Multi Gas Research Articles

Effect on Environment by Burning Different Agricultural Waste

Many of the developing countries produce huge quantities of agro residues but they are used inefficiently causing extensive pollution to the environment. The major residues are rice husk, coffee husk, coir pith, jute sticks, bagasse, groundnut shells, mustard stalks and cotton stalks. The objective was to analyze the burning characteristic of paddy straw briquettes, cotton plant waste, corn sticks, saw dust briquette, wood and paddy straw, these were burnt and combustibles percentage, CO (ppm) and NO (ppm) were noted by multi gas analyzer. By analyzing the flue gases coming out during burning of these fuels, then plotting the graph of different parameters like combustibles, CO and NO which were obtained during burning of fuels with respect to time. Also the ash content left after burning was recorded. On combining all these parameters briquettes proves out to be clean source of energy, briquettes burn slowly giving out a constant amount of heat and less amount of combustibles as compared to other agricultural residue.

Multigas sensors for the quality control of spice mixtures

Spices have an important impact on daily aliment. Changes of their quality resulting in far reaching consequences in different foodstuffs and imply financial losing and even health hazard. In this study it is demonstrated that application of two different portable multi gas sensors (electronic nose and ion mobility spectrometer) supported by multivariate data analysis can contribute to ensure quality control of spice mixtures and to find out product adulteration. Headspace above spice mixtures for sausages and saveloy and product counterfeitings was investigated by a metal oxide based electronic nose (e-nose of KAMINA-type). Linear discriminant analysis (LDA) of sensor resistivity data was performed for differentiation. Simultaneously an ion mobility spectrometer (IMS) was coupled to the emission chamber for detection of gaseous components above spice mixtures. The measured spectra show differences between the two spice mixtures and were discussed using a principal component analysis (PCA). The two multi gas sensors permit discrimination between the types of spice mixtures and can indicate product adulteration. Additionally, a headspace gas analysis by gas chromatography was performed to identify the main volatile components and to prove the chemical basis for the observed differences of the multi gas sensors.

A Study of Downhole Drillable Pulsing Cementing Device with Low Frequency Self-Excited Hydraulic Oscillation and its Field Application

Abstract: Usually we pay more attention on how to improve gas well cementing quality in engineering design and field operations, and there are so many studies on cement agents but few researches on cement slurry injection technology. The field practice proved that conventional cementing technology can not ensure the cementing quality especially in gas well and some abnormal pressure wells. Most of the study is concentrated on cement agents and some cementing aspects such as wellbore condition, casing centralization etc. All the factors analysis on cementing quality has pointed out that a combination of good agents and suitable measurements can improve cementing quality effectively. The essential factor in cementing is to enhance the displacement efficiency, but normal hole condition and casing centralization are the fundamental for cementing only. Pulsing cementing is the technology that it can improve the displacement efficiency especially in reservoir well interval, also it can shorten the period from initial to ultimate setting time for cement slurry or improve thickening characteristics, and then to inhibit the potential gas or water channeling. Based on systematically research, aiming at improving in 7″ liner cementing, where there are multi gas reservoirs in long interval in SiChuan special gas field, well was completed with upper 7″ liner and down lower 5″ liner, poor cementing bonding before this time. So we stressed on the study of a downhole low frequency self-excited hydraulic oscillation pulsing cementing drillable device and its application, its successful field utilization proved that it is an innovative tool, and it can improve cementing quality obviously.

A Study of Downhole Drillable Pulsing Cementing Device with Low Frequency Self-Excited Hydraulic Oscillation and its Field Application

Abstract: Usually we pay more attention on how to improve gas well cementing quality in engineering design and field operations, and there are so many studies on cement agents but few researches on cement slurry injection technology. The field practice proved that conventional cementing technology can not ensure the cementing quality especially in gas well and some abnormal pressure wells. Most of the study is concentrated on cement agents and some cementing aspects such as wellbore condition, casing centralization etc. All the factors analysis on cementing quality has pointed out that a combination of good agents and suitable measurements can improve cementing quality effectively. The essential factor in cementing is to enhance the displacement efficiency, but normal hole condition and casing centralization are the fundamental for cementing only. Pulsing cementing is the technology that it can improve the displacement efficiency especially in reservoir well interval, also it can shorten the period from initial to ultimate setting time for cement slurry or improve thickening characteristics, and then to inhibit the potential gas or water channeling. Based on systematically research, aiming at improving in 7″ liner cementing, where there are multi gas reservoirs in long interval in SiChuan special gas field, well was completed with upper 7″ liner and down lower 5″ liner, poor cementing bonding before this time. So we stressed on the study of a downhole low frequency self-excited hydraulic oscillation pulsing cementing drillable device and its application, its successful field utilization proved that it is an innovative tool, and it can improve cementing quality obviously.

