Carbon Dioxide Equivalent Emissions Research Articles

Life cycle assessment of a wooden single-family house in Sweden

To understand the reasons behind the large environmental impact from buildings the whole life cycle needs to be considered. Therefore, this study evaluates the carbon dioxide emissions in all stages of a single-family house in Sweden from the production of building materials, followed by construction and user stages until the end-of-life of the building in a life cycle assessment (LCA). The methodology applied is attributional life cycle assessment (LCA) based on ‘One Click LCA’ tool and a calculated life span of 100 years. Global warming potential (GWP) and primary energy (PE) are calculated by using specific data from the case study, furthermore the data regarding building materials are based on Environmental Product Declarations (EPDs). The results show that the selection of wood-based materials has a significantly lower impact on the carbon dioxide emissions in comparison with non-wood based materials. The total emissions for this single-family house in Sweden are 6 kg CO2e/m2/year. The production stage of building materials, including building systems and installations represent 30% of the total carbon dioxide equivalent emissions, while the maintenance and replacement part represents 37%. However, energy use during the in-use stage of the house recorded lower environmental impact (21%) due to the Swedish electricity mix that is mostly based on energy sources with low carbon dioxide emissions. The water consumption, construction and the end-of-life stages have shown minor contribution to the buildings total greenhouse gas (GHG) emissions (12%). The primary energy indicator shows the largest share in the operational phase of the house.

Impact of foreign direct investment on greenhouse gas emissions in agriculture of developing countries

This research analyses the impact of foreign direct investment on greenhouse gas emissions in the agriculture sector of developing countries. Panel data from 63 developing countries for the period 2005 to 2014 was used to estimate a dynamic econometric model by applying a system‐generalised method of moments. The empirical results indicate a positive impact of foreign direct investment in agriculture on the carbon dioxide equivalent emission intensity in developing countries. The results provide weak support for the pollution havens hypothesis and imply the importance of coordination between foreign direct investment and environmental policies.

Effects of solar field design on the energy, environmental and economic performance of a solar district heating network serving Italian residential and school buildings

In this paper a centralized hybrid renewable district heating system based on the exploitation of solar energy and integrated with a seasonal borehole thermal energy storage is investigated with reference to a 5-year period by means of the dynamic simulation software TRNSYS. The plant is devoted to satisfy the energy demand for heating purposes and domestic hot water (DHW) production of a small-scale district composed of six residential buildings and three schools under the climatic conditions of Naples (south of Italy).Four configurations of the solar field consisting of different combinations of solar thermal collectors (SCs) and photovoltaic/thermal panels (PVTs) are analyzed upon varying both (i) the technology of SCs (flat plate or evacuated tube heat pipe) as well as (ii) the control logic of solar circuit (operation with constant or variable flow rate of heat carrier fluid).The simulation results have been compared with those associated to a conventional decentralized heating system in terms of primary energy consumption, carbon dioxide equivalent emissions and operating costs in order to assess (i) the potential energy, environmental and economic benefits as well as (ii) the impact of solar field design on the overall system performance.

The choice of climate metric is of limited importance when ranking options for abatement of near-term climate forcers

The practice of using climate metrics to estimate carbon dioxide equivalent emissions has long been subject to scientific discussion. One strand of this literature has analysed whether the choice of metric affects the relative cost-effectiveness of options for climate change abatement, but there has been little discussion on the effect of metric choices on cost-effective abatement of near-term climate forcers (NTCFs). These NTCFs are air pollutants primarily regulated by policies outside the climate policy arena and their estimated carbon dioxide equivalent emissions are not typically considered in the evaluation of cost-effective abatement. However, the attention to NTCFs as climate forcers has increased during the last decade. The objective of this paper is to identify whether the relative cost-effectiveness of different NTCF abatement options is robust to climate metric choices. We assess nine plausible NTCF abatement options available in Sweden (with negligible effect on long-lived GHG emissions) and evaluate the robustness of the ranking of these, according to their estimated cost-effectiveness. Different metric designs are considered as well as climate impact uncertainty of NTCFs, with corresponding uncertainty in metric values. The results indicate that the choice of metric has little effect on the ranking of the options according to their cost-effectiveness, with options affecting NOx indicated as an exception. This suggests that the choice of metric utilised when calculating cost-effectiveness of NTCF abatement options is likely to have minor effect on which NTCF abatement options should be targeted for policy interventions (if NOx emissions are not significantly affected).

