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SACCHARIFICATION OF NATIVE CASSAVA STARCH AT HIGH DRY SOLIDS IN AN ENZYMATIC MEMBRANE REACTOR I Nyoman Widiasa; I Gede Wenten
Reaktor Volume 12, Nomor 3, Juni 2009
Publisher : Dept. of Chemical Engineering, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (217.143 KB) | DOI: 10.14710/reaktor.12.3.129 – 136

Abstract

This study is aimed to develop a novel process scheme for hydrolysis of native cassava starch at high dry solids using an enzymatic membrane reactor (EMR). Firstly, liquefied cassava starch having solids content up to 50% by weight was prepared by three stage liquefactions in a conventional equipment using a commercially available heat stable a-amylase (Termamyl 120L). The liquefied cassava starch was further saccharified in an EMR using glucoamylase (AMG E). By using the developed process scheme, a highly clear hydrolysate with dextrose equivalent (DE) approximately 97 could be produced, provided the increase of solution viscosity during the liquefaction was precisely controlled. The excessive space time could result in reduction in conversion degree of starch. Moreover, a residence time distribution study confirmed that the EMR could be modelled as a simple continuous stirred tank reactor (CSTR). Using Lineweaver-Burk analysis, the apparent Michaelis-Menten constant (Km) and glucose production rate constant (k2) were 552 (g/l) and 4.04 (min-1), respectively. Application of simple CSTR model with those kinetic parameters was quietly appropriate to predict the reactor’s performance at low space time.
Optimizing Food Processing Efficiency: The Role of Forward Osmosis in Concentration Julian, Helen; Lestari, Puji; Wenten, I Gede; Khoiruddin, K
Journal of Engineering and Technological Sciences Vol. 57 No. 2 (2025): Vol. 57 No. 2 (2025): April
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2025.57.2.6

Abstract

This review comprehensively explores the application of Forward Osmosis technology in the food processing industry, focusing on its role in concentration processes. Amidst growing concerns over water scarcity, energy consumption, and environmental impact, Forward Osmosis emerges as a sustainable alternative to traditional methods, offering lower energy requirements and reduced environmental footprint. The paper delves into the theoretical foundations of Forward Osmosis, examining the osmotic process and the dynamics of semi-permeable membranes. It further investigates the technological implementations of Forward Osmosis in food processing, showcasing successful case studies and highlighting the technology performance advantages compared to other methods. Despite its potential, Forward Osmosis faces technical challenges, including membrane fouling and the need for efficient draw solution recovery mechanisms. Recent innovations in membrane and draw solution development are discussed, offering solutions to these hurdles and paving the way for more effective Forward Osmosis applications. The review also projects future directions and research needs to overcome existing limitations and fully harness Forward Osmosis capabilities. Through a critical analysis of current literature, this paper underscores Forward Osmosis transformative potential in making food processing more sustainable and efficient.
Heterogeneous Polypropylene-Based Cation-Exchange Membrane Modified by Functionalized Zinc Oxide Particles for Vanadium Redox Flow Battery Khoiruddin, Khoiruddin; Firmansyah, Rizky W.; Yulanda, Nanda; Wardani, Anita K.; Wenten, I Gede
Reaktor Volume 24 No.2 August 2024
Publisher : Department of Chemical Engineering, Faculty of Engineering, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/reaktor.24.2.58-67

Abstract

This work presents the synthesis and characterization of heterogeneous cation-exchange membranes based on polypropylene (PP) and cation-exchange resin (IER) powder, developed via melt spinning. The membranes were modified with zinc oxide (ZnO) nanoparticles functionalized with polydopamine (PDA) to enhance their electrochemical properties. The effects of varying IER content and ZnO/PDA loading on key membrane properties, including ion-exchange capacity (IEC), water uptake (WU), water contact angle (WCA), proton conductivity, water permeability, and vanadium permeability, were systematically investigated. The results demonstrated that increasing IER content improved proton conductivity and IEC, but also increased vanadium permeability. The PP/ZnO-PDA (Z-2.5) membrane, with 2.5%-wt. ZnO/PDA, showed reduced water permeability (0.46 L·m⁻²·h⁻¹·bar⁻¹) and vanadium permeability (5.67 × 10⁻⁵ cm² min⁻¹), while maintaining moderate proton conductivity (13.17 mS/cm). However, increasing ZnO/PDA content beyond 2.5%-wt. led to declines in WU, IEC, and proton conductivity, likely due to nanoparticle aggregation reducing access to ion-exchange sites.
Circular Economy Approaches in the Palm Oil Industry: Enhancing Profitability through Waste Reduction and Product Diversification Siagian, Utjok Welo Risma; Wenten, I Gede; Khoiruddin, Khoiruddin
Journal of Engineering and Technological Sciences Vol. 56 No. 1 (2024)
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2024.56.1.3

Abstract

Today, facing difficult environmental and sustainability questions, the palm oil industry is an important force in global trade and development. As a transformative solution to these problems, this review assesses the implementation of circular economy (CE) strategies. CE principles promote the transformation of waste into value through recycling, upcycling and other low-carbon innovation applications. This review estimates the capability of palm-based biomass, including palm oil mill effluent (POME) and refinery wastes. It evaluates how different technologies such as gasification are used to change these fuel sources into energy fuels and value-added products for industry. It also involves incorporating Industry 4.0 to boost efficiency and waste value creation into the operation. Although the potential of CE in creating an eco-friendly, profitable palm oil industry is apparent, nevertheless it must overcome all kinds and levels of barriers – from economic to technological to social. This review points out for collaborative efforts, technological advancement, and supportive policies to navigate these challenges, advocating for a unified shift towards sustainability and efficiency in the palm oil sector.
Green Energy Technologies: A Key Driver in Carbon Emission Reduction Wenten, I Gede; Khoiruddin, Khoiruddin; Siagian, Utjok Welo Risma
Journal of Engineering and Technological Sciences Vol. 56 No. 2 (2024)
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2024.56.2.1

Abstract

This paper explores the vital role of green energy technologies in mitigating carbon emissions and advancing sustainable energy transition. It emphasizes the significance of green energy in reducing the carbon footprint, delves into the environmental consequences of carbon emissions, and analyzes the mechanisms through which green energy contributes to carbon reduction. This paper discusses technological advancements across various renewable energy sources, including solar, wind, hydroelectric, biomass, geothermal, tidal, wave, nuclear, osmotic, and salinity-powered energy generation. It also examines emerging green energy technologies, identifies barriers to adoption, offers an Indonesian perspective, and provides recommendations for a greener energy future. Overall, this paper offers a comprehensive exploration of green energy's transformative potential in combatting climate change and promoting sustainable development.