Simulation of Flow Field of Oxygen Lance Gas Jet Utilized for 50 t Converter

Based on the operating conditions of oxygen lance utilized for a 50 t converter in Tangsteel, gas jet flow fields of three types of oxygen lances were simulated by FLUENT software. The influence of lance configuration and lance level on penetrating area was studied through cold model experiment. The results showed that the gas flow velocities of four-hole, variable angle four-hole and five-hole oxygen lances declined rapidly with an increase in gas jet length within 1 m, 1 m and 0.8 m, respectively. Besides, the multi gas streams sprayed from these three lances should be syncretized at 1.6 m, 1.7 m and 1.4 m, respectively. At the highest lance level, the effective penetrating area of these three lances could be 0.255 m 2, 0.385 m 2 and 0.0907 m 2, respectively. It was suggested that the effective penetrating area of variable angle four-hole oxygen lance was the biggest, while that of five-hole oxygen lance was the least. The validity of numerical simulation results was proved through cold model experiment. The lance level was suggested to be controlled in the range of 1 – 1.6 m, 1 – 1.7 m and 0.8 – 1.4 m for the four-hole, variable angle four-hole and five-hole oxygen lances, respectively.

Lean Gasoline Engine Reductant Chemistry During Lean NOx Trap Regeneration

Lean Gasoline Engine Reductant Chemistry During Lean NOx Trap Regeneration

Time Delay for Aerial Ammonia Concentration Measurements in Livestock Buildings

Correct measurements of ammonia concentration in air still present considerable challenges. The high water solubility and polarity can cause it to adsorb on surfaces in the entire sampling system, including sampling lines, filters, valves, pumps and instruments, causing substantial measuring errors and time delays. To estimate time delay characteristics of a Photo Acoustic Multi Gas Monitor 1312 and a Multi Point Sampler continuous measurement of aerial ammonia concentrations at different levels was performed. In order to obtain reproducible data, a wind tunnel was used to generate selected concentrations inside and a background concentration representing the air inlet of the tunnel. Four different concentration levels (0.8 ppm, 6.2 ppm, 9.7 ppm and 13.7 ppm) were used in the experiments, with an additional outdoor concentration level as background. The results indicated a substantial time delay when switching between the measuring positions with high and low concentration and vice versa. These properties may course serious errors for estimation of e.g. gas emissions whenever more than one measuring channel is applied. To reduce the measurement errors, some suggestions regarding design of the measurement setup and measuring strategies were presented.

Optimization of Gas Injection Allocation in a Dual Gas Lift Well System

1. Abstract Optimization problem for oil production in a multi gas lift wells system is discussed. The main problem is to identify allocation of gas injection for each well to obtain maximum total oil production. The gas injection rate is constrained by a maximum limit. Oil production rate is a nonlinear function of gas injection rate, which is unknown explicitly. In existing approaches, the nonlinear function is estimated from empirical or numerical simulation data, by curve fltting using regression method, or estimated by piecewise linear function. We developed here, a mathematical model for gas lift well system, where the ∞uid ∞ow in reservoir and pipes consists of liquid and gas, so the conditions represent two phase ∞ow phenomena. Relationship between gas injection and oil production is given implicitly from the model. We have also developed a computation scheme to solve the optimization problem. Considering complexity of the problem, computation scheme is developed based on genetic algorithms. Our results show quite good estimation for optimum solution. The approach also gives better quality prediction over existing approach, since all computation results come from the model, not from regression or interpolation. 2. Keywords: Gas Lift, Gas Lift Performance Curve, Constrained Optimization, Genetic Algorithm.

