Impact Factors Analysis of Diesel Particulate Filter Regeneration Performance Based on Model and Test

In the application of DPFs (diesel particulate filters), temperature prediction and control technology during the regeneration phase has always been a great challenge, which directly affects the safety and performance of diesel vehicles. In this study, based on theoretical analysis and sample gas bench test results, a one-dimensional simulation model is built with GT-POWER software. The effects of soot loading quantity and oxygen concentration on regeneration temperature performance are studied. Simulation results show that, when the soot loading quantity exceeds 46 g (12.7 g/L), the maximum temperature inside DPF during the regeneration phase would be higher than 800 °C, and the risk of burning crack would be high. When the oxygen concentration in the exhaust gas is low (lower than 7%), the fuel injected into exhaust gas fails to give off enough heat, and the exhaust gas temperature fails to reach the target regeneration temperature, hydrocarbon emission could be found from the DPF outlet position; when the oxygen concentration in the exhaust gas reaches 7% or above, the DPF inlet temperature could reach the target temperature, accompanied by less hydrocarbon emission. Combined with the simulation results, engine test bench validation was carried out. The results show that the simulation results and test results agree well.

Effect of Injection Timing In Reducing The Harmful Pollutants Emitted From CI Engine Using N-Butanol Antioxidant Blended Eco-Friendly Mahua Biodiesel

Consuming non-renewable energy sources has genuine and long-standing unfavorable consequences on people’s health, neighborhood networks and ecosystems, and also on the worldwide atmosphere. The burgeoning demand and use of diesel engines in various fields cause emission of exhaust gases like NOx and CO that lead to serious environmental pollution and hazards like global warming, respiratory problems, and so on, has necessitated a reduction in the use of diesel and addition of suitable biodiesel. Mahua biodiesel blend has also been considered as a safe renewable fuel for conventional engines. This is due to its desirable properties such as rapid growth rate, higher productivity, and the ability to utilize CO2 into fuel. The introduction of an antioxidant, preferably n-butanol eliminates these harmful emissions from the diesel engine. In this experimental investigation, mahua biodiesel blend mixed with n-butanol has been used as test fuel in a conventional engine. Because of the special character n-butanol has been chosen for use with the mahua biodiesel blend. About 20–30 vol.% of n-butanol has been blended with 80 vol.% of diesel and tested. The manufacturer set injection timing was 23oCA bTDC. The injection timing is preferably between 21oCA bTDC and 25oCA bTDC. Nitrogen oxides and carbon monoxide are reduced by 49 percent and 5.88 percent, respectively, when a blend of B20 + D80 + 30% n-butanol is used at 21oCA bTDC relative to diesel fuel. The smoke and hydrocarbon emission of blend B20 + D80 + 30% n-butanol at 25oCA bTDC is reduced by 40% and 38.07%, respectively, related to diesel. The brake thermal efficiency for entire injection timing has been identified to be increased correlated to all other test blends. The brake thermal efficiency in blend B20 + D80 + 30% n-butanol of 25oCA bTDC is increased by 15.30%, when compared with diesel fuel. These promising results assure that mahua biodiesel blend containing antioxidant would be eco-friendly fuel.

Innovative Hydrocarbon Sensor for Real Drive Emission Testing: Optimization of the Gas Inlet

Hydrocarbon emission is very bad for human health. Many efforts were made to reduce the pollution of hydrocarbon sensor especially in vehicle. For that, the development of hydrocarbon sensor for emission testing on the road is one of the great approaches to compare the results from laboratory test and in real driving test. This work focused on numerical investigation and optimization of hydrocarbon sensor prototype that is using glow plug as the heat source. Heat is important in facilitating ionization process for ion current measurement. Therefore, numerical optimization of inlet design and simulation using AVL Fire was done and reported in the following work to obtain the maximized performance of hydrocarbon sensor. We found that the optimum conditions for heating gas inside the chamber is when the inlet create a swirl flow and at low velocity.

