesia. In addition, it can potentially impede the development of skills for reading in Indonesian.

The Relationship Between Debt Literacy and Peer-To-Peer Lending: A Case Study in Indonesia

Taofik HIDAJAT 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.5

This paper discusses the relationship between debt literacy, peer-to-peer lending, and over-indebtedness in Indonesia. It is essential because the number of loans on this platform continues to increase, both legal and illegal. Data was collected online in collaboration with commercial market research firms, JajakPendapat.net. Debt literacy and over-indebtedness were measured by self-assessment with questions from Lusardi and Tufano (2009a). Questions for debt literacy are about interest compounding, debt interest, and the application of time value of money in payment options. The question for over-indebtedness is about the amount of debt and the conditions resulting from that debt. By using descriptive methods, it is clear that the majority of respondents, both borrowers and non-peer-to-peer lending borrowers are debt illiterate, and those who have poor debt literacy have huge debt. Overall, only 1.85% of the respondents were debt literate. Those who live on the island of Java have better literacy because they are the center of economic growth in Indonesia. Debt from peer-to-peer (P2P) lending also has the potential to create problems, namely over-indebtedness. P2P lending borrowers also have very poor debt literacy. However, there is no difference in debt literacy between P2P lending borrowers and non-P2P lending borrowers.

고압 균질기를 이용한 세라마이드가 함유된 나노에멀젼 제조 및 안정성 평가

마르셀죠나단히다잣 ( Marcel Jonathan Hidajat ),노종호 ( Jongho Noh ),박종범 ( Jongbeom Park ),홍재화 ( Jaehwa Hong ),김현효 ( Hyeonhyo Kim ),조완택 ( Wantaek Jo ) 한국화학공학회 2020 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.58 No.4

본 연구에서는 고압 균질기를 이용해 세라마이드가 포함된 나노에멀젼을 제조하고 물성변화 및 장기 안정성을 알아보았다. 고압 균질기 압력 및 통과 횟수를 변화 시켜 제조된 나노에멀젼의 평균입자, 입도분포, 제타전위 그리고 점도를 측정하였다. 고압 균질기 압력이 높고 통과 횟수가 많을수록 평균입자는 작아지고 입도 분포는 조밀하였지만 일정 조건이상에서는 표면에너지 및 계면활성제의 영향으로 입자간 재결합이 확인되었다. 평균입자가 작을수록 점도 값은 높았지만 제타전위 값에는 큰 차이가 없었다. 제조된 나노에멀젼을 25 ℃와 45 ℃로 유지시키며 안정성을 측정한 결과, 초기(7일 이후)에 재결합 현상으로 평균입자가 커진 후 유지되었지만 제조된 나노에멀젼의 안정성에는 큰 변화가 없었다. 이를 통해 고압 균질기를 이용해 세라마이드가 포함된 안정적인 나노에멀젼의 제조가 가능함을 확인하였다. A ceramide-containing nanoemulsion was synthesized by using a High-Pressure Homogenizer (HPH) to observe its changes in properties and long-term stability. The droplet size, droplet distribution and zeta potential of nanoemulsion were examined by varying the pressure and the number of passes of the HPH. The increase in HPH pressure and number of passes decreased the average droplet size and made the nanoemulsion more uniform. However, beyond certain operating condition, the recombination between the droplets was confirmed due to droplet surface energy and emulsifier. This study also shows that the decrease in droplet size increased the nanoemulsion viscosity although only minimal changes occurred in the zeta potential. The formed nanoemulsion was then tested for its stability by storing it at 25 and 45 ℃ for 28 days. During the first week, the average droplet size increased due to recombination and then subsequently remained constant. We confirmed that ceramide nanoemulsion for industrial application could be synthesized by using HPH.

Acoustic Based Safety Emergency Vehicle Detection for Intelligent Transport Systems

Bruno Fazenda,Hidajat Atmoko,Fengshou Gu,Luyang Guan,Andrew Ball 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

A system has been investigated for the detection of incoming direction of an emergency vehicle. Acoustic detection methods based on a cross microphone array have been implemented. It is shown that source detection based on time delay estimation outperforms sound intensity techniques, although both techniques perform well for the application. The relaying of information to the driver as a warning signal has been investigated through the use of ambisonic technology and a 4 speaker array which is ubiquitous in most modern vehicles. Simulations show that accurate warning information may be relayed to the driver and afford correct action.

