Influence of Lining Design Parameters on the Greenhouse Gas Emissions of Chinese Highway Tunnel Construction

Author(s):  
Jianfeng Xu ◽  
Chen Dong ◽  
Dongming Guo ◽  
Chun Guo

To realize low-carbon design for tunnel construction, the authors explored the relationship between tunnel design and greenhouse gas (GHG) emissions. This study proposed typical design models of Chinese highway tunnels based on the lining design specifications and engineering design cases. The research modified the GHG emission calculation method based on the standard quota system. The marginal GHG emissions caused by a change of design parameters of tunnel lining were determined. The results show that the emissions from shotcrete, concrete arch wall, system bolts, and steel frames are sensitive to the change of design parameters, while steel mesh is not. As the design thickness increases, the emissions of the concrete arch wall, inverted arch, and shotcrete increase approximately linearly. The emission distributions of system bolts and steel frames under different spacing are given. Under the same longitudinal spacing condition, the emission ratio of I18 and I16 steel frames is 1.197, and that of I16 and I14 steel frames is 1.316. By defining the marginal emissions caused by the change of design parameters, this study carried out basic work for highway tunnel low-carbon designs. The research is of strategic significance for achieving energy conservation and emission reduction in the tunnel industry.

Author(s):  
Dandan Liu ◽  
Dewei Yang ◽  
Anmin Huang

China has grown into the world’s largest tourist source market and its huge tourism activities and resulting greenhouse gas (GHG) emissions are particularly becoming a concern in the context of global climate warming. To depict the trajectory of carbon emissions, a long-range energy alternatives planning system (LEAP)-Tourist model, consisting of two scenarios and four sub-scenarios, was established for observing and predicting tourism greenhouse gas peaks in China from 2017 to 2040. The results indicate that GHG emissions will peak at 1048.01 million-ton CO2 equivalent (Mt CO2e) in 2033 under the integrated (INT) scenario. Compared with the business as usual (BAU) scenario, INT will save energy by 24.21% in 2040 and reduce energy intensity from 0.4979 tons of CO2 equivalent/104 yuan (TCO2e/104 yuan) to 0.3761 Tce/104 yuan. Although the INT scenario has achieved promising effects of energy saving and carbon reduction, the peak year 2033 in the tourist industry is still later than China’s expected peak year of 2030. This is due to the growth potential and moderate carbon control measures in the tourist industry. Thus, in order to keep the tourist industry in synchronization with China’s peak goals, more stringent measures are needed, e.g., the promotion of clean fuel shuttle buses, the encouragement of low carbon tours, the cancelation of disposable toiletries and the recycling of garbage resources. The results of this simulation study will help set GHG emission peak targets in the tourist industry and formulate a low carbon roadmap to guide carbon reduction actions in the field of GHG emissions with greater certainty.


2017 ◽  
Vol 30 (1) ◽  
pp. 191-214 ◽  
Author(s):  
Meryl Jagarnath ◽  
Tirusha Thambiran

Because current emissions accounting approaches focus on an entire city, cities are often considered to be large emitters of greenhouse gas (GHG) emissions, with no attention to the variation within them. This makes it more difficult to identify climate change mitigation strategies that can simultaneously reduce emissions and address place-specific development challenges. In response to this gap, a bottom-up emissions inventory study was undertaken to identify high emission zones and development goals for the Durban metropolitan area (eThekwini Municipality). The study is the first attempt at creating a spatially disaggregated emissions inventory for key sectors in Durban. The results indicate that particular groups and economic activities are responsible for more emissions, and socio-spatial development and emission inequalities are found both within the city and within the high emission zone. This is valuable information for the municipality in tailoring mitigation efforts to reduce emissions and address development gaps for low-carbon spatial planning whilst contributing to objectives for social justice.


