Detection of LPG Gas by Using Multi Sensors Array and Fabricated ZnO Gas Sensor

The demand for LPG (Liquefied Petroleum Gas) detection constitutes a major and critical problem in the field of gas detection. LPG is used for domestic appliances used in the heating of buildings, producing petrochemicals and as a motor fuel. The current paper used the fabricated ZnO, in addition to TGS 813, TGS 2600, TGS 4160, TGS 3870, TGS 822 as semiconductor gas sensors, in varying temperature and load resistance in a prototype setup so as to explore each model’s accuracy for performance prediction for gas detection. The fabricated ZnO gas sensor is used also to detect the LPG. The comparison is done between gas sensors array and the fabricated one from ZnO. The actual results are put in comparison with the empirical algorithms’ predictions. The optimal model is found to be the full quadratic empirical model based on the lowest error with different sensors.

Fairness, effectiveness, and needs satisfaction: new options for designing climate policies

Financial compensations are often proposed to address regressive distributional impacts of carbon taxes. While financial compensations have shown to benefit vulnerable groups distributionally, little is known about their impacts on emission reduction or needs satisfaction. A potential problem with cash compensations is that if households spend this money back into the economy while no additional decarbonisation policies are implemented, emission reductions that arose from the tax may at least partly be reversed. In this letter, we compare the emission savings and impacts on fuel and transport poverty of two compensation options for carbon taxes in 27 European countries. The first option consists of equal per capita rebates for home energy and motor fuel taxes. The second option is the provision of universal green vouchers for renewable electricity and public transport, supported by additional investments in green infrastructures to meet increased demand for such green consumption. Results show that the first option of tax rebates only supports small emission reductions. In contrast, universal green vouchers with expanded green infrastructures would reduce home energy emissions by 92.3 MtCO2e or 13.4%, and motor fuel emissions by 177.5 MtCO2e or 23.8%. If green vouchers and infrastructure were provided without a prior tax, emission savings would be slightly lower compared to the ‘tax and voucher’ scheme, but fuel and transport poverty would drop by 4.1 and 2.2 percentage points, respectively. In contrast, taxes with rebates would increase fuel and transport poverty by 4.1 and 1.8 percentage points. These findings demonstrate that it is important to take environmental and energy poverty impacts of compensations for unfair distributional impacts of climate policies into account at the design stage. Such compensation measures can achieve higher emission reductions and reduce energy poverty if they involve an expansion of the provision of green goods and services, and if everyone is given fair access to these goods and services.

WHEN CHOOSING CATALYSTS FOR THE CONVERSION OF ISOBUTYLENE PRINCIPLES OF QUALITY AND QUANTITY

Catalysts play an extremely important role in wildlife and industry. Today it is difficult to describe chemistry and petrochemistry without catalytic processes. Catalytic processes account for 80-85% of oil refining. Therefore, the problem of choosing a catalyst is of interest both from the point of view of quality and quantity. In this paper, the activity of a high silicon zeolite catalyst used in the conversion of isobutene was studied at various temperatures, and it was determined that a sample of the zeolite catalyst during the process initially had no catalytic activity during the conversion of isobutene. The release of liquid products is observed only after the formation of 5-8% of compaction products (PM) on the surface within 25-30 minutes from the beginning. Consequently, modifiers have a positive effect on catalytic activity. In this case, the number and strength of the acid sites of the catalyst changes. The study of isobutene conversion process showed that the formation of liquid products is observed at 150°C. It was shown that in this case in the temperature range 150°C-300°C liquid products of isobutene reaction consist of primarily from aliphatic and at 350°C- 450°C from aromatic hydrocarbons. The process of conversion of hexane-1 on the high-silica zeolite catalyst is studied and it was shown that the decomposition of hexene-1 into ethene and propene is occure at the beginning, at 250°C and then the process takes place in a mixture of the two olefins. It was shown by the using of XRD, TG/DTA methods, that the formed products of seals in the conversion of isobutene and 1-hexene over the high silica zeolite catalyst,is composed of two phases that differ from each other in thermal stability. The obtained liquid products during the conversion of isobutene at 150°C-300°C can be used as high-octane gasoline fractions as motor fuel component. The adsorbed NH3 probe molecules method showed that during the conversion of propene, isobutene and hexene-1, the amount of acid sites of spent catalysts is reduced by 43-50%. In this state, the catalyst exhibits high catalytic activity. Keywords: catalyst, activity, isobutene, zeolite.

