Muhammad Roil Bilad
Other affiliations: Khalifa University, Syiah Kuala University, Katholieke Universiteit Leuven ...read more
Bio: Muhammad Roil Bilad is an academic researcher from Universiti Brunei Darussalam. The author has contributed to research in topics: Membrane & Membrane fouling. The author has an hindex of 33, co-authored 196 publications receiving 3335 citations. Previous affiliations of Muhammad Roil Bilad include Khalifa University & Syiah Kuala University.
TL;DR: In this paper, a review of 1660 patents related to biodiesel production were reviewed and grouped into five categories depending on whether they related to starting materials, pre-treatment methods, catalysts, reactors and processing methods or testing methods.
Abstract: Biodiesel is a renewable fuel made from vegetable oils and animal fats. Compared with fossil fuels, it has the potential to alleviate environmental pressures and achieve sustainable development. In this paper, 1660 patents related to biodiesel production were reviewed. They were published between January 1999 and July 2018 and were retrieved from the Derwent Innovation patent database. The patents were grouped into five categories depending on whether they related to starting materials, pre-treatment methods, catalysts, reactors and processing methods, or testing methods. Their analysis shows that the availability of biodiesel starting materials depends on climate, geographical location, local soil conditions, and local agricultural practices. Starting materials constitute 75% of overall production costs and, therefore, it is crucial to select the best feedstock. Pre-treatment of feedstock can improve its suitability for processing and increase extraction effectiveness and oil yield. Catalysts can enhance the solubility of alcohol, leading to higher reaction rates, faster biodiesel production processes, and lower biodiesel production costs. Moreover, the apparatus and processes used strongly affect the oil yield and quality, and production cost. In order to be commercialized and marketed, biodiesel should pass either the American Society for Testing and Materials (ASTM) standards or European Standards (EN). Due to increases in environmental awareness, it is likely that the number of published patents on biodiesel production will remain stable or even increase.
TL;DR: An overview of membrane materials and membrane processes of interest in microalgae cultivation and processing is provided and discussion about specific aspects of membrane applications in microbial cultivation and harvesting is provided, including membrane fouling.
Abstract: Membrane processes have long been applied in different stages of microalgae cultivation and processing. These processes include microfiltration, ultrafiltration, dialysis, forward osmosis, membrane contactors and membrane spargers. They are implemented in many combinations, both as a standalone and as a coupled system (in membrane biomass retention photobioreactors (BR-MPBRs) or membrane carbonation photobioreactors (C-MPBRs). To provide sufficient background on these applications, an overview of membrane materials and membrane processes of interest in microalgae cultivation and processing is provided in this work first. Afterwards, discussion about specific aspects of membrane applications in microbial cultivation and harvesting is provided, including membrane fouling. Many of the membrane processes were shown to be promising options in microalgae cultivation. Yet, significant process optimizations are still required when they are applied to enable microalgae biomass bulk production to become competitive as a raw material for biofuel production. Recent developments of the coupled systems (BR-MPBR and C-MPBR) bring significant promises to improve the volumetric productivity of a cultivation system and the efficiency of inorganic carbon capture, respectively.
TL;DR: Overall results suggest that submerged microfiltration for algal harvesting is economically feasible and a low degree of fouling is indicated, comparable to the one obtained for a submerged MBR.
Abstract: This study was performed to investigate the applicability of submerged microfiltration as a first step of up-concentration for harvesting both a freshwater green algae species Chlorella vulgaris and a marine diatom Phaeodactylum tricornutum using three lab-made membranes with different porosity. The filtration performance was assessed by conducting the improved flux step method (IFM) and batch up-concentration filtrations. The fouling autopsy of the membranes was performed by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and Fourier transform infrared spectroscopy (FTIR). The cost analysis was estimated based on the data of a related full-scale submerged membrane bioreactor (MBR). Overall results suggest that submerged microfiltration for algal harvesting is economically feasible. The IFM results indicate a low degree of fouling, comparable to the one obtained for a submerged MBR. By combining the submerged microfiltration with centrifugation to reach a final concentration of 22% w/v, the energy consumption to dewater C. vulgaris and P. tricornutum is 0.84 kW h/m 3 and 0.91 kW h/m 3 , respectively.
TL;DR: In this article, mixed matrix membranes (MMMs) were prepared using polydimethylsiloxane (PDMS) as a hydrophobic polymer and ZIF-67 as inorganic filler particle.
Abstract: Zeolitic imidazole frameworks (ZIFs), a subclass of metal organic frameworks (MOFs), are composed of metal ions linked by organic ligands which offer an exceptionally high surface area and appealing separation potential. In this study, mixed matrix membranes (MMMs) were prepared using polydimethylsiloxane (PDMS) as a hydrophobic polymer and ZIF-67 as inorganic filler particle. ZIF-67 particles and MMMs were characterized by XRD, SEM, FTIR, BET and contact angle measurements. The prepared membranes were tested for the separation of ethanol/water mixtures via pervaporation. Compared to unfilled PDMS membranes, MMMs loaded with 20 wt% ZIF-67 showed an increase in flux and a doubled separation factor. The easy synthesis of ZIF-67 and its enhanced separation performance make ZIF-67 an attractive candidate to prepare MMMs for a variety of membrane applications.
