Fuel Treatment Research Articles

Societal benefits from wildfire mitigation activities through payments for watershed services: Insights from Colorado

Payments for watershed services (PWS) programs are becoming a popular governance approach in the western United States (US) to fund forest management aimed at source water protection. In this paper we conduct a cost-benefit analysis (CBA) of one of the first collaboratively funded PWS programs in the US, located in the municipal watersheds servicing Denver, Colorado. We combine wildfire modeling, sediment modeling, and primary and secondary data on economic values to quantify the impact of the program on protecting multiple values at risk. Our results show that while the program has led to diverse societal benefits, it is only economically efficient (benefit-cost ratio greater than one) when all co-benefits beyond source water protection are considered, and fuels treatments are assumed to encounter wildfire. When the probability of wildfire is accounted for, economic benefits would need to be triple what was estimated in our analysis to achieve economic efficiency. Our findings suggest that improving spatial prioritization of interventions would increase economic benefits and better data on treatment placement and costs would help facilitate future CBA of PWS programs focused on wildfire mitigation.

Study of the working process of a diesel engine with modified fuel

The research objective is to reduce specific fuel consumption and emissions of exhaust fume pollutants. Specifically treated (modified) fuel is used to comprehensively improve the economic and environmental performance of the diesel operation process. Fuel treatment was carried out at a pilot plant using the process of fuel gas cavitation. During processing, high-molecular fuel compounds were broken down and the fuel was saturated with gas-vapor bubbles. The description of the pilot unit is given. The characteristics of the base distillate and modified fuel are studied. A mathematical model and the numerical study results of the fuel droplet development containing vapor-gas bubbles are presented. An experimental study of the work process in a 10.5/12 H diesel engine single-cylinder compartment when operating on various fuels was carried out. Diesel tests have shown that when using modified fuel, the specific indicative fuel consumption has decreased by 5-7 per g / kWh, the exhaust gas temperature has decreased by 5-8 degrees, the concentration of nitrogen oxides in the exhaust fumes has decreased by 32-46 ppm, the concentration of total hydrocarbons has decreased by 9-14 ppm, the smoke content has decreased by 1.2-1.7 times.

Fostering Carbon Credits to Finance Wildfire Risk Reduction Forest Management in Mediterranean Landscapes

Despite the need for preserving the carbon pools in fire-prone southern European landscapes, emission reductions from wildfire risk mitigation are still poorly understood. In this study, we estimated expected carbon emissions and carbon credits from fuel management projects ongoing in Catalonia (Spain). The planning areas encompass about 1000 km2 and represent diverse fire regimes and Mediterranean forest ecosystems. We first modeled the burn probability assuming extreme weather conditions and historical fire ignition patterns. Stand-level wildfire exposure was then coupled with fuel consumption estimates to assess expected carbon emissions. Finally, we estimated treatment cost-efficiency and carbon credits for each fuel management plan. Landscape-scale average emissions ranged between 0.003 and 0.070 T CO2 year−1 ha−1. Fuel treatments in high emission hotspots attained reductions beyond 0.06 T CO2 year−1 per treated ha. Thus, implementing carbon credits could potentially finance up to 14% of the treatment implementation costs in high emission areas. We discuss how stand conditions, fire regimes, and treatment costs determine the treatment cost-efficiency and long-term carbon-sink capacity. Our work may serve as a preliminary step for developing a carbon-credit market and subsidizing wildfire risk management programs in low-revenue Mediterranean forest systems prone to extreme wildfires.