The Driving Forces of Carbon Dioxide Equivalent Emissions Have Spatial Spillover Effects in Inner Mongolia.

To spatially analyze the effects of the major drivers on carbon dioxide equivalent (CO2eq) emissions in Inner Mongolia, a typical area with high CO2eq emissions in China, this paper quantitatively investigates the factors that affect county-level CO2eq emissions and the corresponding spatial mechanisms. Based on a spatial panel econometric model with related energy and economic data from 101 counties in Inner Mongolia between 2007 and 2012, four main results are obtained: (a) The CO2eq emissions in Inner Mongolia rapidly increased at an average annual growth rate of 7.27% from 2007 to 2012, increasing from 287.69 million tons to 510.47 million tons. (b) The county-level CO2eq emissions in Inner Mongolia increased, but the growth rate decreased annually. Additionally, CO2eq emissions are highly heterogeneous in the region. (c) Geographic factors were the main cause of the spatial spillover effects related to county-level CO2eq emissions. Specifically, the levels of urbanization and technological progress were conducive to CO2eq emission reductions, and the economic growth and industrial structure had the opposite effect in Inner Mongolian counties. (d) Technological progress had a significant spatial spillover effect in Inner Mongolian counties, and the effects of other factors were not significant. Implementing relevant strategies that focus on the inter-county interactions among the driving forces of CO2eq emissions could promote energy savings and emission reductions in Inner Mongolia.

Parametric Analysis of Solar Heating and Cooling Systems for Residential Applications

In this paper, a parametric analysis of two solar heating and cooling systems, one using an absorption heat pump and the other one using an adsorption heat pump, was performed. The systems under investigation were designed to satisfy the energy requirements of a residential building for space heating/cooling purposes and domestic hot water production. The system with the absorption heat pump was analyzed upon varying (i) the solar collectors’ area, (ii) the volume of the hot water storage, (iii) the volume of the cold water tank, and (iv) the climatic conditions. The system with the adsorption heat pump was evaluated upon varying (i) the inlet temperature of hot water supplied to the adsorption heat pump, (ii) the volume of the hot water storage, (iii) the volume of the cold water tank, and (iv) the climatic conditions. The analyses were performed using the dynamic simulation software TRNSYS in terms of primary energy consumption, global carbon dioxide equivalent emissions, and operating costs. The performance of the solar heating and cooling systems was compared with those associated with a conventional system from energy, environmental and economic points of views in order to evaluate the potential benefits.

A framework for developing and projecting GHG emission inventory and preparing mitigation plan: A case study of Delhi City, India

To provide a framework for a systematic study to address the issues of GHG emissions, City of Delhi was selected. The study employs state-of-the-art analytical techniques to develop GHG emission inventory, its forecasting and preparing mitigation plan. The total carbon dioxide equivalent (tCO2e) emission was estimated at 41.26 million tonnes (Mt.) for the year 2014. The major contributors were power plants (46.8%), vehicles (29.7%), municipal solid waste burning (7.6%) and domestic cooking (6%). To achieve a continuous reduction, targets were set for two phases in the years, 2022 and 2030. The emissions were projected by considering growth in population, GDP, vehicles on the road and other activities; 63.64 (year 2022) and 79.19 (year 2030) Mt. tCO2e. The electricity consumption showed the highest increase followed by vehicles. Based on emission intensity (ratio of emission quantity to GDP), the target emission in the year 2030 was 54.74 Mt. tCO2e. The control-plan primarily comprised use of renewable sources, energy efficient devices and introduction of electric vehicles. Electricity generation by renewable sources (40% by 2030) could result in a reduction of 25.6 Mt. tCO2e (32% of tCO2e). It is shown systematic emission estimates and mitigation planning can achieve the target emission.