MINIMIZATION OF CUTTING FLUIDS ECOLOGICAL IMPACT BY NEAR DRY MACHINING

This paper analyses a new technology for minimizing the use of metalworking fluids (MWF) during the machining process. Despite the fact that near dry machining (NDM) produces almost similar cutting performance to conventional flood supply machining while using much less MWF, for being fully utilized in industry is necessary to research ecological impact of these machining techniques. To take full advantage of minimal quantity lubrication (MQL) technique and expand its applicability, an understanding of its environmental consequences is critical. Thus, in this study, the MWF characteristics were analyzed and their changes occurred during the gear milling process were investigated using a multi gas monitor. Emissions composition and component gases concentrations were investigated in dry cutting (DC), MQL via atomized spray mist, in flood cooling (FC), and in open atmosphere.

Study regarding the microclimatic parameters influence on the welfare of pigs reared in intensive system.

The aim of the present study is to assess the level of the microclimatic parameters in a pig farm of S.C. Romsuintest Peris and to relate it with the pigs’ welfare interpreted on the basis of average daily weight gain (ADWG). It was analyzed the air quality in two pig houses – one with growing pigs and one with finishing pigs. There was established the level of physical air parameters (temperature, relative humidity, light intensity, noises, draught), chemical parameters (ammonia, hydrogen sulphide) and biological ones (aerobic plate count – APC, fungal plate count – FPC, fine air particulates). The modern devices used for this purpose were: Drager Miniwarn multi gas detector (NH3 and H2S concentration analyze), BK 2250 sound meter (noise level) and LM 8010 multifunction (temperature, relative humidity and light intensity recording), as well as classic: air filtration for fine particulate analyze, aerobic and fungal plate count. The researches led to the following conclusions: • The air temperature recorded an exceeding with 9° C in growing pigs’ house and with 7°C in finishing pigs’ house, the relative humidity is exceeded in both houses and the noises level is slightly exceeded in the last one, while the other physical parameters recorded normal values; • The maximum admitted limit of ammonia - 26 ppm - is exceeded with 12 ppm in growing pigs’ house and with 4 ppm in finishing pigs’ house and of hydrogen sulphide - 10 ppm - is exceeded with 5 ppm in both assessed houses. • In growing pigs’ house, the maximum value of CFU for APC was exceeded by 2,78 times and in finishing pigs’ house by 1,88. The values of the other two biological parameters, FPC and air particulates, were found in normal limits; • The inadequate air quality results in poor welfare, fact demonstrated by the significant decreasing of the ADWG – 425 g, reported to the breeds standards: 595 g for Large White and SL 345, 588 g for Landrace

Mercury and halogen emissions from Masaya and Telica volcanoes, Nicaragua

We report measurements of Hg, SO2, and halogens (HCl, HBr, HI) in volcanic gases from Masaya volcano, Nicaragua, and gaseous SO2 and halogens from Telica volcano, Nicaragua. Mercury measurements were made with a Lumex 915+ portable mercury vapor analyzer and gold traps, while halogens, CO2 and S species were monitored with a portable multi gas sensor and filter packs. Lumex Hg concentrations in the plume were consistently above background and ranged up to 350 ng m−3. Hg/SO2 mass ratios measured with the real‐time instruments ranged from 1.1 × 10−7 to 3.5 × 10−5 (mean 2 × 10−5). Total gaseous mercury (TGM) concentrations measured by gold trap ranged from 100 to 225 ng m−3. Reactive gaseous mercury accounted for 1% of TGM, while particulate mercury was 5% of the TGM. Field measurements of Masaya's SO2 flux, combined with the Hg/SO2 ratio, indicate a Hg flux from Masaya of 7.2 Mg a−1. At Masaya's low temperature fumaroles, Hg/CO2 mass ratios were consistently around 2 × 10−8, lower than observed in the main vent (Hg/CO2 ∼ 10−7). Low‐temperature fumarole Hg fluxes from Masaya are insignificant (∼150 g a−1). Ratios of S, C and halogen species were also measured at Masaya and Telica volcanoes. CO2/SO2 ratios at Masaya ranged from 2.8 to 3.9, comparable to previously published values. At Masaya molar Br/SO2 was 3 × 10−4 and I/SO2 was 2 × 10−5, suggesting fluxes of 0.2–0.5 Mg HBr d−1 and 0.02–0.05 Mg HI d−1. At Telica the Br/SO2 ratio was also 3 × 10−4 and the I/SO2 ratio was 5.8 × 10−5, with corresponding fluxes of 0.2 Mg HBr d−1 and 0.06 Mg HI d−1. Gases at both volcanoes are enriched in I relative to Br and Cl, compared to gases from volcanoes elsewhere.

