Environmental Impacts of Introducing LNG as Alternative Fuel for Urban Buses – Case Study in Slovakia

The aim of the paper is to assess the possibility of decreasing the chosen environmental indicators like energy consumption, greenhouse gas (GHG) production and other exhaust pollutants in the selected region in Slovakia by introducing Liquefied Natural Gas (LNG) buses into bus transport. The assessment is carried out by comparing the consumption and emissions of current buses (EURO 2) in real operation, with potential buses (EURO 6) and with pilot LNG buses testing on the same lines. Comparison took place under the same conditions over the same period. The study measures the energy consumption and GHG production per bus. The research paper also compares two methodologies of calculation. The first calculation is according to the European Standard EN 16258: 2012 which specifies the general methodology for evaluation and declaration of energy consumption and GHG emissions (all services - cargo, passengers or both). The second calculation is according to the Handbook of Emission Factors for Road Transport (HBEFA). The results of the calculation are compared by both methods, and the most suitable version of the bus in terms of GHG emissions is proposed.

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Achieving Carbon Neutrality for A Future Large Greenhouse Gas Emitter in Quebec, Canada: A Case Study

Atmosphere ◽

10.3390/atmos11080810 ◽

2020 ◽

Vol 11 (8) ◽

pp. 810

Author(s):

Patrick Faubert ◽

Sylvie Bouchard ◽

Rémi Morin Chassé ◽

Hélène Côté ◽

Pierre-Luc Dessureault ◽

...

Keyword(s):

Natural Gas ◽

Literature Review ◽

Greenhouse Gas ◽

Paris Agreement ◽

Liquefied Natural Gas ◽

Potential Solution ◽

Carbon Neutrality ◽

Net Zero ◽

Zero Carbon

To reach the Paris Agreement targets of holding the global temperature increase below 2 °C above the preindustrial levels, every human activity will need to be carbon neutral by 2050. Feasible means for industries to achieve carbon neutrality must be developed and assessed economically. Herein we present a case study on available solutions to achieve net-zero carbon from the get-go for a planned liquefied natural gas (LNG) plant in Quebec, which would classify as a large Canadian greenhouse gas (GHG) emitter. From a literature review, available options were prioritized with the promoter. Each prioritized potential solution is discussed in light of its feasibility and the associated economic opportunities and challenges. Although net-zero carbon is feasible from the get-go, results show that the promoter should identify opportunities to reduce as much as possible emissions at source, cooperate with other industries for CO2 capture and utilization, replace natural gas from fossil sources by renewable sources and offset the remaining emissions by planting trees and/or buying offsets on the compliance and voluntary markets. As some of these solutions are still to be developed, to ensure timely net-zero pledge for the lifespan of the LNG plant, a portfolio and progressive approach to combine offsets and other options is preferable.

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Future Trends and Mitigation Options for Energy Consumption and Greenhouse Gas Emissions in a Developing Country of the Middle East Region: a Case Study of Lebanon’s Road Transport Sector

Environmental Modeling & Assessment ◽

10.1007/s10666-017-9579-x ◽

2017 ◽

Vol 23 (3) ◽

pp. 263-276 ◽

Cited By ~ 2

Author(s):

Marc Georges Haddad ◽

Charbel Joseph Mansour ◽

Charbel Afif

Keyword(s):

Energy Consumption ◽

Middle East ◽

Greenhouse Gas Emissions ◽

Greenhouse Gas ◽

Road Transport ◽

Transport Sector ◽

Future Trends ◽

East Region ◽

Middle East Region

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Methodology for Quantitative Assessment of Greenhouse Gas Emissions Reduction of Solar-Powered Wi-Fi

Electronics ◽

10.3390/electronics10222829 ◽

2021 ◽

Vol 10 (22) ◽

pp. 2829

Author(s):

Samah Temim ◽

Farid Bensebaa ◽

Larbi Talbi

Keyword(s):

Energy Consumption ◽

Greenhouse Gas ◽

Ghg Emissions ◽

Practical Case ◽

Modeling Framework ◽

Ghg Mitigation ◽

Access Points ◽

Technical Requirements ◽

Solar Powered

In this paper, a modeling framework to quantify the reduction of potential greenhouse gas (GHG) emissions when using solar-powered Wi-Fi as an internet access point is developed and tested. This framework includes newly developed MATLAB code and the use of the ATOLL tool for energy consumption and network optimization, respectively. A practical case study is described with scenarios enabling different signal coverage on a university campus. These scenarios are based on technical requirements, including number of access points, budget link, and access duration. Four hundred tons of GHG can be reduced each year if solar Wi-Fi is deployed in solar campuses, which represents 5.5 × 10−5 percent of the total GHG produced by the telecommunications sector. A direct relationship between the number of access points and coverage signal quality on the one hand and energy consumption on the other hand is established. We use this case study to forecast the potential GHG mitigation if a wider deployment of the community Wi-Fi is achieved. This methodology could also be used to estimate GHG reductions when other wireless technologies are deployed.

