A Comparative Emissions Assessment - Drill Cuttings Treatment Alternatives

2021 ◽  
Author(s):  
Gareth Innes ◽  
Steinar Nesse ◽  
Jan Thore Eia

Abstract The offshore industry has for many years been cognisant of its impact on the marine environment. Since 1991, strict regulations relating to oil-based drill cuttings discharge have been in force in the signature countries to the OSPAR (Oslo/Paris) Convention. As the impact of greenhouse gas (GHG) emissions on climate change has become better understood, global carbon dioxide (CO2) emission reduction targets and how to meet them have risen up operators’ agendas. Offshore operations, which involve marine logistics, are also subject to limits on nitrogen dioxide (NOx) emissions, an indirect GHG that's toxic to humans and contributes to soil and water acidification. The choices that operators make today in how they operate, including the disposal of drill cuttings, must therefore address an increasing number of environmental and climate targets, in addition to health, safety and cost. This paper will outline the results of a comparative study between the offshore processing of drill cuttings and relevant conventional alternatives, including skip and ship, bulk transfer and cuttings reinjection (CRI). It is the first paper to show a direct emissions comparison between offshore processing and all other alternative methods for drill cuttings processing. The study assessed the carbon footprint and NOx emissions for each of the different alternatives for the treatment of drill cuttings. The values were then used to create an interactive emissions calculator that can be easily applied to specific projects to clarify the actual potential for emissions reduction within the drilling waste management process. A number of case studies were then run, comparing the different alternatives. For the examples run, the comparative assessment showed that wellsite thermal processing technology was the favourable alternative in terms of emissions, with an emission reduction in the order of 14 - 48%, compared with the onshore alternatives. Emissions of the alternatives, skip and ship and bulk transfer, were highly dependent on sailing and road transport distances, as well as power source for the onshore treatment facility. The assessment showed that CRI has the highest emissions of CO2 per tonne of cuttings. Alternatives involving onshore treatment had the highest NOx emissions when sailing distance was high, however this was highly dependent on the machinery and fuel source of the transport vessel - and for the offshore alternatives, the on-site energy production solution.

2021 ◽  
Vol 99 (10) ◽  
Author(s):  
Agbee L Kpogo ◽  
Jismol Jose ◽  
Josiane C Panisson ◽  
Atta K Agyekum ◽  
Bernardo Z Predicala ◽  
...  

Abstract The objective of this project was to determine the impact of feeding growing pigs with high wheat millrun diets supplemented with a multi-carbohydrase enzyme (amylase, cellulase, glucanase, xylanase, and invertase activities) on nutrient digestibility, growth performance, and greenhouse gas (GHG) output (carbon dioxide, CO2; nitrous oxide, N2O; methane, CH4). Three experiments were conducted utilizing six treatments arranged as a 3 × 2 factorial (0%, 15%, or 30% wheat millrun; with or without enzyme) for the digestibility experiment or as a 2 × 2 factorial (0% or 30% wheat millrun; with or without enzyme) for the performance and GHG experiments. The digestibility, performance, and GHG experiments utilized 48 individually housed pigs, 180 pigs housed 5 per pen, or 96 pigs housed 6 per chamber, respectively. Increasing wheat millrun up to 30% in the diet of growing pigs resulted in decreased energy, nitrogen (N) and phosphorus (P) apparent total tract digestibility and net energy content (P < 0.01). Overall, average daily gain (ADG) and gain to feed ratio were reduced in pigs fed wheat millrun (P < 0.05). Enzyme supplementation had minimal effects on the digestibility or performance parameters measured. Feeding diets with 30% millrun did not affect GHG output (CH4: 4.7 and 4.9; N2O: 0.45 and 0.42; CO2: 1,610 and 1,711 mg/s without or with millrun inclusion, respectively; P > 0.78). Enzyme supplementation had no effect on GHG emissions (CH4: 4.5 and 5.1; N2O: 0.46 and 0.42; CO2: 1,808 and 1,513 mg/s without or with enzymes, respectively; P > 0.51). Overall, the carbohydrase enzyme had minimal effects on parameters measured, regardless of wheat millrun inclusion (P > 0.10). Although energy, N and P digestibility, and ADG were reduced, the inclusion of up to 30% wheat millrun in the diet has no effect on GHG emissions from growing pigs (P > 0.10).


