Effects of acid-rock reaction on physical properties during CO_(2)-rich industrial waste gas(CO_(2)-rich IWG)injection in shale reservoirs

"Carbon peaking and carbon neutrality"is an essential national strategy,and the geological storage and utilization of CO_(2)is a hot issue today.However,due to the scarcity of pure CO_(2)gas sources in China and the high cost of CO_(2)capture,CO_(2)-rich industrial waste gas(CO_(2)-rich IWG)is gradually emerging into the public's gaze.CO_(2)has good adsorption properties on shale surfaces,but acidic gases can react with shale,so the mechanism of the CO_(2)-rich IWG-water-shale reaction and the change in reservoir properties will determine the stability of geological storage.Therefore,based on the mineral composition of the Longmaxi Formation shale,this study constructs a thermodynamic equilibrium model of water-rock reactions and simulates the regularity of reactions between CO_(2)-rich IWG and shale minerals.The results indicate that CO_(2)consumed 12%after reaction,and impurity gases in the CO_(2)-rich IWG can be dissolved entirely,thus demonstrating the feasibility of treating IWG through water-rock reactions.Since IWG inhibits the dissolution of CO_(2),the optimal composition of CO_(2)-rich IWG is 95%CO_(2)and 5%IWG when CO_(2)geological storage is the main goal.In contrast,when the main goal is the geological storage of total CO_(2)-rich IWG or impurity gas,the optimal CO_(2)-rich IWG composition is 50%CO_(2)and 50%IWG.In the CO_(2)-rich IWG-water-shale reaction,temperature has less influence on the water-rock reaction,while pressure is the most important parameter.SO2 has the greatest impact on water-rock reaction in gas.For minerals,clay minerals such as illite and montmorillonite had a significant effect on water-rock reaction.The overall reaction is dominated by precipitation and the volume of the rock skeleton has increased by 0.74 cm3,resulting in a decrease in shale porosity,which enhances the stability of CO_(2)geological storage to some extent.During the reaction between CO_(2)-rich IWG-water-shale at simulated temperatures and pressures,precipitation is the main reaction,and shale porosity decreases.However,as the reservoir water content increases,the reaction will first dissolve and then precipitate before dissolving again.When the water content is less than 0.0005 kg or greater than 0.4 kg,it will lead to an increase in reservoir porosity,which ultimately reduces the long-term geological storage stability of CO_(2)-rich IWG.

Synergistic Treatment of Low-concentration Organic Waste Gas by Micro-nano Bubble Coordinated with Peroxymonosulfate

Continuous dynamic experiment was conducted for the treatment of low-concentration organic waste gas with xylene as a representative, using micro-nano bubble and peroxymonosulfate working in synergy. The degradation rule of xylene under different conditions such as the ORP value of the spray liquid, pH value of the spray liquid, liquid-gas ratio of the spray liquid, residence time of xylene, and initial concentration of xylene was investigated. The results showed that at a low concentration, the pH value of the spray liquid had little effect on the degradation rate of xylene. The degradation rate of xylene rose with the increase of the ORP value of the spray liquid, the liquid-gas ratio of the spray liquid, the residence time of xylene, and the initial concentration of xylene.

Pilot-test about Treatment of Low-concentration Organic Waste Gas Using a Fixed Biological Bed

[ Objective] The study aims to discuss the feasibility of using a fixed biological bed to treat low-concentration organic waste gas. [ Method] A fixed biological bed was used to treat low-concentration organic waste gas from a phosphate workshop, and then the waste gas treated was assessed by human sense of smell to determine the most economical empty bed contact time, thereby verifying the feasibility of using a fixed biolog- ical bed to treat low-concentration organic waste gas. [Result] When empty bed contact time was 60 s, the smell of the treated waste gas was acceptable, and COD value of recycled water in the fixed biological bed was essentially unchanged. It proved that organic load of the waste gas was consumed by microorganisms within 60 s. [ Conclusion] It is feasible to use a fixed biological bed to treat Iow-concantration organic waste gas from a phosphate workshop.

