scholarly journals Comparing the Use of High- to Low-Cost Black Carbon and Carbon Dioxide Sensors for Characterizing On-Road Diesel Truck Emissions

Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6714
Author(s):  
Rebecca A. Sugrue ◽  
Chelsea V. Preble ◽  
Thomas W. Kirchstetter
Keyword(s):  
Carbon Dioxide ◽  
Black Carbon ◽  
Emission Factor ◽  
Lower Cost ◽  
Low Cost ◽  
Ambient Air ◽  
Source Characterization ◽  
Ambient Conditions ◽  
Heavy Duty Diesel ◽  
Carbon Dioxide Co2

The exhaust plume capture method is a commonly used approach to measure pollutants emitted by in-use heavy-duty diesel trucks. Lower cost sensors, if used in place of traditional research-grade analyzers, could enable wider application of this method, including use as a monitoring tool to identify high-emitting trucks that may warrant inspection and maintenance. However, low-cost sensors have for the most part only been evaluated under ambient conditions as opposed to source-influenced environments with rapidly changing pollutant concentrations. This study compared black carbon (BC) emission factors determined using different BC and carbon dioxide (CO2) sensors that range in cost from $200 to $20,000. Controlled laboratory experiments show that traditional zero and span steady-state calibration checks are not robust indicators of sensor performance when sampling short duration concentration peaks. Fleet BC emission factor distributions measured at two locations at the Port of Oakland in California with 16 BC/CO2 sensor pairs were similar, but unique sensor pairs identified different high-emitting trucks. At one location, the low-cost PP Systems SBA-5 agreed on the classification of 90% of the high emitters identified by the LI-COR LI-7000 when both were paired with the Magee Scientific AE33. Conversely, lower cost BC sensors when paired with the LI-7000 misclassified more than 50% of high emitters when compared to the AE33/LI-7000. Confidence in emission factor quantification and high-emitter identification improves with larger integrated peak areas of CO2 and especially BC. This work highlights that sensor evaluation should be conducted under application-specific conditions, whether that be for ambient air monitoring or source characterization.

Design, Modeling and Simulation of CMOS-MEMS Piezoresistive Cantilever Based Carbon Dioxide Gas Sensor for Capnometry

2011 ◽  
Vol 403-408 ◽  
pp. 3769-3774 ◽  
Author(s):  
Asif Mirza ◽  
Nor Hisham Hamid ◽  
Mohd Haris Md Khir ◽  
Khalid Ashraf ◽  
M.T. Jan ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Modeling And Simulation ◽  
Low Cost ◽  
Cmos Technology ◽  
Simulation Software ◽  
Dynamic Mode ◽  
Fully Differential ◽  
Carbon Dioxide Gas ◽  
Carbon Dioxide Co2 ◽  
Relative Change

This paper reports design, modeling and simulation of MEMS based sensor working in dynamic mode with fully differential piezoresistive sensing for monitoring the concentration of exhaled carbon dioxide (CO2) gas in human breath called capnometer. CO2 being a very important biomarker, it is desirable to extend the scope of its monitoring beyond clinical use to home and ambulatory services. Currently the scope of capnometers and its adaption is limited by high cost, large size and high power consumption of conventional capnometers . In recent years, MEMS based micro resonant sensors have received considerable attention due to their potential as a platform for the development of many novel physical, chemical, and biological sensors with small size, low cost and low power requirements. The sensor is designed using 0.35 micron CMOS technology. CoventorWare and MATLAB have been used as simulation software. According to the developed model and simulation results the resonator has resonant frequency 57393 Hz and mass sensitivity of 3.2 Hz/ng. The results show that the longitudinal relative change of resistance is 0.24%/µm while the transverse relative change of resistance is -0.03%/µm.

