Gas Values Research Articles

Analyzing the un-accounted gas causes in Indonesian household gas networks using text analytics

The development and growth process of domestic gas network in Indonesia is one of the Government's efforts towards National Energy Transformation or Zero Net Carbon Emissions by 2060. In its development, a number of challenges have been found to be addressed by the parties concerned. One of the major challenges faced in the development of jargas is the presence of unaccounted gas or gas losses, which is an unknown amount of gas, such as, for example, the value of un-acccounted gaseous gas in 2022 in a region reaches an average of -24,55%. The size of the UAG (Un-Accounted Gas) value needs to be known by the parties, so research is carried out using operational data such as a monthly report containing free text with the method of text analytics. Text analytics is used to perform Analysis to find out the factors causing the occurrence of value of UAG in Jargas. The analysis uses a number of Phyton-supported tools, including Anaconda, and Power BI. The data analysis uses 3,584 word strings, with 42 UAG cause variables, then extracted into 60 Tokens or keywords, then performed the analysis on 52 unique tokens, then focused on 19 main tokens. The results of the analysis showed that -24,55% of UAG causes are due to leakage (15,56%), third-party activity (3.52%), un-registered thieves (2,22%), gas-in activity (1,99%), and accuracy of measuring instruments (1,42%).

Invasive mechanical ventilation in cardiogenic shock complicating acute myocardial infarction: A contemporary Danish cohort analysis

PurposeInvasive mechanical ventilation (IMV) is widely used in patients with cardiogenic shock following acute myocardial infarction (AMICS), but evidence to guide practice remains sparse. We sought to evaluate trends in the rate of IMV utilization, applied settings, and short term-outcome of a contemporary cohort of AMICS patients treated with IMV according to out-of-hospital cardiac arrest (OHCA) at admission. MethodsConsecutive AMICS patients receiving IMV in an intensive care unit (ICU) at two tertiary centres between 2010 and 2017. Data were analysed in relation to OHCA. ResultsA total of 1274 mechanically ventilated AMICS patients were identified, 682 (54%) with OHCA. Frequency of IMV increased during the study period, primarily due to higher occurrence of OHCA admissions. Among 566 patients with complete ventilator data, positive-end-expiratory pressure, inspired oxygen fraction, and minute ventilation during the initial 24 h in ICU were monitored. No differences were observed between 30-day survivors and non-survivors with OHCA. In non-OHCA, these ventilator requirements were significantly higher among 30-day non-survivors (P for all<0.05), accompanied by a lower PaO2/FiO2 ratio (median 143 vs. 230, P < 0.001) and higher arterial lactate levels (median 3.5 vs. 1.5 mmol/L, P < 0.001) than survivors. Physiologically normal PaO2 and pCO2 levels were achieved in all patients irrespective of 30-day survival and OHCA status. ConclusionIn the present contemporary cohort of AMICS patients, physiologically normal blood gas values were achieved both in OHCA and non-OHCA in the early phase of admission. However, increased demand of ventilatory support was associated with poorer survival only in non-OHCA patients.

Value of brain tissue oxygen saturation in neonatal respiratory distress syndrome: a clinical study.

Neonatal respiratory distress syndrome (NRDS) is one of the major causes of pre-term mortality and morbidity among very-low-birth-weight infants (VLBWI) in low- and middle-income countries (LMIC). Some of the neonates pass away despite admission and care in intensive care units (ICUs). The present clinical trial seeks the application value of elevating oxygen saturation in the brain cells of pre-term neonates born with NRDS. Near-infrared spectroscopy (NIRS) was used to monitor the neonates' microscopic cerebral oxygenation levels do determine hemoglobin concentration in brain tissues, whereas the pulse oximetry was used to measure oxygenation levels among the patients. In statistical analyses, the Analysis of Variance (ANOVA), and descriptive statistics was deployed in the Jupyter Notebook environment using Python language. High saturation of oxygen in the brain tissues result in important biological and physiological processes, including enhanced oxygen supply to cells, reduced severity of NRDS, and balancing oxygen demand and supply. The correlations of oxygen saturation with systemic saturation of oxygen, the saturation of oxygen in brain tissues, the association between brain-specific and systemic saturation, and the impact of these outcomes on clinical practices were deliberated. Also, the pH gas values, the saturation of oxygen in neonates' brain tissues, metabolic acidosis, the effect of acid-base balance and cerebral oxygen supply, and the oxygenation of brain tissues and the pH values emerged as important variables of oxygenation of brain tissues in pre-term neonates. Oxygen saturation in brain cells influence vital physiological and biological processes. Balancing acid-base saturation or levels is needed despite the challenging achievement. Oxygenation of brain tissues improve the brain's overall functioning.