Degraded Characteristics of Absorption Solution of Lampblack Waste Gas by Biological Contact Oxidation Process

We got the sludge from secondary sedimentation tank of wastewater treatment plant. After cultivation by simulating aerobic biological reactor for 30 days,the biofilm system that could degrade the oleaginous materials of absorption solution spraying lampblack waste gas was successfully obtained. From different influent concentration and temperature experiments,it was shown that the degradation efficiency of the oleaginous materials was the most,when the influent concentration and the temperature of the biological contact oxidation reactor were 300 mg/L and35 ℃,especially the effluent concentration and the degradation efficiency of the oleaginous materials was 51 mg/L and 83%. The modified Michaelis-Menten equation was used to analyze the data,and the kinetics parameters were obtained： K_m=（ 164. 867 ± 0. 001） mg/L; vmax=（ 0. 595 ±0. 001） mg/（ L·min）.

Benzene degradation in waste gas by photolysis and photolysis-ozonation： experiments and modeling

The degradation of benzene, a carcinogenic air pollutant, was studied in a gas-phase photochemical reactor with an amalgam lamp emitting ultraviolet light at 185 and 254 nm. Efficient benzene degradation （〉70%） was possible for benzene mass flow rates of up to 1.5 mg.min1. Adding ozone allowed benzene mass flow rates of up to 5 m g.min-1 tobe treated with the same efficiency. In terms of energy consumption, ozone doubles the efficiency of the process. A comprenenslve mecnanisnc simulation model was developed incorporating a chemical kinetics model （62 reactions involving 47 chemical species）, a material balance model incorporating diffusion and flow, a flow velocity model,and a light field model. The model successfully predicted the efficiency of the reactor, generally within 20%, which indicates that the model is sound, and can be used for feasibility studies. The prediction of the reactor efficiency in the presence of ozone was less successful, with systematically overestimated efficiency. Condensation of reaction products in the reactor is thought to be the mare cause of model inaccuracy. Both experimental .data and model predictions show that there is a synergistic effect between ozonation and ultraviolet degradation.

Comprehensive Energy-Saving Technology for RTO Flue Gas Waste Heat Utilization

In the automobile painting workshop,the oven will discharge harmful exhaust gas,the exhaust gas can be reused through the TNV system,the natural gas can meet the emission standard to the atmosphere after burning,and the high temperature gas discharged TNV the system can carry considerable heat.Utilization can effectively improve the economic benefits of the factory.At present,the more mature scheme is to heat the high temperature exhaust gas through the heat exchanger,which can reduce the steam consumption of the factory.Based on the analysis of the comprehensive energy saving content of waste heat utilization of RTO flue gas,this paper hopes to provide some reference and reference for readers.

Experiment Study on the Exhaust-Gas Heat Exchanger for Small and Medium-Sized Marine Diesel Engine

This paper aims to design a special exchanger to recover the exhaust gas heat of marine diesel engines used in small and medium-sized fishing vessels,which can then be used to heat water up to 55°C–85°C for membrane desalination devices to produce fresh water.A new exhaust-gas heat exchanger of fins and tube,with a reinforced heat transfer tube section,unequal spacing fins,a mixing zone between the fin groups and four routes tube bundle,was designed.Numerical simulations were also used to provide reference information for structural design.Experiments were carried out for exhaust gas waste heat recovery from a marine diesel engine in an engine test bench utilizing the heat exchanger.The experimental results show that the difference between heat absorption by water and heat reduction of exhaust gas is less than 6.5%.After the water flow rate was adjusted,the exhaust gas waste heat recovery efficiency was higher than 70%,and the exhaust-gas heat exchanger’s outlet water temperature was 55°C–85°C at different engine loads.This means that the heat recovery from the exhaust gas of a marine diesel engine meets the requirement to drive a membrane desalination device to produce fresh water for fishers working in small and medium-sized fishing vessels.

Gas from human waste

A town in Oxfordshire has become the first in the UK to have biomethane(生物甲烷)gas from human waste piped to their homes for gas central heating and cooking.Up to 200 families in Didcot now receive the gas,via the national gas power system.Head of energy and technology at British Gas,Martin Orrill,said customers wouldn’t notice any difference as the gas is purified to the highest standard and has no smell.The gas is produced at a sewage(污物)treatment works in Didcot.