저급원유로부터 초임계공정을 통한 불순물 제거공정 기술 개발

조완택,지성화,( Marcel Jonathan Hidajat ),김현효 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

최근 가채매장량이 풍부하고 저가인 저급원유(고산도원유, 초중질원유, 셰일오일)에 포함된 다양한 종류의 불순물(납센산, 납센산칼슘, 무기물, 아스팔텐, 유기중금속, 황)을 제거하여 고품위화 하려는 연구가 진행되고 있다. 본 연구에서는 저급 원유에 포함된 불순물을 제거하기 위해 초임계 공정을 이용한 공정 기술 개발을 진행하였다. 초임계는 임계점 이상의 온도와 압력인 상태를 뜻하며, 초임계 조건에서는 낮은 유전율, 낮은 점도, 높은 확산도, 고활성 수소 발생 및 라디칼 형성이 가능하다. 초임계 공정을 통해 저급원유에 포함되어 있는 불순물을 제거하기 위해 반응 압력과 온도를 변화 시켜 실험 하였다. 실험을 통해 제조된 시료는 EA, ICP, 아스팔텐 분석을 통해 불순물 함량 변화를 알아보았다. ^** 본 연구는 2015년도 산업통상자원부의 재원으로 한국에너지기술평가원(KETEP)의 지원을 받아 수행한 연구 과제입니다(No.20152010103120).

AN EXPERIMENTAL STUDY OF OXIDATIVE COUPLING OF METHANE IN A SOLID OXIDE FUEL CELL WITH 1 wt%Sr/La2O3-Bi2O3-Ag-YSZ MEMBRANE

Guo, Xui Mei,Hidajat, Kus,Ching, Chi Bun 한국화학공학회 1998 Korean Journal of Chemical Engineering Vol.15 No.5

A solid oxide fuel cell with 1 wt%Sr/La₂O₃-Bi₂O₃-Ag-YSZ membrane was applied to oxidative coupling of methane, Membrane composition had a great effect on the reaction and current generated. An increase in the current generated was accompanied by a decrease in C₂ selectivity and an increase in CH₄ conversion. There is an optimal temperature for C₂-selectivity. CH₄ conversion decreased, C₂-selectivity increased and current generated decreased slightly with a rise in total flow rates. CH₄ conversion and the current generated increased with a rise in oxygen concentration. If only C₂-selectivity and current were concerned, the higher the methane concentration, the more favourable for the cogeneration of electrical energy and ethane and ethylene. Stability of the membrane was also tested.

Extraction of 2-Hydroxyphenol by Surfactant Coated Nanosized Magnetic Particles

Peng, Zan-guo,Hidajat, Kus,Uddin, Mohammad Shahab 한국화학공학회 2003 Korean Journal of Chemical Engineering Vol.20 No.5

A colloidal suspension of magnetic particles coated with double layer surfactant molecules was prepared, characterized and used for separation of some chemicals. The aqueous magnetic fluid was prepared by chemical precipitation method and characterized by total organic carbon analyzer (TOC), themogravimetric analysis (TGA) and transmission electron microscopy (TEM). The TOC and TGA measurements indicate that the prepared magnetic particles are coated with surfactant molecules in double layers. The outer surfactant layer has free polar beeds. TEM measurement result show that magnetic particles are nanosized. A mixture of 2-hydroxyphenol (strong polar) and 2-nitrophenol (weak polar) was chosen as the target system. Results show that the magnetic fluid can selectively adsorb 2-hydroxyphenol from the mixture, whereas the adsorption of 2-nitrophenol is insignificant. For 2-hydroxyphenol, the adsorption equilibrium can be described well by Langmuir isotherm, and the adsorption kinetic can be fitted well by a linear driving force mass transfer model.