Alternative Recovery Methods Research Articles

Peran Arbitrase dalam Penyeleseaian Sengketa di Luar Pengadilan Menurut Undang-Undang No. 30 Tahun 1999

Apart from regulating the use of arbitration, Law Number 30 of 1999 concerning Arbitration and Alternative Conflict Resolution encourages business actors to examine alternative conflict resolution. Arbitration is a method of resolving a civil settlement outside of general court which is based on an arbitration agreement signed between the parties. According to Law Number 30 of 1999, alternative recovery methods include mediation, negotiation, consultation, expert review and conciliation. Arbitration comes from the Latin word arbitrare which means the power to resolve something based on discretion. The appointment of arbitration with discretion gives the impression that an arbitrator is someone who can reach a more reasonable conclusion regarding the settlement. This research method uses a descriptive analysis approach which uses factors that influence the advantages of arbitration and this data source is secondary, namely according to legal documents - Law number 30 of 1999 and related laws, as well as journals and books. The fact that the arbitrators are selected by both parties to the dispute and are experts in their fields indicates that they are informed about the issues at hand, which is one of the benefits of resolving conflicts outside the court system rather than through litigation. Second, settlement decisions are made behind closed doors, so that only a few parties know the main issues at issue. Specialization or expertise in case management gives clients confidence• Arbitration is a popular alternative in business settlements due to several key advantages. The closed process maintains confidentiality and avoids adverse publicity. Arbitration decisions are final and binding, and the process is faster and more predictable than court. Flexibility in selecting arbitrators and arbitration procedural rules also provides parties with greater control over the outcome of their settlements. Overall, arbitration achieves amicable resolutions, supports sustainable commercial relationships, and allows for resolution in a more efficient and effective manner

Study of the corrosion resistance of high chromium white cast iron welds in the presence of NaOH (30% w/w)

– In the mining industry, specifically in bauxite processing, adverse working conditions demand high mechanical and chemical resistance. For such conditions, the choice of potentially resistant materials, such as high chromium white cast iron (HCr-CWI), is necessary. However, presently, there is no effective recovery of equipment made with HCr-CWI, primarily due to the machining difficulties encountered during the repair process. An alternative recovery method is being developed by the Laboratory of Metallic Materials Characterization at UFPA – LCAM, using electric arc welding with two filler metals: the ER307L stainless steel wire andsa high Mn value wire. Within this context, this study aims to investigate the corrosion resistance of the welded joint obtained with these two filler metals. The base metal (HCr-CWI) was analysed as a reference, alongside the metals generated by the welded joints, ER307L and high Mn. The samples underwent tests involving optical microscopy (OM), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and electrochemical tests for corrosion potential, polarization, and impedance. It was observed that the samples exhibited a similar matrix-carbide structure but with different organization and volumes. However, the electrochemical behaviour in terms of corrosion potential, polarization, and impedance was similar, with very close resultant values: 50 V; 3.53 μA; 0.18 kOhms, respectively. This was supported by the corrosion rate of 0.4mmpy and explained by calculations of Cr and Ni volume, which showed inverse concentration magnitudes among the samples.

UV Light-Induced Degradation of Industrial Silicon HJT Solar Cells: Degradation Mechanism and Recovery Strategies

Abstract: The demand for Silicon heterojunction solar cells (HJT) has significantly grown recently. These solar cells have gained recognition for their remarkable performance, which can be attributed to the exceptional passivation properties of bilayers consisting of intrinsic and doped hydrogenated amorphous silicon. This study investigates alternative recovery methods and looks into the deterioration caused by UV radiation in commercial Silicon HJT solar cells. The carrier lifetimes of the samples were measured before and after the HJT solar cells were exposed to ultraviolet radiation. The findings revealed a decrease in carrier lifetime, iVoc, and iFF, indicating the creation of defects in the bulk of a-Si:H and the interface between c-Si and a-Si:H. It was assessed how SiOx performed as a passivation layer. It has been discovered that SiOx can passivate dangling bonds, increase carrier lifetime and reduce trap density. In addition, recovery techniques like current injection, infrared, light soaking, and annealing were applied. The current injection, infrared, and light soaking treatments were discovered to be able to partially restore the efficiency of the solar cells without the combination of temperature, while annealing was found to be more effective. Additionally, the effects of both short and prolonged exposure to UV are investigated. The HJT solar cells exposed to prolonged UV radiation for an extended period of time could not fully regain their efficiency and displayed irreparable flaws. Overall, this study demonstrates the potential of recovery treatments and passivation techniques in increasing the efficiency of Si HJT solar cells and illuminates the processes underlying ultraviolet-induced deterioration. Overall, this study sheds light on ultraviolet-induced degradation mechanisms and highlights the potential of recovery treatments and passivation techniques in enhancing the efficiency of Si HJT solar cells.

