Bench-Scale Testing of Zinc Ferrite Sorbent for Hot Gas Clean-up

Advanced integrated gasification combined cycle （IGCC） power generation systems require the development of high-temperature, regenerable desulfurization sorbents, which are capable of removing hydrogen sulfide from coal gasifier gas to very low levels. In this paper, zinc ferrites prepared by co-precipitation were identified as a novel coal gas desulfurization sorbent at high temperature. Preparation of zinc ferrite and effects of binders on pore volume, strength and desulfurization efficiency of zinc ferrite desulfurizer were studied. Moreover, the behavior of zinc ferrite sorbent during desulfurization and regeneration under the temperature range of 350-400 ℃ are investigated. Effects of binders on the pore volume, mechanical strength and desulfurization efficiency of zinc ferrite sorbents indicated that the addition of kaolinite to zinc ferrite desulfurizer seems to be superior to other binders under the experimental conditions.

Change trend of natural gas hydrates in permafrost on the Qinghai-Tibet Plateau(1960-2050)under the background of global warming and their impacts on carbon emissions

Global warming and the response to it have become a topic of concern in today’s society and are also a research focus in the global scientific community.As the world’s third pole,the global warming amplifier,and the starting region of China’s climate change,the Qinghai-Tibet Plateau is extremely sensitive to climate change.The permafrost on the Qinghai-Tibet Plateau is rich in natural gas hydrates(NGHs)resources.Under the background of global warming,whether the NGHs will be disassociated and enter the atmosphere as the air temperature rises has become a major concern of both the public and the scientific community.Given this,this study reviewed the trend of global warming and accordingly summarized the characteristics of the temperature increase in the Qinghai-Tibet Plateau.Based on this as well as the distribution characteristics of the NGHs in the permafrost on the Qinghai-Tibet Plateau,this study investigated the changes in the response of the NGHs to global warming,aiming to clarify the impacts of global warming on the NGHs in the permafrost of the plateau.A noticeable response to global warming has been observed in the Qinghai-Tibet Plateau.Over the past decades,the increase in the mean annual air temperature of the plateau was increasingly high and more recently.Specifically,the mean annual air temperature of the plateau changed at a rate of approximately 0.308-0.420℃/10a and increased by approximately 1.54-2.10℃in the past decades.Moreover,the annual mean ground temperature of the shallow permafrost on the plateau increased by approximately 1.155-1.575℃and the permafrost area decreased by approximately 0.34×10^(6)km^(2) from about 1.4×10^(6)km^(2) to 1.06×10^(6)km^(2) in the past decades.As indicated by simulated calculation results,the thickness of the NGH-bearing permafrost on the Qinghai-Tibet Plateau has decreased by 29-39 m in the past 50 years,with the equivalent of(1.69-2.27)×10^(10)-(1.12-1.51)×10^(12)m^(3) of methane(CH_(4))being released due to NGHs dissociation.It is predicted that the thickness of the NGH-bearing permafrost will decrease by 23 m and 27 m,and dissociated and released NGHs will be the equivalent of(1.34-88.8)×10^(10)m^(3) and(1.57-104)×10^(10)m^(3)of CH_(4),respectively by 2030 and 2050.Considering the positive feedback mechanism of NGHs on global warming and the fact that CH_(4) has a higher greenhouse effect than carbon dioxide,the NGHs in the permafrost on the Qinghai-Tibet Plateau will emit more CH_(4) into the atmosphere,which is an important trend of NGHs under the background of global warming.Therefore,the NGHs are destructive as a time bomb and may lead to a waste of efforts that mankind has made in carbon emission reduction and carbon neutrality.Accordingly,this study suggests that human beings should make more efforts to conduct the exploration and exploitation of the NGHs in the permafrost of the Qinghai-Tibet Plateau,accelerate research on the techniques and equipment for NGHs extraction,storage,and transportation,and exploit the permafrost-associated NGHs while thawing them.The purpose is to reduce carbon emissions into the atmosphere and mitigate the atmospheric greenhouse effect,thus contributing to the global goal of peak carbon dioxide emissions and carbon neutrality.