An integrated carbon footprint accounting and sustainability index for palm oil mills

Palm oil industry has received criticism from various parties on the issue of sustainability and the greenhouse gases. Carbon footprint accounting are widely used as a metric of climate change impacts and the main focus of many sustainability policies among companies and authorities. However, carbon footprint accounting has limitation to represent sustainability as a whole and may resulting inaccurate selection of further mitigation. This paper evaluates sustainability and greenhouse gases simultaneously using an integrated palm oil mill carbon footprint accounting (POMCFA) and palm oil mill sustainability index (POMSI) method. The integration was performed via the adoption of data synchronization of the carbon footprint accounting and sustainability assessment. The analysis shows that highest carbon dioxide equivalent emission was contributed by palm oil mill effluent followed by diesel consumption and water consumption. In terms of sustainability scoring, the results show that the environmental aspect achieved the lowest scores compared to other aspects (social and economy). Weaknesses identified include diesel consumption, palm oil mill effluent and boiler emission. The assessment analysed in terms of carbon dioxide equivalent and sustainability scoring demonstrates its potential to provide comprehensive mitigation selection purposes.

Evaluating the Efficacy of Zero-Emission Vehicle Deployment Strategies: The Maryland Case

This study aimed to develop a model to estimate the impacts of zero-emission vehicle (ZEV) adoption on CO2 emissions and to evaluate efficacy of ZEV deployment strategies in achieving greenhouse gas (GHG) emission reduction goals. We proposed a modeling scheme to represent ZEVs in four-step trip-based travel demand models. We then tested six ZEV scenarios that were a cross-combination of three ZEV ownership levels and two ZEV operating cost levels. The proposed modeling scheme and scenarios were implemented on the Maryland Statewide Transportation Model (MSTM) to analyze the impacts of different ZEV ownership and cost combinations on travel patterns and on CO2 emissions. The main findings were the following: (1) A high-ZEV ownership scenario (43.14% of households with ZEVs) could achieve about a 16% reduction in statewide carbon dioxide equivalent (CO2Eq) emissions from 2015 base year levels; and (2) CO2Eq emissions at a future year baseline (2030) (the Constrained Long-Range Plan) level dropped by approximately 11% in low-ZEV ownership scenarios, 17% in medium-ZEV ownership scenarios, and 32% in high-ZEV ownership scenarios. The high-ZEV ownership results also indicated a more balanced distribution of emissions per unit area or per vehicle mile traveled among different counties.

On greenhouse gas emissions and thermal efficiency of natural gas/diesel dual-fuel engine at low load conditions: Coupled effect of injector rail pressure and split injection

Replacing diesel by natural gas in diesel engine is of great interest for transportation and power station industry due to larger availability and lower environmental impact of natural gas compared to diesel fuel. However, natural gas/diesel dual-fuel (NDDF) engine has lower thermal efficiency and produces higher greenhouse gas (GHG) emissions than its counterpart diesel engine at low load conditions when conventional diesel combustion strategy is used. In order to overcome this drawback, the present paper experimentally and numerically investigates the coupling of two strategies; namely increasing diesel injection rail pressure and splitting diesel injection of a heavy-duty NDDF engine at low engine load conditions. The results revealed that increasing the injection rail pressure decreases thermal efficiency of the NDDF engine with split injection as a result of overly advanced combustion phasing. However, a higher thermal efficiency (37.2%), than that of the diesel-only and the NDDF engine with a single injection, can be achieved under optimized combustion phasing. Increasing the injection rail pressure significantly reduces the unburned methane emissions of the NDDF engine with split injection, especially at lower split ratios (mass of the injected diesel in the first pulse divided by that of the total injected diesel). However, increasing the injection rail pressure does not affect the unburned methane emissions under a split ratio of 65%. This is due to the fact that a larger portion of diesel fuel impinges onto the cylinder wall surface as revealed by the simulation results. The optimum methane emissions of the NDDF engine with split injection is reduced by 50% compared to the best condition of the NDDF engine with a single injection. Moreover, the indicated specific carbon dioxide equivalent (ISCO2-equivalent) emissions of the NDDF engine with split injection are reduced by 11% compared to those of the NDDF engine with a single injection and diesel-only engine. All in all, the present study demonstrated that thermal efficiency and GHG emissions of the NDDF engine can be further improved when simultaneously varying diesel fuel injection split ratio and rail pressure increase. This strategy is also found to help reducing pressure rise rate (PRR) and NOx and soot emissions.