Lysozymes from natural rubber latex (Hevea brasiliensis): Assay development and recovery using ammonium sulphate and surfactant precipitations

To date, the C-serum and the bottom fraction of natural rubber latex (NRL) are still generally being considered as waste. However, they are rich sources of lysozyme, which is a bacteriolytic enzyme that has huge potential for biotechnological exploitations. So far, there are no reports on lysozyme recovery for the valorisation of NRL by-products. Therefore, this study aimed to (1) develop and validate a lysozyme assay based on the lysoplate method using the cloudy NRL sample and Micrococcus lysodeikticus cells and (2) recover lysozyme from the NRL fractions using ammonium sulphate ([NH4]2SO4) precipitation (direct and fractional modes) and the novel sodium di-(2-ethylhexyl) sulfosuccinate (AOT) surfactant precipitation. The assay developed in this study was high in both accuracy (97.54%) and precision (13.61% relative standard deviation). The detection and quantification limits, as well as the linearity range of the assay were 0.13 U/mL, 0.04 U/mL and 0-10,445.40 U/mL, respectively. As for the lysozyme recovery from the C-serum of NRL, the performance of the AOT precipitation via negative mode (activity recovery [AR] = 67.29%; purification factor [PF] = 2.42) was comparable (p > 0.05) to that of (NH4)2SO4 precipitation (direct mode: AR = 88.44%, PF = 2.18; fractional mode: AR = 95.44%, PF = 3.05). Meanwhile, for the lysozyme recovery from the bottom fraction of NRL, the AOT precipitation (AR = 71.94%; PF = 1.73) was shown to be superior than (NH4)2SO4 precipitation (direct mode: AR = 25.68%, PF = 3.23; fractional mode: AR = 27.88%, PF = 12.87). Hence, considering its effectiveness, simplicity, rapidity, as well as its great potential to be integrated with rubber product manufacturing, the AOT precipitation is an attractive alternative recovery method for lysozyme recovery from NRL. The findings described herein are significant for the development of a downstream processing scheme for lysozyme recovery from NRL.

Novel alternative recovery of polyhydroxyalkanoates from mixed microbial cultures using microwave‐assisted extraction

AbstractBACKGROUNDPolyhydroxyalkanoates (PHAs) are a class of biodegradable biopolymers produced and accumulated by microorganisms. PHAs are recovered from microbial biomass through the stages of pretreatment, extraction and purification. An alternative recovery method is microwave‐assisted extraction (MAE), which involves the supply of energy through an electromagnetic field, generating high temperatures in reduced times. A study to evaluate the recovery of PHAs from mixed microbial cultures was conducted using MAE. This method was evaluated through a four‐factorial experimental design, with the efficiency as the evaluated response. PHAs were also recovered using conventional heat extraction as control.RESULTSIt was found that the highest efficiency achieved using MAE was 68 ± 1.2% (w/w), which was close to the 66 ± 5.3% (w/w) obtained using conventional heat extraction. The following combination of factors corresponded to the optimum conditions of experimental design: extraction time of 1 min, temperature of 130 °C, chloroform‐to‐methanol ratio of 1:1 and solvent‐to‐biomass ratio of 20 volumes. The efficiency increased substantially when the solvent‐to‐biomass ratio and chloroform‐to‐methanol ratio increased, although the temperature was the least significant factor. Functional groups, decomposition temperatures (263–309 °C) and melting point (158 °C) of MAE‐recovered PHAs were similar to those measured for commercial poly[(3‐hydroxybutyrate)‐co‐(3‐hydroxyvalerate)].CONCLUSIONSMAE is a never‐before‐reported useful method for recovering PHAs from mixed microbial cultures, which provides for a high extraction efficiency and quality of the recovered biopolymers. © 2021 Society of Chemical Industry (SCI).

