Suggested policies to encourage coalbed methane development in China

The development of coalbed methane in the People's Republic of China has been selected by the Ministry of Coal Industry as a key strategic project within the coal industry. However, before the recovery of coalbed methane can reach its full economic potential, a number of constraints need to be overcome. Such constraints include the lack of policy framework, and of capital for project investments and equipment. Also needed is additional information on and experience with relevant technologies. Market mechanisms in China are not yet perfected during this initial period of transition to a market economy. In particular, artificially low gas prices and difficulties with repatriation of profits, discourage foreign direct investment and joint ventures. This paper examines internationally adopted, or proposed, policies that promote coalbed methane recovery; it then describes international activities that promote coalbed methane development in China; and finally presents China's options particularly suitable for expanding coalbed methane development .     

Coalbed methane reservoir data and simulator parameter uncertainty modelling for CO2 storage performance assessment

Laboratory studies and a number of field pilots have demonstrated that CO₂ injection into coal seams has the potential to enhance coalbed methane (CBM) recovery with the added advantage that most of the injected CO₂ can be stored permanently in coal. The concept of storing CO₂ in geologic formations as a safe and effective greenhouse gas mitigation option requires public and regulatory acceptance. In this context it is important to develop a good understanding of the reservoir performance, uncertainties and the risks that are associated with geological storage. The paper presented refers to the sources of uncertainty involved in CO₂ storage performance assessment in coalbed methane reservoirs and demonstrates their significance using extensive digital well log data representing the Manville coals in Alberta, Canada. The spatial variability of the reservoir properties was captured through geostatistical analysis, and sequential Gaussian simulations of these provided multiple realisations for the reservoir simulator inputs. A number of CO₂ injection scenarios with variable matrix swelling coefficients were evaluated using a 2D reservoir model and spatially distributed realisations of total net thickness and permeability.     

Tapping the leakages: Methane losses, mitigation options and policy issues for Russian long distance gas transmission pipelines

The Russian natural gas industry is the world's largest producer and transporter of natural gas. This paper aims to characterize the methane emissions from Russian natural gas transmission operations, to explain projects to reduce these emissions, and to characterize the role of emissions reduction within the context of current GHG policy. It draws on the most recent independent measurements at all parts of the Russian long distance transport system made by the Wuppertal Institute in 2003 and combines these results with the findings from the US Natural Gas STAR Program on GHG mitigation options and economics.With this background the paper concludes that the methane emissions from the Russian natural gas long distance network are approximately 0.6% of the natural gas delivered. Mitigating these emissions can create new revenue streams for the operator in the form of reduced costs, increased gas throughput and sales, and earned carbon credits. Specific emissions sources that have cost-effective mitigation solutions are also opportunities for outside investment for the Joint Implementation Kyoto Protocol flexibility mechanism or other carbon markets.     

Pricing of Natural Gas in Developing Countries

The uncertain supply and increasing cost of petroleum products since 1973 has spurred on the development of alternative forms of energy. Natural gas is a major source of energy in over 50 developing countries. In these countries natural gas has many uses as a substitute for other fuels or as a feedstock. This paper discusses the economic concept for pricing of natural gas, in particular marginal costs, and estimates the economic cost of natural gas in developing countries under a wide range of conditions. The marginal cost of natural gas estimated for these countries is far below the border price of competing fuels. Because natural gas is in its early days of development, gas supply costs are not expected to rise in these countries within the next two decades as already proven reserves are tapped.     