Housing arrangement and vegetation factors associated with single-family home survival in the 2018 Camp Fire, California

BackgroundThe 2018 Camp Fire, which destroyed 18,804 structures in northern California, including most of the town of Paradise, provided an opportunity to investigate housing arrangement and vegetation-related factors associated with home loss and determine whether California’s 2008 adoption of exterior building codes for homes located in the wildland-urban-interface (WUI) improved survival. We randomly sampled single-family homes constructed: before 1997, 1997 to 2007, and 2008 to 2018, the latter two time periods being before and after changes to the building code. We then quantified the nearby pre-fire overstory canopy cover and the distance to the nearest destroyed home and structure from aerial imagery. Using post-fire photographs, we also assessed fire damage and assigned a cause for damaged but not destroyed homes.ResultsHomes built prior to 1997 fared poorly, with only 11.5% surviving, compared with 38.5% survival for homes built in 1997 and after. The difference in survival percentage for homes built immediately before and after the adoption of Chapter 7A in the California Building Code (37% and 44%, respectively) was not statistically significant. Distance to nearest destroyed structure, number of structures destroyed within 100 m, and pre-fire overstory canopy cover within 100 m of the home were the strongest predictors of survival, but significant interactions with the construction time period suggested that factors contributing to survival differed for homes of different ages. Homes >18 m from a destroyed structure and in areas with pre-fire overstory canopy cover within 30–100 m of the home of <53% survived at a substantially higher rate than homes in closer proximity to a destroyed structure or in areas with higher pre-fire overstory canopy cover. Most fire damage to surviving homes appeared to result from radiant heat from nearby burning structures or flame impingement from the ignition of near-home combustible materials.ConclusionsStrong associations between both distance to nearest destroyed structure and vegetation within 100 m and home survival in the Camp Fire indicate building and vegetation modifications are possible that would substantially improve outcomes. Among those include improvements to windows and siding in closest proximity to neighboring structures, treatment of wildland fuels, and eliminating near-home combustibles, especially in areas closest to the home (0–1.5 m).

Plant community response to thinning and repeated fire in Sierra Nevada mixed-conifer forest understories

Fire suppression in the western United States has significantly altered forest composition and structure, resulting in a higher risk of stand-replacing fire, large-scale drought mortality, and bark beetle outbreaks. Mechanical thinning and prescribed fire are common treatments designed to reduce high-severity fire risk, but few studies have tracked long-term understory plant community response to these treatments with repeated fire application that emulates historic fire regimes. We evaluate changes in understory plant diversity and composition, as well as light availability, soil moisture, and litter depth over two decades following a factorial field experiment crossing thinning and two applications of prescribed fire at the Teakettle Experimental Forest (TEF) in the southern Sierra Nevada. We compare responses in experimental fuels treatments against those in nearby old-growth, mixed-conifer forests with restored low-severity fire regimes in Yosemite and Kings Canyon National Parks. We hypothesized that 1) understory plant richness, evenness, and beta diversity would increase with each burn event; 2) repeated fire after initial thinning would produce the highest understory plant diversity; 3) the second burn would reduce shrub cover, especially in the initially thinned treatments that demonstrated vigorous Ceanothus cordulatus growth after initial treatments; 4) the second burn would increase light availability and bare ground while reducing litter depth; and 5) treatments with initial thinning followed by multiple prescribed burns would show the greatest similarities to reference forests in diversity metrics, shrub cover, and environmental conditions. Although initially local (10 m2-scale) understory plant richness and diversity increased most following thinning combined with prescribed fire, this treatment did not generate understory conditions similar to those in nearby reference forests over the long term. Vigorous shrub growth resulted in low understory evenness and beta diversity over time, which a secondary burn treatment did not alter. Burning without thinning retained a more heterogeneous understory following initial treatment. Two years after the second burn treatment, this burning without thinning resulted in high understory richness and evenness similar to reference forest understories. Our results suggest management treatments may need to focus on creating heterogeneity in burn effects to limit shrub cover and foster more diverse understory communities.

The Human Dimensions of Spatial, Pre-Wildfire Planning Decision Support Systems: A Review of Barriers, Facilitators, and Recommendations

Decision support systems (DSSs) are increasingly common in forest and wildfire planning and management in the United States. Recent policy direction and frameworks call for collaborative assessment of wildfire risk to inform fuels treatment prioritization using the best available science. There are numerous DSSs applicable to forest and wildfire planning, which can support timely and relevant information for decision making, but the use and adoption of these systems is inconsistent. There is a need to elucidate the use of DSSs, specifically those that support pre-wildfire, spatial planning, such as wildfire risk assessment and forest fuels treatment prioritization. It is important to understand what DSSs are in use, barriers and facilitators to their use, and recommendations for improving their use. Semi-structured interviews with key informants were used to assess these questions. Respondents identified numerous barriers, as well as recommendations for improving DSS development and integration, specifically with respect to capacity, communication, implementation, question identification, testing, education and training, and policy, guidance, and authorities. These recommendations can inform DSS use for wildfire risk assessment and treatment prioritization to meet the goals of national policies and frameworks. Lastly, a framework for organizing spatial, pre-wildfire planning DSSs to support end-user understanding and use is provided.

