Lipase immobilization and its use for biodiesel production : Lipase immobilization and its use for biodiesel production
- 발행기관 고려대학교
- 발행년도 2007
- 학위수여년월 2007. 2
- 학위명 박사
- 학과 대학원 화학공학과 화학공학전공
- 식별자(기타) DL:000018552504
- 서지제어번호 000045355957
초록/요약
바이오디젤을 생산하기 위한 효소공정은 여러 장점에도 불구하고 아직 상업화 단계에 이르지 못하였는데, 그 이유는 수율이 낮고, 반응시간이 화학공정에 비해 오래 걸리기 때문이다. 기존의 효소공정은 바이오디젤의 생산에 적게는 10시간, 많게는 40시간 이상 소요된다. 만약 반응시간을 크게 단축시키고 높은 전환율로 바이오디젤을 생산할 수 있는 효소공정이 개발된다면 충분히 상업화가 가능할 것이다. 본 연구에서는 효소공정을 이용하여 바이오디젤을 상업적으로 생산하기 위한 기반기술을 확립하고자 하였다. 이를 위해서는 두 가지 분야에 있어서 획기적인 발전이 필요하다. 첫째는 바이오디젤의 생산에 적합한 높은 활성을 갖는 고정화 리파아제의 개발이고, 둘째는 반응시간을 획기적으로 단축시킬 수 있는 새로운 효소공정의 개발이다. 본 연구에서는 리파아제의 전처리 기술을 개발하여 고정화 리파아제의 활성을 20배 이상 증가시켰다. 상업적으로 가장 많이 이용되는 고정화 리파아제인 Novo 435 가 콩기름을 분해할 때의 활성이 200 U/g 이하인 반면에 본 연구를 통해 개발된 2종의 고정화 리파아제의 활성은 모두 750 U/g 이상으로 성능이 월등하였다. 또한 기존에 바이오디젤의 생산 능력이 전혀 없다고 보고 되어있는 Candida rugosa 리파아제를 공정에 도입한 신규한 공정의 개발로 20시간 이내에 99%의 전환율로 바이오디젤을 생산하는데 성공하였다. 또한 이 공정의 최적화 연구를 통해 98%의 전환율로 4시간 이내에 바이오디젤을 생산하는데 성공하였다. 본 연구를 통해 개발된 신규한 공정에 대한 scale-up 연구가 이루어진다면 효소공정을 이용한 바이오디젤의 생산은 충분히 상업화가 가능할 것으로 판단한다.
more초록/요약
Although an enzymatic process for biodiesel production has many advantages, it has not been commercialized. That’s because biodiesel conversion is low and it takes much more time to finish the reaction than competing chemical processes; it takes 10 - 40 h for enzymatic processes to produce biodiesel. If an enzymatic process is developed to obtain high yield of biodiesel and to reduce reaction time markedly, it could be commercialized. The objective in this study is to accumulate basic technologies for commercialization of the enzymatic process to produce biodiesel. This needs dramatic advances in two parts. First, immobilized lipase that has high activity and is suitable for biodiesel production should be developed. Second, perfectly new process that can greatly decrease reaction time should be developed. In this study, the activity of immobilized lipase increased by over 20 times through a pretreatment technique newly developed. The activity of Novo 435, immobilized lipase which is most widely used in industrial applications, is less than 200 U/g for soybean oil hydrolysis. However, activities of two immobilized lipases developed in this study were greater than 750 U/g, which is nearly 4 times higher than that of Novo 435. Moreover, biodiesel was successfully produced with 99% conversion within 20 h by developing a new process using Candida rugosa lipase, which can not produce biodiesel in other reports. Also, through optimization study of this process, biodiesel could be produced with 98% conversion within 4 h. If further scale-up studies for the process newly developed in this study is performed, biodiesel production using an enzymatic process could be commercialized.
