Separation biodiesel manufacturing

A key operation in biodiesel manufacturing is the separation of glycerol and FAM E from the reaction mixture by liquid-liquid decanting. Thermodynamic studies on this subject are scarce despite the industrial interest Table 14.11 presents data for... 

During the last decade many industrial processes shifted towards using solid acid catalysts (6). In contrast to liquid acids that possess well-defined acid properties, solid acids contain a variety of acid sites (7). Sohd acids are easily separated from the biodiesel product they need less equipment maintenance and form no polluting by-products. Therefore, to solve the problems associated with liquid catalysts, we propose their replacement with solid acids and develop a sustainable esterification process based on catalytic reactive distillation (8). The alternative of using solid acid catalysts in a reactive distillation process reduces the energy consumption and manufacturing pollution (i.e., less separation steps, no waste/salt streams). 

Biodiesel production via a membrane reactor has shown great performance because it overcomes the serious issues of conventional reactors. Both production and separation using membrane technology have provided a suitable opportunity for companies to manufacture biodiesel beneficially. However, there are some challenges in using membrane reactors for the production of biodiesel that need to be resolved, such as limitation caused by its material, shape, and pore size (Ned Hall), the high cost of some kind of membranes (Murphy et al., 2010), the slow rate of reaction (Dube et al., 2007), and issues related to the presence of alkaline catalyst with water (Baroutian, Aroua, Raman, Sulaiman, 2010a). 

In summary, with respect to benefits and drawbacks of DMC as an alternative reagent for carrying out interesterification of oil and fats to produce biofuel from renewable resources and alternative co-products (GC and glycerol dicarbonate (GDC)), it should be mentioned that DMC is a less toxic chemical than methanol that can be currently manufactured by environmentally safe industrial methods, from CO2 and renewable resources. Besides, GC and its derivatives are characterized by low toxicity, and the remaining nonreacted DMC does not need to be separated from the reaction products, because it is an effective additive for diesel engines, due to its high oxygen content (Bounce et al., 2010). Here we have that the fabrication process is very simplified with respect to the conventional biodiesel obtained from methanol. 

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