The effects of adding a bulking agent and chemically pretreating municipal kitchen waste before aerobic composting were studied using a laboratory-scale system. The system used20-L reactors and each test lasted 28 day...The effects of adding a bulking agent and chemically pretreating municipal kitchen waste before aerobic composting were studied using a laboratory-scale system. The system used20-L reactors and each test lasted 28 days. The objective was to decrease NH3 and H2S emissions during composting. The bulking agent, dry cornstalks, was mixed with the kitchen waste to give a mixture containing 15%（wet weight） bulking agent. A combined treatment was also conducted, in which kitchen waste mixed with the bulking agent was pretreated with ferric chloride（FeC l3）. Less leachate was produced by the composted kitchen waste mixed with bulking agent than by the kitchen waste alone, when the materials had reached the required maturity. The presence of cornstalks also caused less H2 S to be emitted, but had little impact on the amount of NH3 emitted. The FeC l3 was found to act as an effective chemical flocculant,and its presence significantly decreased the amounts of NH3 and H2S emitted. Kitchen waste mixed with cornstalks and treated with FeC l3 emitted 42% less NH3 and 76% less H2 S during composting than did pure kitchen waste.展开更多
To evaluate the influence of lactic acid on the methanogenesis, anaerobic digestion of kitchen wastes was firstly conducted in a two-phase anaerobic digestion process, and performance of two digesters fed with lactic ...To evaluate the influence of lactic acid on the methanogenesis, anaerobic digestion of kitchen wastes was firstly conducted in a two-phase anaerobic digestion process, and performance of two digesters fed with lactic acid and glucose was subsequently compared. The results showed that the lactic acid was the main fermentation products of hydrolysis-acidification stage in the two-phase anaerobic digestion process for kitchen wastes. The lactic acid concentration constituted approximately 50% of the chemical oxygen demand （COD） concentration in the hydrolysis-acidification liquid. The maximum organic loading rate was lower in the digester fed with lactic acid than that fed with glucose. Volatile fatty acids （VFAs） and COD removal were deteriorated in the methanogenic reactor fed with lactic acid compared to that fed with glucose. The specific methanogenic activity （SMA） declined to 0.343 g COD/（gVSS-d） when the COD loading were designated as 18.8 g/（L-d） in the digester fed with lactic acid. The propionic acid accumulation occurred due to the high concentration of lactic acid fed. It could be concluded that avoiding the presence of the lactic acid is necessary in the hydrolysis-acidification process for the improvement of the two-phase anaerobic digestion process of kitchen wastes.展开更多
There are mainly 3 kinds of existing states of oil generating from source rocks,that is,dispersive liquid hydrocarbon inside of source rock,dispersive liquid hydrocarbon outside of source rock and concentrated liquid ...There are mainly 3 kinds of existing states of oil generating from source rocks,that is,dispersive liquid hydrocarbon inside of source rock,dispersive liquid hydrocarbon outside of source rock and concentrated liquid hydrocarbon outside of source rock.Because of the differences in thermal history and medium conditions around,and the interaction of organic and inorganic matter,the liquid hydrocarbon with 3 kinds of existing state has different cracking conditions.The gas generation dynamics experiments of crude oil matching different mediums indicate that the distribution of activation energy of methane changes a lot according to medium difference.The carbonate has a main influence on oil cracking conditions and can largely reduce its activation energy,which reflects the lower cracking temperature of crude oil.The mudstone takes a second place and the sandstone is the smallest.The catalytic cracking function to the oil of the carbonate,of the mudstone and of the sandstone changes weaken in turn.The corresponding Ro values of main gas generation period in different mediums are as follows:1.5%―3.8%with pure crude oil,1.2%―3.2%with dispersive crude oil in carbonate,1.3%~3.4% with dispersive crude oil in mudstone and 1.4%―3.6%with dispersive crude oil in sandstone.The influence of pressure to crude oil cracking is relatively complicated.In the low heating speed condition, pressure restrains the oil cracking and gas generation,but in the high heating speed condition,pressure has an indistinctive influence to the oil cracking and gas generation.Pressure also makes a different effort in different evolvement stage.Taking the middle and lower Cambrian source rocks in the Tarim Basin as an example,primary oil generating quantity is 2232.24×10 8 t,residual oil and oil cracking gas quantity is 806.21×10 8 t and 106.95×10 12 m 3 respectively.展开更多