Alternative acetone–water separation process through the application of aqueous two‐phase systems

AbstractBACKGROUNDThe central stage of biotechnological production is the transformation of renewable raw materials into bioproducts in a water‐based bioreactor. The fermentation broth usually has a low concentration (less than 10%) of the bioproduct, which requires the application of subsequent separation and purification processes. For many bioproducts, separation is complicated by the presence of non‐ideal thermodynamics or azeotropic points, which makes it impossible to purify the bioproduct by traditional methods, such as conventional distillation. In a search for alternative recovery methods for bioproducts or dehydration of organic mixtures this study proposes an alternative process for the dehydration of acetone by liquid–liquid extraction based on experimental results obtained using an aqueous two‐phase system (ATPS) for an acetone–water–potassium carbonate mixture.RESULTSThe experimental results of the liquid–liquid equilibrium for the acetone–water–potassium carbonate ternary system at 25 °C was fitted to an ELECNRTL thermodynamic model (binodal curve and distribution lines). A good correlation with the experimental data was observed. The Hunter–Nash method was applied to the experimental single‐stage liquid–liquid extraction, which operates at room temperature, and a concentration greater than 95 wt% of acetone was achieved starting from a mixture of 10 wt%. By simulation with the decanter block of Aspen Plus, results that were very close to the experimental results were obtained.CONCLUSIONThese findings suggest that in the foreseeable future ATPSs will have wide application both at the laboratory level and on a large scale for the dehydration of bioproducts and the separation of azeotropic mixtures. © 2020 Society of Chemical Industry

De-inked paper sludge and mature compost as high-value components of soilless substrate to support tree growth

Abstract The recycled paper industry produces tons of waste whose disposal is a cost for industry and the environment. This research examines the suitability of de-inked paper sludge (DPS), after pelletization, as a sustainable alternative component to a peat-based growing media, creating ideal root conditions for tree development (e.g. high water storage, low compaction). DPS, tested on Lepidium sativum L. germination, did not show toxicity effects. Three species, Quercus ilex L., Lagerstroemia indica L. and Prunus serrulata “Kanzan”, were planted in 40 cm O pots filled with a control (peat, pumice and zeolite) and the experimental substrate (compost, DPS pellets, pumice and zeolite). After two years in the nursery, the trees were planted in situ. The physical and chemical properties of substrates were analyzed. Plant morphological and physiological parameters were monitored: trunk diameter, leaf dry matter, leaf nitrogen, chlorophyll, and photosynthetic efficiency. The new substrate showed higher Corg (+135%), total N (+73%) and easily available water (+19%), compared to the control substrate used in the nursery. In this new substrate, the trees showed similar radial growth values to the control in the nursery and after transplanting in situ improved their photosynthetic performance in terms of quantum yield of photosystem II (+36%, and +29% in P. serrulata and L. indica, respectively) and electron transport rate (+39%, +25%, and +32% in P. serrulata, Q. ilex and L. indica, respectively). Pelletization represents an attractive amendment for growing media, which enhances the plant’s physiological health status. This study proposes alternative recovery methods for paper industry waste with low environmental impact. As the process is developed locally, it should also contribute to reducing energy-related CO2 emissions from transport. Pelletization represents an attractive novelty in the use of DPS as amendment for growing media, which enhances the plant’s physiological health status. This study proposes alternative recovery methods for paper industry waste with low environmental impact. As the process is developed locally, it should also contribute to reducing energy-related CO2 emissions from transport.

Effective Design of a Vacuum Pressure Swing Adsorption Process To Recover Dilute Helium from a Natural Gas Source in a Methane-Rich Mixture with Nitrogen

The conventional method of helium production is a cryogenic process, which is installed downstream of a liquefied natural gas (LNG) plant, where a helium extraction unit (HeXU) would be usually developed as the byproduct unit, due to the high cost of the process. In this study, pressure swing adsorption method accompanied by a relative vacuum condition for the bed regeneration (PVSA) was investigated as an alternative method for recovery of helium from natural gas source. The PVSA design was studied for a continuous product, utilizing zeolite 13X as the adsorbent, through a formerly validated model, for a dilute feed of 1.5 vol % He, mainly comprised of methane in 82.5 vol % accompanied by nitrogen. The impacts of repressurizing medium and equalization steps of the design conditions on the He purity and recovery were investigated. It was revealed that, generally, the bed repressurizing step should be performed by the feed as compared to the product. However, at high space velocities, a combination of the ...

Efficient recovery of recombinant CRM197 expressed as inclusion bodies in E.coli.