Author(s):  
Sean Garceau ◽  
Amar Jawalkar ◽  
Ryan McKennon ◽  
Christopher Moffatt ◽  
Anthony Pocengal ◽  
...  

Abstract The Oil & Gas industry and environmental agencies around the world are working to find solutions to reduce greenhouse gas (GHG) emissions. A comprehensive study by the US EPA found that emissions from compressor stations, blow down and purge, accounted for 97.7 Bscf or just over 31% of the total methane emissions attributed to the Natural Gas industry. [1] With methane (CH4) having 25 times the impact on global warming compared to carbon dioxide (CO2), and global legislation like the Regulations Respecting Reduction in the Release of Methane and Certain Volatile Organic Compounds Upstream Oil and Gas Sector (or also called Canadian Methane Rule) and regional methane reduction regulations, developing solutions to further mitigate methane emissions from process gas vents and centrifugal gas compressor seals becomes necessary as the industry moves towards near-zero targets. This paper addresses the design requirements and selection of a process gas vent recapture system and primary dry seal vent recapture system. In addition, this paper will review the design consideration during the design phase to the data collected during site operation.


Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6637
Author(s):  
Aleksandra Siudek ◽  
Anna M. Klepacka ◽  
Wojciech J. Florkowski ◽  
Piotr Gradziuk

Energy and climate policies benefit from modernized construction technology and energy supply source choices. Energy-efficiency improvement and CO2 emission reduction will result from renewable energy (RE) utilization in new and retrofit single-family houses in rural Poland. Several house construction scenarios and heating energy sources comparing building costs and potential emission reduction are based on already existing structures calculated for a 100 m2 dwelling corresponding to the average rural home. With the addition of thermal insulation and RE-generating equipment, construction costs increase, but the energy costs of operating the home dramatically shrink between a conventional and energy-neutral house. The latter scenario includes thermal solar panels and a heat pump as heating energy sources as well as electricity-generating PV panels. Replacing coal with environmentally-friendly RE reduces CO2 emissions by about 90% annually. Additionally, lower dependence on coal lessens other GHG emissions leading to immediate air quality improvement. New house building regulations guide homeowner construction and heating energy choice, but even larger gains could result from retrofitting existing rural houses, expanding environmental benefits and generating energy bill savings to households. However, the varying climate throughout Poland will require the purchase of energy in winter to assure residents’ comfort.


2021 ◽  
Vol 13 (14) ◽  
pp. 7985
Author(s):  
Rod Williams ◽  
Rasmus Pettinen ◽  
Pauline Ziman ◽  
Kenneth Kar ◽  
Roland Dauphin

Substantial advances in European road vehicle emissions have been achieved over the past three decades driven by strengthening revisions in emissions legislation and enabled by advances in fuel, vehicle engine and emissions control technologies. As both vehicle technology and emissions legislation in Europe continue to evolve, Concawe has conducted a study to examine the effects that fuels can have on emissions, in this case from commercial road vehicles. A bus certified to Euro VI emissions level and a delivery truck certified to Euro V emissions level have been tested on a chassis-dyno over the World Harmonized Vehicle Cycle (WHVC) and Transport for London Urban Inter-Peak (TfL UIP) test cycles with six fuels: an EN590-compliant B5 (petroleum diesel containing 5% biodiesel by volume), a bioderived paraffinic diesel, a 50:50 blend of the aforementioned fuels, a low-density petroleum-derived B5, a B30 and the same B30 additized with a high dose of cetane number improver (CNI). Results show reduced NOx reductant (AdBlue) consumption with paraffinic diesel in the Euro VI bus due to lower engine-out NOx emissions. More surprisingly, higher hydrocarbon emissions were observed with some low-density hydrocarbon fuels in the Euro V truck. Compared to B5, B30 with and without CNI did not affect tank-to-wheel (TTW) CO2, volumetric fuel consumption or NOx by statistically significant margins. When considered with the findings of a complementary light-duty study, it is apparent that low-density diesel fuels could offer overall benefits to both emissions affecting local air quality and to greenhouse gas emissions on a TTW basis. The addition of higher fatty acid methyl ester (FAME) levels to fuels can be used to increase renewable fuel contribution resulting in no penalty in NOx emissions from modern technology vehicles. Compatibility of these fuels with the existing vehicle fleet would require further specific consideration. Outside of fuel properties considerations, Euro VI aftertreatment systems can increase N2O emissions at the tailpipe through chemical reactions in the catalyst. This can translate into about 10% contribution of N2O emissions to the overall GHG emissions of the vehicle.