煤层气勘探开发和利用的环境影响分析

煤层气是煤层中自生自储的一种非常规天然气，其成分主要是甲烷。与煤和石油比较，煤层气是一种清洁能源，因此加快煤层气的开发和利用，能改善能源结构，缓和能源紧张状况，减少环境污染。根据煤层气的特点，详细分析了其对于大气环境、水环境以及土壤、植物的影响因素后指出：开发利用煤层气对大气环境的影响利大于弊，而对水体、土壤、农作物等则产生一系列不利影响。     

Anaerobic Digestion of Agricultural Solid Residues

Abstract

Agricultural residues can be converted to methane-rich gas mixture. Anaerobic biomethane production is an effective process for conversion of a broad variety of agricultural residues to methane to substitute natural gas and medium calorific value gases. Methane generating bacteria (methanogens) and other microbes that help digest dying plants in anaerobic conditions. Agricultural solid residues (ASR) represent a potential energy resource if they can be properly and biologically converted to methane.     

The Role of Ownership in Environmental Performance: Evidence from Coalbed Methane Development

One way coalbed methane production differs from traditional oil and gas extraction is in the large quantities of produced water. This water must be disposed of for production to occur. Surface discharge has proven to be a low-cost alternative; regulations are in place to protect surface water quality. This paper investigates the effects of alternative ownership regimes on regulatory compliance. A unique dataset linking coalbed methane wells in Wyoming to water disposal permit violations is used to explore differences in environmental performance across severed and unified minerals. Empirical analysis of these data suggest that ownership does impact environmental compliance behavior. Most violations occur on split estate. Federal split estate wells have more severe violations, though not necessarily more of them. Federal unified wells performed best, with fewer and less serious violations. Wells on private land have more, though not necessarily more severe, violations. These results suggest some room for policy proposals accounting for alternative ownership regimes.     

美国油气行业国家温室气体清单和报送体系

甲烷是由人类活动造成的仅次于二氧化碳的第二大温室气体,大幅度减少甲烷排放有助于降低近期温升,是实现巴黎协定目标的必要手段,也是中国实现“碳中和”目标的重要抓手。相比其他排放源,油气行业的甲烷减排最快、最有经济性。而有效的减排政策和监管必须建立在完整、准确的甲烷排放清单基础上。文章以甲烷为重点,概述了美国国家温室气体清单和油气行业的报送制度,介绍了两个报送体系的覆盖范围、要求等相关差异,说明了设施界定、排放因子和活动水平来源、监测方法以及有待改进之处,并针对中国油气行业甲烷排放数据的质量改善提出了建议。     

CO2 storage and enhanced coalbed methane recovery: Reservoir characterization and fluid flow simulations of the Big George coal,Powder River Basin,Wyoming, USA

Coalbeds are an attractive geological environment for storage of carbon dioxide (CO₂) because CO₂ is retained in the coal as an adsorbed phase and the cost of injection can be offset by enhanced coalbed methane (ECBM) production. This paper presents the findings of a CO₂ storage feasibility study on coalbeds in the Wyodak-Anderson coal zone of the Powder River Basin, Wyoming, USA, using reservoir characterization and fluid flow simulations. A 3D numerical model of the Big George coal was constructed using geostatistical techniques, with values of cleat and matrix permeability and porosity constrained through history-matching of production data from coalbed methane (CBM) wells in the field area.Following history-matching, several ECBM and CO₂ storage scenarios were investigated: shrinkage and swelling of the coal was either allowed or disallowed, a horizontal hydraulic fracture was either placed at the injection well or removed from the model, the number of model layers was varied between 1 and 24, and the permeability and porosity fields were constructed to be either homogeneous or heterogeneous in accordance with geostatistical models of regional variability. All simulations assumed that the injected gas was 100% CO₂ and that the coalbed was overlain by an impermeable caprock. Depending on the scenario, the simulations predicted that after 13 years of CO₂ injection, the cumulative methane production would be enhanced by a factor of 1.5–5. Including coal matrix shrinkage and swelling in the model predicted swelling near the injection well, which resulted in a slight reduction (10%) in injection rate. However, including a horizontal hydraulic fracture in the model at the base of the injection well helped mitigate the negative effect of swelling on injection rate. It was also found that six model layers were needed to have sufficient resolution in the vertical direction to account for the buoyancy effects between the gas and resident water, and that capturing the heterogeneous nature of the coal permeability and porosity fields predicted lower estimates of the storage capacity of the Wyodak-Anderson coal zone.After noting that gravity and buoyancy were the major driving forces behind gas flow within the Big George coal, several leakage scenarios were also investigated, in an effort to better understand the interplay between diffusion and flow properties on the transport and storage of CO₂. The modeling predicted that the upward migration of gas due to the buoyancy effect was faster than the diffusion of CO₂ and therefore the gas rapidly rose to the top of the coalbed and migrated into overlying strata when an impermeable caprock was not included in the model.     