Effects of intravenous xylazine versus dexmedetomidine premedication with ketamine-midazolam-isoflurane anaesthesia for castration in horses

The objectives of this research was to study the sedation and anaesthetic characteristics of intravenous xylazine and dexmedetomidine combined with ketamine-midazolam-isoflurane and to evaluate the cardiopulmonary effects during the anaesthetic period. Stallions were premedicated with xylazine (1.1 mg/kg IV) in Group 1 and dexmedetomidine (3.5 µg/kg IV) in Group 2. Sedation quality was evaluated and scored. General anaesthesia was achieved with ketamine (2.2 mg/kg IV) and midazolam (0.1 mg/kg IV) in both groups and anaesthesia was maintained with isoflurane inhalant in fresh oxygen gas flow (6-8 L/min). All the stallions underwent an orchiectomy by the half- closed method. Cardiovascular variables and pulmonary variables were recorded using multi gas vital sign monitor. Anaesthetic parameters, reflex status and quality of muscle relaxation were assessed. After the surgical procedure, recovery was monitored and scored on 6 point scale. Sedation score and quality was clinically better in Group 2. The difference in cardiopulmonary variables was statistically not significant. However, statistically significant changes were noticed between two groups with regard to some blood gas values during the intra-operative and at 15 min post anaesthetic period. Quality of muscle relaxation was better in group 2. Recovery was not significant. Overall quality of anaesthesia and recovery was almost similar in both the groups. In conclusion, both drug combinations produced satisfactory results for castration in the horses studied. In this study, dexmedetomidine at 3.5 µg/kg and xylazine at 1.1 mg/kg sedative doses did not result in much significant changes compared to one other.

Quantifying the economic value of Russian gas in Europe in the aftermath of the 2022 war in Ukraine

This paper examines Russian gas export scenarios to Europe, considering infrastructure, long-term contracts (LTC), and the new geopolitical landscape in Europe. Short-term expectations preclude export growth, while Ukraine transit risks stem from military actions, sanctions, or termination of the transit contract. Export volume may recover in a benign post-conflict resolution, though not to pre-war levels. Available export infrastructure options include the Ukraine transit and the TurkStream pipeline, with a combined capacity of 75 billion cubic meters per annum (bcma), about 50% of Russia's exports in 2021. Gazprom's LTC position will also dictate possible export volume to Europe. Pre-Ukraine war, Gazprom held 135bcma of LTCs with EU buyers. Currently, only 25bcma is active, with the rest terminated or under legal review. Of the remaining LTC, 12bcma faces risk if the Ukraine transit ends in 2025. Considering these issues, we model baseline and counterfactual scenarios with flows from Russia from 0 to 75bcma. Results suggest gas price differences are prominent until 2026 due to a tight global gas market. Beyond 2026, LNG expansion and Europe's decarbonisation commitments lessen the price impact, making Russian gas economically irrelevant. In the context of the war in Ukraine, the divisive issue of Russian gas becomes economically insignificant by mid-decade.

Ventilation Management in a Patient with Ventilation–Perfusion Mismatch in the Early Phase of Lung Injury and during the Recovery

Chest trauma is one of the most serious and difficult injuries, with various complications that can lead to ventilation–perfusion (V/Q) mismatch and systemic hypoxia. We are presenting a case of a 53-year-old male with no chronic therapy who was admitted to the Intensive Care Unit due to severe respiratory failure after chest trauma. He developed a right-sided pneumothorax, and then a thoracic drain was placed. On admission, the patient was hemodynamically unstable and tachypneic. He was intubated and mechanically ventilated, febrile (38.9 °C) and unconscious. A lung CT showed massive non-ventilated areas, predominantly in the right lung, guiding repeated therapeutic and diagnostic bronchoalveolar lavages. He was ventilated with PEEP of 10 cmH2O with a FiO2 of 0.6–0.8. Empirical broad-spectrum antimicrobial therapy was immediately initiated. Both high FiO2 and moderate PEEP were maintained and adjusted according to the current blood gas values and oxygen saturation. He was weaned from mechanical ventilation, and non-invasive oxygenation was continued. After Stenotrophomonas maltophilia was identified and treated with sulfamethoxazole/trimethoprim, a regression of lung infiltrates was observed. In conclusion, both ventilatory and antibiotic therapy were needed to improve the oxygenation and outcome of the patient with S. maltophilia pneumonia and V/Q mismatch.