Helarchaeota and co-occurring sulfate-reducing bacteria in subseafloor sediments from the Costa Rica Margin

Deep sediments host many archaeal lineages, including the Asgard superphylum which contains lineages predicted to require syntrophic partnerships. Our knowledge about sedimentary archaeal diversity and their metabolic pathways and syntrophic partners is still very limited. We present here new genomes of Helarchaeota and the co-occurring sulfate-reducing bacteria (SRB) recovered from organic-rich sediments off Costa Rica Margin. Phylogenetic analyses revealed three new metagenome-assembled genomes (MAGs) affiliating with Helarchaeota, each of which has three variants of the methyl-CoM reductase-like (MCR-like) complex that may enable them to oxidize short-chain alkanes anaerobically. These Helarchaeota have no multi-heme cytochromes but have Group 3b and Group 3c [NiFe] hydrogenases, and formate dehydrogenase, and therefore have the capacity to transfer the reducing equivalents (in the forms of hydrogen and formate) generated from alkane oxidation to external partners. We also recovered five MAGs of SRB affiliated with the class of Desulfobacteria, two of which showed relative abundances (represented by genome coverages) positively correlated with those of the three Helarchaeota. Genome analysis suggested that these SRB bacteria have the capacity of H2 and formate utilization and could facilitate electron transfers from other organisms by means of these reduced substances. Their co-occurrence and metabolic features suggest that Helarchaeota may metabolize synergistically with some SRB, and together exert an important influence on the carbon cycle by mitigating the hydrocarbon emission from sediments to the overlying ocean.

Elements of regional organic geochemistry and separate prediction of oil and gas content of regions

The article considers the elements of organic geochemistry in the regional aspect, which aims to separate quantitative prediction of oil and gas content of regions. The principles and results of balance calculations of generation and emission of liquid and gaseous hydrocarbons for different facies-genetic types of organic matter and methods for calculating the scale of hydrocarbon emission are considered. Finally, a list of the main regularities of organic geochemistry is given.

Elements of regional organic geochemistry and separate prediction of oil and gas content of regions

The article considers the elements of organic geochemistry in the regional aspect, which aims to separate quantitative prediction of oil and gas content of regions. The principles and results of balance calculations of generation and emission of liquid and gaseous hydrocarbons for different facies-genetic types of organic matter and methods for calculating the scale of hydrocarbon emission are considered. Finally, a list of the main regularities of organic geochemistry is given.

Helarchaeota and Co-occurring Sulfate-Reducing Bacteria in Subseafloor Sediments from the Costa Rica Margin

Deep sediments host many archaeal lineages, including those of the Asgard superphylum that may depend on/require syntrophic partnerships. Our knowledge about sedimentary archaeal diversity and their metabolic pathways and syntrophic partners is still very limited. We present here new genomes of Helarchaeota and co-occurring sulfate-reducing bacteria (SRB) recovered from organic-rich sediments off Costa Rica Margin. Our molecular analyses revealed three new metagenome-assembled genomes (MAGs) affiliating with Helarchaeota, each of which has three variants of the methyl-CoM reductase-like (MCR-like) complex that may enable them to oxidize short-chain alkanes anaerobically. These Helarchaeota have no multi-heme cytochromes (MHCs) but have Group 3b and Group 3c [NiFe] hydrogenases, and formate dehydrogenase, and therefore could transfer the reducing equivalents generated from alkane oxidation to external partners via the transfer of these substances. We also recovered five MAGs of SRB affiliated with the class of Desulfobacteria, two of which showed relative abundances (represented by genome coverages) positively correlated with those of the three Helarchaeota. Genome analysis suggested that these SRB bacteria have the capacity of H2 and formate utilizations and may facilitate electron transfers from other organisms by means of these reduced substances. Our findings suggest that Helarchaeota may metabolize synergistically with SRB in marine anoxic sediments, and exert an important influence on the carbon cycle by mitigating the hydrocarbon emission from sediments to the overlying ocean.