Optimizing a steam-methane reformer for hydrogen production

Air pollution is a serious problem that increase in almost all countries, including in developed countries. Increasing in air pollution is generally caused by human activity such as transportation. One of dangerous pollutant substances generated by motor vehicles is CO (carbon monoxide) gas. One effort in controlling air pollution is the utilization of green open space in the roadside area. The purpose of this study is to determine the distribution of CO in road side vegetation area and open area. The research was conducted in roadside green belt of Cikampek Highway. Air sampling was conducted to measure the concentration of CO in the distances of 0, 10, and 30 m from green belt area. Concentration of CO was analyzed using a spectrophotometry method. The result showed that vegetation and distance factors significantly affected the distribution of CO gas concentrations.The existance green belt area reduced the distribution of CO pollutant in the vicinity of Cikampek highway. As a result, the plot of vegetation area can effectively reduce the concentration of CO gas by 8.5% compare to open plot area. In this study, the plot of vegetation area at10 and 30 m distances decreased CO concentrations about 14.5 and 23.55%, respectively. In the open plot area, the 10 and 30 m distances from the open plot area decreased CO concentrations by 7.17 and 15.05%, respectively.

In an era in which environmental pollution and depletion of world oil reserves are of major concern, emissions produced by automotive vehicles need to be controlled and reduced. An ideal solution is to switch to a cleaner fuel such as natural gas, which generates cleaner emissions. In addition, control over the in-cylinder air-fuel mixture can be best achieved through a direct-injection mechanism, which can further improve combustion efficiency. This need for cleaner automobiles provides the motivation for this paper’s examination of the use of computational fluid dynamic (CFD) simulations to analyze the concentrations of the exhaust gases produced by a compressed natural gas engine with a direct-fuel-injection system. In this work, a compressed natural gas direct-injection engine has been designed and developed through a numerical simulation using computational fluid dynamics (CFD) to provide an insight into complex in-cylinder behavior. The emissions analyzed in this study were carbon monoxide (CO), nitric oxide (NO) and carbon dioxide (CO2), i.e. the main pollutants produced by natural gas combustion. Based on a stoichiometric mixture, the concentrations of CO and NO were computed using the dissociation of carbon dioxide and the extended Zeldovich mechanism. CO2 was calculated using a mass balance of the species involved in the combustion process. The simulation results were then compared with the experimental data generated by a single-cylinder research engine test rig. A good agreement was obtained with the experimental data for the engine speeds considered for all emissions concentrations.

A new process for synthesis gas by co-gasifying coal and natural gas

The combustion of natural gas reduces fuel cost and generates less emissions of carbon dioxide and particulate matter (PM) than diesel and gasoline. Replacing diesel by natural gas in internal combustion engines is of great interest for transportation and stationary power generation. Dual fuel combustion is an efficient way to burn natural gas in internal combustion engines. In natural gas–diesel dual fuel engines, unburned hydrocarbon emissions increase with increasing natural gas fraction. Many studies have been conducted to improve the performance of natural gas–diesel dual fuel engines and reported the performance of combustion and emissions of regulated pollutants and total unburned hydrocarbon at various engine operating strategies. However, little has been reported on the emissions of different unburned hydrocarbon components. In this paper, an experimental investigation was conducted to investigate the combustion performance and emissions of various unburned hydrocarbon components, including methane, ethane, ethylene, acetylene, propylene, formaldehyde, acetaldehyde, and benzaldehyde, at a low engine load condition. The operating conditions, such as engine speed, load, intake temperature, and pressure, were well controlled during the experiment. The combustion and emissions performance of pure diesel and natural gas–diesel dual fuel combustion were compared. The effect of diesel injection timing was analyzed. The results show that appropriately advancing diesel injection timing to form a homogeneous charge compression ignition (HCCI)-like combustion is beneficial to natural gas–diesel dual fuel combustion at low load conditions. The emissions of different unburned hydrocarbon components changed in dual fuel combustion, with emissions of some unburned hydrocarbon components being primarily due to the combustion of natural gas, while those of others being more related to diesel combustion.