Effects of Pulsatile and Non-Pulsatile Cardiopulmonary Bypass Techniques in Coronary Artery Bypass Grafting Surgeries on Cerebral Perfusion.

We aimed to evaluate the effects of cardiopulmonary bypass (CPB) machines used in coronary artery bypass grafting surgeries on cerebral perfusion by performing cerebral oximetry monitoring [near-infrared spectroscopy (NIRS)], S100-β protein measurements, and neurocognitive function assessment tests using both pulsatile and non-pulsatile modes. A total of 44 patients, 22 non-pulsatile (Group NP) and 22 pulsatile (Group P), were included in the study. Hemodynamic parameters, arterial blood gas values, NIRS values and blood S100β protein levels were analyzed at five points: pre-induction (T1), initiation of CPB (T2), termination of CPB (T3), end of surgery (T4), and postoperative 24 h (T5). Two different neuropsychological tests were administered to patients in the preoperative and postoperative periods. There were no significant differences between the groups for demographic characteristics such as age, gender, body mass index, aortic cross-clamping, CPB, and operation durations. The mean arterial blood pressure and PaO2 values for the T2 measurements were significantly higher in group NP (P < 0.05). Regional cerebral oxygen saturation (rSO2) (NIRS) values at T3 and T4 were significantly higher in group P (P < 0.05). Serum S100β measurement values at T3 and T5 were significantly higher in group NP than in group P (P < 0.05). Serum S100β protein levels at T3 correlate with rSO2 results. There was no statistically significant difference between the two groups in terms of pH, lactate, glucose, partial pressure of carbon dioxide, and peripheral oxygen saturation values. Despite no difference between the two groups for neurocognitive function tests, we believe that pulsatile perfusion may be more beneficial for cerebral perfusion when S100β protein and NIRS values are considered. Further clinical studies are needed to evaluate the benefits of the pulsatile technique for cerebral perfusion.

中国碳税开征的理论逻辑与政策选择

As a policy tool for reduction of carbon emissions, carbon tax has been implemented in many countries around the world. After “double carbon” strategic goal was put forward, it is the general trend for China to levy carbon tax. On the basis of clarifying the theoretical basis of carbon tax within the framework of political economy, this paper analyzes the nature and structure of China’s carbon tax, and put forwards a policy implementation path for promoting carbon tax collection. The research shows that, based on the negative value theory, carbon tax is a carbon pricing method with neutral fiscal revenue and expenditure; It takes greenhouse gases emitted in the process of social reproduction as the object of levying carbon tax, and the total amount of carbon tax revenue taxed at a certain rate is equal to the total amount of negative value of greenhouse gases; China should pay attention to the coordination of carbon tax, carbon emissions trading and environmental protection tax, and to the reasonable use of carbon tax revenue, actively participate in international cooperation, promote the formation of a reasonable border tax adjustments , and timely and steadily levy carbon tax.

Evaluation of probiotics in the treatment of hypothyroidism in early pregnancy combined with small intestinal bacterial overgrowth.

The aim of this study was to investigate the association between hypothyroidism in early pregnancy and small intestinal bacterial overgrowth (SIBO) and the effect of probiotics. Patients with hypothyroidism in early pregnancy and normal pregnant women during the same period were included in the methane-hydrogen breath test to compare the incidence of SIBO, smoothed curve fit, and differences in clinical symptoms. For those who combined with SIBO, the rate of clinical symptom conversion, thyroid hormones, and changes in associated inflammatory indexes were compared after 21 days of treatment with probiotics on top of conventional levothyroxine sodium tablets. The results are as follows: (1) The incidence of combined SIBO in patients with hypothyroidism in pregnancy was 56.0%, significantly higher than the 28.0% of normal pregnant women during the same period. (2) The highest value of hydrogen plus methane gas in 90 min in pregnancy hypothyroid patients showed a significant negative correlation with FT4 (p < .001, SD = 0.169). (3) Abdominal distension symptoms were significantly increased in both groups after combined SIBO (p = .036, p = .025), and the conversion rate after treatment was 69.2% and 75.0%, respectively. (4) In hypothyroidism, pregnancy combined with SIBO, TSH, and CRP was higher before treatment (p = .001, p = .012) and decreased significantly after treatment (p = .001, p = .008). Hypothyroidism in early pregnancy is associated with SIBO, and probiotic treatment is significantly effective.

