Application of Polysaccharide Biopolymer in Petroleum Recovery
Polymers
Polysaccharide biopolymers are biomacromolecules derived from renewable resources with versatile ... more Polysaccharide biopolymers are biomacromolecules derived from renewable resources with versatile functions including thickening, crosslinking, adsorption, etc. Possessing high efficiency and low cost, they have brought wide applications in all phases of petroleum recovery, from well drilling to wastewater treatment. The biopolymers are generally utilized as additives of fluids or plugging agents, to correct the fluid properties that affect the performance and cost of petroleum recovery. This review focuses on both the characteristics of biopolymers and their utilization in the petroleum recovery process. Research on the synthesis and characterization of polymers, as well as controlling their structures through modification, aims to develop novel recipes of biopolymer treatment with new application realms. The influences of biopolymer in many petroleum recovery cases were also evaluated to permit establishing the correlations between their physicochemical properties and performances....
Application of Polysaccharide Biopolymer in Petroleum Recovery
Polymers
Polysaccharide biopolymers are biomacromolecules derived from renewable resources with versatile ... more Polysaccharide biopolymers are biomacromolecules derived from renewable resources with versatile functions including thickening, crosslinking, adsorption, etc. Possessing high efficiency and low cost, they have brought wide applications in all phases of petroleum recovery, from well drilling to wastewater treatment. The biopolymers are generally utilized as additives of fluids or plugging agents, to correct the fluid properties that affect the performance and cost of petroleum recovery. This review focuses on both the characteristics of biopolymers and their utilization in the petroleum recovery process. Research on the synthesis and characterization of polymers, as well as controlling their structures through modification, aims to develop novel recipes of biopolymer treatment with new application realms. The influences of biopolymer in many petroleum recovery cases were also evaluated to permit establishing the correlations between their physicochemical properties and performances....
Polysaccharide biopolymers are biomacromolecules derived from renewable resources with versatile ... more Polysaccharide biopolymers are biomacromolecules derived from renewable resources with versatile functions including thickening, crosslinking, adsorption, etc. Possessing high efficiency and low cost, they have brought wide applications in all phases of petroleum recovery, from well drilling to wastewater treatment. The biopolymers are generally utilized as additives of fluids or plugging agents, to correct the fluid properties that affect the performance and cost of petroleum recovery. This review focuses on both the characteristics of biopolymers and their utilization in the petroleum recovery process. Research on the synthesis and characterization of polymers, as well as controlling their structures through modification, aims to develop novel recipes of biopolymer treatment with new application realms. The influences of biopolymer in many petroleum recovery cases were also evaluated to permit establishing the correlations between their physicochemical properties and performances. As their performance is heavily affected by the local environment, screening and testing polymers under controlled conditions is the necessary step to guarantee the efficiency and safety of biopolymer treatments.
The deposition of asphaltene on interior pipe surfaces is considered a challenging flow assurance... more The deposition of asphaltene on interior pipe surfaces is considered a challenging flow assurance issue. By exploiting the net charge of the asphaltene molecule, it can be effectively removed from the flow stream by means of electro-deposition before transportation to prevent later deposition. To evaluate this concept, electro-deposition of asphaltene from a synthetic oil using varying electric field strength and solvent type were studied. The results demonstrate that the asphaltene molecule possesses a native positive charge, however an induced negative charge can be observed under high current density; depending on the current density, deposition onto the cathode, anode, or both were observed. Both solvent polarity and viscosity affected the removal performance by way of effect on the asphaltene stability and electrophoretic mobility. The interaction of asphaltene and resin resulted in a slight neutralization of charge and strong repression of charge alternation behavior. A series of experiments were conducted to mimic a continuous process by means of repeated electro-deposition cycles. With 8000 V/cm electric field applied, 119 g/m2 asphaltene can be deposited onto electrodes within 10 min using ∼1 kJ energy input. Finally, electro-deposition of actual crude oil was conducted; the electric field strength required to deposit the asphaltene decreased with higher dilution ratio. The speed and high energy efficiency make electro-deposition a promising strategy for asphaltene removal.
