6^th Asia Pacific Congress on Chemical and Biochemical Engineering September 17-18, 2018 Hong Kong

Biography:

Jian Yu graduated from University of British Columbia (PhD, 1991), Zhejiang University (MSc, 1985) and Zhejiang Institute of Technology (BEng, 1982). He was an assistant professor at Hong Kong University of Science & Technology (1994-2001) and is now a research professor at University of Hawaii at Manoa (2001-present). His research interest is in the area of biochemical engineering for production of value-added products from renewable resources. He has published more than 70 research papers in peer-reviewed journal as the first and/or corresponding author, in addition to numerous book chapters and conference papers and presentations.  His H-index of Google Scholar is 29.  He has three patents that have been licensed to companies and one technology has been successfully scaled up to commercial production.

Abstract:

Carbo dioxide (CO₂) is a prime green-house gas emission from industrial processes. It can be converted into bio-oil by microalgae via conventional photosynthesis. The CO₂ fixation rate, however, is quite low and affected by the intermittent solar radiation. Cupriavidus necator, a hydrogen-oxidizing bacterium, was grown on CO₂ and H₂ in dark gas fermentation to produce single cell proteins and polyhydroxybutyrate (PHB). Sunlight is captured by photovoltaic modules and immediately converted to H₂ as a stable energy source via water electrolysis. The clean H₂ and O₂ are used by C. necator in CO₂ assimilation. Under the chemolithotrophic conditions, the average CO₂ uptake rate was 1.2 kg m^-3 h^-1. The molar ratios of H₂/CO₂ was 7.3 and the biomass/H₂ yield was 1.4 g g^-1. The overall energy efficiency from H₂ to biomass was 22.4%.  Under nutrient control, the PHB content of dry cell mass was 65 wt%. The polymer productivity was 1.87 g L^-1 d^-1, 14 times higher than oil productivity by a typical bio-oil-producing microalga. PHB is a biodegradable thermoplastic that can find various environmentally friendly applications. The biopolyester can also be converted into small functional chemicals (C3-C4). Specifically, PHB was degraded and deoxygenated on a solid phosphoric acid catalyst, generating a hydrocarbon oil (C6-C18) from which a gasoline-grade fuel (77 wt% oil) and a biodiesel-grade fuel (23 wt% oil) were obtained via distillation. Aromatics and alkenes were the major compounds, depending on the reaction conditions. This work demonstrated a bioprocess through which bioplastics and high-grade liquid fuels can be directly produced from carbon dioxide. The novel bioprocess can be continuously operated regardless the intermittency of renewable powers.     

Biography:

Hiroshi Irie studied Inorganic Materials Science and received his B.E. and M.E. degrees from Tokyo Institute of Technology in 1992 and 1994, respectively. From 1994 to 1997, he worked at Sumitomo Metal Industries, LTD. as a research engineer. In 2000, he received his Ph. D. degree from the University of Tokyo in the Department of Interdisciplinary Studies. He was a research staff member at Kanagawa Academy of Science and Technology until 2001. He joined the University of Tokyo as a research associate in 2001 (Prof. Kazuhito Hashimoto’s lab.). He became a lecturer and an associate professor at the University of Tokyo in 2006 and 2008, respectively. He was promoted to a full professor in 2009 at Clean Energy Research Center in University of Yamanashi. His current research interests include creations of high-performance energy-conversion materials, such as photocatalysts, thermoelectric materials, and so on.

Abstract:

Various photocatalytic materials aiming at water splitting have been enthusiastically investigated because produced hydrogen (H₂) is attractive as a clean and renewable fuel. To date, one of the candidate methods to split water to H₂ and oxygen (O₂) at a ratio of 2:1 under visible light is a combined system of half reaction photocatalysts, that is, H₂-evolution and O₂-evolution photocatalysts. However, because such the combination system, which is termed “Z-scheme”, requires a suitable redox couple, the system is not in fact able to split pure water. For the practical application, splitting pure water with no added chemicals is presumed to be favorable.