CO2 residual concentration of potassium-promoted hydrotalcite for deep CO/CO2 purification in H2-rich gas

Elevated-temperature pressure swing adsorption is a promising technique for producing high purity hydrogen and controlling greenhouse gas emissions. Thermodynamic analysis indicated that the CO in H-rich gas could be controlled to trace levels of below 10 ppm by in situ reduction of the COconcentration to less than 100 ppm via the aforementioned process. The COadsorption capacity of potassiumpromoted hydrotalcite at elevated temperatures under different adsorption（mole fraction, working pressure） and desorption（flow rate, desorption time, steam effects） conditions was systematically investigated using a fixed bed reactor. It was found that the COresidual concentration before the breakthrough of COmainly depended on the total amount of purge gas and the COmole fraction in the inlet syngas.The residual COconcentration and uptake achieved for the inlet gas comprising CO（9.7 mL/min） and He（277.6 mL/min） at a working pressure of 3 MPa after 1 h of Ar purging at 300 mL/min were 12.3 ppm and0.341 mmol/g, respectively. Steam purge could greatly improve the cyclic adsorption working capacity, but had no obvious benefit for the recovery of the residual COconcentration compared to purging with an inert gas. The residual COconcentration obtained with the adsorbent could be reduced to 3.2 ppm after 12 h of temperature swing at 450 °C. A new concept based on an adsorption/desorption process, comprising adsorption, steam rinse, depressurization, steam purge, pressurization, and high-temperature steam purge, was proposed for reducing the steam consumption during CO/COpurification.

Abrupt Summer Warming and Changes in Temperature Extremes over Northeast Asia Since the Mid-1990s: Drivers and Physical Processes

This study investigated the drivers and physical processes for the abrupt decadal summer surface warming and increases in hot temperature extremes that occurred over Northeast Asia in the mid-1990s. Observations indicate an abrupt increase in summer mean surface air temperature （SAT） over Northeast Asia since the mid-1990s. Accompanying this abrupt surface wanning, significant changes in some temperature extremes, characterized by increases in summer mean daily maximum temperature （Tmax）, daily minimum temperature （Train）, annual hottest day temperature （TXx）, and annual warmest night temperature （TNx） were observed. There were also increases in the frequency of summer days （SU） and tropical nights （TR）. Atmospheric general circulation model experiments forced by changes in sea surface temperature （SST）/sea ice extent （SIE）, anthropogenic greenhouse gas （GHG） concentrations, and anthropogenic aerosol （AA） forcing, relative to the period 1964- 93, reproduced the general patterns of observed summer mean SAT changes and associated changes in temperature extremes, although the abrupt decrease in precipitation since the mid-1990s was not simulated. Additional model experiments with different forcings indicated that changes in SST/SIE explained 76% of the area-averaged summer mean surface warming signal over Northeast Asia, while the direct impact of changes in GHG and AA explained the remaining 24% of the surface warming signal. Analysis of physical processes indicated that the direct impact of the changes in AA （through aerosol- radiation and aerosol-cloud interactions）, mainly related to the reduction of AA precursor emissions over Europe, played a dominant role in the increase in TXx and a similarly important role as SST/SIE changes in the increase in the frequency of SU over Northeast Asia via AA-induced coupled atmosphere-land surface and cloud feedbacks, rather than through a direct impact of AA changes on cloud condensation nuclei. The modelling results also imply that the abrupt summer surface warming and increases in hot temperature extremes over Northeast Asia since the mid-1990s will probably sustain in the next few decades as GHG concentrations continue to increase and AA precursor emissions over both North America and Europe continue to decrease.