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Wastewater treatment process impact on energy savings and greenhouse gas emissions

Water Science & Technology ◽

10.2166/wst.2014.521 ◽

2014 ◽

Vol 71 (2) ◽

pp. 303-308 ◽

Cited By ~ 48

Author(s):

D. Mamais ◽

C. Noutsopoulos ◽

A. Dimopoulou ◽

A. Stasinakis ◽

T. D. Lekkas

Keyword(s):

Wastewater Treatment ◽

Energy Consumption ◽

Greenhouse Gas ◽

Energy Savings ◽

Wastewater Treatment Plants ◽

Specific Energy Consumption ◽

Ghg Emissions ◽

Wastewater Treatment Process ◽

Conventional Activated Sludge

The objective of this research was to assess the energy consumption of wastewater treatment plants (WWTPs), to apply a mathematical model to evaluate their carbon footprint, and to propose energy saving strategies that can be implemented to reduce both energy consumption and greenhouse gas (GHG) emissions in Greece. The survey was focused on 10 WWTPs in Greece with a treatment capacity ranging from 10,000 to 4,000,000 population equivalents (PE). Based on the results, annual specific energy consumption ranged from 15 to 86 kWh/PE. The highest energy consumer in all the WWTPs was aeration, accounting for 40–75% of total energy requirements. The annual GHG emissions varied significantly according to the treatment schemes employed and ranged between 61 and 161 kgCO2e/PE. The highest values of CO2 emissions were obtained in extended aeration systems and the lowest in conventional activated sludge systems. Key strategies that the wastewater industry could adopt to mitigate GHG emissions are identified and discussed. A case study is presented to demonstrate potential strategies for energy savings and GHG emission reduction. Given the results, it is postulated that the reduction of dissolved oxygen (DO) set points and sludge retention time can provide significant energy savings and decrease GHG emissions.

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Uncertainty Analysis of Embedded Energy and Greenhouse Gas Emissions Using BIM in Early Design Stages

Sustainability ◽

10.3390/su12072633 ◽

2020 ◽

Vol 12 (7) ◽

pp. 2633 ◽

Cited By ~ 3

Author(s):

Patricia Schneider-Marin ◽

Hannes Harter ◽

Konstantin Tkachuk ◽

Werner Lang

Keyword(s):

Sensitivity Analysis ◽

Reinforced Concrete ◽

Greenhouse Gas ◽

Ghg Emissions ◽

Environmental Indicators ◽

Information Modeling ◽

Early Design ◽

Technical Specifications ◽

Early Design Stages

With current efforts to increase energy efficiency and reduce greenhouse gas (GHG) emissions of buildings in the operational phase, the share of embedded energy (EE) and embedded GHG emissions is increasing. In early design stages, chances to influence these factors in a positive way are greatest, but very little and vague information about the future building is available. Therefore, this study introduces a building information modeling (BIM)-based method to analyze the contribution of the main functional parts of buildings to find embedded energy demand and GHG emission reduction potentials. At the same time, a sensitivity analysis shows the variance in results due to the uncertainties inherent in early design to avoid misleadingly precise results. The sensitivity analysis provides guidance to the design team as to where to strategically reduce uncertainties in order to increase precision of the overall results. A case study shows that the variability and sensitivity of the results differ between environmental indicators and construction types (wood or concrete). The case study contribution analysis reveals that the building’s structure is the main contributor of roughly half of total GHG emissions if the main structural material is reinforced concrete. Exchanging reinforced concrete for a wood structure reduces total GHG emissions by 25%, with GHG emissions of the structure contributing 33% and windows 30%. Variability can be reduced systematically by first reducing vagueness in geometrical and technical specifications and subsequently in the amount of interior walls. The study shows how a simplified and fast BIM-based calculation provides valuable guidance in early design stages.

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China’s Electric Vehicle Deployment: Energy and Greenhouse Gas Emission Impacts

Energies ◽

10.3390/en11123353 ◽

2018 ◽

Vol 11 (12) ◽

pp. 3353 ◽

Cited By ~ 7

Author(s):

Feiqi Liu ◽

Fuquan Zhao ◽

Zongwei Liu ◽

Han Hao

Keyword(s):

