济阳坳陷待发现生物气资源量预测新方法

生物气是特殊成因天然气,由于生成机理尚未明确,成因法难以准确预测其资源量。在对生物气成因类型和生成条件分析的基础上划分了评价单元,提出了基于统计学的待发现生物气资源量预测的新方法,即应用截头移位帕雷托分布模型预测各评价单元待发现生物气藏的规模分布,然后构建三角分布函数预测待发现生物气藏数量,最后用Monte Carlo法预测研究区待发现生物气资源量。应用上述方法预测济阳坳陷待发现生物气资源量,研究表明,待发现生物气藏规模服从对数正态分布,下一勘探阶段最可能发现生物气藏储量（0.2~1.2）×108 m3,在惠民凹陷北部和东营凹陷浅层可能发现储量规模较大的原生生物气藏,在沾化凹陷、陈家庄凸起、滨县-林樊家凸起可能发现规模小、数量多的原油降解气藏,预测济阳坳陷待发现生物气藏资源量约424.74×108 m3。

油气藏规模序列法在三湖凹陷北斜坡生物气资源预测中的应用

根据三湖凹陷北斜坡的勘探研究程度和地质条件,选取油气藏规模序列法对其第四系生物气地质资源量展开预测。结果表明,北斜坡第四系生物气地质总资源量为6304.36×108m3,还有39个生物气藏未被发现,剩余地质资源量为3074.05×108m3,具有较好的勘探潜力。同时指出寻找中小储量规模的构造气藏和岩性气藏将是今后北斜坡第四系勘探的主要方向和储量增长的突破口。

非生物天然气资源的特征与前景

根据非生物气可作为资源的有用组分类型及其占天然气总组分份额的多少,将非生物天然气资源划分为主非生物天然气资源和次非生物天然气资源两大类。在主非生物天然气资源中,非生物气组分(CO2、CH4)占天然气总组分的大部分或绝大部分;在次非生物天然气资源中,非生物组分(H e)占天然气总组分的少部分或极少部分。指出主非生物天然气的CO2和烷烃气藏主要分布在中国东部裂谷型盆地中,资源潜力大;次非生物天然气中的H e气在四川盆地、鄂尔多斯盆地和塔里木盆地资源潜力大,在松辽盆地也有一定潜力。

生物气CO2还原途径中碳同位素分馏作用研究及应用

地质历史中,CO2/H2还原产甲烷作用对生物气的形成具有十分重要的意义。中国柴达木盆地第四系生物气主要为CO2/H2还原型生物气。笔者以CO2/H2还原生气理论为指导,进行不同初始碳同位素值和不同赋存状态碳源的生物模拟实验,研究CO2/H2还原产气过程中发生的碳同位素分馏作用。实验结果表明,产物中δ13CH4值与底物的δ13C值呈很好的正相关关系;在反应母质过量的情况下,碳源的赋存状态可以影响产物甲烷的碳同位素组成。以游离形式CO2还原产生的甲烷δ13C值,相对于以HCO3-、CO23-离子形式产生的甲烷δ13C值轻。通过柴达木盆地东部第四系生物气田实例分析,探讨了该区生物气的主要底物CO2的来源及赋存状态,对评价盆地生物气资源和有利勘探区预测有重要的参考价值。

非生物成因天然气形成机制与资源前景

本文论述了细菌(生物)成因气、热成因气、深层气和非生物成因气的形成机制和它们的耦合与差异;评述了非生物成因天然气的研究历史和发展态势,指出迄今在国际上因未发现任何具非生物成因特征的商业气藏,而认为非生物成因天然气不具有资源前景是一种错误结论。本文并讨论了地球深部有机质演化的关键科学问题和判识天然气成因类型地球化学指标的有效性,指出:沉积有机质受生物降解、热降解作用的同位素动力学分馏效应的制约,有机成因烷烃气体(甲烷、乙烷、丙烷和丁烷)的碳氢同位素δ13C值和δ2H值分布均呈正序分布,即:δ13C1<δ13C2<δ13C3<δ13C4和δ2HCH4<δ2HC2H6<δ2HC3H8<δ2HC4H10,二者具有正相关关系;非生物成因天然气受聚合作用同位素动力学分馏效应的制约,其烷烃气体的碳氢同位素分布则不同于前者,δ13C值呈反序分布δ13C1>δ13C2>δ13C3>δ13C4,而δ2H值呈正序分布δ2HCH4<δ2HC2H6<δ2HC3H8<δ2HC4H10,二者具有负相关关系;而且非生物成因甲烷的δ13C1≥-30.0‰。此外,本文评述了中国非生物成因天然气研究所取得的重要进展,论述了松辽盆地非生物成因天然气的地质地球化学特征,指出松辽盆地昌德肇州西非生物成因天然气藏的发现,为研究和寻找非生物成因天然气资源提供了典型实例;并指出伴随松辽盆地深层气勘探的重大突破,以及近20口商业天然气井非生物成因特征的确定,展现了松辽盆地非生物成因天然气勘探开发的良好前景,使松辽盆地成为世界上研究和寻找非生物成因天然气资源最理想的地区。