Interstage Performance and Power Consumption of a Multistage Mixed-Flow Electrical Submersible Pump in Gas–Liquid Conditions: An Experimental Study

Abstract The performance degradation of electrical submersible pump (ESP) caused by high gas volume fraction (GVF) has always been a common problem in the field of oil and gas production. Experiments are conducted to investigate the gas–liquid performances of pressurization, power, and efficiency of a 15-stage mixed-flow ESP self-designed and manufactured. A calculation method of gas–liquid useful power is proposed based on the hypothesis of isothermal compression, with the relative error of calculated results within ±2% between isothermal compression and polytropic compression. The rapid decrease of useful power is found to be the main reason for the rapid decrease of hydraulic efficiency as the pump-inlet gas volume fraction (IGVF) increases. Moreover, the interstage pressurization deterioration gradually weakens along the increasing direction of stage number. The calculation method of interstage gas volume fraction is proposed, and the gas–liquid pressurization of each booster stage is found to follow the same distribution with the variation of interstage gas volume fraction. Increasing the stage number can efficiently improve the critical gas volume fraction of interstage pressurization deterioration, as well as the pressurization boundary and maximum value of average single-stage gas–liquid pressurization. The prediction correlations of gas–liquid operating conditions of the maximum pressurization and the highest hydraulic efficiency are established, respectively, and the gas–liquid condition range of high-efficiency pressurization is discovered.

Arterial Blood Gas Analysis in Patients with Stridor, and the Impact of Emergency Tracheostomy on It: A Tertiary Care Center Experience.

Comparative evaluation of arterial blood gas in patients with stridor, before and after emergency tracheostomy. The present prospective study was conducted in tertiary care Centre from February 2022 to June 2023 on 42 patients who presented with stridor and underwent emergency tracheostomy in our department. After proper history taking and clinical examination, nonsurgical cause of stridor was ruled out. Patients were then classified on the basis of location of cause of stridor (whether oropharyngeal, hypo-pharyngeal, supra-glottic, glottic or sub-glottic). Immediately an arterial blood gas (ABG) analysis was done, and emergency tracheostomy was performed. Following tracheostomy, ABG analysis was done immediately, after 12h and after 24h. The mean age of presentation of stridor in our study was 65.02 ± 3.23years, with male preponderance (Male: female ratio being 3.66:1). Most common etiology of stridor in our study was glottic carcinoma comprising 50%, and least common etiology of stridor was hypopharyngeal carcinoma, and subglottic stenosis comprising 2.4% each. There was statistically significant normalization of ABG in terms of pH, PO2, PCO2, HCO3. Mean pH, PO2, PCO2, and HCO3 before tracheostomy were 7.31, 74.8, 60.6, and 29.8 respectively. Mean pH, PO2, PCO2, HCO3, immediately after tracheostomy were7.38, 91.3, 48.4, and 27.4 respectively. After 12h of tracheostomy, mean pH, PO2, PCO2, HCO3 were 7.41, 95.4, 42.7, 25.3 respectively. Mean pH, PO2, PCO2, HCO3 24h after emergency tracheostomy were 7.441, 95.5, 42.8, 24.6 respectively. Emergency tracheostomy in stridor patients improves the acid base and ventilatory status, by relieving the obstruction as evidenced by statistically significant improvement in arterial blood gas values, and can be used as a diagnostic tool in upper airway obstruction.