Modelling and thermodynamic properties of pure CO_(2)and fue gas sorption data on South African coals using Langmuir,Freundlich,Temkin,and extended Langmuir isotherm models

Carbon sequestration in unmineable coal seams has been proposed as one of the most attractive technologies to mitigate carbon dioxide(CO_(2))emissions in which CO_(2)is stored in the microporous structure of the coal matrix in an adsorbed state.The CO_(2)adsorption process is hence considered one of the more efective methodologies in environmental sciences.Thus,adsorption isotherm measurements and modelling are key important scientifc measures required in understanding the adsorption system,mechanism,and process optimization in coalbeds.In this paper,three renowned and reliable adsorption isotherm models were employed including Langmuir,Freundlich,and Temkin for pure CO_(2)adsorption data,and the extended-Langmuir model for multicomponent,such as fue gas mixture-adsorption data as investigated in this research work.Also,signifcant thermodynamics properties including the standard enthalpy change(ΔH°),entropy change(ΔS°),and Gibbs free energy(ΔG°)were assessed using the van’t Hof equation.The statistical evaluation of the goodness-of-ft was done using three(3)statistical data analysis methods including correlation coefcient(R^(2)),standard deviation(σ),and standard error(SE).The Langmuir isotherm model accurately represent the pure CO_(2)adsorption on the coals than Freundlich and Temkin.The extended Langmuir gives best experimental data ft for the fue gas.The thermodynamic evaluations revealed that CO_(2)adsorption on the South African coals is feasible,spontaneous,and exothermic;and the adsorption mechanism is a combined physical and chemical interaction between the adsorbate and the adsorbent.

Biochar amendments increase soil organic carbon storage and decrease global warming potentials of soil CH4 and N2O under N addition in a subtropical Moso bamboo plantation

Background: Nitrogen(N) deposition affects soil greenhouse gas(GHG) emissions, while biochar application reduces GHG emissions in agricultural soils. However, it remains unclear whether biochar amendment can alleviate the promoting effects of N input on GHG emissions in forest soils. Here, we quantify the separate and combined effects of biochar amendment(0, 20, and 40 t·ha) and N addition(0, 30, 60, and 90 kg N·ha·yr) on soil GHG fluxes in a long-term field experiment at a Moso bamboo(Phyllostachys edulis) plantation.Results: Low and moderate N inputs(≤60 kg N·ha·yr) significantly increase mean annual soil carbon dioxide(CO) and nitrous oxide(NO) emissions by 17.0%–25.4% and 29.8%–31.2%, respectively, while decreasing methane(CH) uptake by 12.4%–15.9%, leading to increases in the global warming potential(GWP) of soil CHand NO fluxes by 32.4%–44.0%. Moreover, N addition reduces soil organic carbon(C;SOC) storage by 0.2%–6.5%. Compared to the control treatment, biochar amendment increases mean annual soil CO2emissions, CHuptake, and SOC storage by 18.4%–25.4%, 7.6%–15.8%, and 7.1%–13.4%, respectively, while decreasing NO emissions by 17.6%–19.2%, leading to a GWP decrease of 18.4%–21.4%. Biochar amendments significantly enhance the promoting effects of N addition on soil COemissions, while substantially offsetting the promotion of N2O emissions, inhibition of CHuptake, and decreased SOC storage, resulting in a GWP decrease of 9.1%–30.3%.Additionally, soil COand CHfluxes are significantly and positively correlated with soil microbial biomass C(MBC) and pH. Meanwhile, NO emissions have a significant and positive correlation with soil MBC and a negative correlation with pH.Conclusions: Biochar amendment can increase SOC storage and offset the enhanced GWP mediated by elevated N deposition and is, thus, a potential strategy for increasing soil C sinks and decreasing GWPs of soil CHand NO under increasing atmospheric N deposition in Moso bamboo plantations.

Global Impact of Gas Flaring

This work deals with the multi-faceted impact of gas flaring on a global scale and the different approach employed by researchers to measure gas flared and its resulting emissions. It gives an overview of methods employed by these researchers in the oil and gas industry, academia and governments in attempt to determine ways of measuring and reducing gas flaring and its emission drastically. This approach so far includes analytical studies, numerical studies, modeling, computer simulations, etc. the goal behind each study being to mitigate the effects of gas flaring. The outcome indicates that there is a seemingly absence of a single global method, emission factor and estimation procedure used in the oil and gas industry all over the world to determine the volume of gas flared and its emissions be it from complete or incomplete combustion, sweet or sulphur present hydrocarbons and this poses a continuous problem in determining the actual impact of gas flaring and its emissions on human and its role in environmental degradation both at a local and global level. An attempt has also being made to cover up-to-date trends in gas flaring and current developments in some of the most flared countries.

