Stringent Emission Standards Research Articles

Development of a phenomenological model for the description of RCCI combustion in a dual-fuel marine internal combustion engine

Increasingly stringent pollutant and CO2 emission standards require engine manufacturers to investigate innovative solutions. Among these techniques, low-temperature combustion (LTC) concepts have a large potential to simultaneously reduce NOx emissions and fuel consumption. A promising manner to realize LTC consists of adopting ultra-lean mixtures, where the combustion evolution is controlled by a proper spatial distribution of fuels with different chemical reactivities. In this context, depending on the proportion and stratification of the fuels, the heat release can primarily depend on chemistry progression, leading to a Reactivity Controlled Compression Ignition (RCCI) mode, or on flame propagation, locally initiated by a high reactivity fuel.In this work, the combustion characteristics of a large-bore research engine are experimentally investigated. Natural gas is supplied into the intake port, while light fuel oil (LFO) is directly injected in the cylinder. An experimental campaign is carried out including sweeps of engine load, air/fuel proportion, LFO amount, valve timing, and intake air temperature. Global engine operating parameters as well as cylinder pressure traces are recorded and analyzed.Based on the available experimental data, a phenomenological model handling both chemistries of fuels with different reactivities and flame propagation is developed and validated. The model is based on a multi-zone approach, where auto-ignition chemistry is solved by a tabulated method to preserve the computational effort. The proposed numerical approach shows the ability to simulate the experimental data with good accuracy, using a fixed tuning constant set. A dedicated correlation is built to reproduce the expected in-cylinder distribution of the directly injected liquid fuel. Global performance and combustion parameters are predicted with an average error below 5%. The model demonstrates to correctly describe the behavior of the tested engine under different operating conditions and to capture the physics behind such advanced combustion concepts.

Comparative Analysis on the Performance and Exhaust Gas Emission of Cars with Spark-Ignition Engines

Conventional fuels commonly used in cars with combustion engines and the effects of their combustion have a very negative impact on the state of the environment. The combustion of liquid fuels causes the introduction of many thousands of tons of CO2 and other harmful substances into the atmosphere every year. That is why the authorities of many countries are introducing more and more stringent emission standards for cars with internal combustion engines, and car manufacturers are trying to meet these standards. Therefore, the aim of the undertaken research was to compile and analyze the power of spark engines in individual capacity ranges, compression ratios, efficiency, CO2 emissions, dependence of combustion on engine capacity, dependence of CO2 emissions on engine capacity, and dependence of combustion on engine power. The conducted research also compared the level of average selected variables related to CO2 emission in terms of engine displacement by country of production using statistical analysis.

Experimental study on transient emissions characteristics of a heavy duty natural gas engine under world harmonized transient cycle

In this study, the transient emissions characteristics under WHTC for both cases with and without an aftertreatment system (AS) were investigated. The engine operating parameters were measured to reveal the factors influencing the emissions. The effects of engine thermal state (the oil temperature, coolant temperature and exhaust temperature) on emissions and AS were analyzed. The results show that emissions under WHTC are influenced by engine operating conditions and are higher in the cold start test. The CO emissions are sensitive to changes in the excess air coefficient. The NOx emissions are highly consistent with changes in the engine throttle values. The HC emissions are almost dominated by variations of the engine torque at high speeds. In addition, the exhaust temperature has a significant impact on AS performance. The conversion efficiencies of CO, NOx, and HC in the cold start test are respectively 95.8%, 97.5%, and 88.3%, while those of CO, NOx, and HC in the hot start test are respectively 98.4%, 99%, and 99.1%. Overall, the CNG engine with AS can meet the China VI emission limits and even more stringent emission standards in the future. This study provides a reference for exploring methods of emission reduction for CNG engines.

