Water Gas Research Articles

CFD and Thermomechanical Analysis on Effect of Curved Surface in IC Engine Cylinder Head

Next generation IC engines are designed to achieve high efficiency and high specific power. As a single most design drivingfactor, combustion pressure is increased more than before. This has major impact on the design aspects of cylinder head. Its featuresbecome more delicate to accommodate various elements. Thermal aspects composing of heat generation (by combustion); heat transfer(combustion, cooling water, intake and exhaust gas) makes the design more challenging. Methods to enhance the heat transfer andcontrolling body temperature are discussed by various authors. In this paper a high specific power engine cylinder head is analysedusing coupled field analysis. To enhance heat transfer, inner flame deck surface is configured as a curved surface instead of flat presentin the conventional cylinder heads. Effect of reduction in the cross sectional area due to curvature is analysed against flat surface. It isfound that this new approach reduces the flame deck temperature considerably without compromising the structural strength factors.CFD, steady state thermal and structural analysis has been carried out for four different cases to conclude the extend of effectivenessdue to curvature.

Catalytic Activities of Bimetallic Catalysts for Low Temperature Water Gas Shift Reaction

Catalytic Activities of Bimetallic Catalysts for Low Temperature Water Gas Shift Reaction

Experimental study on high-pressure rheology of water/crude oil emulsion in the presence of methane

ABSTRACTThe crude oil is in most cases accompanied with water and natural gas. For this reason, it is important to understand the rheology of the oil emulsion. There are already many works relating to rheology of the oil/water emulsion. However, studies on high-pressure rheology of water/crude oil emulsion in the presence of CH4 are rare. In this work, light crude oil with characteristics of high wax content, which is typical in Northwest China, was studied. The rheology of water/crude oil emulsion in the presence of CH4 under various conditions were fully studied. The results show that the crude oil emulsion showed obvious characteristics of non-Newtonian fluid at a lower temperature. Before water fraction reached a certain limit, the viscosity increases with the increase of water fraction, when water fraction reaches and exceeds the limit the emulsion viscosity drops with the increase of water fraction. The shear stress–shear rate curves become similar as the increase of temperature, indicating the decreasing effect of temperature on the relation between shear stress and shear rate. When the pressure reaches 8 MPa, the shear stress measured with CH4 in the system surpasses that measured without CH4. At higher pressure, CH4 shows obvious influence on the rheology.

Prediction of water removal rate in a natural gas dehydration system using radial basis function neural network

ABSTRACTNatural gas commonly contains water as a contaminant that can condense to water or form gas hydrates, which causes a range of problems during gas production, transportation, and processing. Therefore, the removal of gas moisture is of great importance. A common and popular method for removing water contamination from natural gas is using solid dehydrators. Calcium chloride is a nonregenerative desiccant to dehydrate natural gas. With continual water adsorption, CaCl2 changes to consecutively higher states of hydration, finally producing a CaCl2 brine solution. This method does not require heating or moving parts. In addition, it does not react with H2S or CO2. These features make this method a popular one for drying natural gas. Nevertheless, precise and simple methods are needed to predict the water content of natural gas dried by calcium chloride dehydrator units. In this study, an intelligent method, called the radial basis function neural network, was incorporated to predict the gas moisture dehydrated by calcium chloride in dehydration units. Modeling was performed under different conditions of a fresh recharge and before recharging. The overall correlation factor of 0.9999 for both the fresh charge and before charging conditions showed that the outputs of the proposed models were in agreement with the experimental data. In addition, the developed models were compared with the previously proposed intelligent models and classic correlations. The comparison showed that the developed model is superior to the previously proposed models and correlations regarding the accuracy of prediction.