Estimation of greenhouse gas emissions in China and the abatement measures

The major emission sources of carbon dioxide, methane, nitrous oxide and CFCs in China have been identified, and the emission trends has been estimated. Besides fossil fuel combustion, human respiration and biomass burning are important sources. Some feasible abatement measures on energy conservation, afforestation and biomass recycling have been discussed.

Energy return on investment, energy payback time, and greenhouse gas emissions of coal seam gas(CSG) production in China: a case of the Fanzhuang CSG project

The studies and development of coal seam gas（CSG） have been conducted for more than 30 years in China, but few of China＇s CSG projects have achieved large-scale commercial success; faced with the boom of shale gas, some investors are beginning to lose patience and confidence in CSG. China currently faces the following question： Should the government continue to vigorously support the development of the CSG industry？ To provide a reference for policy makers and investors, this paper calculates the EROI_（stnd）[a standardized energy return on investment（EROI） method], EROI_（ide）（the maximum theoretical EROI）, EROI_（3,i）（EROI considering the energy investment in transport）, and EROI_（3,1＋e）（EROI with environmental inputs） of a single vertical CSG well in the Fanzhuang CSG project in the Qinshui Basin. The energy payback time（EPT） and the greenhouse gas（GHG） emissions of the CSG systems are also calculated. The results show that over a 15-year lifetime, EROI_（stnd）, EROI_（ide）, EROI_（3,1）, and EROI_（3,1＋e）are expected to deliver EROIs of approximately11：1, 20：1, 7：1, and 6：1, respectively. The EPT within different boundaries is no more than 2 years, and the life-cycle GHG emissions are approximately 18.8 million kg CO_2 equivalent. The relatively high EROI and short EPT indicate that the government should take more positive measures to promote the development of the CSG industry.

Greenhouse Gas Emission from Inland Open Water Bodies and Their Estimation Process—An Emerging Issue in the Era of Climate Change

The persistent rise in concentrations of greenhouse gases (GHGs) in the earth’s atmosphere is responsible for global warming and climate change. Besides the known source of GHGs emissions like energy, industry, and agriculture, intrinsic emissions from natural inland water bodies like wetland, rivers, reservoirs, estuaries, etc. have also been identified as other hotspots of GHGs emission and gaining the attention of the scientific communities in recent times. Inland fisheries in India are threatened by climate changes such as a change in temperature, precipitation, droughts, storm, sea-level rise, saltwater intrusion, floods that affect mostly the production, productivity and ultimately affect the fishers’ livelihood. There are, however, different mitigation and adaptation strategies to cope with the effects of climate change. Carbon sequestration and other related management interventions are one of the options available minimizing GHGs emissions from inland open waters, particularly the wetlands and coastal mangroves which are well known worldwide for their significant role in the storage of carbon. Assessment of C efflux from exposed sediments in dry streams, reservoirs, lakes, rivers, and ponds into the atmosphere can be considered imperative for a better understanding of their role as a C-sink or as a C-source to the atmosphere.

Simulation of gas production from hydrate reservoir by the combination of warm water flooding and depressurization

Gas production from hydrate reservoir by the combination of warm water flooding and depressurization is proposed,which can overcome the deficiency of single production method.Based on the combination production method,the physical and mathematical models are developed to simulate the hydrate dissociation.The mathematical model can be used to analyze the effects of the flow of multiphase fluid,the kinetic process of hydrate dissociation,the endothermic process of hydrate dissociation,ice-water phase equilibrium,the convection and conduction on the hydrate dissociation and gas and water production.The mechanism of gas production by the combination of warm water flooding and depressurization is revealed by the numerical simulation.The evolutions of such physical variables as pressure,temperature,saturations and gas and water rates are analyzed.Numerical results show that under certain conditions the combination method has the advantage of longer stable period of high gas rate than the single producing method.