Emissions and spatial distribution of air pollutants from anthropogenic sources in Jakarta

This study aims to develop emission inventory and emission spatial distribution of NOX, CO, PM2.5, PM10, NMVOC, BC, and SO2 from anthropogenic sources in Jakarta from 2015 to 2030, using 2015 as a baseline year. The results from this study can be very important to improve the emission data for Jakarta and contribute to the global emission model. Emissions of these pollutants were calculated using GAINS (Greenhouse gas Air pollution INteractions and Synergies) model, considering implementation of emission standards for transport and stationary combustion sources as well as policies stimulating accelerated electrification of vehicle fleets and vehicle scrapping programs. The impact of current policies to emission reduction was also evaluated in this study. The total 2015 emissions of NOX, CO, PM2.5, PM10, NMVOC, BC and SO2 were estimated at around 53 Gg, 144 Gg, 4.6 Gg, 6 Gg, 48.6 Gg, 1.2 Gg, and 20 Gg, respectively. The biggest contribution for NOx, CO, BC and NMVOC emissions originated from road transportation sector which contributed about 57%, 93% and 75%, 96% respectively, while for SO2, industrial combustion contributed about 67%. Heavy duty vehicles contribute the most NOx and BC emissions in the transport sector, while motorcycles emit the most CO. PM2.5 and PM10 in Jakarta are mostly emitted from road transportation and industrial combustion sectors, which contributed around 43%–46% for each sector. Heavy duty vehicles were still the highest contributor of PM2.5 emission in the transport sector. Based on emission spatial distribution and the AERMOD dispersion model, the highest concentration of all pollutants was found in the central of Jakarta, where traffic activities are very busy. Policy implementation could effectively reduce pollution levels in Jakarta. The accelerated implementation of electric vehicles, stringent emission standards, and transport management measures like electronic road pricing could significantly contribute to the reduction of PM2.5, PM10 as well as BC.

Multiple Fuel Injection Strategies for Compression Ignition Engines

Until the early 1990s, the predominant method of fuel delivery for compression ignition engines was the mechanical pump-line-nozzle system. These systems typically consisted of a cam-driven pump that would send pressurized fuel to the fuel injectors where injection timing was fixed according to the pressure needed to overcome the spring pressure of the injector needle. These configurations were robust; however, they were limited to a single fuel injection event per thermodynamic cycle and respectively low injection pressures of 200–300 bar. Due to their limited flexibility, a poorly mixed and highly stratified air fuel mixture would result in and produce elevated levels of both nitrogen oxides and particulate matter. The onset of stringent emissions standards caused the advancement of fuel injection technology and eventually led to the proliferation of high-pressure common rail electronic fuel injection systems. This system brought about two major advantages, the first being operation at fuel pressures up to 2500 bar. This allowed better atomization and fuel spray penetration that improves mixing and the degree of charge homogenization of the air fuel mixture. The second is that the electronic fuel injector allows for flexible and precise injection timing and quantity while allowing for multiple fuel injection events per thermodynamic cycle. To supply guidance in this area, this effort reviews the experimental history of multiple fuel injection strategies involving both diesel and biodiesel fuels through 2019. Summaries are supplied for each fuel highlighting literature consensus on the mechanisms that influence noise, performance, and emissions based on timing, amount, and type of fuel injected during multiple fuel injection strategies.

Assessing heavy-duty vehicles (HDVs) on-road NOx emission in China from on-board diagnostics (OBD) remote report data

Mobile source emissions are some of the major causes of air pollution across the world and are associated with numerous adverse health impacts. China has implemented increasingly stringent emission standards over the past few decades, the most recent one being the sixth emission standard (China VI) first rolled out in 2019. The China VI standard places special emphasis on tightening limits for NOx emission and introduces remote monitoring of vehicles' On-board diagnostics (OBD) data to reduce emissions from diesel and gas-powered heavy-duty vehicles (HDV).This paper aims to establish a methodology to calculate HDV NOx emissions on an extended timescale, and under real-world operations. OBD data was collected and examined from 53 China VI diesel HDVs and 14 China V diesel HDVs, which found that the average NOx emission factors are 1.420 g/km and 3.894 g/km for the two samples respectively; this indicates that the implementation of China VI standard helps to significantly reduce NOx emission from HDVs. Combining the emission factors and calculated travel distances collected by OBD and vehicle sales data, the China VI emission standard is estimated to have resulted in 43,969 tons of NOx emission reduction by the end of 2020. With China announcing country-wide enforcement of the new standard in 2021, >1.7 million tons of NOx emission could be avoided by 2023 annually.

