Green diesel

Fig. 3.8 Green diesel and other products from biomass via Fischer-Tropsch synthesis...

Gerritsen, L. A. Production of green diesel in the BP Amoco Refineries. Akzo Nobel at the WEFA Conference. Berlin, Germany, 2000. 

Lawler, D. and Robinson, S. Update hydrotreaters to process green diesel. Hydrocarbon Processing, 2002, 8, 61. 

Ecofining New Process for Green Diesel Production from Vegetable Oil... 

The main improvement of the Ecofining technology compared to the conventional FAME biodiesel is that it allows refiners to obtain a synthetic fuel that has a similar chemical composition and similar chemical-physical properties to petroleum diesel. For this reason the product can all be easily blended with conventional refinery products. Moreover, the integrated production of the green diesel allows the refiner to... 

Table 8.1 Green diesel fuel properties versus mineral ULSD and conventional biodiesel (FAME).

Ultra low sulfur diesel (ULSD) Biodiesel (FAME) Green diesel... 

From Table 8.1 the evident advantages of green diesel advantages over mineral diesel fuels and FAME are ... 

Green diesel is a high quality cetane component (CN > 80), which means higher engine efficiency. 

Green diesel is a hydrocarbon mixture, not an oxygenated organic compound, which means it has the same energy content as mineral diesel fuel and higher than FAME. 

Green diesel is a stable blending component without double bonds and oxygenated molecules. 

Green diesel maintains car reliability and reduces distribution costs. 

Green diesel low density is an advantage over FAME because it allows to upgrade low valuable and high density refinery streams, thereby expanding the diesel pool. 

Green diesel has the same boiling range as a mineral one. This prevents vaporization problems in the combustion chamber and it does not impact on the boiling point specification in case of blending with mineral diesel fuel. 

Green diesel is produced by a refinery process that permits quality control of biofuel and the use of existing infrastructure and fuel distribution systems. 

Green diesel meets the highest requirements of car manufacturers and can be utilized with all diesel automotives without modification. 

The quality of vegetable oil, in particular the fatty add distribution and the degree of unsaturation can affect the properties of FAM E biodiesel, but they do not affed the properties of green diesel. 

Figure 8.5 Green diesel cloud point as a function of the iso-/n-paraffin ratio.

The scope of this second stage is to control the cold flow properties of the final green diesel. As explained in the open literature [7-9], the diesel yield from the process will depend on the severity required in the isomerization reactor to meet cold flow specifications. 

Figure 8.5 reports the correlation between the green diesel doud point versus the ratio iso-/n-paraflin. Notably, the increase in iso-/n-paraffin ratio is obtained by increasing the severity of the process. The latter results in a different product distribution (diesel, kero and naphtha), with the diesel cut being the larger part (e.g., diesel 88-99 vol.%). Even under more severe conditions the diesel produced has a very high cetane number (>75) and contains no aromatics. 

Figure 8.8 LCA analysis comparison of green diesel versus FAME biodiesel and a petroleum diesel energy consumption per unit of diesel energy.

UOP and Eni have developed the Ecofining process, a new, sustainable, route for converting vegetable oil into premium quality diesel fuel. This green diesel product is a superior alternative to FAME, with significantly better diesel product properties and is fully compatible with conventional mineral diesel products. The Ecofining... 

Holmgren, J., Gosling, C Kokayeff, P., Faraci, G. and Perego, C. Green diesel production from vegetable oils. 

High naphtha and light olefin yields are favored by operation at high temperatures. The naphtha becomes excellent feed for naphtha crackers to make ethylene, the diesel is a green diesel with a cetane number of about 70, and obviously zero sulfur and aromatics, therefore it is an excellent blending component for poorer quality counterparts. The high molecular weight wax can either be cracked to fuels products or isomerized to reduce the pour point and produce lube base stocks. 

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