The combustion of natural gas reduces fuel cost and generates less emissions of carbon dioxide and particulate matter than diesel and gasoline. Replacing diesel by natural gas in internal combustion engines is of great interest for transportation and stationary power generation. Dual fuel combustion is an efficient way to burn natural gas in internal combustion engines. In natural gas–diesel dual fuel engines, unburned hydrocarbon emissions increase with increasing natural gas fraction. Many studies have been conducted to improve the performance of natural gas–diesel dual fuel engines and reported the performance of combustion and emissions of regulated pollutants and total unburned hydrocarbon at various engine operating strategies. However, little has been reported on the emissions of different unburned hydrocarbon components. In this paper, an experimental investigation was conducted to investigate the combustion performance and emissions of various unburned hydrocarbon components, including methane, ethane, ethylene, acetylene, propylene, formaldehyde, acetaldehyde and benzaldehyde, at a low engine load condition. The operating conditions, such as engine speed, load, intake temperature and pressure, were well controlled during the experiment. The combustion and emissions performance of pure diesel and natural gas–diesel dual fuel combustion were compared. The effect of diesel injection timing was analyzed. The results show that appropriately advancing diesel injection timing to form a homogeneous charge compression ignition-like combustion is beneficial to natural gas–diesel dual fuel combustion at low load conditions. The emissions of different unburned hydrocarbon components changed in dual fuel combustion, with emissions of some unburned hydrocarbon components being primarily due to the combustion of natural gas, while those of others being more related to diesel combustion.

Carbon monoxide (CO) is poisonous to human because of its nature which is capable to bind to the haemoglobinin blood stronger than oxygen, so that causing toxication and even death. Therefore a sensor to early detect thepresence of CO gas is necessary. ZnO is one of semiconductor materials which widely applied as a sensormaterial. However, ZnO is rarely reported as a CO gas sensor material. In this study, ZnO as a sensor materialhas been synthesized by thermo-oxidation of Zn powder at oxidation temperature variations of 800, 850 and 900ºC. The synthesized ZnO was crushed and compacted to form pellet for sensor chip. The ZnO pellets were thensintered at 500 ºC. The material structures were examined using Scanning Electron Microscope (SEM), X-RayDiffractometer (XRD), and Brunauer-Emmet-Teller (BET) analysis. The sensitivity test towards CO gas wasconducted with the variations in sensing operating temperatures of 30, 50, 100 ºC and variation of CO gas inputconcentration of 10 ppm, 50 ppm, 100 ppm, 250 ppm, and 500 ppm. The sensitivity test results showed that thesensitivity towards CO gas decreased as the oxidation temperature increased. In addition the sensitivity increasedalong with the increasing of the sensing operating temperature and CO gas input concentration. Hence, thehighest sensitivity value was obtained from ZnO material synthesized at 800 ºC due to the highest active surfacearea of 69.4 m2g-1 with CO concentration of 500 ppm and sensor operating temperature of 100 ºC.Keywords: ZnO, thermo-oxidation, CO gas, sensitivity

Hydrothermal synthesis of ZnO nanotubes for CO gas sensing

At Kakogawa Works, steels of low to high carbon contents are produced by the use of LD converter of top and bottom blowing type. Argon and nitrogen has been used for the bottom stirring gas. In response to the recent increase in argon consumption, carbon monoxide (CO) recovered from LD exhaust gas is now being used to replace argon for bottom stirring.By the COSORB® process using a large scale CO gas generating equipment introduced from Kinetics Technology International Corporation, highly purified CO can inexpensively be produced from LD exhaust gas. The COSORB® process is a gas-liquid absorption method using the COSORB® solution, which is a toluen solution of Cu-AlCl4. By the COSORB® method, the gas having the chemical composition suited for bottom blown gas in the BOF can be produced in large enough quantity.The use CO as the bottom blown gas, particular attention should be paid to the CO concentration in the bulb station room where the possibility of CO leakage is present and to clean the pipe line during the non-blowing period.The characteristics of metallurgical reactions in the converter, for examples [O]F and slag (T.Fe) at turn down, are almost the same as those of argon and nitrogen bottom stirring. However, the carbon content in the molten steel is increased by CO rinsing after the oxygen top blowing; in contrast the carbon content is reduced in the case of argon rinsing.This is attributable to the fact that the decarburization reaction does not occur during CO rinsing due to the presence of CO bubble; otherwise the CO decomposition reaction (CO (gas) in CO bubble→C+O) occurs.At Kakogawa Works, the erosion rate of refractory has been reduced by the development and installation of S.A. tuyere (Single Annular tuyere). By the use of CO as the bottom blown gas, mushroom is formed in a similar manner as in the case of argon blowing. The life of the tuyere can be prolonged 20% as compared with the case of argon blowing due to the cooling effect of CO.By the installation of safety devices, it is possible to substitute CO for argon in order to reduce the gas cost.