Energy Consumption ◽

Greenhouse Gas ◽

Local Governments ◽

Greenhouse Gas Emission ◽

Ghg Emissions ◽

Road Transport ◽

Transport Sector ◽

Commercial Vehicles ◽

Short Term ◽

State And Local

The explosion of the vehicle market in China has caused a series of problems, like energy security, climate change, air pollution, etc. The deployment of electric vehicles (EVs) is considered an effective solution to address these problems. Thus, both the state and local governments in China have launched some policies and incentives to accelerate the development of EVs and the EV industry. Do EVs can effectively solve these problems in short term, viewed from the fleet point? Based on China’s most up-to-date deployment plan for EVs, this paper analyzes the energy consumption and greenhouse gas (GHG) emissions caused by China’s road transport sector in three different scenarios. The results indicate that, based on current planning, the energy consumption and GHG emissions of the whole fleet will peak in 2025 and 2027, at the level of around 403 mtoe (million tons of oil equivalent) and 1763 mt CO2 eq. (million tons of CO2 equivalent), respectively. The introduction of EVs will significantly reduce the reliance on fossil fuel in the long term, with increasing ownership, while, in the short term, the fuel economy regulation will still play a more important role. Policy makers should continually pay attention to this. Meanwhile, commercial vehicles, especially heavy-duty trucks will account for a bigger and bigger proportion in the energy consumption and GHG emissions of the whole fleet. Thus, to some extent the focus should shift from passenger vehicles to commercial vehicles. More measures could be implemented.

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An Investigation of the Uncertainty of Handbook of Emission Factors for Road Transport (HBEFA) for Estimating Greenhouse Gas Emissions: A Case Study in Beijing

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198118796710 ◽

2018 ◽

Vol 2672 (25) ◽

pp. 79-88

Author(s):

Hongyu Lu ◽

Guohua Song ◽

Qi Zhao ◽

Jingyi Wang ◽

Weinan He ◽

...

Keyword(s):

Greenhouse Gas ◽

Ghg Emissions ◽

Road Transport ◽

Emission Factors ◽

Driving Cycles ◽

Positive Acceleration ◽

Acceleration And Deceleration ◽

Selection Of ◽

Key Parameter

The reliability of estimation of emissions under the Handbook of Emission Factors for Road Transport (HBEFA) model has not been thoroughly studied and the mechanics of the model have not been fully investigated. The HBEFA structure of typical driving cycles is analyzed in this study regarding its uncertainty for estimating greenhouse gas (GHG) emissions. The key parameter of the HBEFA model, relative positive acceleration (RPA), is analyzed for its sensitivity to GHG emissions. The results indicate that uncertainties in estimation of GHG emissions do exist in the HBEFA model. The uncertainties are derived from the adoption of selected driving cycles and from the parameter of RPA. Given the uncertainties of estimating the GHG emission factors of driving cycles, it might be difficult for the selected driving cycles to represent all traffic situations. Uncertainties also exist in the selection of the top-20 driving cycles. For the selected samples of driving cycles, the sensitivity of RPA is found to be insufficient in describing the emission differences, due to the insensitivity of RPA to acceleration and deceleration. Different driving characteristics may still yield the same RPA, which indicates the potential inability of RPA to capture specific traffic scenarios such as intersections, ramps, and congestion.

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A novel hybrid liquefied natural gas process with absorption refrigeration integrated with molten carbonate fuel cell

International Journal of Low-Carbon Technologies ◽

10.1093/ijlct/ctab021 ◽

2021 ◽

Author(s):

Mehdi Mehrpooya ◽

Parimah Bahramian ◽

Fathollah Pourfayaz ◽

Hadi Katooli ◽

Mostafa Delpisheh

Keyword(s):

Energy Consumption ◽

Fuel Cell ◽

Natural Gas ◽

Hybrid System ◽

Liquefied Natural Gas ◽

Molten Carbonate Fuel Cell ◽

Cooling Load ◽

Absorption Refrigeration ◽

Molten Carbonate ◽

Carbonate Fuel Cell

Abstract The production of liquefied natural gas (LNG) is a high energy-consuming process. The study of ways to reduce energy consumption and consequently to reduce operational costs is imperative. Toward this purpose, this study proposes a hybrid system adopting a mixed refrigerant for the liquefaction of natural gas that is precooled with an ammonia/water absorption refrigeration (AR) cycle utilizing the exhaust heat of a molten carbonate fuel cell, 700°C and 2.74 bar, coupled with a gas turbine and a bottoming Brayton super-critical carbon dioxide cycle. The inauguration of the ammonia/water AR cycle to the LNG process increases the cooling load of the cycle by 10%, providing a 28.3-MW cooling load duty while having a 0.45 coefficient of performance. Employing the hybrid system reduces energy consumption, attaining 85% overall thermal efficiency, 53% electrical efficiency and 35% fuel cell efficiency. The hybrid system produces 6300 kg.mol.h−1 of LNG and 146.55 MW of electrical power. Thereafter, exergy and sensitivity analyses are implemented and, accordingly, the fuel cell had an 83% share of the exergy destruction and the whole system obtained a 95% exergy efficiency.

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