CRM197, which retains the same inflammatory and immune-stimulant properties as diphtheria toxin but with reduced toxicity, has been used as a safe carrier in conjugated vaccines. Expression of recombinant CRM197 in E. coli is limited due to formation of inclusion bodies. Soluble expression attempts in Bacillus subtilis, P. fluorescens, Pichia pastoris, and E. coli were partially unsuccessful or did not generate yields sufficient for industrial scale production. Multiple approaches have been attempted to produce CRM197 in E. coli, which has attractive features such as high yield, simplicity, fast growth, etc., including expression of oxidative host, concurrent expression of chaperones, or periplasmic export. Recently, alternative methods for recovery of insoluble proteins expressed in E. coli were reported. Compared to traditional denaturation/refolding, these methods used the non-denaturing solubilization agent, N-lauroylsarkosine to obtain higher recovery yields of native proteins. Based on this work, here, we focused on solubilization of CRM197 from E. coli inclusion bodies. First, CRM197 was expressed as inclusion bodies by high-level expression of recombinant CRM197 in E. coli (126.8 mg/g dcw). Then bioactive CRM197 was isolated from these inclusion bodies with high yield (108.1 mg/g dcw) through solubilization with N-lauroylsarkosine including Triton X-100 and CHAPS, and purified by Ni-affinity chromatography and size-exclusion chromatography. In this study, we present a cost-effective alternative for the production of bioactive CRM197 and compare our recovery yield with yields in other production processes.

Investigation of the effects of pH, aging and scrap tire content on the dissolution behaviors of new scrap tire-concrete mixture structures

Scrap tires represent increasing environmental-pollution problems because they are not biodegradable and require a significantly long time for natural degradation, which is caused by the cross-linked structure of polymeric material and the presence of stabilizers and other additives. Potential use of scrap tires in construction is one of its important application areas and an alternative recovery method. In this study, a series of experiments was conducted to investigate the dissolution behaviors of new concrete-scrap tire mixture structures (brick) under different experimental conditions, such as scrap tire content, aging, and in acidic, basic and natural environments. The obtained results revealed different effects of adding scrap tires, aging and the existence of H+ and OH− on the dissolution of the brick structures. The added sulfuric acid dissolved calcium silicate hydrate, calcium aluminosilicate hydrate and calcium hydroxide of the brick via a naturalization reaction and released more soluble metal ions, particularly calcium, in the solution. Additionally, during acidic corrosion, the porosity significantly increased because calcium was removed from the structure; thus, the transport of other ions was enhanced in the corroded layer by diffusion. However, the addition of sodium hydroxide significantly decreased the solubility of calcium because the calcium silicate hydrate, calcium aluminosilicate hydrate and alkali-silica reaction products precipitated in the presence of calcium. The aging test showed that calcium was substantially dissolved from the brick structure in the first days and slightly slowed down in an acidic medium because the corrosion surface was gradually consumed, which caused the dissolution to occur in the lower part of the corroded region. The increase in scrap tire content increased the surface area and porosity, which resulted in more released calcium and silicon. The study affirmed that the use of granular scrap tires in concrete structures was feasible.

Sobolev Duals for Random Frames and ΣΔ Quantization of Compressed Sensing Measurements

Quantization of compressed sensing measurements is typically justified by the robust recovery results of Candes, Romberg and Tao, and of Donoho. These results guarantee that if a uniform quantizer of step size ź is used to quantize m measurements y=źx of a k-sparse signal xźźN, where ź satisfies the restricted isometry property, then the approximate recovery x# via l1-minimization is within O(ź) of x. The simplest and commonly assumed approach is to quantize each measurement independently. In this paper, we show that if instead an rth-order ΣΔ (Sigma---Delta) quantization scheme with the same output alphabet is used to quantize y, then there is an alternative recovery method via Sobolev dual frames which guarantees a reduced approximation error that is of the order ź(k/m)(rź1/2)ź for any 0<ź<1, if mźr,źk(logN)1/(1źź). The result holds with high probability on the initial draw of the measurement matrix ź from the Gaussian distribution, and uniformly for all k-sparse signals x whose magnitudes are suitably bounded away from zero on their support.