Energy balance and environmental impacts of rice and wheat production: A case study in Nepal

Energy and environment are the key concerns in todays’ agriculture. This study investigated energy balance and environmental impact of rice and wheat production systems in terms of energy ratio, impact of energy inputs to the crop yield and CO2e (carbon dioxide equivalent) emissions under terai and hill geographical regions of Nepal. Primary data were collected from 139 randomly selected farms by using structured questionnaire. The results revealed that the total energy consumption in rice and wheat production were 9.70 GJ/hm2 (terai) to 11.78 GJ/hm2 (hill) and 8.40 GJ/hm2 (hill) to 10.95 GJ/hm2 (terai), respectively. The energy balance of rice and wheat production were found 46.33 GJ/hm2 (hill) to 59.29 GJ/hm2 (terai) and 27.14 GJ/hm2 (terai) to 38.52 GJ/hm2 (hill), respectively, where energy use efficiency in terai and hill were found to be 7.14 and 4.97 in rice, and 3.49 and 5.59 in wheat, respectively. The contribution of fertilizer on impacts was significant among other energy inputs in rice and wheat production in both geographical regions. The CO2e emissions from rice and wheat were higher by 52% and 78% in hill as compared to respective crop rice (1786 kg CO2e/hm2) and wheat (843 kg CO2e/hm2) in terai. This study showed that rice production system in terai is more energy and environmentally efficient, whilst wheat production in hill is more energy efficient. Keywords: energy indices, environmental impact, productivity, profitability, GHG emissions, rice, wheat, sensitivity analysis DOI: 10.25165/j.ijabe.20191201.3270 Citation: Pokhrel A, Soni P. Energy balance and environmental impacts of rice and wheat production: A case study in Nepal. Int J Agric & Biol Eng, 2019; 12(1): 201–207.

Energy balance and environmental impacts of rice and wheat production: A case study in Nepal

Energy and environment are the key concerns in todays’ agriculture. This study investigated energy balance and environmental impact of rice and wheat production systems in terms of energy ratio, impact of energy inputs to the crop yield and CO2e (carbon dioxide equivalent) emissions under terai and hill geographical regions of Nepal. Primary data were collected from 139 randomly selected farms by using structured questionnaire. The results revealed that the total energy consumption in rice and wheat production were 9.70 GJ/hm2 (terai) to 11.78 GJ/hm2 (hill) and 8.40 GJ/hm2 (hill) to 10.95 GJ/hm2 (terai), respectively. The energy balance of rice and wheat production were found 46.33 GJ/hm2 (hill) to 59.29 GJ/hm2 (terai) and 27.14 GJ/hm2 (terai) to 38.52 GJ/hm2 (hill), respectively, where energy use efficiency in terai and hill were found to be 7.14 and 4.97 in rice, and 3.49 and 5.59 in wheat, respectively. The contribution of fertilizer on impacts was significant among other energy inputs in rice and wheat production in both geographical regions. The CO2e emissions from rice and wheat were higher by 52% and 78% in hill as compared to respective crop rice (1786 kg CO2e/hm2) and wheat (843 kg CO2e/hm2) in terai. This study showed that rice production system in terai is more energy and environmentally efficient, whilst wheat production in hill is more energy efficient. Keywords: energy indices, environmental impact, productivity, profitability, GHG emissions, rice, wheat, sensitivity analysis DOI: 10.25165/j.ijabe.20191201.3270 Citation: Pokhrel A, Soni P. Energy balance and environmental impacts of rice and wheat production: A case study in Nepal. Int J Agric & Biol Eng, 2019; 12(1): 201–207.