Overstory removal and biological legacies influence long-term forest management outcomes on introduced species and native shrubs

Forests in the western United States are actively managed to increase resilience to fire and extract timber resources. Disturbance from these management activities, however, may reduce forest resilience to invasion and promote shrub expansion, which could compromise treatment efficacy in the long-term. To assess mid- and long-term impacts of forest management practices, we coupled a field experiment with a chronosequence of patch cuts (~0.5 ha cuts) located at Blodgett Forest Research Station in the north-central Sierra Nevada. The field experiment, which was part of the national Fire and Fire Surrogate (FFS) study, compared three fuel treatments to control plots 12–13 years post-treatment. Fuel treatments included mechanical thinning, prescribed fire (that burned twice), and mechanical thinning plus fire. In contrast, the chronosequence assessed the impacts of patch cuts on vegetation across 33 years. The FFS fuel treatments led to increases in introduced species richness initially and in the mid-term. Introduced species richness and cover in the fuel treatments, however, were considerably lower than in patch cuts, which reached over 100% cover six years post-harvesting. In addition, while fuel treatments initially reduced shrub cover and richness, shrubs increased significantly in all fuel treatments in the mid-term. Understory vegetation dynamics in the fuel treatments were influenced by pretreatment flora richness and cover. In contrast, overstory removal was likely the strongest driver of high invasion in patch cuts within the first ten years, suggesting that severe disturbance (e.g., 100% removal of the overstory) may overwhelm biological legacies. Finally, overstory canopy was significantly and negatively associated with introduced species in the fuel treatments and the patch cuts, highlighting that canopy gap dynamics likely influenced invasion in this system. Our study underscored that while pretreatment species composition was a strong determinant of invasion in fuel treatments, management strategies that sustain overstory canopy cover may reduce growth and recruitment of introduced species and native shrubs.

Volatile Liquid Detection by Terahertz Technologies

The prospect of being able to move through security without the inconvenience of separating liquids from bags is an exciting one for passengers, and there are important operational benefits for airports as well. Here, two terahertz (THz) systems, 100 GHz sub-THz line scanner and attenuation total reflection-based THz time domain spectroscopy (TDS), have been used to demonstrate the capability of identifying different liquid samples. Liquid samples’ THz complex permittivities are measured and their differences have contributed to the variation of 100 GHz 2D images of volatile liquids with different volumes inside of cannister bottles. The acquired attenuation images at 100 GHz can easily be used to distinguish highly absorbed liquids (Water, Ethanol, Fuel Treatment Chemicals) and low loss liquids (Petrol, Diesel, Kerosene and Universal Bottle Cleaner). The results give a promising feasibility for mm-wave imager and THz spectroscopy to efficiently identify different volatile liquids.

Sagebrush recovery patterns after fuel treatments mediated by disturbance type and plant functional group interactions