Equilibrium and kinetic studies of ferulic acid adsorption by Amberlite XAD-16

Ferulic acid (FA) is a valuable organic antioxidant, which is contained in various grains and fruits. FA is usually found in water streams of food industry. In order to find an alternative method for recovery of FA, this study was focused in adsorption of FA on XAD-16. The pH effect (2–8) and the contact time effect (1–180min) on adsorption capacity were evaluated. The adsorption capacity was highly dependent on pH and the maximum adsorption capacity was found at pH 3 (133mgFA/g): the adsorption process was well described by the Freundlich isotherm model. Moreover, the adsorption kinetics were conducted by a rapid initial uptake (0–20min), followed by a slow approach to equilibrium (20–90min). The kinetic studies showed that the adsorption rate was well described by the Crank model (deviation<5%), besides that the controlling adsorption mechanism was intraparticle diffusion (Di=7.18×10−8cm2/s). Finally, based on these results, Amberlite XAD-16 has a superior or equal FA adsorption capacity and rapid kinetics than other adsorbents reported in literature, hence this could be considered to be used at industrial scale.

The treatment of TRISO coated particles with CF 4 in a low temperature plasma

An alternative recovery method to the mechanical crushing of off-specification tri-structural-isotropic (TRISO) coated fuel microspheres is demonstrated. It is shown that the inert SiC layer can be completely removed by etching with the active fluorine species from an inductively coupled radio-frequency CF 4 glow-discharge impinging a static bed from the top, at a working pressure of 1 kPa. At this pressure mass transport does not have a rate limiting role and the chemical reaction itself is rate determining. A treatment time of roughly 4 h is required for the conditions reported here.

Reactive Extraction of Caproic Acid Using Tri-n-butyl Phosphate in Hexanol, Octanol, and Decanol

Reactive extraction is an alternative method for recovery of caproic acid as compared to other processes such as distillation, membrane, dialysis, electrodialysis, and so forth. The profound success of reactive extraction has been noted in the recovery of carboxylic acids from dilute solutions. In present paper, reactive extraction of caproic acid using tri-n-butyl phosphate (TBP) (extractant), an organophosphorous compound, in hexanol, octanol, and decanol (diluents) has been studied. Results were presented in terms of distribution coefficients, loading ratio, degree of extraction, and equilibrium complexation constants. Four different models, relative basicity, mass action law, Langmuir, and linear solvation energy relationship (LSER) models, were used to represent the reactive extraction equilibrium for caproic acid−TBP−diluent. The data obtained are useful in understanding the equilibrium characteristics and efficient design of reactive extraction process for the recovery of caproic acid.

Evaluation of bilirubin concentration in hemolysed samples, is it really impossible? The altitude-curve cartography approach to interfered assays

Background Neonatal jaundice might lead to severe clinical consequences. Measurement of bilirubin in samples is interfered by hemolysis. Over a method-depending cut-off value of measured hemolysis, bilirubin value is not accepted and a new sample is required for evaluation although this is not always possible, especially with newborns and cachectic oncological patients. When usage of different methods, less prone to interferences, is not feasible an alternative recovery method for analytical significance of rejected data might help clinicians to take appropriate decisions. Methods We studied the effects of hemolysis over total bilirubin measurement, comparing hemolysis-interfered bilirubin measurement with the non-interfered value. Interference curves were extrapolated over a wide range of bilirubin (0–30 mg/mL) and hemolysis (H Index 0–1100). Results Interference “altitude” curves were calculated and plotted. A bimodal acceptance table was calculated. Non-interfered bilirubin of given samples was calculated, by linear interpolation between the nearest lower and upper interference curves. Conclusions Rejection of interference-sensitive data from hemolysed samples for every method should be based not upon the interferent concentration but upon a more complex algorithm based upon the concentration-dependent bimodal interaction between the interfered analyte and the measured interferent. The altitude-curve cartography approach to interfered assays may help laboratories to build up their own method-dependent algorithm and to improve the trueness of their data by choosing a cut-off value different from the one (−10% interference) proposed by manufacturers. When re-sampling or an alternative method is not available the altitude-curve cartography approach might also represent an alternative recovery method for analytical significance of rejected data.