国内外石油公司甲烷排放差异性分析及启示

甲烷排放管控是国际石油公司推动低碳能源转型的一项重要举措,也是达成净零碳排放愿景的一个重要手段。研究发现,国内外石油公司的油气生产活动水平、甲烷排放控制水平、甲烷排放核算方法等3个方面均存在较大差异性。我国油井单井产量低,地面工程量大、工艺复杂,流程工艺中甲烷排放突出,油气系统甲烷排放水平较高,油气生产甲烷排放控制水平与国外石油公司相比尚有较大差距,与国外甲烷排放核算方法也存在较大差异性。着眼于甲烷排放管控,我国石油公司应充分衡量甲烷排放现状、生产活动水平、甲烷排放控制措施经济性和适用性等多重因素,严格控制潜在甲烷排放节点,并进一步做好甲烷排放检测、监测和数据统计工作,持续完善甲烷排放报告和核查体系。     

Alternative energy balances for Bulgaria to mitigate climate change

Alternative energy balances aimed to mitigate greenhouse gas (GHG) emissions are developed as alternatives to the baseline energy balance. The section of mitigation options is based on the results of the GHG emission inventory for the 1987–1992 period. The energy sector is the main contributor to the total CO₂ emissions of Bulgaria. Stationary combustion for heat and electricity production as well as direct end-use combustion amounts to 80% of the total emissions. The parts of the energy network that could have the biggest influence on GHG emission reduction are identified. The potential effects of the following mitigation measures are discussed: rehabilitation of the combustion facilities currently in operation; repowering to natural gas; reduction of losses in thermal and electrical transmission and distribution networks; penetration of new combustion technologies; tariff structure improvement; renewable sources for electricity and heat production; wasteheat utilization; and supply of households with natural gas to substitute for electricity in space heating and cooking. The total available and the achievable potentials are estimated and the implementation barriers are discussed.

     

Evaluating coal bed methane investment in China based on a real options model

In this paper, a real options based binominal lattices model for the investment of coal bed methane (CBM) is conducted. CBM prices and market demand are incorporated into the model as the predominant uncertain factors and it is solved by using the bidimensional binominal lattices approach. Then the model is employed to evaluate the investment in CBM projects in China, and the effect of related policies is analyzed. The empirical results demonstrate that the model can be used to offer a better explanation of why the CBM industry has developed slowly in China from an investment perspective. It is found that the current policy environment is not positive enough to attract investment in the CBM industry. Among various factors, CBM prices yield the most significant effect on stimulating investment in CBM development. Increasing the price subsidy is also an effective policy to stimulate investment and promote the development of the CBM industry in China.     

Waste Management and Climate Change

Waste management has at least five types of impacts on climate change, attributable to: (1) landfill methane emissions; (2) reduction in industrial energy use and emissions due to recycling and waste reduction; (3) energy recovery from waste; (4) carbon sequestration in forests due to decreased demand for virgin paper; and (5) energy used in long-distance transport of waste: A recent USEPA study provides estimates of overall per-tonne greenhouse gas reductions due to recycling. Plausible calculations using these estimates suggest that countries such as the US or Australia could realise substantial greenhouse gas reductions through increased recycling, particularly of paper.     

