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.

Model Prediction and Optimal Control of Gas Oxygen Content for A Municipal Solid Waste Incineration Process

In the municipal solid waste incineration process,it is difficult to effectively control the gas oxygen content by setting the air flow according to artificial experience.To address this problem,this paper proposes an optimization control method of gas oxygen content based on model predictive control.First,a stochastic configuration network is utilized to establish a prediction model of gas oxygen content.Second,an improved differential evolution algorithm that is based on parameter adaptive and t-distribution strategy is employed to address the set value of air flow.Finally,model predictive control is combined with the event triggering strategy to reduce the amount of computation and the controller's frequent actions.The experimental results show that the optimization control method proposed in this paper obtains a smaller degree of fluctuation in the air flow set value,which can ensure the tracking control performance of the gas oxygen content while reducing the amount of calculation.

Problems of Hazardous Waste Storage Facilities in Coal-fired Power Plants and Countermeasures

The hazardous waste produced by coal-fired power plants are large in quantity and variety. It is important for ecological environment protection to properly store hazardous waste in coal-fired power plants. The environmental management of hazardous waste in coal-fired power plants started late, and there are many problems in the construction and management of their storage facilities. In this paper, taking eight typical coal-fired power plants as examples, the present problems of hazardous waste storage facilities in coal-fired power plants are analyzed, and corresponding countermeasures are put forward to solve the main common problems.

Gasification of Organic Waste:Parameters,Mechanism and Prediction with the Machine Learning Approach

Gasification of organic waste represents one of the most effective valorization pathways for renewable energy and resources recovery,while this process can be affected by multi-factors like temperature,feedstock,and steam content,making the product’s prediction problematic.With the popularization and promotion of artificial intelligence such as machine learning(ML),traditional artificial neural networks have been paid more attention by researchers from the data science field,which provides scientific and engineering communities with flexible and rapid prediction frameworks in the field of organic waste gasification.In this work,critical parameters including temperature,steam ratio,and feedstock during gasification of organic waste were reviewed in three scenarios including steam gasification,air gasification,and oxygen-riched gasification,and the product distribution and involved mechanism were elaborated.Moreover,we presented the details of ML methods like regression analysis,artificial neural networks,decision trees,and related methods,which are expected to revolutionize data analysis and modeling of the gasification of organic waste.Typical outputs including the syngas yield,composition,and HHVs were discussed with a better understanding of the gasification process and ML application.This review focused on the combination of gasification and ML,and it is of immediate significance for the resource and energy utilization of organic waste.

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.

Characteristics of gaseous product from municipal solid waste gasification with hot blast furnace slag

Possibility of combustible gas production from municipal solid waste （MSW） using hot blast furnace （BF） slag has been studied.The objective of this work is to generate combustible gas from MSW using heated BF slag.In this experiment,the thermal stability of the MSW was analyzed by thermogravimetric analysis,and effects of temperature,gasifying agent （air,N2,steam） and BF slag on the gas products were investigated at 600？900 ？C.The thermogravimetric analysis indicates that the weight loss of MSW includes four stages：evaporation of the moisture,combustion of volatile materials,burning of carbon residue and burnout of ash.The contents of the combustible gas increase with increasing temperature,and the lower calorific value （LCV） increases rapidly at 600？900 ？C.It is found that volume fraction of CO,H2 and CH4 at different atmospheres increases in the order N2〈air〈steam.It is believed that BF slag acts as the catalyst and the heat carrier,which promotes the gasification reactivity of MSW.

A power plant for integrated waste energy recovery from liquid air energy storage and liquefied natural gas

Liquefied natural gas(LNG)is regarded as one of the cleanest fossil fuel and has experienced significant developments in recent years.The liquefaction process of natural gas is energy-intensive,while the regasification of LNG gives out a huge amount of waste energy since plenty of high grade cold energy(-160℃)from LNG is released to sea water directly in most cases,and also sometimes LNG is burned for regasification.On the other hand,liquid air energy storage(LAES)is an emerging energy storage technology for applications such as peak load shifting of power grids,which generates 30%-40%of compression heat(-200℃).Such heat could lead to energy waste if not recovered and used.The recovery of the compression heat is technically feasible but requires additional capital investment,which may not always be economically attractive.Therefore,we propose a power plant for recovering the waste cryogenic energy from LNG regasification and compression heat from the LAES.The challenge for such a power plant is the wide working temperature range between the low-temperature exergy source(-160℃)and heat source(-200℃).Nitrogen and argon are proposed as the working fluids to address the challenge.Thermodynamic analyses are carried out and the results show that the power plant could achieve a thermal efficiency of 27%and 19%and an exergy efficiency of 40%and 28%for nitrogen and argon,respectively.Here,with the nitrogen as working fluid undergoes a complete Brayton Cycle,while the argon based power plant goes through a combined Brayton and Rankine Cycle.Besides,the economic analysis shows that the payback period of this proposed system is only 2.2 years,utilizing the excess heat from a 5 MW/40 MWh LAES system.The findings suggest that the waste energy based power plant could be co-located with the LNG terminal and LAES plant,providing additional power output and reducing energy waste.

