Energy supply is one of the most important current issues in the world. The most uses of fossil fuels are for providing power to internal combustion engines. The increase in the global price of fossil fuels and the environmental concerns have made researchers to look for alternate sources of energies, such as biofuels. The main disadvantage of biofuels is their low heating values. However, they can be used as gasoline additives. The aim of this study was to evaluate the energy balance of a four-cylinder gasoline engine with ethanol and n-butanol alcohols in different volume percentages at three different engine speed of 1000, 1500, 2000 rpm. The results showed that the engine brake power increased in fuel blends that contain bio-alcohols compared to pure gasoline fuel. Also, by increasing the engine speed, the engine brake power of the fuel blends increased so that at 2000 rpm, the G70E15B15 fuel blend had the highest brake power of 47. 1 kW. Also, the exhaust heat loss in fuel blends containing ethanol and n-butanol increased compared to pure gasoline, and also increased with the increase in engine speed. The lowest exhaust heat loss of 3. 98 kW related to pure gasoline at 1000 rpm and the highest exhaust heat loss of 6. 38 kW for G70E15B15 fuel blend at 2000 rpm were obtained. Pure gasoline fuel had lower heat loss of cooling system than other fuel blends. Heat loss of cooling system decreased with increasing speed from 1000 to 2000 rpm. Therefore, the G70E15B15 fuel blend with 11. 01 kW and pure gasoline with 2. 89 kW had the highest and lowest heat loss of cooling system, respectively.

One of Main Matters Treated by all countries daily is energy Supply. On one hand, decrease of fossil reservoir and increase of oil price and its products and on the other hand necessity of attention to decreasing environmental Pollutions caused by fossil fuels encourages worldwide companies to apply pure and renewable energies of renewable reservoir attracted European and American countries attention is biofuels.one of main kind of biofuels is bioethanol produced by waste of agricultural products like sugar cane, wheat, corn and sugar beet.In existing research, after introducing biofuels especially bioethanol, we have investigated bioethanol production economically by applying sugar cane wastes, ”Haft tapeh Khuzestan culture and industry“ which is one of the main sugar Producers in the state. Our hypothesis in this research this is:bioethanol production by applying sugar cane wastes, In ”Haft tapeh Khuzestan culture and industry“ have economic justification.Replacing bioethanol with MTBE in gasoline production have economic benefits. Software applied in this research is COMFAR Software which is one of the most important Software used by investment-counseling companies for Study Feasibility.

In late 2019, the outbreak of a deadly Coronavirus shocked the world. Following the Covid-19 pandemic, governments were forced to enact a series of restrictive laws, including road and urban transportation. As a result of these restrictions, the consumption of fossil fuels in the world decreased and reduced the price and demand of these fuels. Because of the decline in this area, alternative fuels also faced serious challenges. Declining demand for alternative fuels has raised concerns about the development and future of these clean fuels. In this study, after presenting a quick look at biofuels' global markets, associated challenges ahead being examined in light of the declining demand and price of fossil fuels and biofuels. The results in this section showed that some social and economic constraints in the world are temporary due to the prevalence of Covid-19. As many countries reduced these restrictions in the second quarter of 2020, these limitation may be minimized shortly to zero with the discovery of vaccines and Covid-19 treatment. If it is supposed that the production of biofuels returns to its initial level in 2021, the development of biofuels should not be ignored because of the Covid-19. Obviously, in this case, the demand for biofuels will increase. According to new findings, the spread of coronavirus increases with air pollution. Therefore, the effects of coronavirus on air pollutants specifically NO2 and CO2 are investigated. The results revealed that the spread of coronavirus in 2020 has reduced NO2 emissions by 40-50% and CO2 emissions are also expected to be declined by 8%. This value is probably the largest reduction in CO2 emissions since 1900.  An effective solution to reduce air pollution is to develop the use of biofuels. At this time, the air pollution has been reduced due to a decrease in urban and road transportation. However, this pollution can be reduced by more development of biofuels to mitigate the spread of this deadly virus. Reduction in emissions is a result of declining social activity, rising unemployment, and severe economic problems.

In many European countries, residues from agricultural products represent a considerable potential for development of bio-energy industry. A significant part of these biomass materials come from the fruit-growing business, i.e., primary fruit production and fruit processing plants. The EU directives require that the disposal of such residues should be environmentally sustainable. The objective of this study was to determine proximate (moisture content, ash, fixed carbon, volatile matter), ultimate (carbon, hydrogen, nitrogen and sulphur) and energy values (higher, lower) of biomass, as well as the Croatian total energy potential generated after the pruning (pruned residues) and processing of plum fruit (stone). Five different plum varieties (Bistrica, Cacanska ljepotica, Cacanska rodna, President, and Stanley), most commonly grown in the territory of Croatia, were analyzed and compared. The analyzed data were compared with the norm CEN/TS 14961 (2005) for solid biofuels and the data from the relevant literature. Both types of investigated biomass proved to be highly valuable sources of energy; and no significant difference between investigated plum varieties were found. Lower heating value, as one of the fundamental parameters of the biomass energy efficiency, averaged in the studied samples: 15.2 MJ kg-1 for plum pits and 17.12 MJ kg-1 for pruned biomass, which classifies plum biomass as a valuable energy raw material. Also, the calculations show that the potential production of the biomass available in Croatia could reach up to 292.13 MJ of renewable "green" energy annually.