Residential wood heating: An overview of U.S. impacts and regulations

ABSTRACT Air pollution from residential wood heating poses a significant public health risk and is a primary cause of PM nonattainment in some areas of the United States. Those emissions also play a role in regional haze and climate change. While regulatory programs have focused on emissions reductions from large facilities, the residential heating sector has received limited attention. The failure to develop effective programs to address this emission source hampers the ability of state and local air quality programs to meet clean air goals. An updated New Source Performance Standard (NSPS) for Residential Wood Heaters was promulgated in 2015, which includes more stringent emissions standards for wood stoves and broadens its scope to regulate additional types of wood heating appliances. However, weaknesses in the test methods and programs used to certify compliance with the NSPS limits hamper the efficacy of those requirements. Current emissions certification tests measure stove performance under defined laboratory conditions that (1) do not adequately reflect operation and performance of appliances in homes, (2) are not sufficiently repeatable to allow for comparison of emissions of different appliances, and (3) allow manufacturers leeway to modify critical test fueling and operating parameters which can significantly impact performance outcomes. These foundational regulatory issues present substantial challenges to promoting the cleanest and most efficient wood heating systems. This paper provides an overview of the air quality and public health impacts of residential wood heating and discusses the weaknesses in the current emission certification approaches and work by the Northeast States for Coordinated Air Use Management (NESCAUM) and the New York State Energy Research and Development Authority to develop improved testing methods. Other articles in this issue discuss the development and testing of those methods in detail. Implications: Air pollution from residential wood heating poses a significant public health risk and is a primary cause of PM nonattainment in some areas of the United States. Those emissions also play a role in regional haze and climate change. While regulatory programs have focused on emissions reductions from large facilities, the residential heating sector has received limited attention. The failure to develop effective programs to address this emission source hampers the ability of state and local air quality programs to meet clean air goals. This paper provides an overview of the issue.

Influences of the control parameters and spark plug configurations on the performance of a natural gas spark-ignition engine

Lean-burn and exhaust gas recirculation (EGR) strategies have been used in natural gas spark ignition (SI) engines for meeting the increasingly stringent emission standards. However, the combustion rate of the natural gas (NG) decreases under the lean or ultra-lean and EGR operating conditions. In this paper, a simulation model based on the two-zone combustion modelling approach is established and validated with the experimental data. Then, configuration with different lambdas and EGR ratios, and twin-spark plugs are simulated by using this calibrated model to predict the performance of the NG SI engine. The results indicate that the EGR strategy is more effective in decreasing NOx emissions than that of the lean-burn strategy due to its thermal, dilution, and chemical effects of the EGR components. In addition, the formations of the HC emissions are amplified due to the dilution and chemical effects of the EGR components. Furthermore, under the lambda value of 1.5, the 50% mass fraction burned of the NG SI engine is located at 21.77 °CA after the top dead center (TDC) when the single-spark plug configuration is used, while it is located at 16.58 °CA after the TDC when the twin-spark plugs configuration is used. Besides, compared to the single-spark configuration, using the twin-spark plugs configuration in the NG SI engine is more conducive to decreasing the ignition delay period and combustion duration. Overall, it is verified that the use of twin-spark plugs configuration can effectively extend the lean-burn limit and enhance the combustion rate for the NG SI engine, particularly under the ultra-lean mixture.

