Computer study of the spectral characteristics of the disperse water methane system

The interaction of water clusters that adsorbed methane molecules with infrared radiation is studied by molecular dynamics. The presence of methane molecules in the disperse water system leads to an increase in absorption and emission of infrared radiation and a strong depletion of the Raman spectrum. In this case, the reflection coefficient of a monochromatic plane electromagnetic wave increases and its frequency spectrum significantly changes. The comparison of experimental data for similar characteristics of water, methane, or their mixtures is presented.

A Pilot-scale Demonstration of Reverse Osmosis Unit for Treatment of Coal-bed Methane Co-produced Water and Its Modeling

This study presents the first demonstration project in China for treatment of coal-bed methane(CBM) co-produced water and recycling.The work aims to provide a research and innovation base for solving the pollution problem of CBM extraction water.The reverse osmosis(RO) unit is applied to the treatment of CBM co-produced water.The results indicate that system operation is stable,the removal efficiency of the total dissolved solids(TDS) is as high as 97.98%,and Fe,Mn,and F-are almost completely removed.There is no suspended solids(SS) detected in the treated water.Furthermore,a model for the RO membrane separation process is developed to describe the quantitative relationship between key physical quantities-membrane length,flow velocity,salt concentration,driving pressure and water recovery rate,and the water recovery restriction equation based on mass balance is developed.This model provides a theoretical support for the RO system design and optimization.The TDS in the CBM co-produced water are removed to meet the "drinking water standards" and "groundwater quality standards" of China and can be used as drinking water,irrigation water,and livestock watering.In addition,the cost for treatment of CBM co-produced water is assessed,and the RO technology is an efficient and cost-effective treatment method to remove pollutants.

A Simple and Effective Method to Fabricate Separation Membranes for Dehydration of Natural Gas

PBT/PEG_(1000)composite membranes were prepared by the phase inversion method and were used to dehydrate natural gas.In this study,evaporation time,coagulation bath concentration,and additives in casting solution were investigated,respectively,on the selectivity and permeability of separation membranes,and optimal conditions were found to include an evaporation time of 30 sec,an 100%PEG400-containing coagulation bath and 2%of PVA used as the additive.The H_(2)O/CH_(4)selectivity reached over 3600,which is about 20 times more selective than the original membrane.It provides a simple and effective preparation method to fabricate membranes for dehydration of methane gas.

Greenhouse gas emissions from oilfield-produced water in Shengli Oilfield,Eastern China

Greenhouse gas（GHG） emissions from oil and gas systems are an important component of the GHG emission inventory. To assess the carbon emissions from oilfield-produced water under atmospheric conditions correctly, in situ detection and simulation experiments were developed to study the natural release of GHG into the atmosphere in the Shengli Oilfield,the second largest oilfield in China. The results showed that methane（CH4） and carbon dioxide（CO2） were the primary gases released naturally from the oilfield-produced water.The atmospheric temperature and release time played important roles in determining the CH4 and CO2emissions under atmospheric conditions. Higher temperatures enhanced the carbon emissions. The emissions of both CH4 and CO2from oilfield-produced water were highest at 27°C and lowest at 3°C. The bulk of CH4 and CO2was released from the oilfield-produced water during the first release period, 0–2 hr, for each temperature, with a maximum average emission rate of 0.415 g CH4/（m3·hr） and 3.934 g CO2/（m3·hr）, respectively. Then the carbon emissions at other time periods gradually decreased with the extension of time. The higher solubility of CO2 in water than CH4 results in a higher emission rate of CH4 than CO2over the same release duration. The simulation proved that oilfield-produced water is one of the potential emission sources that should be given great attention in oil and gas systems.