Recently, the attraction on the bio-composite (known as green composites) materials has significantly increased due to the potential of being substitute to conventional materials used in manufacturing industries. Bio-composite materials are produced with natural fibres or natural resins instead of synthesized fibres (carbon, glass, etc fibres) or resins (poly vinyl alcohol, epoxy, etc resins ). The bio-based fibres such as jute, sisal, flax, hemp, bamboo, hair, wool, silk etc., are obtained from plants or animals. Also, natural matrix materials such as natural rubber, polyester, etc., are produced from plants. The advantages of bio-composites such as the ease of disposal and being able to composted characteristics of bio-composites after the expiration date which is not generally possible with conventional synthetic materials, being renewable, sustainable have attracted many researcher. Furthermore, the comparable mechanical properties of bio-composites make feasible for application to many different products. This study reviews the, recent trends, mechanical and chemical properties, and application of bio-composites in recent years.

The overall objective of this study was to explore the utility of waste plastics as a potential source of diesel fuel. An experimental study was conducted to evaluate the use of various blends of plastic oil produced from waste polyethylene (WPE) with diesel fuel (D). WPE was degraded thermally and catalytically using sodium aluminum silicate as a catalyst. The oil collected at optimum conditions (414°C–480°C range and 1 h reaction time) was fractionated at different temperatures and fuel properties of the fractions were measured. Plastic oil was blended with diesel fuel at the volumetric ratios of 5%, 10%, 15%, 20%, and 100%. Fuel properties of blends are found comparable with those of diesel fuel within the EN 590 Diesel Fuel standard and they can also be used as fuel in compression ignition engines without any modification. Engine performance and exhaust emission studies of 5% WPE-D (WPE5) blend were performed. Experimental results showed that carbon monoxide (CO) emission is decreased by 20.63%, carbon dioxide (CO₂) emission is increased by 3.34%, and oxides of nitrogen (NO_x) emission is increased by 9.17% with WPE-D (WPE5) blend compared to diesel fuel.

This paper presents the results of investigations carried out on a three-cylinder, fourstroke, and direct-injection CI engine operated with terebinth (pistacia terebinthus) oil biodiesel. Terebinth oil was squized using the extraction method and therefore terebinth oil biodiesel was produced via the transesterification method. Terebinth oil biodiesel (B)—diesel fuel (D) blends were tested in a direct injection diesel engine at full load condition. Power values showed a trend of decreasing with all biodiesel fuels at high engine speeds. Specific fuel consumption (SFC) values increased depending on the amount of biodiesel in the test fuels. In general, exhaust emission profile of biodiesel fuels improved. CO and CO₂ emissions decreased up to 34.54% and 10.69% respectively. However, NO_x emissions increased up to 32.97%.

Biodiesel has been produced from various vegetable oils, such as palm, canola (rapeseed), cottonseed, sunflower, and soybean oils as well as a variety of less common oils. This study evaluated the production of biodiesel using tea seed (Camellia sinensis) oil as a raw material. Methyl ester was produced by transesterification of tea seed oil with methanol in the presence of a catalyst (NaOH). The fuel properties such as pour point (PP), kinematic viscosity, cetane number, flash point, density, copper strip corrosion, and heating value were determined and discussed in light of American (ASTM D6751) and European (EN 14214) biodiesel standards. Not only the specifications of pure biodiesel but also its blends with diesel fuel were analyzed. Biodiesel produced from tea seed oil exhibit a low pour point value of −5°C, one of the lowest found for a biodiesel fuel. The cold flow properties of tea seed methyl ester (TSME) demonstrate its operational viability during the cold weather conditions. As a result, tea seed oil, as agricultural crop, might be a reasonable raw material for the biodiesel production.

The current study investigates the fuel properties, performance and emission characteristics in a variable compression ratio (VCR) diesel of the biodiesel produced from the waste cooking oil (WCO). The WCO samples were collected from the university and converted to biodiesel fuel with a two-step transesterification reaction. The fuel property tests showed that the properties of the WCO biodiesel were within the biodiesel standards. Diesel, WCO biodiesel and diesel-WCO biodiesel blend (B20) was used as fuel in a VCR engine. The performance and emission characteristics of the engine were measured at two different compression ratios (14:1 and 16:1) under partial load conditions. The experimental results showed that WCO biodiesel slightly decreased the brake thermal efficiency and thus increased specific fuel consumption. Biodiesel usage improved CO emissions up to 21,75% compared to diesel fuel. But, biodiesel usage increased CO 2 and NO x emission due to higher combustion temperature and extra oxygen content of the biodiesel.