AbstractFire and fuel management is a high priority in North American sagebrush ecosystems where the expansion of piñon and juniper trees and the invasion of nonnative annual grasses are altering fire regimes and resulting in loss of sagebrush species and habitat. We evaluated 10‐yr effects of woody fuel treatments on sagebrush recruitment and plant functional group interactions using Sagebrush Steppe Treatment Evaluation Project data. We used mixed‐effects ANOVAs to examine treatment effects on sagebrush density and cover and perennial and annual grass cover in expansion woodlands (prescribed fire and cut‐and‐leave) and annual grass invasion areas (prescribed fire, mowing, tebuthiuron herbicide application). We used piecewise structural equation models to evaluate interactions among sagebrush seedling density, juvenile and adult density, and cover and perennial and annual grass cover. Fuel treatments were equated to pulse or press disturbances varying in resource release and subsequent intra‐ and interspecific interactions. Prescribed fire, a high magnitude pulse disturbance with more severe effects in warm and dry sites, reduced sagebrush cover and decoupled associations among sagebrush seedlings, juvenile and adult density, and cover indicating changed population structure. Cutting and leaving trees, a low magnitude pulse disturbance in cooler and moister woodlands, increased sagebrush density and cover and generally had lesser effects on sagebrush intraspecific associations. Mowing, a moderate magnitude pulse disturbance, and tebuthiuron herbicide application, a multiyear press disturbance, reduced sagebrush cover and disrupted intraspecific relationships. Competitive release increased cover of perennial grass in all treatments but tebuthiuron. Annual grass increased in all treatments, especially prescribed fire and tebuthiuron. Annual and perennial grass interactions with sagebrush were generally rare, but in woodland treatments perennial grass suppressed annual grass through year 6. Treatments in cooler and moister woodland sites had more positive effects on sagebrush recruitment and perennial grass cover, less negative effects on sagebrush intraspecific interactions, and smaller increases in annual grass cover indicating potential increases in resilience to fire. In warmer and drier invasion sites, reductions in woody fuels resulted in lack of sagebrush recruitment, disruption of sagebrush intraspecific interactions, and progressive increases in annual grass indicating reduced resilience to fire and resistance to invaders.

Understanding How Fuel Treatments Interact With Climate and Biophysical Setting to Affect Fire, Water, and Forest Health: A Process-Based Modeling Approach

Fuel treatments are a key forest management practice used to reduce fire severity, increase water yield, and mitigate drought vulnerability. Climate change exacerbates the need for fuel treatments, with larger and more frequent wildfires, increasing water demand, and more severe drought. The effects of fuel treatments can be inconsistent and uncertain and can be altered by a variety of factors including the type of treatment, the biophysical features of the landscape, and climate. Variation in fuel treatment effects can occur even within forest stands and small watershed management units. Quantifying the likely magnitude of variation in treatment effects and identifying the dominant controls on those effects is needed to support fuel treatment planning directed at achieving specific fire, water, and forest health goals. This research aims to quantify and better understand how local differences in treatment, landscape features, and climate alter those fuel treatment effects. We address these questions using a mechanistic coupled ecohydrologic model—the Regional Hydro-Ecological Simulation System (RHESSys). We ran 13,500 scenarios covering a range of fuel treatment, biophysical, and climate conditions, for the Southern Sierra Nevada of California. Across fuel treatment type, biophysical, and climate parameters, we find nontrivial variation in fuel treatment effects on stand carbon, net primary productivity, evapotranspiration, and fire-related canopy structure variables. Response variable estimates range substantially, from increases (1–48%) to decreases (−13 to −175%) compared to untreated scenarios. The relative importance of parameters differs by response variable; however, fuel treatment method and intensity, plant accessible water storage capacity (PAWSC), and vegetation type consistently demonstrate a large influence across response variables. These parameters interact to produce non-linear effects. Results show that projections of fuel treatment effects based on singular mean parameter values (such as mean PAWSC) provide a limited picture of potential responses. Our findings emphasize the need for a more complete perspective when assessing expected fuel treatment outcomes, both in their effects and in the interacting biophysical and climatic parameters that drive them. This research also serves as a demonstration of methodology to assess the likely variation in potential effects of fuel treatments for a given planning unit.