Identifying specifications of in-use vehicles failing the inspection/maintenance emission test

The objective of this study is to illustrate the vehicle deterioration by usage condition, and identify characteristics of vehicles that fail the Inspection/Maintenance emission test. Using the data sampled from the I/M program of Nanjing, China in 2018, we found vehicle mileage is a better indicator for the deterioration than vehicle age, and newer vehicles have higher deterioration rates than older ones. A random forest model was developed to predict the result of the emission test using vehicle specifications as independent variables. The specifications of vehicles that potentially violate the emission limit were also identified from the model. The result shows vehicles with engine displacement lower than 1.5L, less stringent emission standards, 10-year-old to 17-year-old, or cumulative mileage longer than 120,000 km have a higher probability to fail the test. The proposed method can be used to target on potential high emitters, which improves the efficiency of vehicle inspection.

Numerical analysis of the use of different lattice designs and materials for reciprocating engine connecting rods

Nowadays, the use of lattice structure designs in metallic parts to produce lightweight systems has gained importance owing to advances in additive manufacturing technology. On the other hand, vehicle manufacturers are constantly looking for new ways to reduce weight due to the depletion of fossil fuels, the demand for vehicles having higher performance, global warming and increasingly stringent emission standards. In this study, in order to reduce the weight of the internal combustion engine, different lattice designs were made in the connecting rods. Four different 2.5D lattice designs, hexagonal, octagonal, square and triangular, were created in reference connecting rod body. The dimension of the lattice designs was 10x10x12 mm with the wall thickness of 1.5 mm. The fatigue behaviors of the connecting rods as well as mechanical properties under static conditions were analyzed using finite element approach. Three different materials were used in the analyzes: AISI 4140, Inconel 718 and Ti6Al4V. As a result, it was seen that weight reduction of up to 15.75% was possible in the connecting rod thanks to the lattice designs and the maximum stresses were below the yield stresses of the materials. Moreover, connecting rods with lattice design had satisfactory safety factor values.

A novel one-step wet denitration method by hydrodynamic cavitation and chlorine dioxide

Ships have brought substantial economic benefits, and meanwhile, they release exhaust gases, including plenty of nitrogen oxides (NOx). Increasingly stringent air pollutant emission standards (e.g., MARPOL) for ships have been established at home and abroad to reduce the pollution of NOx. In this paper, a promising technology for removing NOx from ship exhaust by hydrodynamic cavitation (HC) and chlorine dioxide (ClO2) was proposed. The mechanism of HC promoting denitration was discussed. The various influencing factors of the HC enhancing ClO2 circulation denitration, such as the pressure difference (∆P) between the inlet and outlet of the HC reactor, solution temperature (10.0 – 55.0 ℃), NO initial concentration (500–1000 ppm), gas flow rate (1.0–1.6 L/min), solution pH (3.00 – 11.00), and ClO2 concentration (0.001–0.100 mmol/L) on denitration effect were studied in the experiments, in which the optimal conditions were established. On the basis of the results of HC enhancing ClO2 circulation denitration, HC enhancing ClO2 non-circulation denitration experiments were carried out. The results showed that the NO and NOx removal efficiencies reached 93% and 90%. We also measured the final anions in solutions after denitration by ion chromatography and discussed the reaction pathways.

Hierarchical Fibrous Honeycomb Ceramics with High Load Capability and Low Light-Off Temperature for the Next-Generation Auto Emissions Standards.

Novel and stringent automotive exhaust gas emissions standards are urgently needed to counter the problems posed by the worsening global climate and environment. However, the traditional cordierite-based honeycomb ceramics substrates with ultimate pore density have seriously restricted the establishment of new emission standards. Herein, we introduce a novel robust substrate with tailored volume-specific surface area and low heat capacity. This substrate employs the synergy of high-strength ceramic fibers and ultrathin TiO2 nanosheets. The micro-sized fibers provide support to ensure structural strength during the catalytic reaction, while the nanosheets play the dual role of connecting the fibers and providing a high surface area for catalyst immobilization. The new three-dimensional (3D) microarchitecture exhibits a high volume-specific surface area of 3.59×104 cm2 /cm3 , a compressive strength of 2.01 MPa, and remarkable stability after high-speed air erosion at 800 °C. The honeycomb-like structure exhibit low resistance to gas flow. Furthermore, after loading with Pt and Pd nanoparticles, the composite 3D microarchitecture delivered an excellent catalytic performance and prominent structural stability, with a super low light-off temperature of 150 °C. The outstanding mechanical and thermal stability and the high surface area and light-off temperature of the new substrate indicate its potential for use as a highly efficient catalytic carrier to meet the next-generation auto emissions standards.