Continental shale oil is a general term for liquid hydrocarbons and many kinds of organic matter in continental organic-rich shale series with vitrinite reflectance of more than 0.5%at buried depth of more than 300 m,...Continental shale oil is a general term for liquid hydrocarbons and many kinds of organic matter in continental organic-rich shale series with vitrinite reflectance of more than 0.5%at buried depth of more than 300 m,and is an important type of source-rock oil and gas.Based on the evolution model of oil generation and expulsion in organic-rich shale series controlled by maturity,continental shale oil is divided into two types:medium-high maturity and medium-low maturity.(1)The continental shale series in China develop high-quality source rocks of freshwater and saltwater lacustrine facies,as well as multiple types of reservoirs,including clastic rocks,carbonate rocks,diamictite,tuff and shale,forming a number of"sweet sections"and"sweet areas"of continuous distribution inside or near source rocks,which have large scale resources.(2)Experimental analysis of organic rich shale samples shows that the shale samples with wavy and horizontal beddings have good storage conditions,and the horizontal permeability of shale is tens to hundreds of times of its vertical permeability,which is conducive to the lateral migration and accumulation of shale oil in the source rocks.(3)After evaluation,the geological resources of medium-high maturity shale oil are about 10 billion tons,which can be effectively developed by horizontal drilling and volumetric fracturing,and will be a practical field of oil exploration in recent years.Shale oil with medium and low maturity has huge resource potential,and technological recoverable resources of(70?90)billion tons,making it a strategic alternative resource of oil industry.However,economic development of this type of shale oil needs in-situ conversion technology breakthroughs.Continental shale oil is an inevitable choice in the process of Chinese continental petroleum exploration from"outside source"to"inside source".Making breakthroughs in the core technologies such as"sweet area"evaluation and optimization,horizontal well volume fracturing and in-situ conversion technology and equipment i展开更多
The effects of adding a bulking agent on the performance and odor emissions（ammonia and eight sulfur-containing odorous compounds） when biodrying kitchen waste were investigated. Three treatments were considered： t...The effects of adding a bulking agent on the performance and odor emissions（ammonia and eight sulfur-containing odorous compounds） when biodrying kitchen waste were investigated. Three treatments were considered： the addition of either cornstalks（CS） or wood peat（WP） to kitchen waste as a bulking agent before biodrying, and a control treatment（CK）. The water-removal rates for CK, CS, and WP treatments were 0.35, 0.56, and0.43 kg/kg, respectively. Addition of bulking agents to kitchen waste produced less leachate,higher moisture-removal rates, and lower consumption of volatile solids. The CS treatment had the highest biodrying index（4.07）, and those for the WP and CK treatments were 3.67 and 1.97, respectively. Adding cornstalks or wood peat decreased NH3 emissions by 55.8%and 71.7%, respectively. Total sulfur losses were 3.6%–21.6% after 21 days biodrying, and H2 S and Me2 SS were the main（〉 95%） sulfur compounds released. The smallest amounts of sulfur-containing odorous compounds were emitted when cornstalks were added, and adding cornstalks and wood peat decreased total sulfur losses by 50.6%–64.8%.展开更多
基金supported by the National Natural Science Foundation of China (No. 41275161)the National Science and Technology Support Program (No. 2012BAD14B01)+1 种基金the National Natural Science Foundation of China (NSFC) (No. 41275161)the Ministry of Science and Technology of the People's Republic of China (MOST) (No. 2012BAD14B01) for financing the projects
文摘The effects of adding a bulking agent and chemically pretreating municipal kitchen waste before aerobic composting were studied using a laboratory-scale system. The system used20-L reactors and each test lasted 28 days. The objective was to decrease NH3 and H2S emissions during composting. The bulking agent, dry cornstalks, was mixed with the kitchen waste to give a mixture containing 15%（wet weight） bulking agent. A combined treatment was also conducted, in which kitchen waste mixed with the bulking agent was pretreated with ferric chloride（FeC l3）. Less leachate was produced by the composted kitchen waste mixed with bulking agent than by the kitchen waste alone, when the materials had reached the required maturity. The presence of cornstalks also caused less H2 S to be emitted, but had little impact on the amount of NH3 emitted. The FeC l3 was found to act as an effective chemical flocculant,and its presence significantly decreased the amounts of NH3 and H2S emitted. Kitchen waste mixed with cornstalks and treated with FeC l3 emitted 42% less NH3 and 76% less H2 S during composting than did pure kitchen waste.
文摘To evaluate the influence of lactic acid on the methanogenesis, anaerobic digestion of kitchen wastes was firstly conducted in a two-phase anaerobic digestion process, and performance of two digesters fed with lactic acid and glucose was subsequently compared. The results showed that the lactic acid was the main fermentation products of hydrolysis-acidification stage in the two-phase anaerobic digestion process for kitchen wastes. The lactic acid concentration constituted approximately 50% of the chemical oxygen demand （COD） concentration in the hydrolysis-acidification liquid. The maximum organic loading rate was lower in the digester fed with lactic acid than that fed with glucose. Volatile fatty acids （VFAs） and COD removal were deteriorated in the methanogenic reactor fed with lactic acid compared to that fed with glucose. The specific methanogenic activity （SMA） declined to 0.343 g COD/（gVSS-d） when the COD loading were designated as 18.8 g/（L-d） in the digester fed with lactic acid. The propionic acid accumulation occurred due to the high concentration of lactic acid fed. It could be concluded that avoiding the presence of the lactic acid is necessary in the hydrolysis-acidification process for the improvement of the two-phase anaerobic digestion process of kitchen wastes.