Ancillary Impacts of Harvest Residue Pelletization

This paper analyzes the implications on employment, taxation, and wildfire fuel reduction costs when using mobile pellet mills to remove biomass and reduce wildfire fuels. Wildfire suppression costs in British Columbia have exceeded the set budget in 9 of the last 10 years and the province has only reduced the fuel load on a fraction of the high-risk hectares. Using a novel high-moisture mobile pellet mill allows the production of 89,000 tonnes of wood pellets each year for a price of $293 . Each tonne produced also provides $546 in additional benefits from employment, taxation, and reductions in the cost to perform fuel treatments. The presented research found that 11 employees are needed to operate a mobile pellet mill, with total employment of 242 for 22 systems across BC. The assessed system can also avoid $5.5 million in employment insurance payments. The 22 systems also provide $323,000 in taxable profits and $524,000 from income taxes from employees. Fuel treatment with the researched systems costs $1112 . A cost-benefit analysis shows that the system provides $2.97 in benefits for every dollar invested.

Prescribed fire and fire suppression operations influence wildfire severity under severe weather in Lassen Volcanic National Park, California, USA

Fuels treatments and fire suppression operations during a fire are the two management influences on wildfire severity, yet their influence is rarely quantified in landscape-scale analyses. We leveraged a combination of datasets including custom canopy fuel layers and post-fire field data to analyse drivers of fire severity in a large wildfire in the southern Cascade Range, California, USA. We used a statistical model of tree basal area loss from the fire, factoring in weather, fuels and terrain to quantify the extent to which prescribed burning mitigated wildfire severity by simulating potential wildfire severity without prescribed fire and comparing that with modelled severity from areas burned with prescribed fire. Similarly, using a map of operations intensity, we calculated predicted fire severity under a scenario with no operations and used these predictions to quantify the influence of operations. We found that prescribed fires and operations reduced tree basal area loss from the wildfire by an average of 32% and 22% respectively, and that severity was reduced by 72% in areas with both prescribed fire and operations. Our approach could be applied to other wildfires and regions to better understand the effects of fuel treatments and fire suppression operations on wildfire severity.

A Theoretical Investigation into the Comparative Adsorption Between Dissolved Oxygen and Oxygenate Species on Zeolite 3.7 Å During Aviation Fuel Treatment for Thermal Stability Improvement

A Theoretical Investigation into the Comparative Adsorption Between Dissolved Oxygen and Oxygenate Species on Zeolite 3.7 Å During Aviation Fuel Treatment for Thermal Stability Improvement

Development of stochastic model of particulate coal fluidized bed expansion and axial structure

Particulate solids are in the state of fluidization at many stages of preparation and treatment of solid fuels. An effective drag force coefficient Cd is used to describe a mechanical contact between gas stream and an individual particle. The evaluation of the effective drag force coefficient is not limited by the force of hydraulic resistance but also includes a set of different forces. This set of forces is rather indeterminate, and a lot of empirical equations for effective drag force coefficient calculations can be found in the scientific papers. Choosing the applicable formula for calculation is often difficult. In addition, it requires taking into account the flow patterns around an individual particle. Thus, a comparative study to examine the most well-known drag force models with a uniform approach to account the flow patterns around an individual particle is important. The Markov chain approach is used as a mathematical basis for modeling of the flow patterns in a fluidized bed. The identification of the model parameters is completed and the complementation of transition matrices with the current physical properties of substances involved into the flow makes the model non-linear. The comparative study of the results obtained with using of the two correlations for drag force coefficient is performed. The stochastic model of fluidized bed expansion and axial structure has been proposed. The comparative analysis of two different scenarios of fluidized bed expansion using different drag force models has been performed. The authors developed and tested the model to describe fluidized bed expansion and axial structure on the basis of the Markov chain approach. The low certainty of physical drag coefficients models under conditions of flow patterns around an individual particle has been shown. The conducted research proves that consistent description of structure inhomogeneity of fluidized bed is possible using the nonlinear mathematical models based on mesoscale level of the object decomposition. Predictive efficiency of similar models is limited by low reliability of formula for calculation of drag force coefficient. Thus, it is possible to state the importance of further comparative research to check different formulas for calculation of gas-particle drag force coefficient in order to provide a reliable forecast of the fluidized bed height.

