Biomass is a promising sustainable and renewable energy source, due to its high diversity of sources, and as it is profusely obtainable everywhere in the world. It is the third most important fuel source used to generate electricity and for thermal applications, as 50% of the global population depends on biomass. The increase in availability and technological developments of recent years allow the use of biomass as a renewable energy source with low levels of emissions and environmental impacts. Biomass energy can be in the forms of biogas, bio-liquid, and bio-solid fuels. It can be used to replace fossil fuels in the power and transportation sectors. This paper critically reviews the facts and prospects of biomass, the pyrolysis process to obtain bio-oil, the impact of different pyrolysis technology (for example, temperature and speed of pyrolysis process), and the impact of various reactors. The paper also discusses different pyrolysis products, their yields, and factors affecting biomass products, including the present status of the pyrolysis process and future challenges. This study concluded that the characteristics of pyrolysis products depend on the biomass used, and what the pyrolysis product, such as bio-oil, can contribute to the local economy. Finally, more research, along with government subsidies and technology transfer, is needed to tackle the future challenges of the development of pyrolysis technology.

This research presents the development of R463A refrigerant, a nonflammable refrigerant that was retrofitted to replace R404A. R463A is primarily composed of hydrofluorocarbons/hydrocarbons/carbon dioxide (HFCs/HCs/CO₂), and has global-warming potential (GWP) of 1494. It is a nonazeotropic mixture of R32 (36%), R125 (30%), R134a (14%), R1234yf (14%), and R744 (6%). R463A is composed of polyol ester oil (POE), and it is classified as a Class A1 incombustible and nontoxic refrigerant. R463A has a higher cooling capacity (Qe) than that of R404A, as it is composed of hydrofluorocarbons (HFCs) R32 and carbon dioxide (CO₂) R744, and has lower GWP than that of R404A due to the use of hydrofluoroolefins (HFOs) from R1234yf. The results of this research showed that R463A can be retrofitted to replace R404A due to its composition of POE, Class A1 incombustibility, and lower toxicity. The properties of R463A and R404A, as analyzed using national institute of standards and technology (NIST) reference fluid thermodynamic and transport properties database (REFPROP) software and NIST vapor compression cycle model accounting for refrigerant thermodynamic and transport properties (CYCLE_D-HX) software, are in accordance with the CAN/ANSI/AHRI540 standards of the Air-Conditioning, Heating, and Refrigeration Institute (AHRI). The normal boiling point of R463A was found to be higher than that of R404A by 23%, with a higher cooling capacity and a 63% lower GWP value than that of R404A. The critical pressure and temperature of R463A were found to be higher than those of R404A; it can be used in a high-ambient-temperature environment, has higher refrigerant and heat-rejection effects, and has lower GWP than that of R404A by 52% due to the HFOs from the R1234yf component. The cooling coefficient of performance (COPc) of R463A was found to be higher than that of R404A by 10% under low-temperature applications. R463A is another refrigerant option that is composed of 7% carbon dioxide (CO₂), and is consistent with the evolution of fourth-generation refrigerants that contain a mixture of HFCs, HFOs, HCs, and natural refrigerants, which are required to produce a low-GWP, zero-ozone-depletion-potential (ODP), high-capacity, low-operating-pressure, and nontoxic refrigerant.

This paper presents the improvement of eco-friendly and power consumption saving refrigerants for refrigeration systems. The novel azeotropic refrigerant mixtures of HFCs and HCs can replace refrigeration systems, and using the R134, R32, R125, and R1270 refrigerants in several compositions found using the decision tree function of the RapidMiner software (which came first in the KDnuggets annual software poll). All refrigerant results are mixed of POE, which is A1 classification refrigerant, non-flammable, and innocuous refrigerant, and using REFPROP software and CYCLE_D-HX software are under the CAN/ANSI/AHRI540 standards. The boiling point of the new refrigerant mix R-No.595 is 4.58%, lower than that of R404A, with a higher refrigerant effect and 50.34% lower GWP value than R404A. The proposed mix R-No.595 can be operated in hot environmental country and has high critical temperature and heat-rejection effects, due to the presence of R32 and R1270. The COPc of R463A is 13.49%, higher than R404A in freeze condition. The novel refrigerant mixes provide alternate refrigerant options mixed of 1% R1270, and which are related with the development of current refrigerants, containing a compose of HFOs and eco refrigerants for producing low-GWP, zero ODP, high-refrigerant effect, low-operating pressure, and innocuous refrigerants.

This research presents an energy efficiency improvement solution for supermarkets with the use of low-E glass doors for open refrigerators and a digital semi-hermetic compressor to fix the speed of semi-hermetic compressors. The impact of a door’s installation causes its load to be reduced by 40%, and the compressor shuts down frequently, which decreases its lifetime. In order to ensure that energy-saving solutions do not affect maintenance costs, the installation of a digital semi-hermetic compressor is proposed to lower costs and save energy. Our economic results from tests carried out at a 3000 square meter supermarket, which was open from 6:00 a.m. to 12:00 a.m. and in which we installed 82 doors on 15 open refrigerators, showed a 1.1-year payback period with an energy saving rate of 192,220 kWh/year for store No.1 (R22) and in which we installed 80 doors on 15 open refrigerators, showed a 1.4-year payback period with an energy saving rate of 171,185 kWh/year for store No.2 (R404A). The energy-saving effects of the digital semi-hermetic compressor, which fixes the speed of the semi-compressor and solves the problem of impact from fridge door installation, showed a 2.9-year payback period with an energy saving rate of 26,890 kWh/year for store No.1 (R22) and showed a 2.9-year payback period with an energy saving rate of 26,571 kWh/year for store No.2 (R404A). The results of store No.1 (R22) and store No.2 (R404A) showed no differences. This research is an extension of an energy-saving project that can be carried out on a continuous basis, increasing the efficiency of energy use and being a sustainable source of energy conservation.