基金the National Basic Research Program of China(Grant No.2007CB209500)the National Natural Science Foundation of China(Grant No.40672097)
文摘There are mainly 3 kinds of existing states of oil generating from source rocks,that is,dispersive liquid hydrocarbon inside of source rock,dispersive liquid hydrocarbon outside of source rock and concentrated liquid hydrocarbon outside of source rock.Because of the differences in thermal history and medium conditions around,and the interaction of organic and inorganic matter,the liquid hydrocarbon with 3 kinds of existing state has different cracking conditions.The gas generation dynamics experiments of crude oil matching different mediums indicate that the distribution of activation energy of methane changes a lot according to medium difference.The carbonate has a main influence on oil cracking conditions and can largely reduce its activation energy,which reflects the lower cracking temperature of crude oil.The mudstone takes a second place and the sandstone is the smallest.The catalytic cracking function to the oil of the carbonate,of the mudstone and of the sandstone changes weaken in turn.The corresponding Ro values of main gas generation period in different mediums are as follows:1.5%―3.8%with pure crude oil,1.2%―3.2%with dispersive crude oil in carbonate,1.3%~3.4% with dispersive crude oil in mudstone and 1.4%―3.6%with dispersive crude oil in sandstone.The influence of pressure to crude oil cracking is relatively complicated.In the low heating speed condition, pressure restrains the oil cracking and gas generation,but in the high heating speed condition,pressure has an indistinctive influence to the oil cracking and gas generation.Pressure also makes a different effort in different evolvement stage.Taking the middle and lower Cambrian source rocks in the Tarim Basin as an example,primary oil generating quantity is 2232.24×10 8 t,residual oil and oil cracking gas quantity is 806.21×10 8 t and 106.95×10 12 m 3 respectively.
基金Supported by the China National Science and Technology Major Project(2016ZX05046)
文摘Continental shale oil is a general term for liquid hydrocarbons and many kinds of organic matter in continental organic-rich shale series with vitrinite reflectance of more than 0.5%at buried depth of more than 300 m,and is an important type of source-rock oil and gas.Based on the evolution model of oil generation and expulsion in organic-rich shale series controlled by maturity,continental shale oil is divided into two types:medium-high maturity and medium-low maturity.(1)The continental shale series in China develop high-quality source rocks of freshwater and saltwater lacustrine facies,as well as multiple types of reservoirs,including clastic rocks,carbonate rocks,diamictite,tuff and shale,forming a number of"sweet sections"and"sweet areas"of continuous distribution inside or near source rocks,which have large scale resources.(2)Experimental analysis of organic rich shale samples shows that the shale samples with wavy and horizontal beddings have good storage conditions,and the horizontal permeability of shale is tens to hundreds of times of its vertical permeability,which is conducive to the lateral migration and accumulation of shale oil in the source rocks.(3)After evaluation,the geological resources of medium-high maturity shale oil are about 10 billion tons,which can be effectively developed by horizontal drilling and volumetric fracturing,and will be a practical field of oil exploration in recent years.Shale oil with medium and low maturity has huge resource potential,and technological recoverable resources of(70?90)billion tons,making it a strategic alternative resource of oil industry.However,economic development of this type of shale oil needs in-situ conversion technology breakthroughs.Continental shale oil is an inevitable choice in the process of Chinese continental petroleum exploration from"outside source"to"inside source".Making breakthroughs in the core technologies such as"sweet area"evaluation and optimization,horizontal well volume fracturing and in-situ conversion technology and equipment i
基金financially supported by the Ministry of Science and Technology of the People's Republic of Chinathrough the High Effective Intelligent Composting Process and Key Technology Research program(No.2016YFD0800601)the project of“State Key Laboratory of Solid Waste Reuse for Building Materials”(No.SWR-2014-005)
文摘The effects of adding a bulking agent on the performance and odor emissions（ammonia and eight sulfur-containing odorous compounds） when biodrying kitchen waste were investigated. Three treatments were considered： the addition of either cornstalks（CS） or wood peat（WP） to kitchen waste as a bulking agent before biodrying, and a control treatment（CK）. The water-removal rates for CK, CS, and WP treatments were 0.35, 0.56, and0.43 kg/kg, respectively. Addition of bulking agents to kitchen waste produced less leachate,higher moisture-removal rates, and lower consumption of volatile solids. The CS treatment had the highest biodrying index（4.07）, and those for the WP and CK treatments were 3.67 and 1.97, respectively. Adding cornstalks or wood peat decreased NH3 emissions by 55.8%and 71.7%, respectively. Total sulfur losses were 3.6%–21.6% after 21 days biodrying, and H2 S and Me2 SS were the main（〉 95%） sulfur compounds released. The smallest amounts of sulfur-containing odorous compounds were emitted when cornstalks were added, and adding cornstalks and wood peat decreased total sulfur losses by 50.6%–64.8%.