Performance of two biofilters with neutral and low pH treating off-gases

Two different functional biofilters were carried out and compared for the treatment of off-gas containing multicomponent odors and volatile organic compounds (VOCs) in this study. The effects of pH values and the empty bed retention time (EBRT) on the performance of the bioreactors were studied; and the characteristics of microbial populations in the two biofilters were also determined. The experimental results indicated that the removal effciencies of hydrophilic compounds such as butyric acid and ammonia ...

Development and commercial application of Baosteel sintering flue gas recirculating process

Because of the low temperature, large waste gas volume, high pollutant content, and complicated compositions, waste heat recovery and emission gas treatment of sintering flue gas have always presented a challenge in the steel industry, and this issue has attracted widespread attention both locally and abroad. Recently, based on the first domestic pilot plant and demonstration project, Baosteel has performed a series of innovative research and development investigations on its sintering flue gas recirculating （SFGR） process,in which the system design and optimization, dioxin-related contaminant source suppression, ore matching structure optimization, wear- resistant design of cycling fans and pipelines, high-efficiency dust removal equipment, system control and stable operation strategy, flue gas mixing and switching control, circular hood sealing, oxygen content conditioning, recirculation sintering system process control, and model development have been studied, and a complete set of equipment and technology for the SFGR process has been initially developed. The investigation results suggest that the SFGR process can not only significantly reduce exhaust gas volume and pollutant emissions but also recover low-temperature waste heat and reduce the energy consumption of sintering; therefore, the overall technologies possess great value in energy savings ,pollution emission reduction, and sintering ore quality/yield improvement.

Utilization and recycling of low-temperature waste heat of stainless steel continuous annealing furnace

Stainless steel continuous annealing furnace is mainly used for heat treatment of hot-rolled strip steel.The combustion air will be enabled to heat to 520℃by waste heat recovery system,but the discharge temperature is still up to about 300℃.Owing to with development of global emphasis on energy conservation energy saving and discharge reduction,it's significant to lower the discharge temperature to below 200℃, for the sake of achieving rational use of waste heat resource.Through the analysis of the existing heat recovery system by this study,it is proved that mixing low temperature with flue gas in high temperature standard will increase the capacity of the flue gas and deteriorate the quality of remaining heat resource.In stead of that,increasing the combustion air temperature to 600℃on the basis of stability temperature for the prerequisite of recuperator design,and giving priority to reducing fuel consumption are the better way.The recovery and recycle of low temperature gas are also be introduced.It is demonstrated by the way of setting a secondary recuperator at the exit of the primary recuperator,and using low temperature flue gas to heat the air used for drying the strip steel,the exhuast temperature of flue gas can be reduced to lower than 200℃.At the same time,the steam required for heating air is saved,the energy reserve as high as 2 300 t of standard coal per year.

Preparation of gangue ceramsite by sintering pot test and potential analysis of waste heat recovery from flue gas

Preparation of ceramsite from solid waste based on the sintering process is a new technology and had a high efficiency in improving producing capability, decreasing consumption of liquefied petroleum gas (LPG), and recovering waste heat of flue gas. An experiment sintering gangue ceramsite was conducted in a 25 kg scale sintering pot with a 100 cm height. The combustion characteristics, phase transformation, and the release profile of SO_(2)^(*) (SO and/or SO_(2)) and NO_(x)^(*) (N_(2)O, NO, and/or NO_(2)) of gangue ceramsite during the sintering process were studied by X-ray diffraction analysis, X-ray fluorescence spectrometry, thermogravimetry–differential thermogravimetry–differential scanning calorimetry, and measurement of physical properties of ceramsite and gas components of flue gas. The results showed that the gangue ceramsite had excellent properties, and its compressive strength and water absorption were 8.2–9.6 MPa and 8.9%–9.8%, respectively, far exceeding the requirement of standard (GB/T 17431.1–2010). The ignition temperature of gangue ceramsite was 443 ℃, and the ignition loss was 14.60 mass% at 1000 ℃. Kaolinite and calcite disappeared at 600 and 800 ℃, respectively. Albite disappeared and mullite formed at 1000 ℃. Two peaks of SO_(2)^(*) emissions emerged in the range of 311–346 mg m^(-3) near 500 ℃ of upper layer ceramsite and 420–489 mg m^(-3) near 1000 ℃ of lower layer ceramsite, respectively. NO_(x)^(*) emissions peak emerged in the range of 227–258 mg m^(-3) near 550 ℃ of the upper layer ceramsite, which was related to the oxidation of sulfide and the combustion of LPG. Gangue is a direct heat source for sintering of ceramsite as well. During sintering process, the heat of flue gas above and below 400 ℃ accounts for 55.9% and 30.0% of the all-output heat, respectively, and was potentially used for producing waste-heat steam or electricity as by-products and drying raw materials during its own initial sintering process, which can realize combined mass and heat utilization for the gangue and further reduce the cost of sintered gangue ceramsite.