S. I. Engine Pollution Control Using Low-Cost Palletized Catalytic Converter

Volume 2 ◽  
2004 ◽  
Author(s):  
Madhuri Jakkaraju ◽  
Vasudha Patri
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Pollution Control ◽  
Noble Metals ◽  
Fossil Fuel ◽  
Catalytic Converter ◽  
Low Cost ◽  
Hydrocarbon Emissions ◽  
Oxides Of Nitrogen ◽  
Carbon Dioxide Co2

I. C. Engines consume large amounts of fossil fuel emitting harmful pollutants like carbon monoxide (CO), unburnt hydrocarbons (UBHC), and oxides of nitrogen (NOx). By using a catalytic converter (CC), the carbon monoxide, hydrocarbon emissions can be transformed into less harmful carbon dioxide (CO2) & water vapor (H2O). Currently available CC’s are using costly noble metals like platinum (pt), palladium (pd), rhodium (rh) etc., hence making them expensive. This paper deals with the use of low-cost palletized silver coated alumina as the catalyst element in a CC. In this study, alumina and silver were used in the ratio of 10:1. All tests have been conducted on a stationary S.I. Engine at a constant speed of 1500 r.p.m with and without CC. Also, the performance of the palletized CC in combination with promoters like Bismuth, Cerium and Lanthanum was tested which have shown better results than silver alone as the coating element. It has been experimentally determined that the CO emissions have dropped from 7.25 (% vol) to 3.03(% vol) and the HC values have reduced from 350 ppm to 190 ppm.

scholarly journals ЕКОЛОГІЧНА ЕФЕКТИВНІСТЬ ОХОЛОДЖЕННЯ ПОВІТРЯ НА ВХОДІ ГТУ В РІЗНИХ КЛІМАТИЧНИХ УМОВАХ

2019 ◽  
pp. 4-8
Author(s):  
Андрій Миколайович Радченко ◽  
Микола Іванович Радченко ◽  
Ян Зонмін ◽  
Сергій Анатолійович Кантор ◽  
Богдан Сергійович Портной
Keyword(s):  
Nitric Oxide ◽  
Carbon Dioxide ◽  
Gas Turbine ◽  
Fuel Consumption ◽  
Environmental Effect ◽  
Ambient Air ◽  
Climatic Conditions ◽  
Temperate Climate ◽  
Air Cooling ◽  
Carbon Dioxide Co2

The operation of gas turbine unites significantly depends on the ambient air temperature at the inlet, and the higher it is, the greater the specific fuel consumption is spent for the production of a unit capacity (mechanical/electrical energy), and, accordingly, the more harmful substances are removed to the atmosphere with exhaust gases. To reduce the negative impact of unproductive fuel consumption during the operation of gas turbine units at elevated ambient temperatures, the inlet air cooling is applied. The paper studies the ecological efficiency of gas turbine unite inlet air cooling, taking into account the variable climatic operation conditions for regions with different climatic conditions over a period of five years (2014-2018): temperate climate of Ukraine (on the example of cities Sumy and Ternopol) and the subtropical climate of the PRC (cities Beijing and Nanjing). The annual reduction in emissions of carbon dioxide CO2 and nitric oxide NOX was chosen as indicators for assessing the environmental effect of air cooling. It has been shown that deeper cooling gas turbine unite inlet air to 7...10 °C provides almost a half to two times greater reduction in specific fuel consumption, respectively, and harmful emissions compared with traditional cooling to 15 °C by the most widespread absorption lithium-bromide chillers, and for the temperate climate of Ukraine the relative effect is much greater than for the subtropical climatic conditions of the PRC. Reducing carbon dioxide CO2 over five years for the PRC climate when cooling air to 10 °C is approximately more than 500 t, and for Ukraine – more than 240 t, and NOX nitric oxide – about 3.5 t for China and 1.6 t for Ukraine, while with traditional cooling to 15 °C: more than 300 t for China, and for Ukraine about 120 t, and nitric oxide NOX – about 2 t for China and 0.7 t for Ukraine. Based on the results of a rough assessment of the environmental effect of cooling the ambient air at the inlet of gas turbine units, in the temperate climate of Ukraine, deep cooling of the air is especially advisable, which provides almost twice the effect compared with traditional cooling to 15 °C.

scholarly journals Evaluation and enhancement of a low-cost NDIR CO<sub>2</sub> sensor

2017 ◽  
Author(s):  
Cory R. Martin ◽  
Ning Zeng ◽  
Anna Karion ◽  
Russell R. Dickerson ◽  
Xinrong Ren ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Standard Deviation ◽  
Low Cost ◽  
Linear Regression Analysis ◽  
Ambient Air ◽  
Multivariate Linear Regression Analysis ◽  
Laser Absorption ◽  
Accuracy And Precision ◽  
Carbon Dioxide Concentrations ◽  
Ambient Air Monitoring