Cultivation of microalgae for biodiesel production:A review on upstream and downstream processing

Fluctuating market price of fossil fuel and overwhelming emission of greenhouse gases to the atmosphere have resulted in climate change and have been a global concern in this decade. Hence, biodiesel has become an alternative option to fossil diesel as it is renewable and environmentally friendly. Nevertheless, this alternative fuel that is usually derived from terrestrial oil crops will cause shortage in food supply and deforestation if mass production is realized. In recent years, cultivation of aquatic microorganism(particularly microalgae) to produce biodiesel is considered as a practical solution due to their high growth rate and ability to synthesize large quantity of lipid within their cell. However, the development of energy and cost-efficiency of microalgae cultivation system are the main issues in producing renewable microalgae biodiesel. Of late, wastewater or organic compost has been used as the cultivation medium as it can provide sufficient nutrients to sustain microalgae growth.Microalgae cultivation method and system are vitally important as these factors undoubtedly affect the final microalgae biomass and lipid yield. In this review, the cultivation system of microalgae, nutrients demanded for microalgae production, cell harvesting and drying, microalgae oil extraction, and utilization of microalgae biomass for biodiesel production are introduced and discussed. It is anticipated to convey clearer perspectives in upstream and downstream processes in microalgae-derived biodiesel production.

The green fuel from carbon waste： optimization and product selectivity model studies

Increase in greenhouse gases, has made scientists to substitute alternative fuels for fossil fuels. Nowadays, converting biomass into liquid by Fischer-Tropsch synthesis is a major concern for alternative fuels （gasoline, diesel etc.）. Selectivity of Fischer-Tropsch hydrocarbon product （green fuel） is an important issue. In this study, the experimental data has been obtained from three factors; temperature, H2/CO ratio and pressure in the fixed bed micro reactor. T = 543-618 （K）, P = 3-10 （bar）, H2/CO = 1-2 and space velocity = 4500 （l/h） were the reactor conditions. The results of product modeling for methane （CH4）, ethane （C2H6）, ethylene （C2H4） and CO conversion with experimental data were compared. The effective parameters and the interaction between them were investigated in the model. H2/CO ratio and pressure and interaction between pressure and H2/CO in ethane selectivity model and CO conversion and interaction between temperature and H2/CO ratio in methane selectivity model and ethylene gave the best results. To determine the optimal conditions for light hydrocarbons, ANOVA and RSM were employed. Finally, products optimization was done and results were concluded.

Improved Model for Semideciduous Seasonal ForestProduction of Leaves and Deciduousness

The climate,mainly the water availability and temperature,drives the renewal of biomass inseasonal forest ecosystem,and the greenness and leaf area of its canopy are responsive climate variations.This study verified models to explain the phenomenon of leaf production and deciduousness by time,with LAI（Leaf Area Index）,NDVI（Normalized Difference VegetationIndex）and climate variables,on period 2011-2016. The data were obtained in satellite images and in plots installed at forestmonitoring sites,visited monthly.The analysis incorporated the water balance.Three equations were compared,two alreadypublished and the equation that was adjusted in this work.The model was improved and validated with new variables and data.It is possible to estimate the fall and renew of leaves biomass in semideciduous forests with reasonable precision.

Experimental Study on Combustion Characteristics of Unused Biomasses in Compact Combustor

The aim of the present study is to develop the biomass furnace combustor which can effectively employ four unused biomasses, i.e., wood bark, wood branch, bamboo, and grass as a fuel. Emphasis is placed on the combustion gas components and combustion gas temperature in the combustor. It is found from the study that： （1） Four unused biomasses can take plate self combustion and the stable combustion yield; （2） Different combustion temperature distribution appears in combustor and is affected by each biomass; （3） The concentrations of nitrogen oxide and sulfur oxides are lower than the discharge standard value; （4） Higher thermal efficiency yields for bark, bamboo and grass.