Two-stage fluidized bed gasification enhanced with oxidative pyrolysis for low-tar producer gas from biomass

Oxidative pyrolysis of fuel was adopted to configure an advanced two-stage fluidized bed gasification system, aiming to produce low-tar producer gas efficiently. A series of tests were carried out to investigate the effect of oxygen allocation in supply on gasification of pine chips in terms of both efficiency and producer gas quality. Compared with the case without pre-oxidation, coupling oxidative pyrolysis increased gas volume fraction of CO, CH4, and CnHm while decreasing that of CO2 and H2 in the produced gas. Further analysis showed that adopting oxidative pyrolysis reduced fuel gas yield, but the tar in the produced gas was lighter. The generated tar is easily transformed into small-molecule combustible gas by the catalytic action of hot char, thus increasing the calorific value of product gas. The long-term operation of the pilot plant presents a great steady continuous running with a minimum tar content in the producer gas of 1.3 g/Nm3. The above-mentioned results thus well verified the technical advantage and feasibility of the two-stage fluidized bed gasification with oxidative pyrolysis.

Novel Treatment of Laryngomalacia: A Case Series

Background: Laryngomalacia is a prevalent neonatal condition characterized by the increased pliability of laryngeal tissues, leading to airway obstruction and associated respiratory complications. It necessitates a nuanced approach to diagnosis and management, given its variable clinical presentation and potential for significant morbidity. Objective: This study aims to investigate the clinical presentation, management, and outcomes of neonates with laryngomalacia, focusing on the efficacy of individualized treatment approaches including bronchoscopy, laser ablation, and various ventilation strategies. Methods: This retrospective case series analyzed data from two neonates treated for laryngomalacia at Children Center Hospital Tehran between 2021 and 2022. Inclusion criteria were neonates beyond 28 weeks gestation without congenital abnormalities and with an RDS score ≥8. Exclusion criteria included preterm neonates (&lt;28 weeks), an RDS score &lt;8, and congenital abnormalities. Data collection involved measures such as respiratory assistance, stridor, feeding issues, oxygen requirement, hospital stay duration, ventilation days, gestational age, RDS score, retraction severity, and amniotic blood gas values. Ethical considerations were observed throughout the study. Results: The first neonate, a 29-day-old female with a gestational age of 36 weeks and 5 days, required HFNC and laser ablation, leading to the resolution of stridor and feeding difficulties. Her hospital stay was 46 days. The second neonate, a 16-day-old male born at 38 weeks gestation, experienced complications including VAP and required a more extended treatment course, including intubation, NIV, CPAP, and HFNC, culminating in an 80-day hospital stay. Conclusion: The study highlights the importance of personalized and adaptable treatment strategies in managing laryngomalacia in neonates. The variability in clinical presentations and responses to treatment underscores the need for ongoing research and the development of refined management protocols. A multidisciplinary approach, incorporating timely diagnosis and flexible intervention, is crucial for optimal patient outcomes.

Prediction of Cotton Shell from Sodecoton Behavior in Thermal Conversion and Theoretical Energy Potential

This work focuses on the evaluation of the energy potential of cotton shells from SODECOTON and to predict suitable thermal conversion conditions. To achieve this goal, structural and proximate analyses were performed, while ultimate analysis, flue gas and higher heating value were calculated from models. This study reveals that cotton shells highly contain cellulose, volatile matter, lignin and carbon, which make it suitable for bioethanol, bio-oil/syngas and biochar production via biochemical and thermochemical technologies as well as fuel briquette. Heating value from cotton shell ranging from 17 MJ/kg to 19 MJ/kg, is set in the interval to be used as fuel. From the results, the value of flue gas is within acceptable limits and the pollutant emissions are less than the values of regulated threshold set. The energy potential released is around 1.30 GJ per year, 1.58 × 107 Nm3/year, 1.62 × 104 m3/year, 15.21 × E6 L and 26 × E6 L for annual combustion energy, syngas, methane, bioethanol and bio oil, respectively. Amongst them combustion via fuel briquette is suitable for less developing country such as Cameroon thus, it could supply 40% of cooking energy consumption in Garoua center town and can improve environmental sustainability in company.

