Method for producing biodiesel by autotrophic culture and heterotrophic culture of chlorella

Abstract

The invention discloses a method for producing biological diesel oil by two steps of culture of chlorellas, namely, autotrophy and heterotrophy, which belongs to the renewable biological energy field. Concentrated autotrophic algae is put into a fermentation tank to perform heterotrophic growth from the processes of autotrophic culture, cell concentration and fermentation pollution controlling of the chlorellas, to ensure the chlorellas to be synthesized into neutral fat. Effective feeding strategy is established to ensure the fat to be synthesized into optimal after the optimization of the fermentation conditions and the process control. The biomass can reach 108g.L-1, and the grease content can reach 52 percent of cell dry weight. After the culturing is finished, biological diesel oil can be prepared after extracting algal oil and transesterification reaction. The cell concentration technology adopted by the invention can effectively avoid the problem of light restriction during the high density culture process Not only is the carbon dioxide emission reduced, but also the organic carbon source consumption is reduced, thus the preparation cost of the biological diesel oil material is saved. The whole technical line is environmental friendly, high efficient, and can meet the industrial application requirements of the microalgae biological diesel oil.

Description

technical field [0001] The invention belongs to the field of renewable bioenergy, and particularly relates to a new process for producing biodiesel by cultivating chlorella in two steps from autotrophic to heterotrophic. Specifically, first let the chlorella cells grow autotrophically under light conditions using carbon dioxide; after concentration, add an organic carbon source (glucose) to the system for the heterotrophic growth of the microalgae, and at the same time make a large amount of oil accumulate in the microalgae , so as to provide sufficient and cheap raw materials for large-scale production of biodiesel. Background technique [0002] Biodiesel refers to the long-chain fatty acid alkyl monoester obtained after esterification of animal, vegetable or microbial oil. Due to its clean, renewable and environmentally friendly features, biodiesel has been increasingly valued by some countries with large energy consumption in Europe, America and Asia and has achieved con...

AI Technical Summary

Problems solved by technology

Although heterotrophic culture has the advantages of fast growth rate, short culture period, and easy control of the culture process, the main problem of using heterotrophic microalgae to produce biodiesel is that this method relies on organic carbon sources (such as glucose, starch, etc.) cost of production

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