Shortened Duration of Global Warming Slowdowns with Elevated Greenhouse Gas Emissions

Continuous emissions of anthropogenic greenhouse gases(GHGs)and aerosols in the last 160 years have resulted in an increasing trend of global mean surface temperatures(GMSTs).Due to interactions with natural variability,rates of the combined anthropogenically and naturally induced warming trends are characterized by significant slowdowns and speedups on decadal timescales.Here,by analyzing observed and model-simulated data,we investigate how the duration of these episodes will change with different strengths of GHG and aerosol forcing.We found that the duration of warming slowdowns can be more than 30 yr with a slower rate of anthropogenic emissions but would shorten to about 5 yr with a higher one.This duration reduction depends on both the magnitude of the climate response to anthropogenic forcing and the strength of the internal variability.Moreover,the warming slowdowns can still occur even towards the end of this century under high emissions scenarios but with significantly shortened duration.

Transient simulation of a differential piston warm gas self-pressurization system for liquid attitude and divert propulsion system

In order to obtain the dynamic characteristics of a differential piston warm gas selfpressurization system for liquid attitude and divert propulsion system, a transient model is developed using the modular modeling method. The system includes the solid start cartridge,pressure-amplified tank with liquid monopropellant, liquid regulator, gas generator, and pipes.The one-dimensional finite-element state-variable model is applied to the pipes and the lumped parameter method is adopted for the other modules. The variations of the system operation parameters over time during the startup, steady-state, and pulsing operational processes are obtained from the transient model, and the characteristics of starting time changing with different system parameters are also analyzed. It is shown that the system startup process can be divided into three distinct processes. The starting time monotonically changes with variations of the liquid regulator parameters, first decreasing and then increasing with the mass change of the solid propellant charge of the start cartridge, initial gas cavity volume of the pressure amplified tank and initial gas cushion of the propellant tank. The starting time can be reduced to less than 1.0 s（0.68–0.75 s for the current system）. For meeting the deviation requirements of ±10% of the steady-state propellant tank pressure, the positive deviation requirement is assured by the self-locking pressure and the negative deviation can be assured within an allowable maximum propellant tank volume flowrate（1.6 times the design value for the proposed system） for downstream thrusters for a designed system. The results from the simulation are useful as a guide for further system design and testing.

Responses of greenhouse gas fluxes to experimental warming in wheat season under conventional tillage and no-tillage fields

Understanding the effects of warming on greenhouse gas（GHG, such as N2O, CH4 and CO2 ）feedbacks to climate change represents the major environmental issue. However, little information is available on how warming effects on GHG fluxes in farmland of North China Plain（NCP）. An infrared warming simulation experiment was used to assess the responses of N2O, CH4 and CO2 to warming in wheat season of 2012–2014 from conventional tillage（CT） and no-tillage（NT） systems. The results showed that warming increased cumulative N2O emission by 7.7% in CT but decreased it by 9.7% in NT fields（p 〈 0.05）. Cumulative CH4 uptake and CO2 emission were increased by 28.7%–51.7% and 6.3%–15.9% in both two tillage systems,respectively（p 〈 0.05）. The stepwise regressions relationship between GHG fluxes and soil temperature and soil moisture indicated that the supply soil moisture due to irrigation and precipitation would enhance the positive warming effects on GHG fluxes in two wheat seasons.However, in 2013, the long-term drought stress due to infrared warming and less precipitation decreased N2O and CO2 emission in warmed treatments. In contrast, warming during this time increased CH4 emission from deep soil depth. Across two years wheat seasons, warming significantly decreased by 30.3% and 63.9% sustained-flux global warming potential（SGWP） of N2O and CH4 expressed as CO2 equivalent in CT and NT fields, respectively. However, increase in soil CO2 emission indicated that future warming projection might provide positive feedback between soil C release and global warming in NCP.