2021 ◽  
Author(s):  
B. Chudnovsky ◽  
I. Chatskiy ◽  
A. Lazebnikov

Abstract Over the past decades there has been a dramatic increase in natural gas burning as the benign fossil fuel, offering far lower emissions than oil or coal. Its place had been established in a clean, or at least, cleaner energy future. Today, the national and international energy policy has been shifted to carbon neutrality — achieving net zero carbon emissions — and as result has moved natural gas from the “benign” to the “menace” category At present, there are chiefly two alternatives for fuel carbon neutrality under discussion: power-to-gas (PtG) producing methane (or synthetic natural gas, SNG, hydrogen etc.) and power-to-liquid, which stores electric power in the form of methanol. In opposite to other synthetic or fossil fuels, like synthetic methane, NG or hydrogen, methanol burning leads to significant reductions in emissions of nitrogen oxides without any substantial firing system design change. Burning of synthetic methane or hydrogen requires significant effort for NOx reduction. Hydrogen as a fuel offers many advantages in power production. It is a carbon-free fuel that can decarbonize power and heat generation, and transportation, to help meet long-term CO2 emission-reduction targets. However, things are different for NOx emissions are a different matter. The more hydrogen is added to a NG, the higher the NOx is anticipated. Dry Low NOx (DLN) combustor has traditionally mixed NG with sufficient air upstream the combustor, so burning can take place in a lean atmosphere to maintain a relatively cool flame and thus keep NOx down. That approach does not work so well when more hydrogen enters the picture due to auto ignition occurring in the premix zone. Some companies already have diffusion-type combustor technology where fuel and air are supplied separately. Combustion of hydrogen, specifically in diffusion mode, implies combustion with a hotter flame, leading to higher combustion temperatures and the formation of local hot spots. These, in turn, can cause NOx to increase. The generalized solution is to cool the flame using diluents, such as demineralized water, steam or nitrogen. However, reducing NOx, by dilution reduces efficiency compared to a DLN combustor. Another option of providing wide load range of GT operation, while maintaining low NOx emissions is fuel dilution with flue gas being recirculated from the exhaust (FGR - Flue gas recirculation). The present paper discusses the effect of burning renewable fuels produced from carbon dioxide and hydrogen which are being diluted with a flow of FGR on GT performance and emissions reduction in diffusion combustors. For the prediction of the combustion behavior a methodology that combines experimental work and computational simulations was used. Given the fact that due to the increase in renewable energy introduction into the grid, addition of renewable fuel-based energy produced from carbon dioxide becomes very significant. Hence, the development of enhanced firing systems burning synthetic clean fuels with low emissions is challenging and should be promoted. Using renewable fuels for energy supply would reduce the unfavorable impact of CO2 and allow meeting the targets established in the Kyoto and Paris Protocols.