Sequential process of sorption and incineration for recovery of gold from cyanide solutions: Comparison of ion exchange resin, activated carbon and biosorbent

This study evaluated the gold(I) sorption capacities of various types of sorbents such as ion exchange resin, granular activated carbon, and chemically modified biosorbent. The gold(I)-loaded sorbents were incinerated and the purity of gold in the ashes was compared. As a biosorbent, polyethylenimine modified biomass (PEIB) was prepared by cross-linking the biomass of Corynebacterium glutamicum with polyethylenimine. The sorption capacity of the sorbents of gold(I) ion from the gold(I)–cyanide complex solution were examined by the pH edge and isotherm experiments. The maximum uptakes of gold by ion exchange resin (Amberjet™ 4400), activated carbon, and PEIB were 427.77, 170.64 and 361.76 mg g −1, respectively. To recover gold as a metallic form, the gold(I) sorbed sorbents were incinerated. The recovery efficiency of incineration process and purity of gold in the ash were estimated to be higher than 85.6% and 97.72% for the PEIB, 97.23% and 94.57% for activated carbon and 92.72% and 96.56% for the Amberjet™ 4400, respectively. These sorbent constituents could be burnt out and at the same time, the sorbed Au + could be reduced to Au 0. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) results indicated that the remaining ash contained metallic form of zero-valent gold. These results support that the sequential process comprising of sorption of gold ions followed by incineration of the loaded sorbents could be an alternative method for recovery of metallic zero-valent gold from gold–cyanide complex solution.

Chemical characterization of medium‐chain‐length polyhydroxyalkanoates (PHAs) recovered by enzymatic treatment and ultrafiltration

AbstractBACKGROUND: Medium‐chain‐length polyhydroxyalkanoates (PHAs) are biodegradable polyesters accumulated intracellularly as energy resources by bacterial species such as Pseudomonas putida. The most popular method for PHA recovery is solvent extraction using trichloromethane (chloroform) and methyl alcohol (methanol). An alternative method is enzymatic treatment, which eliminates usage of these hazardous solvents. This research focuses on the characterization of PHAs recovered by enzymatic treatments and ultrafiltration. Comparisons are made with conventional solvent extracted PHA.RESULTS: The purity of PHA in water suspension recovered by enzymatic treatments as analyzed by gas chromatography was 92.6%. Enzymatically recovered PHA was comparable to conventional solvent‐extracted PHA, which had a purity of 95.5%. PHA was further characterized for functional group analysis, structural composition analysis and molecular weight determination. It was found that the molecular weight of the PHA recovered by enzymatic treatment was less than solvent‐extracted PHA, probably due to degradation of the lipopolysaccharide layer. However, functional group and structural composition analyses showed similar results for PHA recovered by both methods.CONCLUSION: PHAs recovered through enzymatic digestion treatment have good comparability with solvent‐extracted PHAs. Thus enzymatic digestion has great potential as an alternative recovery method. Copyright © 2007 Society of Chemical Industry

The Role of Diffusion and Convective Dispersion in Vapour Extraction Process

Abstract Vapour extraction (VAPEX) is a potentially economic process for the recovery of heavy oil and bitumen in Canadian reservoirs, as all of the injected solvent is effectively delivered to the zone of interest. In addition, the process has the potential to sequester greenhouse gases, and is capable of in situ upgrading of heavy oil. The research described in this paper was undertaken to identify the main processes governing the interfacial mass transfer of solvent into bitumen. A number of experiments were carried out in a Hele-Shaw cell, and the results were incorporated into a predictive model. Good agreement between theory and experiment was found when dispersion effects were incorporated into a mass transfer model of the process at identical values of Peclet number. Introduction Vapour extraction (VAPEX) is an alternative method for recovery of heavy oil and bitumen. This technique, which involves a solvent-leaching gravity drainage mechanism, reduces the viscosity of heavy oil by dissolution of a vapourized solvent into the bitumen. VAPEX has recently received a lot of attention from industry, as a promising means for recovery of heavy oil deposits in Canada. The primary drive for this interest is the potential economic attractiveness of the process in comparison to other heavy oil recovery techniques. Unlike steam injection, which is associated with significant heat losses to the media surrounding the wellbore and reservoir, all of the injected solvent by VAPEX is effectively delivered to the zone of interest. This process also appears to provide an alternative method for potential sequestration of greenhouse gases, particularly in regions at close proximity to power plants of northern Alberta. Moreover, experimental work has proved that VAPEX is capable of in situ upgrading of the heavy oil, due to the stripping phenomenon associated with scavenging the lighter end hydrocarbons by the flowing solvent(1). Therefore the costs associated with treatment and processing of produced oil by VAPEX is considerably less than that for other heavy oil production schemes. The prime objective of this paper is to identify the main processes governing the interfacial mass transfer of solvent into bitumen and incorporate those mechanisms into a reliable, predictive model. The estimated recovery rates for laboratory experiments in a Hele-Shaw cell appears to be well within the range of drainage rates predicted by molecular diffusion-based models(1). However, subsequent experiments in sand-packed porous media resulted in drainage rates, considerably higher than predicted values from analytical models(1, 3-5). Earlier researchers had suggested several different factors that might potentially enhance the mass transfer of solvent into the bitumen in the VAPEX process(5). However, no systematic investigation was carried out to understand and/or verify the viability of either of their proposed enhancement mechanisms. In order to have a better understanding of the dispersion and diffusion mechanisms of mass transfer for VAPEX, we began our experiments in a Hele-Shaw cell. Further experiments will be conducted in porous media, once the questions surrounding the process in a Hele-Shaw cell are addressed.