Regional Level Data Server for Fire Hazard Evaluation and Fuel Treatments Planning

Both fire risk assessment and management of wildfire prevention strategies require different sources of data to represent the complex geospatial interaction that exists between environmental variables in the most accurate way possible. In this sense, geospatial analysis tools and remote sensing data offer new opportunities for estimating fire risk and optimizing wildfire prevention planning. Herein, we presented a conceptual design of a server that contained most variables required for predicting fire behavior at a regional level. For that purpose, an innovative and elaborated fuel modelling process and parameterization of all needed environmental and climatic variables were implemented in order to enable to more precisely define fuel characteristics and potential fire behaviors under different meteorological scenarios. The server, open to be used by scientists and technicians, is expected to be the steppingstone for an integrated tool to support decision-making regarding prevention and management of forest fires in Catalonia.

Long‐term fuel and understorey vegetation response to fuel treatments in oak and chaparral stands of northern California

AbstractAimsFuel reduction treatments are broadly implemented to reduce the risk of extreme wildfire, but research on the long‐term effectiveness and impacts of these treatments is lacking. In this study, we examined short‐ and long‐term (two and 15 years) changes in fuels and understorey vegetation after treatment in chaparral and oak‐dominated stands.LocationWhiskeytown National Recreation Area, California, USA.MethodsTreatments, including hand thinning, mastication only, burn only, and mastication + burning, were applied randomly to one or two units within each of 10 blocks across two vegetation types (chaparral and oak‐dominated). Vegetation data were initially measured two years after treatment and remeasured 15 years later with additional sampling of dead surface fuels and shrubs. Fuel and vegetation data were analyzed to examine the effect of treatment, time, and vegetation type.ResultsIn chaparral stands, shrub height and cover in the hand‐thinning, mastication, and mastication + burning treatments were still lower than in the control after 15 years. However, only the hand‐thinning treatment reduced fine woody fuels. Hand thinning and mastication + burning increased native species richness after two years, but this was also associated with an increase in exotic species richness and cover that persisted after 15 years. In oak‐dominated stands, treatments had varied and relatively fewer changes to fuels and vegetation. Shrub height was reduced in both the hand‐thinning and Burn‐only treatments, but only mastication reduced shrub cover. Species richness and vegetative cover were largely unaffected by treatment in oak‐dominated stands, except for lower native plant cover in mastication and mastication + burning treatments.ConclusionTreatments varied in their level of effectiveness and most involved trade‐offs between their impacts on fuels and vegetation responses that differed by vegetation type and time. Our findings provide insights for managers interested in balancing these trade‐offs when making fuel treatment decisions and emphasize the importance of examining longer‐term effectiveness of fuels treatments.

Can we manage a future with more fire? Effectiveness of defensible space treatment depends on housing amount and configuration

Fire in forested wildland urban interface (WUI) landscapes is increasing throughout the western United States. Spatial patterns of fuels treatments affect fire behavior, but it is unclear how fire risk and fuel treatment effectiveness will change under future conditions. (1) How do area burned, forest and fuel characteristics, and fire risk change over time under twenty-first-century climate? (2) When defensible space fuels treatments are applied around all houses, which scenarios of WUI housing amount and configuration minimize fire risk? In generic 10,000-ha US Northern Rocky Mountain subalpine forest landscapes, we simulated 21 scenarios differing in fuels treatment, housing amount and configuration (neutral landscape models), and projected future climate using the process-based model iLand. We compared fire risk at three scales: 1-ha home ignition zone (HIZ), 9-ha safe suppression zone (SSZ), and landscape. Under warm-dry climate, annual area burned increased, but area burned at high fire intensity peaked in the 2060s and then declined sharply; fire risk followed similar trends. Defensible space treatments maintained low flame lengths in HIZs. Clustered housing was more effective at reducing SSZ risk compared to dispersed housing. At landscape scales, treating more of the landscape reduced fire risk but configuration was unimportant. The most effective strategy for reducing fire risk depends on the scale at which risk is assessed. Clustering WUI developments and treating between 10 and 30% of the landscape every 10 years can reduce fire risk across multiple scales.