The use of wood construction materials as a way of carbon storage in residential buildings in Brazil

Wood-based building materials are environmentally advantageous because of their lower greenhouse gas (GHG) emissions during manufacturing and capability of storing carbon permanently in their structure. The use of these materials can contribute for reaching the construction industry 2030 international goal of having carbon neutral buildings. Using carbon uptake estimation models, for these materials, improves the accuracy of GHG emissions quantification by construction industry and promotes the forestry sector. In this paper, the amount of carbon stored in wood materials is compared to amount emitted by the construction of residential apartments using traditional materials in Brazil. A sample of five apartments, representative of Brazilian typical construction scenarios, was analyzed, and the amount of carbon stored in wood products (such as doors, floors and ceiling linings) calculated. The impact of stored carbon n CO2eq (carbon dioxide equivalent) emission figures was assessed. The study shows that the stored carbon accounts, on average, for approximately 10% of the total CO2eq emitted during the construction.

Modelling and analysis of a hybrid solar concentrating-waste incineration power plant

Concentrating solar power plant will be a key component of the future energy systems in which the share of renewable energy is extremely high. A major challenge of this technology is, however, its intermittent power output, slowing down its rate of implementation in the global energy matrix. As such, waste incineration is a popular technology in the developed countries as a smart measure for the disposal of municipal waste and generating free energy. In this study, a hybrid configuration of a concentrating solar power plant accompanied with a waste incineration unit is proposed. In the proposed system, the waste incinerator offers a variable heating duty in order to regulate the power output of the concentrating solar power plant. The hybrid plant is designed for a case study in Denmark and is thermodynamically analyzed. The results of the simulations are presented and discussed. It is shown that the hybrid system can pave the bed for increasing the share of solar thermal power and bringing more waste incinerators to the electricity market. A 10 MWe hybrid power plant may prevent up to 8000 tonnes of carbon dioxide equivalent emission per month. The overall efficiency of the hybrid system is expected to be 24%.

Valorisation of solid waste as key opportunity for green city development in the growing urban areas of the developing world

Lack of integrated solid waste management practice in fast-growing cities of developing countries is posing a threat to sustainable and green cities development. The fast growing Jimma City in Ethiopia requires up-to-date waste quantification and characterization data for the planning and implementation of sound waste management options such as composting and energy recovery that could create new jobs and promote private sector involvement. Therefore, we quantified, characterized and evaluated energy potential and nutrient value of household solid waste from Jimma City. Total daily waste generated from the city’s households was estimated to be 85.8 tons, with an average per capita generation rate of 0.56 ± 0.17 kg/day. The biodegradable organic waste comprises 76% by weight and had optimum moisture content and carbon to nitrogen ratio for composting. The energy content of combustible household waste was estimated to be 17.5 MJ/kg for gross heating value and 9.54 MJ/kg for the net heating value that surpasses the lower limit for thermal treatment process to be economically viable. Waste-to-energy conversion of combustible waste of cities could reduce annually about 25,303 metric tons of carbon dioxide equivalent greenhouse gas emissions. Char briquettes produced through pyrolysis of solid waste could be a potential substitute for firewood to prevent deforestation and indoor air pollution. In conclusion, composting and pyrolysis are sound waste management options for green cities development in developing countries while minimizing public health risks and cost of treatment and disposal.

Urban Mobility and Greenhouse Gas Emissions: Status, Public Policies, and Scenarios in a Developing Economy City, Natal, Brazil

This study aims to deepen the understanding of the role of the urban mobility sector in the current and future greenhouse gas (GHG) emissions of a middle-sized city of Brazil, which is also a developing economy. With the cross-reference between road and rail mobility data, governmental mobility planning, the Global Protocol for Community-Scale Greenhouse Gas Emission Inventories (GPC) of the Intergovernmental Panel on Climate Change (IPCC) emission quantification methodology, and the creation of scenarios for up to 10 subsequent years, it is possible to verify that individual motorized transport accounts for 60% of the total emissions from the urban transportation sector, with the largest amount of carbon dioxide equivalent (CO2eq) emissions per passenger among all of the forms of mobility. However, in the case of this study, government mobility planning, by not encouraging more energy-efficient transport and non-motorized modes, ends up aggravating GHG emissions in the scenarios considered for 2020 and 2025. In turn, the mitigation scenarios proposed herein integrate public transport and non-motorized transport solutions that would reduce the total of equivalent carbon dioxide (tCO2eq) by at least 45,000 tCO2eq per year by 2025. This cross-referencing of the environmental impact of government mobility policies can be replicated in other cities in developing countries that do not yet present municipal inventories or emission monitoring.