Analysis on the Characteristics of Environmental Kuznets Curve and Assessment of Air Quality in Qingdao City

[Objective] The aim was to analyze the characteristics of environmental Kuznets curve (EKC) and assess air quality in Qingdao City. [Method] The EKC characteristics of Qingdao from 1996 to 2008 were studied based on air pollutant discharge indices, air pollution indices and economic data from the environmental quality reports and statistics yearbooks of Qingdao, and the air quality of Qingdao City was assessed. [Result] With the increase of GDP per capita, the total discharge of industrial waste gases improved remarkably, and its EKC showed inverted U type. Meanwhile, the discharge of SO2, industrial fumes and industrial dusts decreased on the whole, and the EKC of sulfur dioxide and industrial fumes was close to inverted N type. In addition, air pollution composite index also showed decrease trend, and its EKC showed inverted N type. In recent 13 years, the concentration of SO2, particles and NO2 in ambient air of Qingdao City showed decrease trend on the whole, especially particles. In addition, PM10 has replaced SO2 as the primary pollutant since 2001, and air pollution type has changed from coal smoke pollution to mixed mode pollution of coal smoke and motor vehicle. The mitigation of air pollution in Qingdao City could be attributed to the implementation of industrial waste gas management by the governments of Qingdao City. [Conclusion] The study could provide theoretical foundations for the establishment of environmental policies in Qingdao City.

Preparation of La_(0.9)K_ (0.1)CoO_3 Perovskite Composite Oxide

Two methods for preparing La0.9K0.1CoO3 perovskite composite oxides.traditional solid state reaction method and sol-gel method.were compared.The characteristics of the powders,such as purity.particle diameter,BET surface area,pore diameter,were inrestigated by using TG-DTA,XRD,SEM and BET methods.The experimental results shou that La0.9K0.1CoO3 perorskite composite oxide can be obtained by using the two methods.The purity of La0.9K0.1CoO3 powders can be increased by raising the calcining temperature while the particle diameter increased and BET surface area decreased.At the same calcining temperature,the properties of the La0.9K0.1CoO3 powders synthesized by the sol-gel method are superior to those synthesized by the solid state reaction method.such as purer phase,smaller particle diameter,which can be used as a satisfactory catalyst in diesel waste gas cleaning.

Removal of NO_x and Diesel Soot Particulates Catalyzed byPerovskite-type Oxide La_(0.9)K_(0.1)CoO_3

The catalytic performance of perovskite composite oxide catalyst La0.9 K0.1 CoO3 coated on catalyst supports by traditional solid state reaction method and sol-gel method were investigated by a series of experiments. The restdt shows that the catalytic performance of the La0.9 K0.1 CoO3 perovskite composite oxide catalyst synthesized by sol-gel method is superior to that synthesized by solid state reaction method, having lower ignition temperature of the diesel soot particulates, lower start temperature of NOx treatment, and lower concentration of byproduct CO.