Spatio-Temporal Variations of Lower Tropospheric Pollutants and Their Relationship With Meteorological Factors in Karachi, Pakistan

Purpose: Karachi is the third most populous city globally, inhabiting over 20 million people. Its air quality is hardly ever comprehended despite ever-increasing vehicular and industrial emissions. The present paper investigates the outdoor concentrations of 10 air pollutants, viz. NO, NO2, NOx, SO2, CO, O3, CH4, methane carbon, non-methane hydrocarbons, and total hydrocarbons at three sites of the city and their relationship with meteorological parameters. Method: All ten air pollutants were measured continuously for 24 hours at all three city sites by the Air Quality Monitoring Station, equipped with the Horiba AP-370 series, which has a built-in calibration solenoid valve for calibration simply by connecting the calibration gas. The meteorological parameters were measured simultaneously by the device installed outside the station. The data were then transferred to a computer for analysis. Results: The results demonstrate that these pollutants severely affected the city’s air quality. The annual mean concentrations of both NO2 and SO2 exceeded the WHO guidelines at some sites. The city experiences varied concentrations of major air pollutants because three fuels, viz. diesel, gasoline, and compressed natural gas operate the motor vehicles in this conurbation. The study also correlates the air pollutants with each other and with meteorological factors. All three nitrogen oxides are related to each other at all three sites, with SO2 at Defense Housing Authority, CO at North Nazimabad, and meteorological factors at Sohrab Goth and Defense Housing Authority. Conclusion: The higher air pollution in the city is due to the adoption of lenient vehicular emission standards. Stringent emission standards cannot be adopted because of the non-availability of low or zero sulfur fuel. Moreover, ineffective regulation of exiting standards also contributes to higher vehicular emissions in the city.

Investigation of an efficient model-based fuel economy optimization methodology for diesel engines focusing on real world driving emission cycles

Together with stringent emission standards, meeting fuel consumption, and performance targets have made engine calibration process complicated, lengthy, and costly. For this reason, it is crucial to develop an efficient methodology for the optimization of a diesel engine calibration. In this study, a novel automated fine tuning methodology using genetic algorithms and data driven models is proposed. Fuel consumption of a light commercial vehicle with 2.0-L diesel engine was optimized for a predefined Real Driving Emissions (RDE) cycle. During the optimization, tail pipe emission limits were maintained by taking the aftertreatment system efficiency into account. To this end, a representative engine control unit, internal combustion engine, and Selective Catalyst Reduction (SCR) system models were built by using empirical data and neural networks. Moreover, the effect of choosing different tailored optimization points for a predefined route was investigated by comparison of frequency and fuel consumption based weighting. The cost function, related to the optimization problem, was defined based on fuel consumption, performance, and mechanical limits of the engine, and in accordance with tailpipe emission limits defined by Euro 6d-Temp regulations. Compared to previous model-based calibration studies, tailpipe emissions, and regulation limits have been incorporated in this study in order to obtain more realistic calibrations. After testing different genetic algorithm configurations, the fuel efficiency over the predefined route was improved by 3.07% without violating any of the limits while the smoothness of the calibration maps was also preserved. This route specific calibration methodology is believed to have the potential to increase fuel economy in real world applications such as daily commuting routes or repetitive driving patterns for instance, operation vehicle use cases in factories, airports, and construction areas. As for further development, this can be achieved by running simulations and the optimization on cloud and updating the calibration remotely based on the selected route before the trip.