Carbon monoxide (CO) concentrations, sea-to-air fluxes and microbial consumption rate constants, along with atmospheric CO mixing ratios, were measured in the East China Sea (ECS) in autumn. Atmospheric CO mixing ratios varied from 96 to 256 ppbv, with an average of 146 ppbv (SD = 54 ppbv, n = 31). Overall, the atmospheric CO concentrations displayed a decreasing trend from inshore to offshore stations. The surface water CO concentrations in the investigated area ranged from 0.24 to 6.12 nmol L−1, with an average of 1.68 nmol L−1 (SD = 1.50 nmol L−1, n = 31). The surface water CO concentrations were affected significantly by sunlight. Vertical profiles showed that CO concentrations declined rapidly with depth, with the maximum appearing in the surface water. The surface CO concentrations were oversaturated, with the saturation factors ranging from 1.4 to 56.9, suggesting that the ECS was a net source of atmospheric CO. The sea-to-air fluxes of CO in the ECS ranged from 0.06 to 11.31 µmol m−2 d−1, with an average of 2.90 µmol m−2 d−1 (SD = 2.95µmol m−2 d−1, n = 31). In the incubation experiments, CO concentrations decreased exponentially with incubation time and the processes conformed to the first order reaction characteristics. The microbial CO consumption rate constants in the surface water (KCO) ranged from 0.063 to 0.22 h−1, with an average of 0.12 h−1 (SD = 0.062 h−1, n = 6). A negative correlation between KCO and salinity was observed in the present study.

Distinction of carbon monoxide (CO) gas from other combustible gases (especially from H 2 gas) is difficult using conventional SnO2-based ceramic sensors. Special methods, such as measurements under periodic temperature cycling between 100 and 300 °C, are required for CO gas sensing by SnO2based ceramic sensors [1]. A heterocontact of pand n-type semiconducting ceramics is one type of sensor using an interface [2-5]. For making heterocontacts, sintered ceramics of p-type and n-type semiconductors are physically contacted by pressing. In these sensors, the contact points are open to atmosphere gases due to the surface roughness, and the gas phases can react at the interface. This reaction changes the electrical properties of the interface, so that the devices can be used as gas sensors. In previous experiments, a CuO/ZnO sensor has shown excellent CO gas selectivity and a tunable sensing property by control of the applied bias voltages [5, 6]. The preparation of the ceramic contacts is simple, but these contacts do not provide the quantitative reproducibilities important for industrial gas sensors. To make stable p-n contacts, CuO/ZnO thin films were prepared by the sputtering method. This showed sensing properties for humidity and CO gas similar to those of the ceramic heterocontact, but CO gas sensitivity is not high due to the small open-interface area [7, 8]. In the present study, in order to increase the contact area and improve the reproducibility of the CO gas sensing properties, a ZnO-CuO composite was prepared by infiltration of aqueous solution of copper into porous ZnO, and firing. Microstructure and gas sensitivities for CO and H2 gases were examined for the CuO-infiltrated ZnO ceramics. Powder of ZnO (99.99% purity) was pressed into rectangular bars of 5 x 3 x 15 mm at 98 MPa, and sintered at 700 °C for 3 h. The relative density of the ZnO ceramics was 70-80% of the theoretical value. An aqueous solution of copper was obtained from 99.9% cupric nitrate (Cu(NO3)23H20; Kojundo Chemical). A part of the ZnO ceramics was dipped into 0.7 N cupric solution and fired at 600 °C for 1 h. The firing temperature was determined from the results of differential thermal analysis (DTA) which shows three endothermic peaks at 109 °C, 223 °C and 435 °C. Phases in the sample were confirmed

The present study sought to investigate the formation of carbon monoxide (CO) during aerobic biostabilization (AB) of the organic fraction of municipal solid waste (OFMSW) in forced aerated piles. Understanding the factors influencing CO formation may be important not only for safety, but also for environmental and technical reasons. The objective of the study was to determine the effect of the technical parameters of the piles on the concentration of CO in the process gas during AB of the OFMSW in a full-scale waste treatment system: rate of waste aeration (from 3365 to 12,744 m3∙Mg−1), waste mass loads in the pile (from 391 to 702 Mg), thermal conditions, application of sidewalls as an element of pile bioreactor construction, concentration of O2 and CO2 in the waste piles and the duration of the process from 6 to 9 weeks. The temperature and concentration of O2, CO2, CO, CH4 were measured in each pile at weekly intervals. All six reactors provide stable thermal and aerobic conditions, but the presence of CO was observed, ranging from a few to over 2000 ppm, which demonstrated that ensuring optimum conditions for the process is not sufficient for CO to be eliminated. A moderate, non-linear rise in CO concentration was observed along with a rise in the temperature inside the reactors. Concentrations of CO were not highly correlated with those of O2 or CO2. An increase in waste mass loads increased the CO concentration in waste piles, while application of sidewalls decreased CO concentration. Increasing aeration rate had an influence on CO production, and the highest CO concentrations were noted under air flow rate 5.3 m3·Mg−1·h−1.