Municipal solid waste degradation and landfill gas resources characteristics in self-recirculating sequencing batch bioreactor landfill

Based on the degradation characteristics of municipal solid waste(MSW)in China,the traditional anaerobic sequencing batch bioreactor landfill(ASBRL)was optimized,and an improved anaerobic sequencing batch bioreactor landfill(IASBRL)was put forward on the basis of leachate self-recirculation.By monitoring MSW composition,leachate characteristics variation and landfill gas(LFG)generation,the effect of IASBRL was comparatively studied by simulation landfill.Based on the adjusting,scouring and carrying effects of leachate self-recirculation,IASBRL can rapidly decrease Eh value to about-500mV and form a suitable biochemical environment for methanogens,which provides a precondition for stable cooperation between non-methanogens and methanogens.IASBRL can avoid the accumulation of organic acids,make VFA(volatile fatty acid)concentration and CODCr decrease along with the small range fluctuations,and form a stable decomposition-consumption synergy during MSW degradation,therefore,the hydrolysis rate of easy hydrolyze material reaches 71.2% in IASBRL.From the viewpoint of LFG resources in IASBRL,the cumulative LFG production increases to 2327.0L,CH4 mass fraction stabilizes at about 50%,and these provide a favorable precondition for LFG development.

Responses of aboveground biomass of alpine grasslands to climate changes on the Qinghai-Tibet Plateau

Aboveground biomass in grasslands of the Qinghai-Tibet Plateau has displayed an overall increasing trend during 2003–2016, which is profoundly influenced by climate change. However, the responses of different biomes show large discrepancies, in both size and magnitude. By applying partial least squares regression, we calculated the correlation between peak aboveground biomass and mean monthly temperature and monthly total precipitation in the preceding 12 months for three different grassland types(alpine steppe, alpine meadow, and temperate steppe) on the central and eastern Qinghai-Tibet Plateau. The results showed that mean temperature in most preceding months was positively correlated with peak aboveground biomass of alpine meadow and alpine steppe, while mean temperature in the preceding October and February to June was significantly negatively correlated with peak aboveground biomass of temperate steppe. Precipitation in all months had a promoting effect on biomass of alpine meadow, but its correlations with biomass of alpine steppe and temperate steppe were inconsistent. It is worth noting that, in a warmer, wetter climate, peak aboveground biomass of alpine meadow would increase more than that of alpine steppe, while that of temperate steppe would decrease significantly, providing support for the hypothesis of conservative growth strategies by vegetation in stressed ecosystems.

Future biomass carbon sequestration capacity of Chinese forests

Chinese forests, characterized by relatively young stand age, represent a significant biomass carbon （C） sink over the past several decades. Nevertheless, it is unclear how forest biomass C sequestration capacity in China will evolve as forest age, climate and atmospheric CO2 concentration change continuously. Here, we present a semi-empirical model that incorporates forest age and climatic factors for each lbrest type to estimate the effects of forest age and climate change on total forest biomass, under three different sce-narios based on the fifth phase of the Coupled Model Intercomparison Project （CMIPS）. We estimate that age-related forest biomass C sequestration to be 6.69 Pg C （~0.17 Pg C a^-1） from the 2000s to the 2040s. Climate change induces a rather weak increase in total forest biomass C sequestration （0.52-0.60 Pg C by tile 2040s）. We show that rising CO2 concentrations could further increase tile total forest biomass C sequestration by 1.68-3.12 Pg C in the 2040s across all three scenarios. Overall, the total forest biomass in China would increase by 8.89-10.37 Pg C by the end of 2040s. Our findings highlight the benefits of Chinese afforestation programs, continued climate change and increasing CO2. concentration in sustaining the forest biomass C sink in the near future, and could therefore be useful for designing more realistic climate change mitigation policies such as continuous forestation programs and careful choice of tree species.

Remediation of Fly Ash Dumpsites Through Bioenergy Crop Plantation and Generation: A Review

Utilization of fly ash, a byproduct of coal combustion in thermal power plants, is a sustainable use of waste for power generation.Discarding fly ash as waste in landfills/ash ponds may not only be regarded as a loss of valuable land and essential nutrients, but also pose a significant health hazard due to fine air-borne particles and leaching of heavy metals. The presence of essential macro-and micronutrients and its porosity make fly ash an excellent soil amendment for plant growth as an organic nitrogen(N) and carbon(C)supplementation. As harmful heavy metals make fly ash unsafe for agronomy, bioenergy crop plantation and energy generation from different thermochemical conversions of the biomass would be an ideal method for coal fly ash utilization through which carbon-neutral fuel can be generated from fossil fuel, thus reducing climate change impact. This review summarizes the development of bioenergy plantation and silviculture at fly ash dumpsites with an integrated phyto-bio-rhizo-mycoremediation approach and assesses utilization of the valuable biomass for thermal energy, electricity, and biofuel generation with inclusion of a SWOT analysis(a strategic technique typically used to help identify the strength, weakness, opportunities, and threat). Bioenergy crop production through integrated phytomanagement can generate billions of dollars of wealth from waste and provides a sustainable solution for fly ash management,with environmental, economic, and social benefits.