2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Philip J. Ball

Abstract A review of conventional, unconventional, and advanced geothermal technologies highlights just how diverse and multi-faceted the geothermal industry has become, harnessing temperatures from 7 °C to greater than 350 °C. The cost of reducing greenhouse emissions is examined in scenarios where conventional coal or combined-cycle gas turbine (CCGT) power plants are abated. In the absence of a US policy on a carbon tax, the marginal abatement cost potential of these technologies is examined within the context of the social cost of carbon (SCC). The analysis highlights that existing geothermal heat and power technologies and emerging advanced closed-loop applications could deliver substantial cost-efficient baseload energy, leading to the long-term decarbonization. When considering an SCC of $25, in a 2025 development scenario, geothermal technologies ideally need to operate with full life cycle assessment (FLCA) emissions, lower than 50 kg(CO2)/MWh, and aim to be within the cost range of $30−60/MWh. At these costs and emissions, geothermal can provide a cost-competitive low-carbon, flexible, baseload energy that could replace existing coal and CCGT providing a significant long-term reduction in greenhouse gas (GHG) emissions. This study confirms that geothermally derived heat and power would be well positioned within a diverse low-carbon energy portfolio. The analysis presented here suggests that policy and regulatory bodies should, if serious about lowering carbon emissions from the current energy infrastructure, consider increasing incentives for geothermal energy development.


With growing concerns about global warming and greenhouse gas (GHG) emissions, there is an urgent need to evaluate and reduce the carbon footprint (CF) of surface excavation (SE). CF are GHG emissions caused by an activity or event. It is expressed in terms of the amount of carbon dioxide (COR2 R), or its equivalent of other emitted GHGs. Choosing an appropriate low-carbon emission method for SE is a vital task and involves environmental concerns due to several energy-consuming activities. Since essentially, every SE impacts the environment, it becomes very important to evaluate this impact and take necessary actions to minimize any negative consequence. The objective of this paper is to present a comprehensive overview on progress acquired over the years in understanding GHG emissions from SE and to discuss the steps in CF estimation. Publications were identified that reported GHG emissions and CF of SE over past 30 years. This literature review suggests that for most of the SE, the material production phase consumes a large amount of energy and is a major contributor of GHG emissions. Early phases of project planning should include appropriate ecological decisions consistent with the life-cycle assessment (LCA) and CF considerations. Pipe material and outside diameter should be considered during the SE to allow a detailed evaluation and reduction of their environmental impacts (EI). Incorporation of additional factors, such as cost and duration of the project into the environmental analysis is also recommended.


2020 ◽  
Vol 15 (3) ◽  
pp. 67-82
Author(s):  
David A. Ness ◽  
Ke Xing

ABSTRACT In accordance with international protocols and directions, the APEC Energy Working Group has concentrated on constraining operational energy use and greenhouse gas (GHG) emissions in cities across the Asia Pacific, especially from the widespread consumption of fossil fuels. In addition to economy level policies and recognising the different characteristics within the region, APEC has sought to take action at the town/city level via the Low-Carbon Model Town (LCMT) project, including the development of self-assessment tools and indicator systems. However, the “low carbon” landscape is changing. There is increasing recognition of embodied carbon, accompanied by the emergence of methods for its measurement, while the C40 Cities Climate Leadership Group has recently highlighted the significance of consumption-based carbon. Similarly, the Greenhouse Gas Protocol for Cities (GPC) is likely to extend its ambit from Scope 1 GHG emissions, derived from energy use within a city boundaries, and Scope 2 emissions from grid-supplied electricity, heating and / or cooling, to Scope 3 emissions derived from materials and goods produced outside the boundaries of a city but associated with construction within that city. After describing these emerging approaches and the current landscape, the paper examines the significance and implications of these changes for APEC approaches, especially in relation to the LCMT project, its indicators and the varying characteristics of towns and cities within the Asia-Pacific region. Special attention is given to the built environment, which is known to be a major contributor to operational and embodied emissions. Consistent with the theme of the Asia-Pacific Energy Sustainable Development Forum covering “sustainable development of energy and the city,” a case is put forward for the current APEC approach to be extended to encompass both embodied and consumption-based emissions.