We analyzed measurements of the total carbon monoxide (CO) content in the atmosphere in the region of St. Petersburg (59.88°N, 29.83° E; 20 m above sea level) in the period from 1995 to 2009. The aver� age annual behavior for the entire measurement period has a maximum in February-March and a minimum in July with an amplitude of ~20%. In the absence of strong forest fires in the European part of the Russian Federation and Siberia, the annual minimum of the total CO content is usually recorded in August-Septem� ber. In winter 1995-2009 (November-January), there was a decrease in the total CO content with a gradual shift in the maximum of the annual behavior from January (1995-1999) to February (2000-2004) and March (2005-2009). The total CO content in January-February 2009 was ~20% lower than the multiyear average level. Estimates of the linear trend for the maximum, minimum, and average values for the period of 1996- 2009 showed an absence of statistically significant longterm changes in the total CO content. A spectral anal� ysis of data showed that the spectral components with periods of 12, 14, 17, 24, and 46 months are extracted with 80% confidence. It is shown that the irregular component of the time series of the total CO content (cal� culated for the period from May to September) agrees well with data on the areas of the forest fires and on the volume of the burnt forest and that 1999, 2001, 2005, 2007, and 2009 can be considered "background" years with the least numbers of forest fires.

Air pollution, particularly from carbon monoxide (CO) in vehicle emissions, poses a health threat to chronically exposed populations, including traders in traditional markets. Bersehati Market in Manado is a shopping center with high vehicle activity, potentially leading to increased ambient CO concentrations. This study aimed to analyze the non-carcinogenic environmental health risks due to CO gas exposure among traders at Bersehati Market. This observational study with an Environmental Health Risk Assessment (EHRA) approach was conducted from March to July 2025. Ambient air samples were measured at three different points and times (morning, afternoon, evening) using a Carbon Monoxide Meter, and exposure characteristics (duration, frequency, length) and anthropometric data were collected from 30 purposively selected trader respondents. Risk analysis was performed by calculating the intake and Risk Quotient (RQ) for both real-time and lifetime (70 years) exposure. The measurement results showed an average CO concentration of 348.67 µg/m³, with the highest concentration of 973 µg/m³ at a morning measurement point. However, all concentrations remained below the threshold set by Indonesian Government Regulation No. 41 of 1999 (30,000 µg/m³). The average real-time intake was 0.018 mg/kg/day, while the lifetime intake was 0.009 mg/kg/day. The highest real-time RQ value was 0.02788 and the highest lifetime RQ was 0.03584. Since all RQ values were < 1, this study concludes that, statistically, CO exposure to traders at Bersehati Market does not yet indicate a significant non-carcinogenic health risk, either under current conditions or in long-term projections. Nonetheless, the long daily exposure duration and fluctuating CO concentrations necessitate ongoing vigilance and monitoring.

A blast furnace is a reaction vessel in which iron ore is converted to molten iron. High rate pulverized coal injection (PCI) into a blast furnace (BF) is an existing process that is known to decrease the amount of coke in the ironmaking process. Natural gas co-injection with pulverized coal increases the burnout and devolatilization rates of pulverized coal. Also, hydrogen produced from natural gas combustion is a powerful reducing agent of iron (III) oxide, releasing pure iron that trickles down and is eventually removed through the taphole. Due to the inherent complexity of the blast furnace ironmaking process, numerical simulation can prove to be quite difficult. This paper describes a three step methodology for modeling blast furnace combustion, and its application to a furnace in operation at USSC Hamilton Works.

Detection of trace carbon monoxide (CO) dissolved in an aqueous phase is key for monitoring and optimizing biological and chemical gas conversions. So far, irrespective of the nonequilibrium nature of these conversion processes, because of low water solubility of CO, such detection has been performed indirectly, under the assumption of thermodynamic equilibrium, by the combination of chromatographic measurement of relatively abundant CO in a gas phase and Henry's law. Direct and sensitive detection of dissolved CO under nonequilibrium has not been explored yet. Here, we report the direct, ultrasensitive, and real-time monitoring of nonequilibrium dynamics of CO in an aqueous phase during biochemical conversions by devising miniaturized fluidic reactors with built-in CO-specific optical probes via surface-enhanced Raman spectroscopy. As the sensitive and selective probes, we fabricate ligand-free Au@Pd core-shell nanoparticle monolayers to maximize the Raman signal of single CO in the aqueous phase. We confirm that under equilibrium conditions, aqueous and gaseous CO concentrations estimated by our method are in good agreement with those measured directly and indirectly by gas chromatography (GC). We show that our probe can detect the aqueous CO concentrations as low as ca. 0.01% with high signal reproducibility, which is 200-fold more sensitive than that achieved by infrared spectroscopy. Finally, we successfully observe the nonequilibrium dynamics of the aqueous CO during biochemical reactions, which cannot be sensed by other detection methods including even indirect measurement by GC. We anticipate that our method can be widely applied not only for monitoring of biochemical gas reactions on multiple scales from a large reactor to a single-molecule level but also for molecular imaging of biological systems.