Bioisobutanol as a Promising Feedstock for Production of “Green” Hydrocarbons and Petrochemicals (A Review)

The existing approaches to bioisobutanol synthesis and commercial production are considered. Ways of using bioisobutanol as a component of motor fuel and as a promising feedstock for the production of “green” hydrocarbons and other petrochemicals that favor the progress of low-carbon economy are discussed. Particular attention is paid to catalytic processes of isobutanol conversion to isobutylene and butenes, aromatic hydrocarbons, C2–С4 olefins, and hydrogen-containing gases. Data on the mechanism of isobutanol transformations on zeolite catalysts are given.

Evaluation of the efficiency of using biodiesel fuel as a motor fuel

The article analyzes the problem of replacing traditional fossil fuels with alternative renewable fuels. Indicators characterizing the operation of a diesel engine when it is converted to biodiesel fuel are given. The main criteria that are recommended for assessing the efficiency of using biodiesel fuel as a motor fuel are considered. Key words: DIESEL ENGINE, FUEL, MIXTURE, ECOLOGY, INDICATOR, CRITERION, EFFICIENCY

Investigation of the Performances of a Diesel Engine Operating on Blended and Emulsified Biofuels from Rapeseed Oil

The article discusses the possibility of using blended biofuels from rapeseed oil (RO) as fuel for a diesel engine. RO blended diesel fuel (DF) and emulsified multicomponent biofuels have been investigated. Fuel physicochemical properties have been analyzed. Experimental tests of a diesel engine D-245 in the operating conditions of the external characteristic curve and the 13-mode test cycle have been conducted to investigate the effect of these fuels on engine performances. CFD simulations of the nozzle inner flow were performed for DF and ethanol-emulsified RO. The possibility of a significant improvement in brake thermal efficiency of the engine has been noted. The efficiency of using blended biofuels from RO as a motor fuel for diesel engines has been evaluated based on the experimental test results. It was shown that in comparison with the presence of RO in emulsified multicomponent biofuel, the presence of water has a more significant effect on NOx emission reduction. The content of RO and the content of water in the investigated emulsified fuels have a comparable influence on exhaust smoke reduction. Nozzle inner flow simulations show that the emulsification of RO changes its flow behaviors and cavitation regime.

PROSPECTS OF BIOMETHANE PRODUCTION IN UKRAINE

Biogas upgrading to quality of natural gas (NG) creates possibility to supply biomethane to the NG grid, easy transportation and production of electricity and heat in locations where there is guaranteed consumption of thermal energy. Biomethane as a close NG analogue can be used for heat and electricity production, as soon as motor fuel and raw material for chemical industry. The International Energy Agency (IEA) estimates that the world's annual biomethane production potential is 730 bcm (20% of current world's NG consumption). World biomethane production reached almost 5 bcm/yr in 2019. According to forecast of the European Biogas Association the biogas and biomethane sector may almost double its production by 2030. According to IEA estimates, annual world biomethane production could reach 200 bcm in 2040 in case the sustainable development strategy is implemented Currently, the Bioenergy Association of Ukraine estimates the potential for biogas/biomethane production in Ukraine using fermentation technology as 7,8 bcm/yr (25% of the country's current NG consumption). The roadmap of bioenergy development in Ukraine until 2050 envisages growth of biomethane production to 1,7 bcm in 2035 and up to 3 bcm in 2050. Currently the prospects for green hydrogen development are well known. The authors support the need of hydrogen technologies as one of the way for production and use of renewable gases. However, they believe that biomethane has no less prospects. Transporting of one cubic meter of biomethane through gas pipeline at 60 bar pressure transmits almost four times more energy than transporting of one cubic meter of hydrogen. This is fundamental advantage of biomethane. Another advantage is the full readiness of gas infrastructure for biomethane. Given the cost of gas infrastructure modernization to use hydrogen, it is more cost-effective to convert green hydrogen to synthetic methane. Currently, biomethane is in average three times cheaper than green hydrogen, the cost of the two renewable gases is expected to equalize by 2050, and only further possible reduction in the cost of green hydrogen below $2/kg will make green hydrogen cheaper than biomethane. Therefore, the greatest prospects can be seen in the combination of the advantages of both renewable gases and conversion of green hydrogen into synthetic methane (power-to-gas process). Authors believe that after adoption of legislation to support the development of biomethane production and use in Ukraine, the bulk of biomethane produced in the country will be exported to EU, where more favourable conditions for biomethane consumption are developed. As Ukraine's economy grows, more and more of the biomethane produced will be used for domestic consumption.