Modeling co-seismic thermal infrared brightness anomalies in petroliferous basins surrounding the North and East of the Qinghai–Tibet Plateau

Co-seismic gas leakage usually occurs on the edge of seismic faults in petroliferous basins,and it may have an impact on the local environment,such as the greenhouse effect,which can cause thermal infrared brightness anomalies.Using wavelet transform and power spectrum estimation methods,we processed brightness temperature data from the Chinese geostationary meteorological satellite FY-C/E.We report similarities between the co-seismic thermal infrared brightness(CTIB)anomalies before,during and after earthquakes that occurred at the edges of the Sichuan,Tarim,Qaidam,and Junggar basins surrounding the North and East of the Qinghai–Tibet Plateau in western China.Additionally,in each petroliferous basin,the area of a single CTIB anomaly accounted for 50%to 100%of the basin area,and the spatial distribution similarities in the CTIB anomalies existed before,during and after these earthquakes.To better interpret the similarities,we developed a basin warming effect model based on geological structures and topography.The model suggests that in a petroliferous basin with a subsurface gas reservoir,gas leakage could strengthen with the increasing stress before,during,and even after an earthquake.The accumulation of these gases,such as the greenhouse gases CH4 and CO2,results in the CTIB anomalies.In addition,we conclude that the CTIB anomalies are strengthened by the high mountains(altitude^5000 m)around the basins and the basins’independent climatic conditions.This work provides a new perspective from which to understand the CTIB anomalies in petroliferous basins surrounding the North and East of the Qinghai–Tibet Plateau.

Effects of Rising Temperature on Secondary Compounds of Yeheb (<i>Cordeauxia edulis</i>Hemsley)

The effects of temperature on net photosynthesis and stomatal conductance, emission of foliar volatile organic compounds (VOCs), and phenolics were investigated after exposing Cordeauxia edulis seedlings to control (27/19°C) and three levels of elevated (32/23, 37/27, or 42/31°C) day/night temperature regimes in controlled growth chambers. Emissions of foliar VOC were measured on 7th and 14th day (d) of exposures, whereas net photosynthesis and stomatal conductance were measured on the 8th and 15th d. Net photosynthesis and stomatal conductance were not significantly affected by elevated temperatures. Emission rate of isoprene increased by 4-fold with 10°C rise from the control on 7th d of exposure. Emission rates of monoterpenes, sesquiterpenes and total isoprenoids increased to 2-5-fold higher than that of control plants with 5°C rise. Foliar isoprene emission peaked at daytime maximum of 37°C and the mono- and sesquiterpenes at 32°C. Few individual foliar phenolics, and total foliar phenolics showed significant concentration differences between treatments. Although high VOC emissions under warming appeared to help plants to sustain abiotic stresses, arid/semi-arid species might substantially release highly reactive compounds that affect atmospheric chemistry. Hence, more studies are required on plant species of arid/semi-arid ecosystems of Africa to estimate the emission patterns and their role in atmospheric chemistry under the predicted future atmospheric warming.

Multi-transition study of the peculiar merger Arp 299

We present a multi-transition study to investigate the physical properties of dust and molecular gas in the archetypical merger Arp 299 by using data including James Clerk Maxwell Telescope(JCMT)850 and 450 μm observations, Herschel 500, 350, 250, 160 and 70 μm continuum maps, as well as the CO(3–2), CO(4–3) low-J CO lines and CO(11–10), CO(13–12), CO(14–13) high-J CO lines. The CO(3–2) and CO(4–3) lines are observed by JCMT, and the CO(11–10), CO(13–12), CO(14–13) lines are available on the Herschel Science Archive. The resolution of the Herschel Spectral and Photometric Imaging Receiver(SPIRE) Fourier transform spectrometer(FTS) CO(11–10) data is similar to that of the JCMT CO(3–2) line, while the resolution of the SPIRE/FTS CO(13–12) and Photodetector Array Camera and Spectrometer(PACS) CO(14–13) data is similar to that of JCMT CO(4–3), allowing us to obtain accurate line ratios of I(CO(11-10))/I(CO(3-2)), I(CO(13-12))/I(CO(4-3))and I(CO(14-13))/I(CO(4-3)).By modeling the spectral energy distribution of the continuum data, we conclude that two components(cold and warm) exist in the dust, with the warm component occupying a small percent of the total dust mass. We further use a radiative transfer analysis code, RADEX, to calculate the density, temperature and column density of warm gas in the central region, which shows that the kinetic temperature Tkinis in the range 110 to 150 K and hydrogen density n(H2) is in the range 104.7-105.5cm-3. We show that the hot dust is located in the central region of IC 694 with a radius of ~ 4′′and estimate that the warm gas mass is in the range 3.8 × 10~7M⊙to 7.7 × 10~7M⊙, which contains 5.0%–15.0% of the total H2mass for the region of IC 694. We also calculate the star formation rate of the galaxy in particular,which is much higher than that of the Milky Way.