Asphaltene deposition and plugging of pipelines during oil production and transportation is consi... more Asphaltene deposition and plugging of pipelines during oil production and transportation is considered a challenging flow assurance issue. Instead of adding dispersants, the concept proposes to remove asphaltenes from the flow stream by means of electro–deposition prior to transportation to prevent later deposition. This study mainly examined the effect of molecular composition on the efficiency of electro-deposition. Two sources of asphaltene, namely asphaltenes from coal tar ("AS-C") and asphaltenes from bitumen ("AS-B") with different molecular composition were collected in this study. Elemental analysis revealed that both AS-B and AS-C possessed transition metals (V and Ni) and heteroatoms (O, N and S). The effect of oil components on the stability of two asphaltenes was studied. After conducting the electro–deposition of both asphaltenes with various oil components and electric field strength, the deposition charge and recover rate was recorded and compared. During stability test, the amount of precipitated AS-B decreased with increasing aromaticity of solvent, while that of AS-C was constant. For electro–deposition, the electro– kinetic behavior of AS-C reveals strong sensitivity to the oil components. Interestingly, both asphaltenes exhibited a change in the net charge, which occurred under 6000 V/cm and 12000 V/cm for AS-B and AS-C respectively, as evidenced by a change in the electrode upon which deposition ocurred. Based on the results, the efficiency of electro–deposition is confirmed to depend upon the metal and heteroatoms of asphaltenes; in addition, and by interaction with these elements, the oil composition and electric field affected the stability, net charge, and electro–kinetic behavior of apshaltene. However, our study is the first to show that the current density plays a role in the net charge of the asphaltene molecule and offers an explanation to the controversy over the polarity or the charge sign of asphaltenes, which gives a clue to understanding the microstructure of asphaltenes. In addition, this is the first study to include the effect of oil components and electric field strength on the performance of deposition, which makes further optimization of the proposed process possible.
Blending crude oil with short-chain paraffins is a common method to improve the oil quality durin... more Blending crude oil with short-chain paraffins is a common method to improve the oil quality during heavy oil upgrading. The additional paraffins will cause precipitation of asphaltene that is removed by filtration or sedimentation; both processes are slow and inefficient. As a potential faster and more efficient removal method, an electric field can be applied in order to electro-deposit the asphaltene on the electrodes. Electro-deposition (E-D) experiments were conducted in a bench scale vessel while varying several process parameters such as the dilution ratio of paraffin to heavy oil, the paraffin used as the diluent, electric field strength, and the effect of resins on the E-D process. Increasing the dilution ratio resulted in more precipitated asphaltene and required a lower electric field strength for the E-D process. The electro-deposition process could affect the net charge of the asphaltene, and hence, both cathode and anode were closely observed: deposition onto the cathode was favored with higher dilution ratio and a lower electric field strength, while anode deposition occurred using a lower dilution ratio and higher electric field strength. This result is related to the higher resin content at low dilution ratio which adsorbs onto the asphaltene aggregate and shields or inhibits the effect of the electric field. To recover 1 kg of asphaltene, the energy input is estimated to be as low as 10 kJ. The process is relatively fast and requires low energy input, which can overcome the disadvantages of current filtration methods.
Based on a practical project, the construction method of circular reinforced concrete (RC) column... more Based on a practical project, the construction method of circular reinforced concrete (RC) columns strengthened with externally wrapped steel plates was introduced in this paper. In order to study the bearing capacity and seismic performance of circular RC columns after strengthening, a formula for calculating the bearing capacity of circular RC columns strengthened with externally wrapped steel plates was derived, with reference to the Code for Design of Strengthening Concrete Structure. rough ABAQUS software, the vertical monotone static loading analysis and the horizontal low-cyclic reversed loading analysis were carried out, respectively, before and after the strengthening of the full-size RC columns in this project. e results showed that the bearing capacity of the normal section of the RC column after strengthening was about 80% higher than that before strengthening, and the results of FEM software were in accord with the calculation results of theoretical formula to some degree. Under horizontal low-cyclic reversed loading, the columns after strengthening had both plumper hysteresis curves and higher ductility factors and equivalent viscous damping coefficient than those before strengthening, indicating the energy dissipation capacity, plastic deformation capacity, and seismic performance of the RC columns after strengthening were all obviously improved.
As biocatalytic carbon capture has attracted wide attraction due to its high energy efficiency, t... more As biocatalytic carbon capture has attracted wide attraction due to its high energy efficiency, the preference of carbon species of the reaction is concerned. The self-evolution between carbon species makes the determination of preference a changeling issue. In this study, by comparing the isocitrate dehydrogenase reaction rate profiles with pre-equilibrated and un-equilibrated HCO3-CO2 solutions, gas phase carbon dioxide was believed as the optimum substrate, as it can provide higher reaction rate. During the carbon capture process, the partial pressure of the carbon dioxide affected both the reaction equilibrium and kinetics, while the interfacial area can only determine the reaction rate.
Carbon capture can be realized effectively through isocitrate dehydrogenase reaction and the reac... more Carbon capture can be realized effectively through isocitrate dehydrogenase reaction and the reaction rate was strongly affected by the environmental parameters such as pH and temperature. Enzyme immobilization was conducted to improve the enzyme stability during the capture process. By simply adsorbing enzyme on the surface of mesoporous silica foam, enzyme stability against temperature, pH and shear stress was improved. The immobilization process can be completed in 5 mins, and 0.87 U enzyme activity was kept for each gram of immobilization material. After 10 cycles, more than 50 percent of enzyme activity remained. The reusability and improved stability made immobilized ICDH a better candidate for large-scale application of carbon capture.