Research into the physical and chemical properties of fire-retardant materials of structural elements of trucks running on gas engine fuel with the aim of increasing their fire-retardant efficiency

The fire load is an integral part of the fire hazard definition. Reducing this load is one of directions to fight fires in transport. To study the physicochemical processes and thermal effects occurring as a result of thermal decomposition of wood fire-proofed by retardants like BAN, OK-GF, OK-DS (OK-GFM), SPAD-0 and their chemical compositions, we used the methods of differential thermal analysis, thermogravimetry, and derivative thermogravimetry. In addition, to study the intensity of physicochemical combustion processes, tests to control changes in woodwork masses and temperature at the top of pipe depending on the duration of combustion of the samples and the consumption of fire retardants were conducted. Fire retardant compositions like OK-GF, OK-DS, Pirilax biopyrene at the consumption of 0.1 kg / m2 ensure flame and combustion resistance of the wood. The analysis of the research results confirmed the possibility of assigning to wood structures of a lorry’s body of the group 1 of flame and combustion resistance. Using the above fire retardants and their compositions in the treatment of lodgment elements and runners significantly affects the possibility and duration of the combustion process of a lorry. This was tested by means of an artificial fire source method (without chemical treatment, the burning time does not exceed 50 minutes). This significantly improves post-collision safety of vehicles with an increased fire load in terms of fire resistance because of using the natural gas as a motor fuel.

Heat and mass transfer of multicomponent gas mixtures in cryogenic tank of automotive equipment

The use of liquefied gas as a motor fuel for automotive equipment has both certain advantages and significant problems. The paper deals with the solution of one of the main problems, reducing the speed of the phase transition of liquefied methane in a cryogenic tank in the mode of drainage-free storage. In solving the above problem, the process of convective heat and mass transfer caused by the chemical and physical state of natural gas and the external heat flow was investigated. The two-phase state of the gas is unstable in the event of an increase in heat input from the environment, which causes an imbalance of pressure and temperature in the volumes of the liquid and gaseous parts of the gas and creates the risk of an emergency. To prevent the formation of critical gas pressure in a cryogenic tank, a method is proposed for calculating the phase transition of liquefied methane to determine the volume fraction of vaporized gas using equilibrium constants, which will allow developing an algorithm for the technological process of gas recirculation in a specially designed tank design. This will also allow you to choose the best option for a thermal insulation layer that can reduce the rate of penetration of heat from the environment and increase the period of drainage-free storage of liquefied natural gas by 1.5-2 times.

PROSPECTS FOR OBTAINING GAS MOTOR FUEL FROM BIOGAS OF ANAEROBIC DIGESTION OF AGRICULTURAL WASTE

The ability of gas hydrates to concentrate gas into a solid chelate structure and the properties of self-preservation of gas hydrates at negative temperatures allows us to consider the possibility of developing a method for the utilization of biogas, environmentally safe storage and transportation of biomethane. (Research purpose) The research purpose is in substantiation the technological possibilities of obtaining synthetic mixed gas hydrates of biogas components, their storage and transportation based on the analysis of the existing regularities of the formation of gas hydrates in time, temperature and external pressure. (Materials and methods) The article presents the accumulated results of studies of the process of obtaining artificial hydrates of natural gas and methane- containing gas mixtures at various initial static pressures and temperatures. The object of research to substantiate the parameters of artificial creation of gas hydrates is biogas obtained during anaerobic thermophilic fermentation of organic waste at an existing experimental biogas plant. Mixed feed SK-8 with a humidity of 90-92 percent was used as an organic substrate of constant composition. The composition of biogas was studied using the Optima-7 Biogas gas analyzer. (Results and discussion) The article presents a process model and a technical appearance of an installation for producing gas motor fuel from the biogas of anaerobic digestion of organic waste of the agro-industrial complex. The hydrate formation time depends on the increase in the interfacial surface and the movement of gas bubbles relative to the liquid, which can be regulated by acting on the hydrate formation zone (shock wave, electromagnetic, mechanical, chemical, temperature). (Conclusions) The research results can be used in modeling processes in two-phase media during the formation of gas hydrates and the creation of installations for their production.