Dependence of the fire retardant and fire extinguishing efficiency of compositions based on phosphates of bivalent and trivalent ammonium metals on their physicochemical properties

Purpose. The object of research were fire-retardant and fire-extinguishing agents based on ammonium phosphates of bivalent and trivalent metals used for the treatment of forest combustible materials (FCM), including wood and peat. The subject of the research was to determine the fire-retardant and fire-extinguishing effectiveness of these agents, depending on their physical and chemical properties determined by the conditions of synthesis. The aim was to establish common traits or difference in the mechanism of inhibition of combustion of FCM by metallophosphate systems of various chemical compositions, as well as to reveal the role of the processes occurring in the condensed phase under the influence of their thermal decomposition products. The main task was to study the physicochemical, thermal properties of fire-retardant and fire-extinguishing agents, as well as fire-protected samples of peat and other FCM in the temperature range on the burning surface of natural materials (200–500 °C).&#x0D; Methods. X-ray phase analysis, differential scanning calorimetry, chemical analysis.&#x0D; Findings. The factors determining the fire-retardant and fire-extinguishing efficiency of synthetic agents based on phosphates of bivalent and trivalent ammonium metals with controlled properties depending on the synthesis conditions with respect to FCM, wood and peat have been determined. A process has been established that has a dominant effect on stopping their combustion – inhibition of radical reactions in the gas phase by volatile nitrogen-containing products. At the same time, it was shown that when developing new fire-retardant and fire-extinguishing agents, it is necessary to take into account their properties such as the ability to form thermal insulating structures in the condensed phase.&#x0D; Application field of research. The results obtained in this work can be used to create new fire-retardant and fire-extinguishing synthetic compositions based on ammonium phosphates of bivalent and trivalent metals for the treatment of forest fuels.

Effect of cavitation treatment of coal-water and composite liquid fuels on their characteristics

The effect of mechano-cavitation treatment of coal-water and artificial composite liquid fuels, based on brown coals and anthracite, on particle size distribution of their coal mass and dynamic viscosity is studied experimentally. It is shown that the treatment of both fuels leads to significant regrinding of their coal mass and a noticeable increase in viscosity.

Catalytic Technologies for Solving Environmental Problems in the Production of Fuels and Motor Transport in Kazakhstan

This research is devoted to solving an environmental problem, cleaning of the Kazakhstan air basin, through treatment of auto-transport toxic exhaust by improving the hydrocarbon composition of motor fuels and neutralizing exhaust gas toxic components. The catalytic hydrodearomatization of gasoline fractions (from the reforming stage) of the Atyrau and Pavlodar Refineries and the neutralization of exhaust gas toxic components from an internal combustion engine (ICE) were studied. Two hydrotreated gasoline fractions were tested during ICE operation. The research shows that 100% benzene conversion is observed over Rh-Pt(9:1)/γ-Al2O3 catalysts; that is, benzene is completely removed from both fractions, and the aromatics content decreases from 56.24–58.12% to 21.29–21.89%, within the values of the Euro-5,6 standard. Catalytic treatment of fuels reduces fuel consumption of the ICE engine by 2–3% compared to the initial gasoline fractions, the CO content in the exhaust gases decreases by 6.6–16.2%, and the hydrocarbon content decreases by 7.8–24.7%. In order to neutralize the ICE exhaust gas toxic components, the catalyst 10% Co + 0.5% Pt/Al2O3 was used, with which the CO conversion reaches 100% and the hydrocarbon conversion 94.2% and 91.5% for both gasoline fractions. The catalysts were characterized by electron microscopy (EM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), thermoprogrammed desorption (TPD) and thermoprogrammed reduction (TPR) methods. It was shown by the TPD and EM methods that at the addition of Pt to the Rh-catalyst, the formation of mixed bimetallic Rh-Pt-agglomerates occurs, and hydrogen appears in the TPD spectrum, adsorbed in the form of a new single peak uncharacteristic for the Rh-catalyst. This leads to high activity and selectivity in the hydrogenation of benzene and aromatic compounds in the gasoline fractions. The XRD and TPR results show the formation of CoAl2O4 spinels, on which inactive oxygen is formed for the oxidation of CO and hydrocarbons. Modification of the catalyst by Pt and Mg prevents spinel formation, thereby increasing the activity of the catalysts.