Advances in air pollution control for vessels in China

Vessel emissions have contributed a great deal to air quality deterioration in China. Hence, the Chinese government has promulgated a series of stringent emission regulations. It is in this context that vessel emission control technology research is in full swing. In particular, during the 13th Five-Year Plan, the air pollution control technology of vessels has greatly improved. Vessel emission control has followed two main governance routes: source emission reduction and aftertreatment technology. Source control focuses on alternative fuels, with two main directions, the development of new fuels and the modification of existing fuels. Moreover, after-treatment technologies have also been developed, including wet desulfurization technology using seawater or alkaline liquids as wet washing liquids and selective catalytic reduction (SCR) for the control of NOx emission. Due to China's increasingly stringent emissions standards and regulations, work on the development of clean alternative fuels and further upgrading the collaborative application of after-treatment technologies to meet the near-zero-emissions requirements of vessels is still necessary.

Toward Cleaner Transport Alternatives: Reduction in Exposure to Air Pollutants in a Mass Public Transport.

Commuters are often exposed to higher concentrations of air pollutants due to its proximity to mobile sources. Despite recent trends in urban transport toward zero- and low-tailpipe emission alternatives, the assessments of the impact of these transformations on commuter exposure are limited by the low frequency of such studies. In this work, we use a unique data set of personal exposure concentration measurements collected over the span of 5 years to analyze changes due to the introduction of a new fleet for Bogotá's Bus Rapid Transit System. In that system, over a thousand Euro-II and -III diesel-powered buses were replaced with Euro-VI compressed natural gas and filter-equipped Euro-V diesel buses. We measured personal exposure concentrations of equivalent black carbon (eBC), fine particulate (PM2.5), and ultra fine particles (UFP) during and after the retirement of old buses and the introduction of new ones. Observations collected prior to the fleet renewal were used as baseline and later compared to data collected over two follow-up campaigns in 2019 and 2020. Significant reductions in the concentration of PM2.5 and eBC were observed during the 2019 campaign, with a 48% decrease for mean in-bus eBC (89.9 to 46.4 μg m-3) and PM2.5 (180.7 to 95.4 μg m-3) concentrations. Further reductions were observed during the 2020 follow-up, when the fleet renovation was completed, with mean in-bus eBC decreasing to 17.7 μg m-3 and PM2.5 to 42.3 μg m-3. These observations imply nearly a 5-fold reduction in eBC exposure and a 4-fold decrease in PM2.5. There was a much smaller reduction of in-bus UFP concentration between 2019 and 2020, indicating a persistent presence of high particle number concentrations in the near-road environment despite the fleet renovation process. In-bus UFP concentrations ranged between 65 000 and 104 500 cm-3 during the follow-up campaigns. The results in this work illustrate the immediate benefits of reducing personal exposure through the adoption of vehicles with more stringent emission standards.

Modelling the absorption of nitrogen oxides by ferrous chelate solution in rotating packed bed

ABSTRACT With mushrooming growth of coal-based industry, the discharged tail gas containing nitrogen oxides had given significant effect on air quality and people’s health in China. Therefore, more stringent NOx emission standards were proposed. Among many technologies, wet scrubbing technology may be an effective way to solve the above problem, but it was limited by absorption of nitrogen oxides. Therefore, rotating packed bed (RPB) was used to intensify the absorption process of nitrogen oxides by ferrous chelate solution. To speed up its industrialization, a theoretical model was proposed by considering chemical reactions, gas and liquid mass transfer rate, liquid holdup and gas–liquid effective interfacial area. The effects of high gravity factor, gas velocity, gas–liquid ratio, temperature and concentration of ferrous chelate solution on NOx removal efficiency were conducted by model and also compared with experimental results. With high absorption efficiency and small equipment size in RPB, it had a great potential to apply in the absorption other harmful matters.