2020 ◽  
Vol 2 ◽  
Author(s):  
Astley Hastings ◽  
Pete Smith

The challenge facing society in the 21st century is to improve the quality of life for all citizens in an egalitarian way, providing sufficient food, shelter, energy, and other resources for a healthy meaningful life, while at the same time decarbonizing anthropogenic activity to provide a safe global climate, limiting temperature rise to well-below 2°C with the aim of limiting the temperature increase to no more than 1.5°C. To do this, the world must achieve net zero greenhouse gas (GHG) emissions by 2050. Currently spreading wealth and health across the globe is dependent on growing the GDP of all countries, driven by the use of energy, which until recently has mostly been derived from fossil fuel. Recently, some countries have decoupled their GDP growth and greenhouse gas emissions through a rapid increase in low carbon energy generation. Considering the current level of energy consumption and projected implementation rates of low carbon energy production, a considerable quantity of fossil fuels is projected to be used to fill the gap, and to avoid emissions of GHG and close the gap between the 1.5°C carbon budget and projected emissions, carbon capture and storage (CCS) on an industrial scale will be required. In addition, the IPCC estimate that large-scale GHG removal from the atmosphere is required to limit warming to below 2°C using technologies such as Bioenergy CCS and direct carbon capture with CCS to achieve climate safety. In this paper, we estimate the amount of carbon dioxide that will have to be captured and stored, the storage volume, technology, and infrastructure required to achieve the energy consumption projections with net zero GHG emissions by 2050. We conclude that the oil and gas production industry alone has the geological and engineering expertise and global reach to find the geological storage structures and build the facilities, pipelines, and wells required. Here, we consider why and how oil and gas companies will need to morph from hydrocarbon production enterprises into net zero emission energy and carbon dioxide storage enterprises, decommission facilities only after CCS, and thus be economically sustainable businesses in the long term, by diversifying in and developing this new industry.


Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 84 ◽  
Author(s):  
Jorge M. Islas-Samperio ◽  
Fabio Manzini ◽  
Genice K. Grande-Acosta

Considering that the world transport sector is the second largest contributor of global greenhouse gas (GHG) emissions due to energy use and the least decarbonized sector, it is highly recommended that all countries implement ambitious public policies to decarbonize this sector. In Mexico the transport sector generates the largest share of greenhouse gas emissions, in 2014 it contributed with 31.3% of net emissions. Two original scenarios for the Mexican transport sector, a no-policy baseline scenario (BLS) and a low carbon scenario (LCS) were constructed. In the LCS were applied 21 GHG mitigation measures, which far exceeds the proposals for reducing transport sector GHG emissions that Mexico submitted in its National Determined Contributions (NDC). As a result, the proposed LCS describes a sector transformation path characterized by structural changes in freight and passenger mobility, new motor technologies for mobility, introduction of biofuels, price signals, transportation practices and regulations, as well as urban planning strategies, which altogether achieve an accumulated reduction of 3166 MtCO2e in a 25 year period, producing a global net benefit of 240,772 MUSD and a GHG emissions’ reduction of 56% in 2035 in relation to the BLS.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Bin Chen ◽  
Guoxuan He ◽  
Jing Qi ◽  
Meirong Su ◽  
Shiyi Zhou ◽  
...  

Global climate change caused by greenhouse gas (GHG) emissions, which severely limits the development of human society and threatens the survival of humanity, has drawn the international community's long-term attention. Gathering the most important production factors in the region, an industrial park usually represents the development level of specific industries in the region. Therefore, the industrial park should be regarded as the base unit for developing a low-carbon economy and reducing GHG emissions. Focusing on a typical high-end industrial park in Beijing, we analyze the carbon sources within the system boundary and probe into the emission structure in view of life-cycle analysis. A GHG inventory is thereby set up to calculate all GHG emissions from the concerned park. Based on the results, suggestions are presented to guide the low-carbon development of the high-end industrial park.


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