Removal of odors and VOCs in municipal solid waste comprehensive treatment plants using a novel three-stage integrated biofilter:Performance and bioaerosol emissions

A novel three-stage integrated biofilter(TSIBF)composed of acidophilic bacteria reaction segment(ABRS),fungal reaction segment(FRS)and heterotrophic bacteria reaction segment(HBRS)was constructed for the treatment of odors and volatile organic compounds(VOCs)from municipal solid waste(MSW)comprehensive treatment plants.The performance,counts of predominant microorganisms,and bioaerosol emissions of a flill-scale TSIBF system were studied.High and stable removal efficiencies of hydrogen sulfide,ammonia and VOCs could be achieved with the TSIBF system,and the emissions of culturable heterotrophic bacteria,fungi and acidophilic sulfur bacteria were relatively low.The removal efficiencies of different odors and VOCs,emissions of culturable microorganisms,and types of predominant microorganisms were different in the ABRS,FRS and HBRS due to the differences in reaction conditions and mass transfer in each segment.The emissions of bioaerosols from the TSIBF depended on the capture of microorganisms and their volatilization from the packing.The rational segmentation,filling of high-density packings and the accumulation of the predominant functional microorganisms in each segment enhanced the capture effect of the bioaerosols,thus reducing the emissions of microorganisms from the bioreactor.

Spatio-temporal variation of landfill gas in pilot-scale semi-aerobic and anaerobic landfills over 5 years

Variation of CH4, CO2, and O2 concentrations in layers of different depths in semi-aerobic and anaerobic landfills was analyzed over a period of 5 years. The results showed that most of the municipal solid waste became basically stable after 5 years of landfill disposal. In the upper and middle layer, the concentration of CH4 in the semi-aerobic landfill was significantly lower than that in the anaerobic landfill in different landfill periods, while in the lower layer, there was little difference in the CH4 concentration between the semi-aerobic and anaerobic landfills. The average concentration of CH4 and CO2in the anaerobic landfill was always higher than that in the semi-aerobic landfill, while the O2 concentration showed an opposite variation in different landfill periods. This was related to the aerobic reaction of landfill waste around the perforated pipe in the semi-aerobic landfill,which inhibited effective landfill gas generation.

Characterization of a new total heat recovery system using CaCl_(2) as working fluid:Thermal modeling and physical analysis

This paper introduces a kind of open cycle absorption heat wet flue gas heat recovery system,which use CaCl_(2) as the working medium.The system will use the wet heat recovery method and combined with an efficient heat pump system for flue gas as a heat source generator.Through direct contact with the solution in the absorber,the flue gas is going to carry out gas,liquid heat transfer between heat exchanger,realization of sensible heat and latent heat step by step.As the key part of the system,absorber is established by one-dimensional steady-state heat transfer and mass transfer model.This paper uses the finite difference method to model the discrete numerical methods,and an-alyzes the characteristics of heat and mass transfer in the absorber.We obtain the concentration curves of the three kinds of working medium’s temperature and flow along the height direction.We also analyze the influence of CaCl_(2) solution parameters changes on the absorption process,parsing the reason of the temperature change by analyzing the three working medium’s energy flow trend.We found that the temperature change of flue gas is non-monotonic,which decreases gradually in the range of absorption tower height 0-0.9 m,and then increases gradually.The reason for this change is that sensible heat exchange and latent heat exchange exist between flue gas and solution.Although such a change has an impact on the efficiency of the system,it prevents the"white smoke"from condensing in the air,which effectively protects the environment.Compared with conventional LiBr absorption heat pump,the system constructed in this paper has certain advantages in latent heat recovery,flue gas heat energy utilization,energy conservation and emission reduction and economy.

Near carbon‑zero cycle from VOCs capture to carbon fixation

A new technical route of organic matter capture and carbon fixation is proposed in response of the increasingly strict emission standards of volatile organic compounds(VOCs)in petrochemical industry and the Chinese national strategic development goals of carbon peak and carbon neutralization.A closed loop from raw materials to adsorbents for gas treatment can be achieved by two key technical characteristics:(1)construct a new mesoporous adsorbent with complete desorption and regeneration function by carbon nanotubes(CNTs);(2)convert gaseous organic matter which cannot be recycled in liquid/gas state to CNTs.It realizes the resource integration of"turning waste into treasure"and maximizes the carbon emission reduction effect of waste gas treatment process without consuming extra precious fossil fuel,compared with the traditional technologies of VOCs treatments,including combustion or catalytic oxidation.What’s more,the increase in supply of various green electricity is expected to change the current situation of large investment and heavy cost burden of environmental protection technology,and make a great contribution to the national carbon peak and carbon neutrality policy.