A MINI MULTI-GAS DETECTION SYSTEM BASED ON INFRARED PRINCIPLE

To counter the problems of gas accidents in coal mines, family safety resulted from using gas, a new infrared detection system with integration and miniaturization has been developed. The infrared detection optics principle used in developing this system is mainly analyzed. The idea that multi gas detection is introduced and guided through analyzing single gas detection is got across. Through researching the design of cell structure, the cell with integration and miniaturization has been devised. The way of data transmission on Controller Area Network (CAN) bus is explained. By taking Single-Chip Microcomputer (SCM) as intelligence handling, the functional block diagram of gas detection system is designed with its hardware and software system analyzed and devised. This system designed has reached the technology requirement of lower power consumption, mini-volume, big measure range, and able to realize multi-gas detection.

Multi-gas Mitigation Analysis on Stabilization Scenarios Using Aim Global Model

Non-CO2 gas (CH4, N2O and F gas) emissions account for 25percent of all greenhouse gas in the year of2000. Main sources of CH4 and N2O emissions are agriculture-related activities such as enteric fermentation, paddy rice cultivation, soil management. A recursive dynamic CGE (Computer General Equilibrium) model has been developed to analyze greenhouse gas reduction options including non-CO2 gas abatement technologies. Multi-regional, multisectoral and multi-gas CGE model and simple climate change model simulated long-term climate stabilization emission path. Preliminary results showed that multi gas mitigation options including CH4 and N2O abatement technologies will reduce GDP loss more than CO2 only mitigation options for long-term climate stabilization, even though CO2 mitigation options will reduce not only CO2 emissions but non-CO2 gas emissions simultaneously. It is necessary to collect regional non-CO2 gas data (emission, technology options, and so on) and conduct more sensitivity analysis with computer simulation model to reduce uncertainty of non-CO2 gas.

Exhaust Emission Characteristics of an Un-Modified Diesel Engine Operated on Bio-Diesel Fuels

Among the biomass-based fuels, plant oil esters (bio-diesel) hold good promise as an alternate fuel for compression ignition (CI) engines, especially during periods of diesel shortage. A study on the use of bio-diesels in an unmodified diesel engine was carried out in the Deptt. of Farm Power and Machinery, Punjab Agricultural University, Ludhiana. A commercially available single cylinder 3.67 kW, direct-injection diesel engine was fuelled with bio-diesels made from five different feed stocks, namely, linseed, rice-bran, gobhi sarson (Brassica napur), sunflower and jatropha curcas. The exhaust emission characteristics of these fuels were studied. "Nucon" Multi Gas Analyzer (model MGA) was used to monitor the concentration of combustibles, carbon-monoxide (CO) and oxides of Nitrogen (NO) in the exhaust gases. The combustibleconcentration was found to be in the range of 0.1 to 0.167 % for all the bio diesels studied. However, the oxides of Nitrogen (NO.) was found to be 0.2 to 26% higher as compared to petro-diesel. Among different feed stocks, the sunflower oil based biodiesel had the highest NO. emissions (26% higher). Carbon monoxide emissions of all bio-diesels were observed to be 25 to 45% lower as compared to petro-diesel. The lowest CO emissions were observed for sunflower oil based bio-diesel. Similarly, the combustible emissions for all bio-diesels were observed to be lower as compared to petrol diesel.

Economic Impact Assessment of Alternative Climate Policy Strategies

This paper investigates the world economic implications of climate change policy strategies, especially the evaluation of impacts by an implementation of Clean Development Mechanisms, Joint Implementation and Emissions trading with a world integrated assessment model. Of special interest in this context are the welfare spill over and competitiveness effects that result from diverse climate policy strategies. In particular, this study elaborates and compares multi gas policy strategies and explores the impacts of the inclusion of sinks. Because of the recent decision of an isolated climate policy strategy by the United States of America, we examine the economic impacts of all world regions by a non cooperative and free rider position of the USA. It turns out that Clean Development Mechanisms and Joint Implementation show evidence of improvement in the economic development in the host countries and increase the share of new applied technologies. The decomposition of welfare effects demonstrates that the competitiveness effect including the spill over effects from trade have the strongest importance because of the intense trade relations between countries. Climatic effects have a significant impact within the next 50 years, cause considerable welfare losses to world regions and will intensify if some highly responsible nations like the USA do not reduce their emissions.