Laboratory Studies on Fluid-Recovery Enhancement and Mitigation of Phase Trapping by Use of Microemulsion in Gas Sandstone Formations

Summary One of the challenges in slickwater fracturing of gas reservoirs is post-treatment fluid recovery. More than 60% of the injected fluid remains in the critical near-wellbore region and has a significant negative impact on the relative permeability to gas and well productivity. The trapping of water could be caused by capillary forces around the fractured formation. Commonly available surfactants are added to slickwater to reduce surface tension between the treating fluids and gas. The problem with surfactants is that, upon exposure to the formation, they adsorb on the surface of the rock. The addition of microemulsions to the fracturing fluids can result in a reduction in the pressure needed to displace injected fluids and/or condensate from the formations. This alteration of the fracturing fluid effectively reduces the capillary forces in the near-wellbore region, and in the case of fracturing, the fluids that have been trapped in the region surrounding the fracture. This will result in the removal of water and condensate blocks, as well as the mitigation of phase trapping, and therefore, an increase in permeability to gas. This paper examines the effectiveness of microemulsions in the improvement of fluid recovery by use of sandstone cores with permeability greater than 10 md. Compatibility tests were performed for microemulsions to investigate their compatibility with the condensate and stability upon dilution with brine. One microemulsion showed incompatibility and was excluded from further experiments. Coreflood runs that used 20-in. Bandera sandstone cores with permeabilities greater than 10 md showed that the improvement factor in effective gas permeability because of treatment with microemulsions was up to 2.5, depending on the type of microemulsion. Thermal stability tests were performed on microemulsions, and the results showed stability of the microemulsions at high temperatures up to 400°F. A newly developed microemulsion (Nguyen 2013) that was formulated with a blend of anionic and nonionic surfactants, short-chain alcohol, oil, and water was tested and showed a significant reduction in the surface tension between water and nitrogen gas when compared with mutual-solvent and fluoropolymer-surfactant solutions. Among the tested chemicals, ME-V with a contact angle of 63.4° had the lowest capillary pressure, which makes this microemulsion the best treatment fluid among the four chemicals tested for gas-permeability enhancement and cleanup of the fluid in the near-wellbore region. The resulting capillary pressure for the fracture fluid treated with 0.25 wt% of this chemical in 2 wt% KCl is nearly six times lower than that of the untreated fluid with no microemulsion.

Heat transfer and pressure drop of a gasket-sealed plate heat exchanger depending on operating conditions across hot and cold sides

In a gas engine based cogeneration system, heat may be recovered from two parts: Jacket water and exhaust gas. The heat from the jacket water is often recovered using a plate-type heat exchanger, and is used for room heating and/or hot water supply applications. Depending on the operating conditions of an engine and heat recovery system, there may be an imbalance in the flow rate and supply pressure between the engine side and the heat-recovery side of the heat exchanger. This imbalance causes deformation of the plate, which affects heat transfer and pressure drop characteristics. In the present study, the heat transfer and pressure drop inside a heat exchanger were investigated under varying hot-side and cold-side operating conditions. Thermal efficiency of the plate heat exchanger decreases up to 30% with an operating engine load of 50%. A correction factor for the pressure drop correlation is proposed to account for the deformation caused by an imbalance between the two sides of a heat exchanger.

English

The great social and economic importance of sugarcane makes it critical to understand the responses of the crop to adverse stress. This study was carried out to characterize the morpho-physiological index of sugarcane cultivated under different levels of water replacement with four replicates, corresponding to five levels of water replacement (100, 75, 50, 25 and 0% of soil humidity at field capacity) and either associated or not with a nitrogen source (100 kg ha-1 de N). Leaf area, leaf water potential, gas exchange, and chlorophyll fluorescence were determined at different stages of plant development. Suboptimal maintenance of turgor pressure by water potential reduced the photosynthetically active area of sugarcane submitted to hydric deficit. A water replacement of 75% in association with nitrogen promoted optimal maintenance of the photosynthetic process. Key words: Photosynthetic efficiency, nitrogen supply, water potential.

Study of thermoviscous dissipation on axisymmetric wave propagating in a shear pipeline flow confined by rigid wall. Part II. Numerical study

Axisymmetric acoustic wave propagating in a shear pipeline flow confined by a rigid wall is studied in the two-part paper. The effects of viscous friction and thermal conduction on the acoustic wave propagating in the liquid and perfect gas are respectively analyzed under different configurations of acoustic frequency and shear mean flow. In Part 2 of this paper, comprehensive analysis of the effects of shear mean flow and acoustic frequency on the features (relative phase velocity and attenuation coefficient) of the acoustic wave are numerically addressed in cases of water and perfect gas respectively. Comparisons between the non-isentropic and isentropic models are provided in details. Meanwhile, discussions of the thermoviscous effects on the acoustic wave between water and perfect gas are given.