Abstract. Non-dispersive infrared (NDIR) sensors are a low-cost way to observe carbon dioxide concentrations in air, but their specified accuracy and precision are not sufficient for some scientific applications. An initial evaluation of six SenseAir K30 carbon dioxide NDIR sensors in a lab setting showed that without any calibration or correction, the sensors have an individual root mean square (RMS) error between ~ 5 to 21 parts per million (ppm) compared to a research-grade greenhouse gas analyzer using cavity enhanced laser absorption spectroscopy. Through further evaluation, after correcting for environmental variables with coefficients determined through a multivariate linear regression analysis, the calculated difference between the each of six individual K30 NDIR sensors and the higher-precision instrument had for one minute data a standard deviation of between 1.6 ppm and 4.4 ppm. The median standard deviation improved from 8.08 for off the shelf sensors to 1.89 ppm after correction and calibration, demonstrating the potential to provide useful information for ambient air monitoring.

Evaluation of the carbon dioxide (CO2) emission factor from lime applied in temperate upland soil

Geoderma ◽  
2019 ◽  
Vol 337 ◽  
pp. 742-748 ◽  
Author(s):  
Song Rae Cho ◽  
Seung Tak Jeong ◽  
Gun Yeob Kim ◽  
Jeong Gu Lee ◽  
Pil Joo Kim ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Co2 Emission ◽  
Emission Factor ◽  
Upland Soil ◽  
Carbon Dioxide Co2

scholarly journals Low Cost tool for finding ventilation rates for Airborne Infection Control in the Built Environment

2020 ◽  
Author(s):  
Raja Singh
Keyword(s):  
Carbon Dioxide ◽  
Natural Ventilation ◽  
Low Cost ◽  
Ambient Air ◽  
Disease Spread ◽  
Indoor Space ◽  
Airborne Infection ◽  
New Apparatus ◽  
The Cost ◽  
Ventilation Rates

Dilution Ventilation is an accepted way of providing Natural Ventilation for reduction of Disease spread in Indoor Spaces. It is most relevant in low resource settings where the cost of advanced technologies may be a barrier. Studies have been performed in India to find a correlation between Ventilation of spaces and its role in the prevention of Tuberculosis, which is a major airborne disease with high incidence levels in India. These studies lack the measurement of the air changes in the room which is an important criterion to find out the disease spread by transmission models. This paper presents a new apparatus prepared to measure Air changes in an indoor space using Carbon Dioxide as a biomarker which acts as a surrogate for the ventilation in the space. The apparatus prepared uses a pre-existing carbon dioxide meter but adds value to it by creating a tamper-proof, vandal-resistant and a poke-resistant system. It also includes a built-in air suction and withdrawal system so that the sensor can be supplied with the ambient air in the room so that it can accurately give the carbon dioxide measurements. The study enhances the methods of investigation for Indoor Air Quality studies.

scholarly journals Correlation of Respiratory Aerosols and Metabolic Carbon Dioxide

2021 ◽  
Vol 13 (21) ◽  
pp. 12203
Author(s):  
Niklas Kappelt ◽  
Hugo Savill Russell ◽  
Szymon Kwiatkowski ◽  
Alireza Afshari ◽  
Matthew Stanley Johnson
Keyword(s):  
Carbon Dioxide ◽  
Oral Fluid ◽  
Low Cost ◽  
Co2 Concentration ◽  
Transmission Route ◽  
Viral Loads ◽  
Co2 Concentrations ◽  
Carbon Dioxide Co2 ◽  
The Individual ◽  
Metabolic Carbon

Respiratory aerosols from breathing and talking are an important transmission route for viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Previous studies have found that particles with diameters ranging from 10 nm to 145 μm are produced from different regions in the respiratory system and especially smaller particles can remain airborne for long periods while carrying viral RNA. We present the first study in which respiratory aerosols have been simultaneously measured with carbon dioxide (CO2) to establish the correlation between the two concentrations. CO2 concentrations are easily available through low-cost sensors and could be used to estimate viral exposure through this correlation, whereas source-specific aerosol measurements are complicated and not possible with low-cost sensors. The increase in both respiratory aerosols and CO2 was linear over ten minutes in a 2 m3 chamber for all participants, suggesting a strong correlation. On average, talking released more particles than breathing, with 14,600 ± 16,800 min−1 (one-σ standard deviation) and 6210 ± 5630 min−1 on average, respectively, while CO2 increased with 139 ± 33 ppm min−1 during talking and 143 ± 29 ppm min−1 during breathing. Assuming a typical viral load of 7×106 RNA copies per mL of oral fluid, ten minutes of talking and breathing are estimated to produce 1 and 16 suspended RNA copies, respectively, correlating to a CO2 concentration of around 1800 ppm in a 2 m3 chamber. However, viral loads can vary by several orders of magnitude depending on the stage of the disease and the individual. It was therefore concluded that, by measuring CO2 concentrations, only the number and volume concentrations of released particles can be estimated with reasonable certainty, while the number of suspended RNA copies cannot.