Energy Recovery from Municipal Solid Waste through Co-Gasification Using Steam or Carbon Dioxide with Olive By-Products

The valorization of untreated municipal waste (MSW) biochar for energetic uses, through its co-gasification with olive stone (OST) biochar under a steam or carbon dioxide atmosphere, was investigated. The experiments were conducted in a fixed bed unit and a thermal analysis–mass spectrometer system. The thermal behavior, reactivity, conversion, product gas composition, syngas yield and energy potential were determined, while the influence of the fuel’s internal structure, chemical functional groups and operating conditions were examined. The concentrations of H2 and CO2 in the product gas mixture under a steam atmosphere were increased with steam/biochar ratio, while that of CO was reduced. At a steam/biochar = 3 H2 yield, the higher heating value and conversion for the OST were 52.8%, 10.8 MJ/m3 and 87.5%; for the MSW, they were 44.4%, 9.9 MJ/m3 and 51.5%, whereas for their blend, they were 50%, 10.6 MJ/m3 and 76.6%, respectively. Under a carbon dioxide atmosphere, the reactivity and conversion of the OST biochar (84%) were significantly higher as compared with the MSW biochar (50%). The higher heating value of the product gas was 12.4–12.9 MJ/m3. Co-gasification of the MSW with OST (in proportions 30:70) resulted in the enhanced reactivity, conversion, syngas yield and heating value of product gas compared with gasification of solely MSW material.

The fate of carbon dioxide generated by decomposition of the organic matter in the Boom Clay upon heating at 80 °C: The buffering role of carbonates and implications for the geological disposal of heat-emitting waste

Short-term and long-term hydrothermal experiments were performed with the bulk Boom Clay (Rupelian, Belgium) involving all its constituents (organic matter, minerals and water) in order to follow CO2 generation primarily formed by organic matter decomposition at 80 °C, the temperature to be reached in the near-field of a repository hosting heat-emitting radioactive waste. The carbon speciation and isotopic data in the sampled gas, liquid and solid phase served as a base for mass balance calculations and evaluation of the fate of the carbon dioxide in the studied system. The maximum CO2 yields are lower (1.9 mmol CO2/kg clay after 21 days) in the short-term hydrothermal tests as compared to the long-term tests (maximum 13.3 mmol CO2/kg clay after 7 years) thus underestimating the total capacity of the clay to generate CO2. This is supported by still continuous generation of the carboxylic acids, important precursors of the released CO2 gas, after 21 days. The stable isotope data (δ13C and δ18O) confirm that CO2 gas released from the Boom Clay is of organic origin. The early released CO2 gas is isotopically lighter (−22.2 to −23.3‰) than the reference δ13C of the CO2 (g) and isotopically heavier than the parent kerogen (−25.5 ‰) in the undisturbed Boom Clay. The early CO2 gas is likely out of isotope equilibrium with either dissolved inorganic carbon or solid carbonates. However, measured and extrapolated δ13C values of CO2 gas indicate the tendency towards isotope equilibrium between CO2 gas and both dissolved and solid inorganic carbon on the longer runs (up to 7 years). The precipitation of the carbonates and recycling of the organic matter derived CO2 in the carbonates is further supported by elemental chemistry and mass balance calculations. Altogether, our results suggest that the CO2 (g) released by Boom Clay organic matter is buffered by the carbonates (both dissolved and solid) present in Boom Clay. Thus, no net accumulation of CO2 (g) from organic matter is expected.

Environmental Impacts of Emissions Streams Within the Ironmaking in Understanding SOX and NOX Formation Using Factsage Software

The manufacturing process of coke in steel plants, emits SOx and NOx which contributes around 30% of the total environmental pollution. The environmental norms from the Central Pollution Control Board of India may implement stringent norms on steel plants for their emission into its environment. In the present study, fact sage software was used for stimulating and quantifying the emissions like SOX and NOX in volume % by incorporating different possible operating parameters such as – its composition, suction pressure, flow rate, and fuel-to-air ratio. The simulation results were also compared with the plant data. The result showed peak flame temperature increased and also shifted toward a lower mixed gas-to-air-to-fuel ratio, indicating the combustion product at different mixed gas-to-air ratios. At an increased % of coke oven gas in mixed gas at a higher value of the mixed gas to air ratio, the percentage volume of COG was reduced. The new aspect of this work involves using a higher ratio of mixed gas to air, increasing the proportion of COG (carbonaceous gas) in the mixture, reducing the volume of CO2 produced, and increasing the formation of CO and SO2, indicating incomplete burning of hydrocarbons. However, when the COG decreases and the ratio of mixed gas to air increases, it leads to higher emissions of NOX. In the study the CEMS data matches with simulated results.