TL;DR: Overall results suggest that the MMV offers a good fouling control and the process was proven to be economically attractive.
Abstract: This study was performed to investigate the effectiveness of submerged microfiltration to harvest both a marine diatom Phaeodactylum tricornutum and a Chlorella vulgaris in a recently developed magnetically induced membrane vibrating (MMV) system. We assess the filtration performance by conducting the improved flux step method (IFM), fed-batch concentration filtrations and membrane fouling autopsy using two lab-made membranes with different porosity. The full-scale energy consumption was also estimated. Overall results suggest that the MMV offers a good fouling control and the process was proven to be economically attractive. By combining the membrane filtration (15× concentration) with centrifugation to reach a final concentration of 25% w/v, the energy consumption to harvest P. tricornutum and C. vulgaris was, respectively, as low as 0.84 and 0.77 kW h/m 3 , corresponding to 1.46 and 1.39 kW h/kg of the harvested biomass.
TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …
TL;DR: In this paper, various technologies currently used for dewatering microalgal cultures along with a comparative study of the performances of the different technologies are reviewed and compared, as well as a comparison of the performance of different technologies.
Abstract: Microalgae dewatering is a major obstruction to industrial-scale processing of microalgae for biofuel prodn. The dil. nature of harvested microalgal cultures creates a huge operational cost during dewatering, thereby, rendering algae-based fuels less economically attractive. Currently there is no superior method of dewatering microalgae. A technique that may result in a greater algal biomass may have drawbacks such as a high capital cost or high energy consumption. The choice of which harvesting technique to apply will depend on the species of microalgae and the final product desired. Algal properties such as a large cell size and the capability of the microalgae to autoflocculate can simplify the dewatering process. This article reviews and addresses the various technologies currently used for dewatering microalgal cultures along with a comparative study of the performances of the different technologies.
TL;DR: An empirical and critical analysis on the potential of translating research findings from laboratory scale trials to full scale application and current methods for biomass harvesting and lipid extraction are critically evaluated.
Abstract: The economically significant production of carbon-neutral biodiesel from microalgae has been hailed as the ultimate alternative to depleting resources of petro-diesel due to its high cellular concentration of lipids, resources and economic sustainability and overall potential advantages over other sources of biofuels. Pertinent questions however need to be answered on the commercial viability of large scale production of biodiesel from microalgae. Vital steps need to be critically analysed at each stage. Isolation of microalgae should be based on the question of whether marine or freshwater microalgae, cultures from collections or indigenous wild types are best suited for large scale production. Furthermore, the determination of initial sampling points play a pivotal role in the determination of strain selection as well as strain viability. The screening process should identify, purify and select lipid producing strains. Are natural strains or stressed strains higher in lipid productivity? The synergistic interactions that occur naturally between algae and other microorganisms cannot be ignored. A lot of literature is available on the downstream processing of microalgae but a few reports are available on the upstream processing of microalgae for biomass and lipid production for biodiesel production. We present in this review an empirical and critical analysis on the potential of translating research findings from laboratory scale trials to full scale application. The move from laboratory to large scale microalgal cultivation requires careful planning. It is imperative to do extensive pre-pilot demonstration trials and formulate a suitable trajectory for possible data extrapolation for large scale experimental designs. The pros and cons of the two widely used methods for growing microalgae by photobioreactors or open raceway ponds are discussed in detail. In addition, current methods for biomass harvesting and lipid extraction are critically evaluated. This would be novel approach to economical biodiesel production from microalgae in the near future. Globally, microalgae are largest biomass producers having higher neutral lipid content outcompeting terrestrial plants for biofuel production. However, the viscosities of microalgal oils are usually higher than that of petroleum diesel.
TL;DR: In this article, the main harvesting processes applied to microalgae, presenting the main advantages and disadvantages of each method, to allow the selection of an appropriate procedure to effectively separate microalgal biomass from the culture medium.
Abstract: Research studies on microalgae have increased in the last decades due to the wide range of applications associated to these photosynthetic microorganisms. Microalgae are an important source of oils and other biomolecules that can be used in the production of biofuels and high-valued products. However, the use of microalgae in these green processes is still not economically viable. One of the main costs associated to microalgal production is related to the harvesting process, as it usually accounts for about 20–30% of total cost. Therefore, this review focuses on the main harvesting processes applied to microalgae, presenting the main advantages and disadvantages of each method, to allow the selection of an appropriate procedure to effectively separate microalgal biomass from the culture medium. To reduce the associated costs, it is common to harvest microalgae in a two-step separation: (i) thickening procedures, in which microalgal slurry is concentrated to about 2–7% of total suspended solids; and (ii) dewatering procedures, which result in the concentration of microalgal slurry to 15–25% of total suspended solids. Selection of the adequate harvesting methods depends on the characteristics of the target microorganism and also on the type and value of the end product.