As a compound with antitumor activities, prodigiosin was produced by Serratia marcescens with kit... more As a compound with antitumor activities, prodigiosin was produced by Serratia marcescens with kitchen waste as a substrate. The initial yield of prodigiosin was 223mg/l and can be further improved with supplementation of nitrogen source and inductor to the medium. A 290% increase of the prodigiosin production was achieved with 1% peptone and 0.2% proline. Physiological fermentation factors such as incubation time (36h), substrate concentration (35g/l), pH of the medium (pH 8.0), and fermentation parameter such as temperature (28℃), agitation speed (150rpm), inoculum level (1%), and liquid volume (20/150ml) all have impact on the prodigiosin production. With optimization, the maximum prodigiosin yield was 890mg/l and kitchen waste was proved to be a novel and economic substrate for prodigison production.
The wild-type of Serratia marcescens which could produce prodigiosin was isolated by our laborato... more The wild-type of Serratia marcescens which could produce prodigiosin was isolated by our laboratory. With utilizing the kitchen waste by solid fermentation method, the strategy for obtaining inexpensive prodigiosin was established. Optimum prodigiosin production was achieved when the moisture level was 200%; the ratio of biomass of rice husk to kichen waste material was 1.2 and adding 1.5% level proline to the substrate. The physiological fermentation factors such as incubation time (60h), pH of the medium (pH 8.0), and fermentation parameter such as temperature (28℃), inoculum level (1%) also have impact on the prodigiosin production. After modifying the fermentation contions, the maximum prodigiosin yield was more than 4155 milligram per kilo kitchen waste at 60h, which was two times more than initial production yield.
Biological conversion of carbon dioxide has been examined with growing interest in recent years f... more Biological conversion of carbon dioxide has been examined with growing interest in recent years for its potential in reduction of greenhouse gas emission. While many conversion routes have been suggested and demonstrated, understanding the constraints and limits of such reaction routes, either in vivo or in vitro , is becoming increasingly important. The current work examines the pH sensitivity of the reaction catalyzed by isocitrate dehydrogenase with respect to its potentials in carbon capture and conversion via both experimental measurements and theoretical analysis. As a result, the reaction equilibrium constant determined experimentally shifted by a factor of ∼500-fold when pH changed between 5 and 9. Thermodynamic analysis agreed well with such a pH sensitivity, indicating the impact of pH on Gibbs free energy of the species involved in the reaction helped to shift the reaction equilibrium.
The practice of carbon capture and storage (CCS) requires efficient capture and separation of car... more The practice of carbon capture and storage (CCS) requires efficient capture and separation of carbon dioxide from its gaseous mixtures such as flue gas, followed by releasing it as a pure gas which can be subsequently compressed and injected into underground storage sites. This has been mostly achieved via reversible thermochemical reactions which are generally energy-intensive. The current work examines a biocatalytic approach for carbon capture using an NADP(H)-dependent isocitrate dehydrogenase (ICDH) which catalyzes reversibly carboxylation and decarboxylation reactions. Different from chemical carbon capture processes that rely on thermal energy to realize purification of carbon dioxide, the biocatalytic strategy utilizes pH to leverage the reaction equilibrium, thereby realizing energy-efficient carbon capture under ambient conditions. Results showed that over 25 mol of carbon dioxide could be captured and purified from its gas mixture for each gram of ICDH applied for each carboxylation/decarboxylation reaction cycle by varying pH between 6 and 9. This work demonstrates the promising potentials of pH-sensitive biocatalysis as a green-chemistry route for carbon capture.
Thermochemical processes developed for carbon capture and storage (CCS) offer high carbon capture... more Thermochemical processes developed for carbon capture and storage (CCS) offer high carbon capture capacities, but are generally hampered by low energy efficiency. Reversible cascade enzyme reactions are examined in this work for energy-efficient carbon sequestration. By integrating the reactions of two key enzymes of RTCA cycle, isocitrate dehydrogenase and aconitase, we demonstrate that intensified carbon capture can be realized through such cascade enzymatic reactions. Experiments show that enhanced thermodynamic driving force for carbon conversion can be attained via pH control under ambient conditions, and that the cascade reactions have the potential to capture 0.5 mol carbon at pH 6 for each mole of substrate applied. Overall it manifests that the carbon capture capacity of biocatalytic reactions, in addition to be energy efficient, can also be ultimately intensified to approach those realized with chemical absorbents such as MEA.
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