New green and low-carbon technology for all-sensible heat recovery of converter gas

The smelting process of converter determines the explosive, dusty and intermittent nature of gas itself. Therefore, either the way of water (oxygen converter gas recovery system) or mist spraying (Lurgi-Thyssen system) is usually adopted to treat the converter gas after passing through the vaporization cooling flue for further reducing temperature and removing dust. This will lead to a waste of gas sensible heat resources of approximately 800–1000 °C. In this paper, an all-sensible heat recovery technology for converter gas, that is completely different from the oxygen converter gas recovery and Lurgi-Thyssen system, is proposed and implemented in an actual converter with a capacity of 100 tons. For the implementation, the new process is paralleled with the original Lurgi-Thyssen system, and successfully recovers the waste heat of converter gas through a gas-solid separator and waste heat boiler instead of an evaporative cooler. The main advantages of the all-sensible heat recovery process are reflected in the increased steam yield, the reduced energy consumption and the improved calorific value of converter gas. Obviously, this process can be used to further improve the negative energy consumption level of converter, and is expected to become the development trend of converter gas treatment in the future.

Evaluation of a green methanol production system using the integration of water electrolysis and biomass gasification

For a long time, the development of green shipping has been highly valued by countries and organizations. Biomass gasification-based green methanol is seen as a long-term alternative to conventional shipping fuel to reduce greenhouse gas emissions in the maritime sector. While the operational benefits of renewable methanol as a marine fuel are well-known, its cost and environmental performance depend largely on the production method. In this study, a green methanol production system based on the integration of biomass gasification and water electrolysis is proposed and evaluated via the parametric and thermodynamic analysis methods. The water electrolysis is used to increase the hydrogen content in syngas, thereby increasing the production of methanol. The results show that as the S/C ratio increases, the mass flow rate and the calorific value of product gas, the mole flow rate of methanol decreases. The enhancement of the H2/CO ratio can increase the mole fraction of H2, thereby increasing the methanol yield. The mole flow rate of methanol dramatically increases from 925.0 kmol/h to 3725.2 kmol/h. Additionally, the mole flow rate of methanol in the proposed system is 10776.0 kmol/h, larger than the traditional system of 3603.4 kmol/h. The carbon element conversion rate of the proposed system is 94.6%, higher than the 31.5% of the traditional system. This system can significantly provide an efficient green methanol production method for the shipping sector, while also helping to find a feasible solution for the consumption of renewable energy.

Catalytic hydrolysis of methyl mercaptan and methyl thioether on hydroxyl-modified ZrO2: a density functional theory study.

The purification and removal of organic sulfur from natural gas is conducive to increasing the added value of natural gas and reducing environmental pollution. In this study, the adsorption properties of methyl mercaptan (CH3SH), dimethyl sulfide (C2H6S) and H2O on the surface of hydroxyl-modified ZrO2 were investigated using density functional theory (DFT) calculations. Additionally, a reaction mechanism was proposed for hydroxyl-modified ZrO2 catalyzing the hydrolysis of CH3SH and C2H6S. The chemisorption of H2O molecules on the catalyst surface is attributed to H-O and H-Zr bonds. The chemisorption of CH3SH and C2H6S on the catalyst surface is attributed to Zr-S bonds. Competitive adsorption between the three gases exists only between CH3SH and C2H6S. It reveals the water-resistant properties of hydroxyl-modified ZrO2 in desulfurization. The adsorption energies of the three gas molecules on the hydroxyl-modified ZrO2 surface are in the order of CH3SH - (Zr) > C2H6S - (Zr) > H2O - (OH). The natural hydrolysis of CH3SH and C2H6S is a heat-absorbing process that cannot occur spontaneously. The rate-determining step for CH3SH catalytic hydrolysis is the formation of CH3O. The fracture of CH3SHO is the rate-determining step for C2H6S catalytic hydrolysis. The depletion of the surface hydroxyl groups can be replenished by the dissociation of H2O molecules. Hydroxyl-modified ZrO2 facilitated the hydrolysis process of CH3SH to a greater extent than that of C2H6S. This study provides theoretical guidance for industrial applications and the design of hydroxyl-containing hydrolysis catalysts.