2013 ◽  
Vol 19 (4) ◽  
pp. 606-620 ◽  
Author(s):  
Dalia Štreimikienė

The aim of the paper is to address the EU policy for achieving low carbon economy by assessing energy technologies in electricity and road transport sector based on costs and impact on climate change and to indicate the most competitive electricity and transport technologies taking into account EU policy targets in GHG emission reduction, utilization of renewable and energy efficiency improvements. The main tasks of the paper are: to develop the multi-criteria framework for comparative assessment of energy technologies by applying MCDM methods for the electricity generation and transport technologies assessment. The interval TOPSIS method is employed in order to tackle the uncertain criteria. The assessment framework allows the comparison of electricity generation technologies and road transport technologies in terms of their GHG emission reduction and economic impacts and facilitates decision making process in energy sector seeking to implement EU energy policies. The main indicators selected for technologies assessment are: private costs and life cycle GHG emissions. The ranking of energy technologies based on private costs and GHG emissions allowed prioritizing these technologies taking into account the lowest GHG emission reduction costs.


2021 ◽  
Vol 13 (5) ◽  
pp. 2612
Author(s):  
Alun Scott ◽  
Richard Blanchard

Greenhouse gas (GHG) emissions from dairy farms are significant contributors to global warming. However, much of the published work on GHG reduction is focused on either methane (CH4) or nitrous oxide (N2O), with few, if any, considering the interactions that changes to farming systems can have on both gases. This paper takes the raw data from a year of activity on a 300-cow commercial dairy farm in Northern Ireland to more accurately quantify GHG sources by use of a simple predictive model based on IPCC methodology. Differing herd management policies are examined together with the impact of integrating anaerobic digestion (AD) into each farming system. Whilst significant success can be predicted in capturing CH4 and carbon dioxide (CO2) as biogas and preventing N2O emissions, gains made can be lost in a subsequent process, negating some or all of the advantage. The process of extracting value from the captured resource is discussed in light of current farm parameters together with indications of other potential revenue streams. However, this study has concluded that despite the significant potential for GHG reduction, there is little incentive for widespread adoption of manure-based farm-scale AD in the UK at this time.


Author(s):  
A. H. Lefebvre

The attainment of very low pollutant emissions, in particular oxides of nitrogen (NOx), from gas turbines is not only of considerable environmental concern but has also become an area of increasing competitiveness between the different engine manufacturers. For stationary engines, the attainment of ultra-low NOx has become the foremost marketing issue. This paper is devoted primarily to current and emerging technologies in the development of ultra-low emissions combustors for application to aircraft and stationary engines. Short descriptions of the basic design features of conventional gas turbine combustors and the methods of fuel injection now in widespread use are followed by a review of fuel spray characteristics and recent developments in the measurement and modeling of these characteristics. The main gas turbine generated pollutants and their mechanisms of formation are described, along with related environmental risks and various issues concerning emissions regulations and recently-enacted legislation for limiting the pollutant levels emitted by both aircraft and stationary engines. The impact of these emissions regulations on combustor and engine design are discussed first in relation to conventional combustors and then in the context of variable-geometry and staged combustors. Both these concepts are founded on emissions reduction by control of flame temperature. Basic approaches to the design of “dry” low NOx and ultra-low NOx combustors are reviewed. At the present time lean, premix, prevaporize, combustion appears to be the only technology available for achieving ultra-low NOx emissions from practical combustors. This concept is discussed in some detail, along with its inherent problems of autoignition, flashback, and acoustic resonance. Attention is also given to alternative methods of achieving ultra-low NOx emissions, notably the rich-bum, quick-quench, lean-burn and catalytic combustors. These concepts are now being actively developed, despite the formidable problems they present in terms of mixing and durability. The final section reviews the various correlations which are now being used to predict the exhaust gas concentrations of the main gaseous pollutant emissions from gas turbine engines. Comprehensive numerical methods have not yet completely displaced these semi-empirical correlations but are nevertheless providing useful insight into the interactions of swirling and recirculating flows with fuel sprays, as well as guidance to the combustion engineer during the design and development stages. Throughout the paper emphasis is placed on the important and sometimes pivotal role played by the fuel preparation process in the reduction of pollutant emissions from gas turbines.


Sign in / Sign up

Export Citation Format

Share Document