Feedback regulation of irrigation via soil moisture monitoring and its effects on plant growth and physiology

Currently, 80% of the world's available fresh water resource is used for irrigated agriculture. Growers usually try to ensure profitable crop production rather than considering possible environmental impacts, which can lead to misjudgement of the plant's actual needs and result in under- or over-irrigation. To understand how manual watering influences soil water status, soil moisture sensors were deployed in a representative commercial nursery. By automatically scheduling irrigation according to soil moisture thresholds, this work tries to understand the effects of deficit irrigation (under-irrigation - applying less than full water requirements) on possible growth regulation through changes in leaf water status, gas exchange and plant hormone balance. Tomatoes (Solanum lycopersicum Mill. 'Ailsa Craig') were grown in a peat-based substrate in a controlled environment, and exposed to different irrigation treatments by varying the number of drippers in the pot (1 water deficit, 2 control). Hand-watering in a commercial nursery resulted in significant variation in soil water content that may compromise crop uniformity and quality. In contrast, feedback regulation of irrigation via soil moisture monitoring provides a useful tool to water plants according to their actual water needs, with significantly less variation in soil moisture. Under-irrigating containerised tomato plants significantly reduced evapotranspiration, crop fresh weight, height and leaf area and decreased leaf water potential and stomatal conductance. Although foliar concentrations of the phytohormone abscisic acid (ABA) varied throughout the treatment period, ethylene emission from shoot increased. However, the role of these plant hormones during water deficit requires further experimentation using mutants deficient in these hormones. Although deficit irrigation as applied here limited tomato vegetative growth, further long-term experiments (that measure fruit yield) are needed to evaluate whether automatic irrigation scheduling can be used as a water-saving technique.

K teorii protsessa gidratoobrazovaniia v trubchatom reaktore pri inzhektsii kapel' vody i gaza

K teorii protsessa gidratoobrazovaniia v trubchatom reaktore pri inzhektsii kapel' vody i gaza

Surface modifications of agrowaste biomass for Hg(II) and MeHg(II) removal from aqueous solution, oilfield produced water and natural gas condensate

The removal process of Hg(II) and MeHg(II) from aqueous solution by surface modified agrowaste biomass (AWB) was studied. The surface modifications were carried out by methods of mercerization, oxidative delignification, acid treatment, and biological treatment using laccase. The modifications promoted disruption of AWB structural surfaces and thus changed their physical and chemical properties as well as Hg(II) and MeHg(II) adsorption performances. The adsorption efficiency of Hg(II) was higher than MeHg(II) for all AWB adsorbents. The adsorption capacity of Hg(II) and MeHg(II) for AWB-Pure was 0.97 and 0.17 mmol/g, respectively. The highest adsorption capacity of Hg(II) and MeHg(II) was respectively observed for the AWB-Laccase (0.98 ± 0.04 mmol/g) and AWB-NaOCl/NaOH (0.40 ± 0.07 mmol/g). The adsorption selectivity of modified AWB adsorbents towards Hg(II) and MeHg(II) studied using oilfield produced water and natural gas condensate samples was found to be lower as compared to AWB-Pure, but higher selectivity was observed for other metals. The renewability studies show that the pure and modified AWB adsorbents had similar adsorption performance characteristics. The high Hg(II) adsorption efficiency (η > 90 %) was observed up to the third adsorption cycle, while for the MeHg(II), it decreased after each adsorption–desorption cycle.

Daytime and nighttime wind differentially affects hydraulic properties and thigmomorphogenic response of poplar saplings.

This study tested how wind in daytime and nighttime affects hydraulic properties and thigmomorphogenic response of poplar saplings. It shows that wind in daytime interrupted water balance of poplar plants by aggravating cavitation in the stem xylem under high xylem tension in the daytime, reducing water potential in midday and hence reducing gas exchange, including stomatal conductance and CO2 assimilation. The wind blowing in daytime significantly reduced plant growth, including height, diameter, leaf size, leaf area, root and whole biomass, whereas wind blowing in nighttime only caused a reduction in radial and height growth at the early stage compared with the control but decreased height:diameter ratios. In summary, the interaction between wind loading and xylem tension exerted a negative impact on water balance, gas exchanges and growth of poplar plants, and wind in nighttime caused only a small thigmomorphogenic response.