Recovery of Oil from Underground Drill Sites

Abstract A significant quantity of oil is left in reservoirs after conventional oil recovery techniques have been applied. In West Virginia and Pennsylvania alone, this oil has been estimated at over 4.5 billion barrels (0.72 billion m3). Conventional recovery methods are already being used when applicable. But a new recovery method is needed for use in reservoirs that have been abandoned. One alternative method for recovery of the residual oil is known as ‘oil recovery from underground drill site’ This recovery technology is a combination of proven methods and equipment from the petroleum, mining, and civil construction industries. Underground oil recovery can be an economically viable method of producing oil. This has been shown in producing fields, field tests, and feasibility studies. Faced with decreasing domestic oil production, the petroleum industry should give serious consideration to the use of oil recovery from underground drill sites as a safe, practical, and environmentally sensitive alternative method of producing oil from many reservoirs.

Heavy Oil Production By Carbon Dioxide Injection

Abstract Currently, there is a great deal of interest in carbon dioxide for the recovery of both heavy and light oils. This paper deals with an investigation of the efficiency of gaseous carbon dioxide as a recovery agent for moderately viscous oils. The paper gives numerical model results, and compares and contrasts the findings with laboratory and field test observations, pointing out the range of conditions over which carbon dioxide is likely to be effective. The carbon dioxide injection simulator used simulates three- phase flow, and was checked out for numerical dispersion grid effects, material balance, etc. It was then employed for a variety of carbon dioxide injection simulations. The base cases were in qualitative agreement with the reported experimental data. It was found that over the viscosity range of J 10 1000 mPa.s, carbon dioxide was superior to natural depletion, inert gas injection or water flooding, jar oil viscosities above 70 mPa. s. The gain over water flooding was as much as 9 per cell· tiles in oil recovery, being greater for the more viscous crudes. Oil saturation was an important variable, as oil recovery decreased rapidly with a decrease in saturation. Another significant factor affecting ultimate oil recovery was the critical gas saturation. Viscous oils showed a 27% increase in recovery as the critical gas saturation varied from 0 to 10%. The blow down recovery on curtailment 0/ carbon dioxide injection was about 1 percentile; field values are as high as 4 percentiles. Reasons for this discrepancy are outlined. The amount of carbon dioxide left in the reservoir was used as a measure of the efficiency of the process; it was high for low oil saturations, especially for the more viscous oils. An economic analysis of the carbon dioxide injection process showed that the economics are tenuous; a variety of factors in addition to the oil price would determine the economic viability of the process. Introduction Although there is little debate that a significant amount of oil remains held in the ground by current technical and economic constraints, opinion is widespread as to the proper recovery technique or techniques to unlock these reserves. (Infill drilling and a handful of alternative recovery methods, such as thermal, miscible and improved mobility floods, compete for the over 52 billion cubic metres of United States and Canadian oil (&amp;lt;980 Kg/m3) that remains in place. Carbon dioxide injection, as one of these processes, has long been thought of as a miscible process best applied in light oils with densities less than 930 Kg/m3. However, immiscible carbon dioxide flooding as part of the suite of enhanced oil recovery methods being tested may be promising in the case of heavy, moderately viscous oils where carbon dioxide injection improves recovery by lowering oil viscosity and promoting swelling. Deposits of heavy oil total over one-half trillion metres3 in the U.S., Venezuela and Canada. In the U.S. alone, there are over 2,000 heavy oil reservoirs occurring in 1500 fields in 26 states.