scholarly journals Use of Multiple Low Cost Carbon Dioxide Sensors to Measure Exhaled Breath Distribution with Face Mask Type and Wearing Behaviour

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6204
Author(s):  
Naveed Salman ◽  
Muhammad Waqas Khan ◽  
Michael Lim ◽  
Amir Khan ◽  
Andrew H. Kemp ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Low Cost ◽  
Co2 Concentration ◽  
Face Mask ◽  
Base Station ◽  
Exhaled Breath ◽  
Co2 Sensor ◽  
Improper Use ◽  
The Face ◽  
Carbon Dioxide Co2

The use of cloth face coverings and face masks has become widespread in light of the COVID-19 pandemic. This paper presents a method of using low cost wirelessly connected carbon dioxide (CO2) sensors to measure the effects of properly and improperly worn face masks on the concentration distribution of exhaled breath around the face. Four types of face masks are used in two indoor environment scenarios. CO2 as a proxy for exhaled breath is being measured with the Sensirion SCD30 CO2 sensor, and data are being transferred wirelessly to a base station. The exhaled CO2 is measured in four directions at various distances from the head of the subject, and interpolated to create spatial heat maps of CO2 concentration. Statistical analysis using the Friedman’s analysis of variance (ANOVA) test is carried out to determine the validity of the null hypotheses (i.e., distribution of the CO2 is same) between different experiment conditions. Results suggest CO2 concentrations vary little with the type of mask used; however, improper use of the face mask results in statistically different CO2 spatial distribution of concentration. The use of low cost sensors with a visual interpolation tool could provide an effective method of demonstrating the importance of proper mask wearing to the public.

scholarly journals Capture and Activation of Carbon Dioxide Using Guanidine Superbases

2021 ◽  
Author(s):  
◽  
Grace Bomann
Keyword(s):  
Carbon Dioxide ◽  
Low Cost ◽  
Ambient Air ◽  
Ionic Species ◽  
Molecular Structures ◽  
Organic Transformations ◽  
H Nmr ◽  
Proton Source ◽  
Hygroscopic Nature ◽  
Bicarbonate Formation

<p>Due to its abundance and low-cost, carbon dioxide is a desirable C₁-building block within organic transformations. However, the thermodynamic and kinetic stability of CO₂ often necessitates preliminary activation before it can be inserted into organic molecules. This prompts the need for compounds that can effectively promote the activation of CO₂. This research investigates the capture and activation of carbon dioxide using a class of superbases that incorporate the bicyclic guanidine unit, 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]-pyrimidine (hppH, 1). A series of compounds containing multiple hpp-units assembled around a phenyl ring scaffold were synthesized and investigated in the functionalization of CO₂. The work presented in this study has demonstrated the ability of protonated superbasic hppH derivatives to efficiently and effectively capture and activate carbon dioxide from ambient air to form the corresponding guanidinium bicarbonate salts. A series of optimization reactions was carried out, and showed that addition of substoichiometric concentrations of a proton source activates these guanidine compounds to their fully protonated cationic forms, and results in CO₂ capture through bicarbonate formation.  A series of protonation studies were employed to fully characterize the cationic species. The tetraphenylborate and hydrochloride guanidinium salts were synthesized, isolated, and characterized by ¹H NMR and ¹³C NMR spectroscopic analysis. Molecular structures of relevant crystals were obtained through single crystal X-ray diffraction. These structures revealed a complex hydrogen-bonding network within these ionic species, and showed efficient delocalization of the formal positive charge within the protonated guanidinium units.  The guanidine superbases were implemented in a series of reactions attempting the functionalization of CO₂ and an alcohol to form corresponding alkylcarbonate products. However, the synthesis of these carbonate products was not achieved under the reaction conditions employed. This lack of success has been attributed to the hygroscopic nature of this class of compounds, resulting in the preferential capture of ambient water.</p>

Sign in / Sign up

Export Citation Format

Share Document