Modelling equilibrium distribution of carbonaceous ions and molecules in a heterogeneous system of CaCO3–water–gas.

Modelling equilibrium distribution of carbonaceous ions and molecules in a heterogeneous system of CaCO₃–water–gas.

Analysis of multicriteria models application for selection of an optimal artificial lift method in oil production

In the world today for the exploitation of oil reservoirs by artificial lift methods are applied different types of deep pumps (piston, centrifugal, screw, hydraulic), water jet pumps and gas lift (continuous, intermittent and plunger). Maximum values of oil production achieved by these exploitation methods are significantly different. In order to select the optimal exploitation method of oil well, the multicriteria analysis models are used. In this paper is presented an analysis of the multicriteria model's application known as VIKOR, TOPSIS, ELECTRE, AHP and PROMETHEE for selection of optimal exploitation method for typical oil well at Serbian exploration area. Ranking results of applicability of the deep piston pumps, hydraulic pumps, screw pumps, gas lift method and electric submersible centrifugal pumps, indicated that in the all above multicriteria models except in PROMETHEE, the optimal method of exploitation are deep piston pumps and gas lift.

Safety of life activity and environmental friendliness in beet processing department of a beet-sugar factory

The branch of processing of a beet is characterized by a variety of dangerous and harmful production factors. To maintain the optimal values of microclimate in beet processing department carried out installation of systems of ventilation and heating. To implement the protection measures for impacts include the use of low-power equipment; the attenuation of the noise in the way of its propagation by means of sound insulation; maintenance equipment; install equipment on vibration isolation bases. Electrical safety in industrial environments by the appropriate design of electrical installations, technical means and means of protection, organizational and technical measures. For protection against static electricity use of protective grounding. The safe operation of lifting and handling equipment is provided by the audit of the reliability and strength of their structural elements, as well as ropes, lifting devices. To reduce the harmful impact of the use of the Department of toxic substances into the running, you must use individual protection equipment: special clothing, anti-dust respirators. Of technical means of protection used in the supply and exhaust ventilation, are also used cyclones. To protect surface and groundwater from effluent applied field of filtration, aeration tanks, biofilters. The amount of emissions into the atmosphere can reduce the reduction of steam consumption for technological needs. For dust removal in dusty offices with equipment install the cyclone. One of the measures to prevent the explosion is to install explosion protection. For fire in a sugar factory used fire boards, fire hoses, automatic water extinguishing systems, steam and gas fire. All facilities and process plant should be provided with primary fire extinguishing means. Place them in conspicuous places, readily accessible at any time. In addition, the company is required to lay special network of fire water. Thus, security and compliance with of sustainability in this branch of the sugar factory depends on many factors and requires careful control of all processes.

Safety and environmental implications of coal mining

This paper presents an investigation on the global issues associated with coal mining, including frequent accidents, occupational diseases and environmental impacts. These problems are caused by complex geological conditions, lack of technology implementation, human factors, lack of financial investment, and ineffective safety and environmental management. A comparison analysis of mine safety and environmental protection in selected coal producing countries is presented from the perspective of regulations and practices related to coal mining. The results show that comprehensive and stringent regulations, practical policies, and best practices have been developed to enhance coal mining safety and environmental protection in the past decades in coal producing countries. Risk assessment in coal mines is an important part of protecting workers and the environment, which includes three steps: risk identification, risk analysis, and risk evaluation. Some suggestions for controlling and preventing disasters, such as water inrush, coal dust, gas disaster, roof collapse, fire, and subsidence, are proposed for the improvement of mine safety and environmental impacts in coal mines in the future.