Analysis of Solid Waste Management and Greenhouse Gas Emissions in México: A Study Case in the Central Region

In this work, an analysis of the generation, composition and management of the urban solid waste in Mexico and its relation to greenhouse gas emissions is described;as well a case study in Morelos, a state in the central region of the country. Data were collected from the scientific literature and existing data bases at state and national levels. In addition, the emissions of greenhouse gas were calculated for a period of 14 years, using the Intergovernmental Panel on Climate Change (IPCC) methodology. The municipal solid waste data collected from 1998 to 2012 reveal an increase in the amount of waste generated in Mexico and in Morelos (38% and 43%, respectively), which have been influenced by the urbanization process and the population increase. According to the official data, the composition of the urban solid waste in Mexico, is mostly organic matter (50%), represented by food and garden residues, as well as paper and cardboard (near to 14%). While in Morelos, the percentages of generation for these materials are 44% and 9%, respectively. The management of the urban waste mainly consists of house collection, principally in metropolitan zones and medium and small cities, representing 78.7% in Mexico and 89.2% in Morelos. The second way to eliminate the solid wastes is open burning (mostly in semi-urban and rural areas), representing 14.5% and 6.7% for Mexico and Morelos, respectively. During this period, the nationwide greenhouse gas emissions derived from solid waste management (SWM) increased by 180%, while in Morelos, an increase of 42.5% was calculated. Thus, the population increment and urbanization process were correlated with the rise in the amount of residues generated in Mexico and Morelos.

Technical and Economic Aspects and Experience from 6 Years of Operating the Technology Using the Waste Heat from the Exhaust Gases of Heat Sources and 3 Years of Operating a Heating Plant in an Autonomous, Island Regime

This article is focused on technical and economic evaluation of more than 6-years experiences of operating the Waste Heat Recovery technology—the manner and system of flue gas processing generated in the combustion process in heat & power plants, cogeneration units, etc., which burn the gaseous fuel, primarily natural gas, or methane, biogas, geothermal gas, or other gaseous mixtures containing hydrogen. The solution proposes a more effective and non-traditional use of gaseous fuel for heating, the flue gases of which are processed in order to extract additional utilisable heat, with potential elimination of CO2 from them. Deploying of the heating plant in an island regime (OFF-GRID) enables definition of the benefits brought by the 3 years of operational experience and presents visions for the future offering the possibility to utilise the support energy services at the municipal as well as regional level.

Determination of thermal parameters for waste liquid and gas fluidized-bed incinerator

Equations are established for calculation of dense and dilute phase zone combustion temperatures, quantity of auxiliary fuel and thermal efficiency for a fluidized bed incinerator with coal burnt as auxiliary fuel, waste liquid burnt in dense phase zone and waste gas burnt in dilute phase zone while there is a heat transfer, thereby providing theoretical basis for design of waste liquid and gas fluidized bed incinerators.

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.

Model for Assessment Evaluation of Methane Gas Yield Based on Hydraulic Retention Time during Fruit Wastes Biodigestion

This paper presents an assessment evaluation of methane gas yield using a derived model based on the hydraulic retention time (HRT) of the feed stock (waste fruits) undergoing biotreatment in the digester. The derived model;γ = e(3.5436 α + 2.0259) indicates an exponential relationship between methane yield and the HRT. Statistical analysis of the model-predicted and experimental gas methane yield for each value of HRT considered shows a standard error of 0.0081 and 0.0114% respectively. Furthermore, the correlation between methane yield and HRT as obtained from derived model and experimental results were evaluated as 0.9716 and 0.9709 respectively. Methane gas yield per unit HRT as obtained from derived model and experiment are 0.0196 and 0.0235 (m3kg-1 VS) days-1 respectively. Deviational analysis indicates that the maximum deviation of the model-predicted methane yield from the corresponding experimental value is less than 16%. It was also found that the validity of the model is rooted on the expression 0.2822 ln γ = α + 0.5717 where both sides of the expression are correspondingly approximately equal.

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）.

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.

Regulations and Practice on Flue Gas Denitrification for Coal-Fired Power Plants in China

In China, according to the relative up-to-date regulations and standards, the maincontrol measure for NOX emission of coal-fired power plants is, in principle, low NOXcombustion. However, in recent years, more and more newlyapproved coal-fired plantswere required to install flue gas denitrification equipment. This article expounds if fluegas denitrification is necessary from several aspects, including constitution of NOX, itsimpact to environment, operation ofdeNOXequipment in USA, as wellas the differencein ambient air quality standard between China and World Health Organization. It setsforth themes in urgent need of study and areas where deNOX equipment is necessaryfor new projects, besides a recommendation that the emission standards for thermalpowerplants should be revised as soon as possible in China.

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.