Development of a new dynamic chamber system for measuring harmful gas emissions from composting livestock waste

A dynamic chamber system consisting of a chamber covering a composting mixture (3 m in diameter, 2.2 m in height, 13 m3), a ventilator for suction of air into the chamber, and equipment to measure the gas composition and indicate temperature, was developed for evaluation of harmful gas emissions from such livestock waste composting. Fresh air was introduced through the space between the floor and the lower edge of the chamber, and exhaust gas was removed through an outlet placed on top of the chamber. NH3, CH4 and N2O concentrations in exhaust air from the chamber were measured by Infrared Photoacoustic Detector (IPD, multi gas monitor type 1312, INNOVA, Copenhagen, Denmark) at 5 minutes intervals. The system was evaluated with standard gas of NH3, CH4 and N2O. High recoveries of 98.5% (NH3, SD 6.25), 96.6% (CH4, SD 4.03) and 99.5% ( N2O, SD 2.68) were obtained for each gas emission in the chamber over 17-20 min. The measured values of those gases obtained by the IPD method and conventional method at the time of a composting examination of swine waste were measured, and the differences were only a few percent of the total emissions.

Transient multi gas—solid reactions in a bubbling fluidized bed

AbstractA “multimodel” for gas‐solid reactions in a reacting particle has been applied to a bubbling fluidized bed reactor. The particle is tracked and bed and particle variables are determined continuously. The conservation equations of mass and heat with auxiliary relations are solved in an accelerating particle, which may rise or fall. The effects of bulk pressure, velocity and temperature, and particle diameter are studied. Heat and mass transfer coefficients may fluctuate up to 75% and 148% respectively. Doubling the pressure changes hc by 75% and kc by −45%. Increase in pellet diameter reduces both hc and kc.

Modelling of multi gas/solid reactions – effect of structural parameters

AbstractA unified gas/ solid reaction model has been formulated for multi reactions with multi gas and solid species. The transient formulation has been followed by finite‐difference method and subsequent solution via an iterative procedure. The simulation produces intermediate results for concentration profiles of various components and pressure and temperature distribution, in addition to various structural parameters within a reacting pellet. The effect of structural parameters is analysed. The general formulation allows homogeneous and heterogeneous reactions. Solid state processes can also be accommodated.

Partial Casting Method on Water Surface and Preparation of Multi-Channel Saw Chemical Sensor

Surface acoustic wave (SAW) devices can be used as vapor phase chemical sensors. If we make use of SAW devices with high frequency properties and multi-channel structures, highly sensitive and multi gas sensors can be realized. However, it is generally difficult to deposit different gas sensitive films on the propagation paths of monolithic multi-channel SAW devices. This paper describes the new coating method by which several types of gas-sensitive molecular films can be coated on the paths. The method is called partial casting method on water surface. It makes use of the water surface segmented by a trapezoidal frame, and the molecular film spread in the frame is compressed by the vertical movement of the frame and deposited on the substrate placed on the frame top. Several bilayers of dialkyl polyion complex and dimyristoyl phosphatidyl ethanolamine were coated on 36°Y-X LiTaO 3 SAW delay line oscillators, and odor sensor characteristics were successfully measured. It was confirmed from the present experiments that the method can be applicable to fabrication of multi-channel SAW chemical sensors with various kinds of molecular films.

Laryngeal mask and anaesthetic waste gas exposure.

In recent years there has been a growing awareness of the possible hazards caused by anaesthetic gases in operating theatres. The laryngeal mask airway provides an alternative both to tracheal intubation and the face mask although the implications for operating theatre contamination have not been quantified. This paper describes the incidence and magnitude of exposure of theatre personnel to waste anaesthetic gases during laryngeal mask airway anaesthesia. The leakage of anaesthetic gases to the anaesthetist's breathing zone was monitored using a Bruel & Kjaer Multi Gas Monitor, Type 1302 during 50 general anaesthetics employing either spontaneous (n = 24) or controlled (n = 26) ventilation. All patients were anaesthetised with propofol, alfentanil and nitrous oxide. There was no statistically significant association between the amount of anaesthetic gas leakage and ventilation method. The laryngeal mask airway meets occupational safety requirements on nitrous oxide concentrations in the operating theatre environment.