电絮凝＋电氧化法处理山西某区块煤层气采出水研究与实践

山西省某区块煤层气采出水水质均值为COD 170 mg/L,BOD₅29.7 mg/L,氨氮5.36 mg/L,氟化物6.59 mg/L,4个污染物指标超过GB 3838—2002《地表水环境质量标准》Ⅳ类水质限值要求。文章针对该地区煤层气采出水的可生化性差(BOD₅/COD≤20%)、氯离子含量较高等特点,采用“电絮凝+电氧化”法进行中试试验,处理后水质COD≤17 mg/L,氨氮≤0.1 mg/L,氟化物≤1.0 mg/L,试验结果表明:采用该方法可以有效降低COD、氨氮、氟化物等主要污染物指标,使该区块煤层气采出水达到GB 3838—2002标准Ⅳ类水质要求(COD≤30 mg/L、氨氮≤1 mg/L、氟化物≤1 mg/L)。应用中试试验研究成果,采用“双电+保障(过滤)”工艺在该区块建成了煤层气采出水处理示范工程,水处理站建成投运后出水水质稳定,始终满足GB 3838—2002《地表水环境质量标准》Ⅳ类水质要求。     

Do natural resources and economic components exhibit differential quantile environmental effects?

In view of the resource curse assumption, the environmental aspects of resource utilization are arguably posing more dangers to human existence. In the Middle East and North Africa (MENA) region, the region that holds more than 60% and 50% of the world's oil and gas reserves respectively, the need to examine the contribution of natural resources to environmental quality among other factors cannot be overemphasized. By leveraging on the novelty of observing the differential impact of natural resources and other economic components such as income and primary energy utilizations across the quantiles of carbon emission, this study implements the quantile regression approach alongside other relevant techniques to analyze data between 1990 and 2018 for selected countries in the MENA region including Saudi Arabia, Iran, Kuwait, Qatar, Algeria, Morocco, Oman, Egypt, and the United Arab Emirates (UAE). The result posits that natural resource utilization generally hampers the environment across the quantiles. However, this negative effect decreases until the 50th quantile before starting to rise again toward the upper quantiles. Additionally, primary energy utilization and globalization respectively worsen and improve environmental quantile, especially toward the upper quantiles while income affirms the inverted U-shaped hypothesis across the entire quantiles. Moreover, there is a statistically significant one-way directional causality from natural resources, economic expansion, primary energy use, and globalization to carbon emission levels. Hence, the study offers environmentally friendly resource utilization policies to the MENA economies and other resource-rich states by extension.     

Characteristics of coal mine ventilation air flows

Coal mine methane (CMM) is not only a greenhouse gas but also a wasted energy resource if not utilised. Underground coal mining is by far the most important source of fugitive methane emissions, and approximately 70% of all coal mining related methane is emitted to the atmosphere through mine ventilation air. Therefore, research and development on mine methane mitigation and utilisation now focuses on methane emitted from underground coal mines, in particular ventilation air methane (VAM) capture and utilisation. To date, most work has focused on the oxidation of very low concentration methane. These processes may be classified based on their combustion kinetic mechanisms into thermal oxidation and catalytic oxidation. VAM mitigation/utilisation technologies are generally divided into two basic categories: ancillary uses and principal uses. However, it is possible that the characteristics of ventilation air flows, for example the variations in methane concentration and the presence of certain compounds, which have not been reported so far, could make some potential VAM mitigation and utilisation technologies unfeasible if they cannot cope with the characteristics of mine site ventilation air flows. Therefore, it is important to understand the characteristics of mine ventilation air flows. Moreover, dust, hydrogen sulphide, sulphur dioxide, and other possible compounds emitted through mine ventilation air into the atmosphere are also pollutants. Therefore, this paper presents mine-site experimental results on the characteristics of mine ventilation air flows, including methane concentration and its variations, dust loadings, particle size, mineral matter of the dust, and other compounds in the ventilation air flows. The paper also discusses possible correlations between ventilation air characteristics and underground mining activities.     