Three-stage pyrolysis–steam reforming–water gas shift processing of household,commercial and industrial waste plastics for hydrogen production

Five common single plastics and nine different household,commercial and industrial waste plastics were processed using a three-stage(i)pyrolysis,(ii)catalytic steam reforming and(iii)water gas shift reaction system to produce hydrogen.Pyrolysis of plastics produces a range of different hydrocarbon species which are subsequently catalytically steam reformed to produce H_(2)and CO and then undergo water gas shift reaction to produce further H_(2).The process mimics the commercial process for hydrogen production from natural gas.Processing of the single polyalkene plastics(high-density polyethylene(HDPE),low-density polyethylene(LDPE),and polypropylene(PP))produced similar H_(2)yields between 115 mmol and 120 mmol per gram plastic.Even though PS produced an aromatic product slate from the pyrolysis stage,further stages of reforming and water gas shift reaction produced a gas yield and composition similar to that of the polyalkene plastics(115 mmol H_(2)per gram plastic).PET gave significantly lower H_(2)yield(41 mmol per gram plastic)due to the formation of mainly CO,CO_(2)and organic acids from the pyrolysis stage which were not conducive to further reforming and water gas shift reaction.A mixture of the single plastics typical of that found in municipal solid waste produced a H_(2)yield of 102 mmol per gram plastic.Knowing the gas yields and composition from the single plastics enabled an estimation of the yields from a simulated waste plastic mixture and a‘real-world’waste plastic mixture to be determined.The different household,commercial and industrial waste plastic mixtures produced H_(2)yields between 70 mmol and 107 mmol per gram plastic.The H_(2)yield and gas composition from the single waste plastics gave an indication of the type of plastics in the mixed waste plastic samples.

Tourism Waste Management in the European Union: Lessons Learned from Four Popular EU Tourist Destinations

From a sustainability perspective, achieving greater efficiencies in environmental waste management is at the heart of current academic discussion on climate change science. Over the last few decades the tourism industry has developed exponentially and is now considered one of the most dynamic economic activities worldwide. Solid waste is a commonly identified and ever increasing aspect of tourism;the improper management of which can lead to substantial and irreversible direct and indirect environmental, economic and social impacts. However, the management of solid waste in tourism dominated island communities is particularly problematic due to climatic conditions, topography, financial restraints, planning issues, changing consumption patterns, transient population, and seasonal variations in solid waste quantity and composition. In addition, there is often a lack of momentum to implement new initiatives and programs as stakeholders involved in the design, construction and operation of tourist resorts have conflicts of interest. Using information gathered from key informant interviews, participation observations and literature reviews, this article appraises current waste management practices in four European tourist destinations, namely: Mallorca, Tenerife, Kefalonia and Rhodes. Findings indicate that, although there are signs of compliance with global best practice, a variety of locally-based measures need to be implemented to enhance sustainability.

Combustion Characteristics of Solid Refuse Fuels from Different Waste Sources

In the production(as co-fuel or alone)of solid refuse fuel(SRF),knowledge about the characteristics of the raw materials is required for an ecofriendly and effective combustion process.SRFs are commonly produced by drying combustible waste and removing incombustible matter,resulting in a higher combustibility as compared to the original waste.However,the characteristics of SRFs may highly vary depending on where and from which materials they were produced.Thus,we investigated the characteristics of various SRFs using thermogravimetric analysis(TGA).As a TGA sample is commonly small,on the scale of milligrams,and,unlike homogeneous fuels,SRFs are heterogeneous,individual SRF samples analysed with this method may not represent the bulk material,and sample properties may vary significantly between batches.Therefore,we further performed combustion experiments using a small-scale combustor and sample sizes from 1 to 10 g.To optimise SRF combustor design and determine the SRF characteristics,proximate,elemental,heating value,TG,and differential thermogravimetric analyses were conducted,and weight losses and gas concentrations at different temperatures were measured upon combustion.The lower heating values of the three analysed SRFs were 20,976,16,873,and 19,762 kJ/kg,and their Cl contents were 0.89,0.95,and 1.27 wt.%(legal criterion[Cl]<2.0 wt.%).TGA and small combustor experiments showed that complete weight loss was achieved below 500°C.However,CO was detected until 620°C.

Rapid Laboratory Comparison Method for Identification of Hazardous Wastes from Illegal Oil Refining

[Objective] This paper aimed to study the rapid identification method of hazardous wastes from illegal oil refining,and provide a new theoretical basis and practical basis for shortening the appraisal cycle and reducing the cost of identification.[Method] The identified substance and the qualified oil products were diluted by carbon disulfide with a ratio of 1∶100 for the gas chromatographic analysis.According to the corresponding national standard,the oil change indexes,such as the moisture content,viscosity,acid value and mechanical impurities of the identified substance,were measured.[Result] By the comparison between the gas chromatogram spectrograms of the identified substance and the qualified oil,it is found that the main component of the identified substance was the mineral oils.And the test results of oil change index showed that the mineral oil was unqualified.[Conclusion] This method was of great significance to save the cost of appraisal and improve the efficiency of case handling.