Characteristics of permafrost degradation in Northeast China and its ecological effects: A review

Latitudinal permafrost in Northern Northeast(NNE)China is located in the southern margin of the Eurasian continent,and is very sensitive to climatic and environmental change.Numerical simulations indicate that air temperature in the permafrost regions of Northeast China has been on the rise since the 1950s,and will keep rising in the 21st century,leading to extensive degradation of permafrost.Permafrost degradation in NNE China has its own characteristics,such as northward shifts in the shape of a"W"for the permafrost southern boundary(SLP),discontinuous permafrost degradation into islandlike frozen soil,and gradually disappearing island permafrost.Permafrost degradation leads to deterioration of the ecological environment in cold regions.As a result,the belt of larch forests dominated by Larix gmelinii has shifted northwards and wetland areas with symbiotic relationships with permafrost have decreased significantly.With rapid retreat and thinning of permafrost and vegetation change,the CO2 and CH4 flux increases with mean air temperature from continuous to sporadic permafrost areas as a result of activity of methanogen enhancement,positively feeding back to climate warming.This paper reviews the features of permafrost degradation,the effects of permafrost degradation on wetland and forest ecosystem structure and function,and greenhouse gas emissions on latitudinal permafrost in NNE China.We also put forward critical questions about the aforementioned effects,including:(1)establish long-term permafrost observation systems to evaluate the distribution of permafrost and SLP change,in order to study the feedback of permafrost to climate change;(2)carry out research about the effects of permafrost degradation on the wetland ecosystem and the response of Xing'an larch to global change,and predict ecosystem dynamics in permafrost degradation based on long-term field observation;(3)focus intensively on the dynamics of greenhouse gas flux in permafrost degradation of Northeast China and the feedback of greenhouse gas emissions to climate change;(4)quantitative studies on the permafrost carbon feedback and vegetation carbon feedback due to permafrost change to climate multi-impact and estimate the balance of C in permafrost regions in the future.

Study on Lignite-Blended Burning Technology in the 1025t/h Bituminous Boiler

Due to a serious shortage of the coal in Tonghua, a retrofit solution of mixing warm flue gas extracted from reversing chamber into the coal pulverizing system and cold air into the hot air coal pulverizing system is proposed so as to reduce oxygen content. At the end of the pulverizing system and medium temperature of the conveying system, dual-channel combustion burner is transformed into horizontal bias combustion burner. The measurement results show that 50% ratio of lignite blended in the 1025t/h bituminous boiler is feasibility. It is also an important technology to reduce NOx pollutant emission.

Economic Evaluation of the UCSRP-HP Process in IGCC Applications

With financial assistance from the US Department of Energy and the Illinois Clean Coal Institute, Gas Technology Institute (GTI) has been working with the University of California, Berkeley, for further development of their UCSRP-HP (University of California Sulfur Recovery Process-High Pressure) technology. The key focus of the UCSRP-HP technology is integrated multi-contaminant removal of hydrogen sulfide (H2S), carbonyl sulfide (COS), ammonia (NH3), chlorides and heavy metals present in coal-derived syngas. The process has two major components: 1) removal of various trace components with a solvent (e.g., diethylene glycol or water) using a high-pressure scrubbing unit and 2) removal of H2S as sulfur via reaction with SO2 (in the presence of a solvent mixed a small quantity of a homogeneous catalyst) at 120?C to 150?C and at any syngas pressure. During this research, data critical to developing and evaluating UCSRP-HP technology for multi-contaminant removal from syngas derived from Illinois #6 coal were obtained. In this paper, we have presented key economic evaluations of the UCSRP-HP process, including potential integrations with other technology options for CO2 and hydrogen separations, for a nominal Illinois #6-coal-based 550-MWe Integrated Coal Gasification Combined Cycle (IGCC) facility with CO2 capture and sequestration. GTI is exploring various options to demonstrate this technology in a pilot plant using actual syngas from a coal gasifier.