An assessment of energy recovery methods applicable to domestic refuse disposal

Any recycled material for re-use must be competitive in both quality and cost when compared with virgin raw materials. In the case of domestic refuse these two constraints mean that direct recycling for materials re-use is very restricted and indirect uses are sought instead. One major area of indirect recycling is energy recovery. This paper presents economic analyses performed on a net energy output basis for incineration for both heat and electrical energy production and also for gas production by pyrolysis. Acid hydrolysis of refuse for the production of ethyl alcohol or protein is also presented and analysed in detail since by this means finite oil reserves are conserved. An economic case is made for further work in this area as it is shown to be the only refuse recycling process with the potential to accomplish both refuse disposal and energy recovery at costs substantially less than straight incineration.     

Comparison of adsorption models in reservoir simulation of enhanced coalbed methane recovery and CO2 sequestration in coal

Coalbed methane is an important resource of energy. Meanwhile CO₂ sequestration in coal is a potential management option for greenhouse gas emissions. An attractive aspect to this process is that CO₂ is adsorbed to the coal, reducing the risk of CO₂ migration to the surface. Another aspect to this is that the injected CO₂ could displace adsorbed methane leading to enhanced coalbed methane recovery. Therefore, in order to understand gas migration within the reservoir, mixed-gas adsorption models are required. Moreover, coal reservoir permeability will be significantly affected by adsorption-induced coal swelling during CO₂ injection. Coal swelling is directly related to reservoir pressure and gas content which is calculated by adsorption models in reservoir simulation. Various models have been studied to describe the pure- and mixed-gas adsorption on coal. Nevertheless, only the Langmuir and Extended Langmuir models are usually applied in coal reservoir simulations. This paper presents simulation work using several approaches to representing gas adsorption, implemented into the coal seam gas reservoir simulator SIMED II. The adsorption models are the Extended Langmuir model (ELM), the Ideal Adsorbed Solution (IAS) model and the Two-Dimensional Equation of State (2D EOS). The simulations based on one Australian and one American coal sample demonstrated that (1) the Ideal Adsorbed Solution model, in conjunction with Langmuir model as single-component isotherm, shows similar simulation results as the ELM for both coals, with the IAS model representing the experimental adsorption data more accurately than the ELM for one coal and identically with the ELM for the other coal; (2) simulation results using the 2D EOS, however, are significantly different to the ELM or IAS model for both coal samples. The magnitude of the difference is also dependent on coal swelling and the well operating conditions, such as injection pressure.     

RENEWABLE ENERGY SOURCES: THE CASE OF BRAZIL

Industrial nations have based their economic and social development on the use of fossil fuels (coal, petroleum and natural gas). This trend is being followed by many developing countries which have neither the natural resources nor the manpower to adopt this path. As a result one finds in many of these countries 'islands of prosperity' (based on consumption patterns copied from industrial nations) surrounded by a 'sea of poverty.' The problems resulting from this dual social structure are obvious in many parts of the world. It is argued here that renewable energy sources are a natural basis for the development of the poorer countries and that intelligent use of hydropower, biomass and direct solar energy can shortcut many of the problems faced today by industrial nations. The case of Brazil is analyzed as one of the countries in which these solutions are being tried.     

Waste Management and Climate Change

Waste management has at least five types of impacts on climate change, attributable to: (1) landfill methane emissions; (2) reduction in industrial energy use and emissions due to recycling and waste reduction; (3) energy recovery from waste; (4) carbon sequestration in forests due to decreased demand for virgin paper; and (5) energy used in long-distance transport of waste: A recent USEPA study provides estimates of overall per-tonne greenhouse gas reductions due to recycling. Plausible calculations using these estimates suggest that countries such as the US or Australia could realise substantial greenhouse gas reductions through increased recycling, particularly of paper.