A Correlative Study of Modern Logistics Industry in Developing Economy and Carbon Emission Using ARDL: A Case of Pakistan

The modern logistics industry in relation to economic growth and carbon emission has opened new strategic perspectives. Recent research work have analyzed such complex interference from a broad perspective. However, analyzing this overlap needs comprehensive insight into the logistics industry while simultaneously estimating its short-run and long-run effects from regional aspects due to continue-evolving factors and their impact on it. This paper competently analyzes logistics industry components in connection with economic prosperity, energy consumption, trade development, and carbon emission from a more specific regional perspective of a developing country. Methodologically, an autoregressive distributive lag model (ARDL) is employed using correlative evaluation of the dynamic factors and their interactive impact in short and long run on this relation, based on time-series data of Pakistan from 1990 to 2019. The study results endorse the previous studies’ outcomes by recognizing that an increase in carbon emission depends on trade development, energy usage, economic development, and the logistics industry’s various components except for air logistics. However, study results show a unidirectional long-run causality directing from economic development, logistics industry, energy utilization, and trade development to carbon emission. Moreover, these results reveal that this emission is the leading factor to introduce stringent emission standards that further overlap with regional demographics trends, i.e., carbon emission implications. These findings imply that economic development applies a substantial demand-pull impact on national logistics, i.e., regional economic development directs to the growth of the logistics industry in the corresponding region. Consequently, high-income geographical regions have higher long-run risk concerning contemporary developmental activities of the logistics industry when adhering to carbon emission standards. Particularly, the influence of upcoming emission standards must be prioritized when planning the future returns of contemporary research and development activities of the logistics industry in a given geographic area, such as CPEC. Given Pakistan’s perspective, the proposed empirical analysis can be exampled to other developing countries. This analysis may facilitate the design and development of strategies for upcoming financial funding in the modern logistics industry to seek its sustainable development-goals in developing economies.

Environmental regulations as industrial policy: Vehicle emission standards and automotive industry performance

In this paper, we examine a potential causal link between vehicle emission standards and local automotive industry performance, using a 42-country panel data set covering a 19-year period between 2000 and 2018. Our panel logit analysis shows that having a sizeable local automotive industry decreases the chance of adopting stringent vehicle emission standards, while the stock of automotive FDI increases the chance. This finding suggests that the primary motivations for vehicle emission standards may not be purely environmental. Our follow-up Granger causality test demonstrates that such non-environmental motivations have in fact translated into an actual industry-promotion outcome. Stricter emission standards in OECD member countries tend to promote local automotive output and international vehicle export with a 3-year time lag, while this causal link is limited to up-market exports for non-OECD panels. Automotive FDI hosts with large domestic markets and/or local-brand automakers also present a similar causal link, but in this case significant long-term industry-promotion effects appear only after a short-term negative shock. These results suggest that a regulation-induced short-term efficiency loss may be partly offset by a long-term productivity gain through advance/timely local adoption of cleaner technologies.

Comparison of Selected Technologies to Improve the Quality of Exhaust Gases from Landfill Gas Combustion

This paper presents the results of research on exhaust gases from landfill gas combustion. The measurements were carried out in a reclaimed landfill in Kiełcz (a passive degassing system based on gas flare). The research concerned the effects of selected exhaust gas purification technologies (platinum catalyzer on a ceramic carrier, molecular sieve, copper(II) oxide) for the quality of exhaust gases, and their particulate matter content. This paper aims to indicate which catalytic systems are most suitable for this gas type and their most efficient positioning in the flue gas duct. Due to increasingly stringent emission standards, the outcomes presented in this article could be helpful for landfill owners who wish to avoid paying fines for not complying with applicable limits. The measurements were carried out using a flue gas analyser, a particulate matter analyser fitted with a probe, and four thermocouples connected with the data recorder. The research outcomes determined the percentage reduction of pollutant emissions into the atmosphere (CO, NOx, and particulate matter) using catalysts. The potential benefits of using catalysts in landfill gas combustion systems due to their operating temperature ranges are discussed.