Recent Trends in Greenhouse Gases Levels in the Soils of the Coconino National Forest

We have taken near-surface soil measurements of the gases CO2 , CH4 , H2 O and isoprene in several regions of the Coconino National Forest, Arizona, USA. Sets of measurements were taken both prior to the start of the seasonal monsoon season, in addition to while the monsoon season was underway. We have also compared the current monsoon season readings with readings taken at the same locations four years prior. For CO2, the relative level in the pristine forest soil is just under 3.7 percent lower than that measured in 2017, while the CO2 relative levels for the thinned and logged sites are lower by 13.5 and 5.4 percent, respectively. Even accounting for small increases in forest vegetation, these lower readings appear to be correlated to lower overall soil H2 O concentrations. The pristine CH4 relative concentration in 2021 is 9.6% higher and the thinned CH4 level is 19% higher. For the logged region, the measured methane level is over 70% lower than in 2017, but still approximately triple the methane level as seen in the other forest areas. We conclude that this result also may also be correlated to lower measured H2 O levels in the soils.

The Impact of Cutting With a Shearer on the Conditions of Longwall Ventilation

The data from the extended system was recorded on-going basis in the archives of the monitoring system, and the multipoint system was directly stored in the methane-anemometers, which allows one to perform a comparative analysis of the obtained records from many methane detectors. An important element of the analyses was the simultaneous registration of the methane concentration in the longwall, together with information on operating time, direction of shearer operation and type of work: mining/cleaning. Mining practice shows that in methane coal mines, methane is often the basic limitation for modern and high-efficiency longwall complexes. The paper reports on selected observations and tests carried out in the Cw-4 longwall in seam 364/2 of the Budryk mine belonging to JSW SA. In observation of the methane level in the Cw-4 longwall, additional sensors installed in the end part of the longwall from the side of the gobs and registration of air velocity and methane concentration in the multipoint system built in the selected longwall cross-section were used, regardless of the air parameters recorded in the monitoring system.

How return sludge increase biogas production from cow manure?

The energy needs in Indonesia are mainly fulfilled by fossil fuels based energy. Since there is the rise of fuel price, Indonesia government considers seeking alternative energies from renewable resources. Biogas becomes one of the alternative energy that supplies energy needs and manages cow manure waste in Indonesia. To increase adoption of biogas technology, biogas production through methane enrichment is required. The experiment was conducted with return sludge system. These instruments consist of a series portable bio-digester, gas holder and return sludge unit. There were three treatments on biogas production without and with sludge addition or re-use bio-digester sludge that produced after biogas production as raw material for next biogas production. Biogas that produced was observed every two days during 40 days. The results showed that the addition of bio-digester sludge increased biogas production and methane concentration. The optimum retention time of biogas production with sludge addition was 20 days with accumulation biogas volume of 156.38 liters or increased of 38.75 from biogas production without bio-digester sludge). The optimum retention time to increase methane level was 15 days with methane enrichment from 0.8% to 29.41%.

Characterization of Natural Zeolite and Chicken Manure Derived Biochar for Carbon Dioxide Adsorption in Biogas

Although biogas is clean and environmentally friendly, its existence is often unsustainable, especially in rural area. Consumption of fossil fuel energy still dominates because cheaper, higher in energy efficiency and ready to use than biogas. One of the efforts to make biogas can compete with fossil fuel energy is by increasing calorific value. Reduction of carbon dioxide by adsorption enhances the calorific value that evidenced by methane enrichment. In this study, we investigated the effect three types of combined adsorbent: pure natural zeolite (Z-Z), zeolite-biochar from chicken manure (Z-B1) and zeolite-modified biochar (Z-B2) on methane content. The result showed that adsorption of biogas using Z-Z, Z-B1 and Z-B2 increased methane level with enhancement of 1,36; 28,92; and 11,27% respectively compared before adsorption. To confirm whether these results were influenced by adsorbent’s character or not as consequence adsorbent characterization have been done in this study.

High Drilling Methane Drainage in Fracturing Zones Formed by Water Injection into Boreholes

Methane drainage method should be used before coal mining of many modern collieries because venti lation air methane is in sufficient to keep methane level within regulation values. The technology of high drilling methane drainage (HDMD) has been used for methane drainage although its effect is not very stable due to parameter design. The height of the fracturing zones is determined mostly according to empirical formula, on-site observation and numerical simulation analysis. In this paper, a method was introduced for determining the height of the air f ract uring zones (AFZs) based on its high similarity to the characteristics of Fracturing zones and the relationship between the height of Fracturing zones and the strain of overl ying rock strata. The application of water injection in both Shuangdingshan and Dongrong collieries found that the theoretically calculated the height of the Fracturing zones was approximately equal to the measured one in field tests within a permissible error of less than 5%, proving that the method is feasible. Based on the designed drainage parameters, the u tilization of HDMD technology in the collieries mentioned above found that the methane concentrations in both tail gate and upper corner were controlled in the ranges of 0.17% to 0.32% and 0.26% to 0.84%, respectively. These results showed that the water injection verified HDMD in Fracturing zones could effectively solve the problem of metha ne overrun and also verified the accuracy and reliability of its related theory.

Characterization of Methanotrophic Bacterial Populations in Soils Showing Atmospheric Methane Uptake

ABSTRACT The global methane cycle includes both terrestrial and atmospheric processes and may contribute to feedback regulation of the climate. Most oxic soils are a net sink for methane, and these soils consume approximately 20 to 60 Tg of methane per year. The soil sink for atmospheric methane is microbially mediated and sensitive to disturbance. A decrease in the capacity of this sink may have contributed to the ∼1% · year−1 increase in the atmospheric methane level in this century. The organisms responsible for methane uptake by soils (the atmospheric methane sink) are not known, and factors that influence the activity of these organisms are poorly understood. In this study the soil methane-oxidizing population was characterized by both labelling soil microbiota with14CH4 and analyzing a total soil monooxygenase gene library. Comparative analyses of [14C]phospholipid ester-linked fatty acid profiles performed with representative methane-oxidizing bacteria revealed that the soil sink for atmospheric methane consists of an unknown group of methanotrophic bacteria that exhibit some similarity to type II methanotrophs. An analysis of monooxygenase gene libraries from the same soil samples indicated that an unknown group of bacteria belonging to the α subclass of the class Proteobacteria was present; these organisms were only distantly related to extant methane-oxidizing strains. Studies on factors that affect the activity, population dynamics, and contribution to global methane flux of “atmospheric methane oxidizers” should be greatly facilitated by use of biomarkers identified in this study.