Recently, we reported an Ag-inserted solid-state hetero-junction photocatalyst for water-splitting under visible light, similar to a Z-scheme system but is not required for a redox mediator. So, this system is capable of splitting pure water. In this system, Ag acts as a solid electron mediator for water-splitting. We selected ZnRh₂O₄ (band-gap (Eg) = 1.2 eV) and AgSbO₃ (Eg = 2.5 eV) as H₂- and O₂-evolution photocatalysts, respectively. The system was able to respond to visible light up to 545 nm depending on the photo-absorption capability of AgSbO₃ (in fact, defective AgSbO₃). So, we replaced AgSbO₃ with Bi₄V₂O₁₁ (Eg = 1.7 eV) as the O₂-photocatalyst. Utilizing thus constructed Ag-inserted ZnRh₂O₄ and Bi₄V₂O₁₁ photocatalyst, the simultaneous liberation of H₂ and O₂ from pure water at a stoichiometric ratio was achieved under irradiation with visible light up to wavelengths of 740 nm. In place of Ag, Au-inserted ZnRh₂O₄ and Bi₄V₂O₁₁ photocatalyst was also able to accomplish overall pure-water splitting under visible light up to 740 nm with improved activity. Detailed investigations will be discussed at the conference.

Biography:

Dr. Ping Zhang has been an assistant professor in Faculty of Science and Technology, University of Macau since November 2017. He received his B.S. degree in Environmental Science from Nankai University, Tianjin, China in 2006. He obtained his M.S. and Ph.D. degrees both in Civil and Environmental Engineering from Rice University in Houston, Texas, in 2008 and 2011, respectively. He obtained his professional engineer (P.E.) license in the dual disciplines of Chemical/Environmental Engineering in the State of Texas in 2016. He is also a Chartered Chemist (CChem) of Royal Society of Chemistry of the U.K. since 2017. His research interests are solid precipitation and deposition, oilfield mineral scale control and environmental aquatic chemistry.

Abstract:

Mineral scale (scale) is the sparingly soluble inorganic deposit from aqueous solution. Scale deposition can pose a serious problem to the safe and economical operations of various industrial facilities, costing hundreds of billions of dollars of damage globally per year. Scale deposition can lead to equipment blockage with a narrowed tubing inner diameter and a reduced flow rate. In this presentation, laboratory investigation of mineral scale deposition kinetics was evaluated by use of a plug-flow type tube reactor. Compared with the conventional approach, the tube reactor has the advantage to maintain a constant solution pH, surface area and a controlled saturation index and hydraulic condition during the deposition study. Two scenarios of scale solid deposition were considered in this study, including deposition of scale on clean surfaces and also deposition of scale on a surface pre-coated with scale solid. The results show that the overall scale deposition process can be divided into multiple stages with different deposition kinetics and different solid morphologies. It is obvious that experimental conditions, such as solution chemistry, flow rate, temperature and saturation index, can have a considerable impact on scale deposition kinetics. These results provide an in-depth understanding of the process involving scale deposition onto the surface of a pipe material or a conduit. This tube reactor apparatus expands our capability of investigating mineral scale deposition kinetics and the influences of various experimental factors on scale deposition kinetics.

Biography:

Chinmoy Dutta is a M.Tech student specialized in Petroleum Exploration & Production Department under Dibrugarh University, India. His interested area of research is Enhanced oil recovery of Petroleum. In 2017 He published an paper titled "Phase behavior study for Chemically Enhanced water flooding" international journal IJESM, Volume 6, Issue 7, November 2017. He also presented two paper in oral presentation in two different international conferences. This approach is responsive to surfactant and alkali flooding in EOR analyzed with the Low saline brine.

Abstract:

The discovery of new oil reserves has steadily declining over the years, so increasing the recovery factors from the oil fields is the only logical way to meet the growing demands. With this objective the different enhanced oil recovery (EOR) methods are designed. It has been observed that oil recovery by water flooding is influenced by the salinity and composition of injected water. Although low saline waterflooding (LSW) has the potential to recover additional oil, its recovery is less compared to chemical and gas EOR methods. The purpose of this study is to investigate the EOR potential of the novel low saline water-alkaline-surfactant/alternated/CO₂ (LSWASG) method in an oilfield of Assam, India. Reservoir cores and crude oils from an Upper Assam depleted oilfield were analysed for their characterization and for preparing the synthetic formation brine (SFB). Chemical formulations that will best recover crude oil were next screened based on interfacial tension (IFT) measurements. Finally, lab-scale core flooding experiments were conducted to evaluate the oil recovery potential of the proposed method. From the coreflooding experiments, it was observed that secondary waterflooding of crude oil saturated core plugs resulted in recovery of about 33% oil initially in place (OIIP). Additional oil recovery by low saline waterflooding in the tertiary mode was 4.8 % OIIP.  However, the oil recovery with LSW combined with the selected formulation (0.5 wt% SDS + 1 wt% Na₂CO₃) with and without alternated CO₂ gas injection increased to 19.34% and 22.57% OIIP respectively. Higher oil recovery by the synergic combination of LSW, chemicals and CO₂ gas, highlighted the EOR potential of the novel LSWASG process in the Assam oilfield producing medium gravity crudes