Characteristics of Structural Behavior of Unplasticized Polyvinyl Chloride (PVC-U) Pipe Buried Underground

The industrialization and urbanization forced to increase the density of pipelines such as water supply, sewers, and gas pipelines. The materials used for the existing pipe lines are mostly composed of concretes and steels, but it is true that the development for more durable and efficient materials has been continued performed to produce long lasting pipe lines. Recently, underground pipes serve in diverse applications such as sewer lines, drain lines, water mains, gas lines, telephone and electrical conduits, culverts, oil lines, etc. In this paper, we present the result of investigation pertaining to the structural behavior of unplasticized polyvinyl chloride (PVC-U) flexible pipes buried underground. In the investigation of structural behavior such as a ring deflection, pipe stiffness, 4-point bending test, experimental and analytical studies are conducted. In addition, pipe stiffness is determined by the parallel plate loading tests and the finite element analysis. The difference between test and analysis is about 8% although there are significant variations in the mechanical properties of the pipe material. In addition, it was found by the 4-point bending test there is no problem in the connection between the pipes by coupler.

SUSTAINABLE ENERGY: PRODUCER GAS AS AN ENERGY RESOURCE

Global warming and pollution due to Carbon emissions is an immediate worldwide concern. Fossil fuels continue to be a prime source for third world countries. Large Industrialised nations continue to pour pollution into the environment with impunity, expecting CO2 absorption by the forested underdeveloped nations. Replacement of fossil fuels by other carbon neutral and carbon negative technologies is now imperative at a global level. In this regard, Producer gas is proposed as an alternative energy cource. Biogas obtained by bacterial action on waster matter, results in high N and C sludge content after methane production. This sludge can be processed to give Producer Gas. Other crop waste like coconut husk, agricultural wastes and cellulosic wastes could be used directly. The slow reaction times of biogas (methane) production by bacterial action is avoided. The Producer gas can be stored or used directly as a substitute for methane which has hazardous qualities. In the earlyhalf of the 20th century it was piped directly to homes for cooking. Producer or Water gas was a petrol substitute in times of scarcity.

Seismic exploration of the world’s deepest gold and platinum orebodies in South Africa - Overview of the past, present and a look into the future Minerals keynote paper

Without doubt, the geologically complex Witwatersrand Basin in South Africa is by far the most important known gold-producing province. It has produced about one-third of the gold ever mined, worldwide. Gold mining in the goldfields takes place at depths ranging from 500 to 4200 m below surface. Many call the underground workings the 'devil's workplace'. This means that there are an increasing number of technical challenges in exploration and optimizing new resources, with rising costs and reduced effective mine designs. There are about 20 or more gold ore bodies (quartz pebble conglomerates) that have been mined, or are currently in production. Furthermore, the Bushveld Complex of South Africa is estimated to contain about 70% of the world's reserves of platinum group elements. The most important platinum ore bodies are the Merensky Reef and the UG2. This paper presents the past and current research activities on the use and implementations of seismic methods for gold and platinum exploration and deep mine planning and designs. It, particularly, presents a state-of-the-art in seismic design and acquisition, processing, interpretation of the seismic data as well as modelling of strato-structural complexies of the basin using advance techniques. The current challenges and possible future solutions are further discussed with special emphasis on the reflection seismic imaging limitations. For example, reflection seismic data acquired on the surface in the Witwatersrand Basin and Bushveld Complex have wavelengths of approximately 60-100 m, providing vertical seismic resolution of approx. 20 m. Consequently, it is difficult to resolve the top and bottom of thin reefs (~ 1m in thickness) due to seismic wave interference as well as to detect faults with throws less than 20 m. However, gold reefs as thin as 20 cm to 1m are currently the main targets for deep mining and faults that crosscut these reefs with throws as small two meters may present difficulties to deep future mining operations. Recent research work has further demonstrated that some of these minor faults may act as conduits for ingress of water and flammable gas into underground workings. There has been more of hard-rock reflection seismics undertaken in South Africa than anywhere else in the world. Therefore, this paper attempts to answer the following trickier question: Will seismic application in the mining industry in South Africa accelerate or decline in the coming years?

The Energy-Saving and Carbon Emission Analysis of Solar-Assisted Air Source Heat Pump System for Hot Water Supply

The innovation of solar water heating system of students living community in Shanghai Ocean University is illustrated in this paper. A new water heating system including solar, air source heat pumps and gas boiler is established owing to the high energy consumption of original system. The comprehensive energy consumption, carbon emission and operating cost comparison between the original and new system is analysed based on the measured water, power and natural gas consumption. The results show that the comprehensive energy consumption is reduced by about 27.5%, the carbon commission decreased by 6%, and the operating costs reduced by approximately 23.6%, which means the new hot water system is successful.