Capacitated multi-modal network flow models for minimizing total operational cost and CO2e emission

Abstract Green logistics and transportation impose new requirements on distribution planning and flow optimization over complex logistics network. Carbon-dioxide equivalent (CO2e) emission on a road, for instance, depends on the transportation mode and vehicle type selected along the road. The handling cost of a load at a transshipment city also depends on the change of transportation mode and vehicle type from inbound to outbound at the city. Compared with traditional network structure, multi-modal network is characterized by multi-attributes link and dependent transshipment node (in terms of minimizing total cost and emission), which significantly increases problem complexity. This study attempts to address key issues in modeling and analysis of such systems. Analytical models are developed to characterize the problem structure/features explicitly and integrate decisions at single- and multi-objective levels. A set of experiments, designed based on real transportation logistics network, are carried out to verify and validate models’ functions, analyze sensitivity of parameters, and evaluate solution convergence behavior. The results indicated that while the problem is NP-hard, solutions via proper analytical models can be derived efficiently for problems of practical scale.

Impact of Climate Change Policies on Environmental Inequalities in Great Britain

The UK Climate Change Act of 2008 requires an 80% reduction in carbon dioxide-equivalent emissions by 2050 compared with 1990. Strategies implemented to achieve this target offer the opportunity to...

Energy and environmental evaluation of construction materials used for VW cars production

Production and operation of vehicles currently has a significant impact on the environment. The choice of more environmentally friendly construction materials which a car is made from can significantly reduce its environmental impact. The main aim of this article was to compare the environmental impact assessment of changes in the design of passenger cars by using the life cycle assessment analysis (LCA). The paper presents a simplified LCA method of a car, which in specific cases can be used to analyse environmental impacts associated with the manufacturing process to assess the ecological performance of new passenger cars. In the adopted LCA simplification, the carbon dioxide equivalent emission CO2eq was used to assess the impact. The values of these variables were determined based on the mass of materials used to build the car. A practical example of using the simplified LCA method for a comparative assessment of the ecological efficiency of Volkswagen Group passenger cars manufactured over the last 30 years is presented.

Preparation of cleaner one-part geopolymer by investigating different types of commercial sodium metasilicate in China

One-part geopolymers prepared by powder activators, similar to Portland cement in cast-in-situ application, are promising building materials due to the relatively slighter embodied environmental impact. There are three types of commercial sodium metasilicate powders in the China market, and they are Na2SiO3-anhydrous/NS0, Na2SiO3·5H2O/NS5 and Na2SiO3·9H2O/NS9, respectively. This study employed ultra-fine fly ash sinking beads (FASB) and ground granulated blast furnace slag (GGBS) as precursor materials to analyze the influences of NS0, NS5 and NS9 on the properties, microstructure and environmental impact of one-part geopolymer by measuring and characterizing compressive strength, porosity, reaction heat release, geopolymerization products and carbon dioxide equivalent (CO2-e) emission. The experimental results indicate that NS0 has the most rapid and effective activated effect in both single GGBS and GGBS-FASB composites. The strength of geopolymer activated with NS0 is the highest, followed by that with NS9, and followed by that with NS5. The products are mainly gelatinous phases, and the gels in NS0 and NS9 activated geopolymers are better geopolymerized than those in NS5 activated geopolymer, which is proved to be responsible for the difference in macro-performance. The evaluations of the cost and CO2-e emission per MPa of one-part geopolymer demonstrate that NS0 and NS9 are much cheaper and cleaner than NS5 for preparing one-part geopolymer. The embodied CO2 indexes of NS0 and NS9 activated single GGBS are only about 26.5% and 34.0% of that of ordinary Portland cement. This study not only partially explains the reasons for the different properties of one-part geopolymer activated by different types of sodium metasilicate, but also provides a guidance for preparing one-part geopolymer with reasonable cost and slight environmental impact.