**5. B100 and "Bio-circular engine"**

The "Bio-Circular Engine" that results from considering the possibility of using B100, not only as a biofuel but also as biolubricant, once its properties have been determined, we can define it as: "Procedure, apparatus, bio-lubricant and bio-fuel for simultaneous use of b100 with dual function in diesel engines". But it can also be expressed as follows in a more descriptive way as: "Procedure and apparatus for simultaneous use of b100, with double function, in diesel engines: stage 1, as bio-lubricant and stage 2, as bio-fuel".

The Bio-Circular Engine is related to the use of biodiesel in 4T diesel engines (vehicular, commercial, industrial, railway, river, sea, aviation, etc.), but also applicable to all kinds of internal combustion engine which run a crankcase (oil inside the engine), from B100 or pure biodiesel to different mixtures (B10, B20, B50, etc.), to reduce polluting emissions from petroleum diesel. It is also related to the use of biodiesel (B100), with or without additives of organic origin, such as biolubricant, to avoid contamination of lubricating fossil oils used in internal combustion engines in general. It is also related to a procedure to make diesel engines work with biodiesel, in such a way that it simultaneously and successively fulfills the two functions: as biolubricant in stage 1, and as biofuel in stage 2; either with B100 or with the required diesel-biodiesel mixture. The application or use of any type of procedure, apparatus, or device that uses biodiesel to lubricate the engine and once this task is carried out, is successively and continuously taken to the injection system to be used as fuel is unknown. Currently, it is very common to use biodiesel obtained from different oilseeds (with different characteristics, depending on the geographical region where they are grown), to be used as fuel, in a pure form (B100 or 100% Biodiesel); but also mixed with petroleum diesel (B10, B20, B50, etc.). The first aspect of the new Bio-Circular Engine, a procedure applicable to diesel engines is provided, certified to use biodiesel B100 (100% pure biodiesel.), but also certified for any percentage of mixture with mineral diesel fuel (B10, B20, B50, etc.); with double function, in two successive and/or simultaneous stages: In stage 1, B100 or pure biodiesel is conducted from the fuel tank to the crankcase or engine lubricant tank (previously filtered), where it will fulfill the first integral function as biolubricant. In stage 2,—successively and/or simultaneously—it is conducted from the same crankcase to the injection system of the diesel engine (previously filtered), where it will fulfill the second function, as biofuel. The complete process will be governed by the Control Unit (ECU), which will control the two successive and simultaneous stages, through the data obtained through specific sensors. This procedure can be adapted to virtually any modern diesel engine, as virtually any modern diesel engine would be capable of using B100. The second aspect of the Bio-Circular Engine consists of an apparatus or device to carry out the 2 stages of the aforementioned procedure, which is made-up of a series of electrical, electronic, and mechanical elements. These items include low- and high-pressure piping for the B100; electric pumps, pressure, temperature, level, flow sensors, etc.; filters; in some cases, radiator for the B100 just removed from the crankcase; electric cables; electronic control unit (ECU) and others, which when installed in 4T diesel engines and then interconnected with each other, will allow the supply of the B100 from the vehicle's fuel tank, passing through the engine crankcase for its first function as biolubricant and from there direct it to the fuel injection pump and later to the injectors located in the cylinder head for its second function as biofuel. This general configuration of the device is designed for use with B100, in 4T diesel engines manufactured from the year 2000 onwards, as they were built with sealing materials and plastic elements (Viton), resistant to the detergent action of B100. It is included in the Bio-Circular Engine, a variation of the device, which in addition to being able to use B100, allows it to be installed in 4T diesel engines manufactured before the year 20,000 that have been refurbished to use biodiesel but for technical reasons or due to poor availability of B100 must add fossil diesel (B10, B20, B50, etc.). This addition of the fossil diesel is made after the B100 has performed its first lubrication function. Once extracted from the engine crankcase, it is taken through the duct corresponding to a new device where B100 duct and the fossil diesel duct converge, which arrives from its own totally independent tank and pipe, located in a

#### **Figure 4.** *Bio-circular engine, conceptual diagram.*

place away from the fuel tank B100. For this variation of the original procedure and apparatus, some additional elements must be installed, such as, the mixing station and fuel percentage selection monitor, in addition to its interconnections with the ECU, which allows the use of at least B5–B100 (with this variation, operation with only B100 in the two stages is also planned; it is enough to suspend the supply of fossil diesel), which will guarantee that B100 will always be renewed in its function as a biolubricant inside the engine, to a lesser or greater degree flow rate, which will depend on the amount of B100 chosen on the selector provided for it. As mentioned earlier, the entire process will be governed by the ECU, which will control the two successive and simultaneous stages, using the data obtained through specific sensors. The third aspect of the Bio-Circular Engine, a biolubrican biodiesel (B100) A as a new oil for 4-stroke internal combustion engines, 100% biodiesel, which is the only fluid known and indicated for the total performance of the procedure and device characteristic of the Bio-Circular Engine; with all the required and recognized physicochemical characteristics of modern commercial synthetic oils, for its performance in 4T engines, composed entirely of 100% biodiesel (B100); the base is a B100 obtained from a certain raw material, to which one or more portions of other B100 of the same or different generation (including hydro-biodiesel) and the same or different raw materials are added, to enhance the properties of the base and/or introduce new properties, always obtaining B100 at the

end. In exceptional cases, it is also possible to add some type of substance that improves some of its properties (eg cold flow). The main characteristics of B100 as a biolubricant may vary depending on the raw materials (rapeseed, soybean, sunflower, palm, animal fat, used vegetable oil, etc.) from which it is obtained; the most important ones are: B100 is a polar substance (all additives in commercial mineral and synthetic oils are polar substances). It is a triester (a commercial synthetic oil is a diester). It is a Newtonian fluid (shear rate proportional to shear stress). It forms layers of molecules with greater strength of adhesion to metals (3 carbonyls per molecule). The higher the effort and pressure, the higher the viscosity. Palm reduction of NOx emissions due to saturated triglycerides (B100 from Colombian palm), greater thermal and chemical stability, no rust, no sludge, no deposits. There is no acidification of the lubricant due to the Blow-By phenomenon (passage of fuel through the piston rings towards the crankcase). High polar strength (3 carbonyls). Low viscosity (fuel saving). High detergency (impeccable cleaning). No carbon in carter. Does not require the use of toxic additives. It does not pollute water, air, and land. High flashpoint (>170°C; Colombian palm B100). Volatility >300°. Excellent antiwear protection in limit and elastohydrodynamic lubrication in cases of high pressure, load, and temperature.