more목차
2.4. Preparation of activated silica gel for lipase immobilization
2.5. Immobilization of lipase
2.6. Assay of immobilized lipase activity
3. Results and discussion
3.1. Effect of pretreating materials on lipase pretreatment
3.2. Effect of temperature on lipase pretreatment
3.3. Effect of agitation speed on lipase pretreatment
3.4. Effect of pretreatment concentration on lipase pretreatment
3.5. Effect of pretreating time on lipase pretreatment
3.6. Reusability of immobilized lipase
4. Conclusion
Chapter 3. Effect of buffer on the activity of immobilized pretreated lipase
1. Introduction
2. Materials and method
2.1. Materials
2.2. Preparation of lipase
2.3. Pretreatment of lipase
2.4. Preparation of activated silica gel for lipase immobilization
2.5. Immobilization of lipase
2.6. Assay of immobilized lipase activity
3. Results and discussion
3.1. Effect of pH of various buffers on the activity of immobilized pretreated lipase
3.2. Effect of ionic strength of various buffers on the activity of immobilized pretreated lipase
4. Conclusion
Chapter 4. Biodiesel production using a mixture of immobilized Rhizopus oryzae and Candida rugosa lipases.
1. Introduction
2. Materials and methods
2.1. Materials
2.2. Preparation of lipase
2.3. Pretreatment of lipase
2.4. Preparation of activated silica gel for lipase immobilization
2.5. Lipase immobilization.
2.6. Biodiesel production
2.7. Analysis
3. Results and discussion
3.1. Effects of temperature and agitation speed on biodiesel production
3.2. Effects of Methanol concentration on biodiesel production
3.3. Biodiesel production using a mixture of immobilized R. oryzae and C. rugosa lipases
3.4. Reusability of immobilized lipase for biodiesel production
4. Conclusion
Chapter 5. Optimization of the process for biodiesel production using a mixture of immobilized Rhizopus oryzae and Candida rugosa lipases
1. Introduction
2. Materials and methods
2.1. Materials
2.2. Preparation of lipase
2.3. Pretreatment of lipase
2.4. Lipase immobilization
2.5. Biodiesel production
2.6. Analysis
3. Results and discussion
3.1. Effect of temperature and agitation speed on biodiesel production using a mixture of immobilized lipases
3.2. Effects of molar ratio of methanol and soybean oil and ratio of immobilized R. oryzae and C. rugosa lipases on biodiesel production using a mixture of immobilized R. oryzae and C. rugosa lipases
3.3. Biodiesel production using a mixture of immobilized R. oryzae and C. rugosa lipases at the ratio of 3:1(w:w)
3.4. Effect of concentration of immobilized lipase on biodiesel production
3.5. Repeated biodiesel production by reusing the mixture of immobilized lipases
3.6. Biodiesel production in large scale.
4. Conclusion
Overall Conclusion
References
Acknowledgment.
List of Figures
Fig. 1. Biodiesel from triglyceride and methanol
Fig. 2. Chemical process to produce biodiesel
Fig. 3. Enzymatic process to produce biodiesel
Fig. 4. Effect of temperature on immobilized R. oryzae lipase activity
Fig. 5. Effect of temperature on immobilized C. rugosa lipase activity.
Fig. 6. Effect of agitation speed on immobilized R. oryzae lipase activity.
Fig. 7. Effect of agitation speed on immobilized C. rugosa lipase activity
Fig. 8. Effect of immobilization time on immobilized R. oryzae lipase activity
Fig. 9. Effect of immobilization time on immobilized C. rugosa lipase activity
Fig. 10. Effect of lipase concentration on immobilized R. oryzae lipase activity
Fig. 11. Effect of lipase concentration on immobilized C. rugosa lipase activity
Fig. 12. Schematic model of the lipase pretreatment prior to immobilization
Fig. 13. Effect of immobilization time on the activity of immobilized pretreated R. oryzae lipase
Fig. 14. Effect of immobilization time on the activity of immobilized pretreated C. rugosa lipase
Fig. 15. Effect of lipase concentration on the activity of immobilized pretreated R. oryzae lipase
Fig. 16. Effect of lipase concentration on the activity of Immobilized pretreated C. rugosa lipase
Fig. 17. Effect of lipase concentration and immobilization time on the activity of immobilized pretreated R. oryzae lipase
Fig. 18. Effect of lipase concentration and immobilization time on the activity of immobilized pretreated C. rugosa lipase
Fig. 19. Effect of immobilization time within 18 h on the activity of immobilized pretreated R. oryzae lipase
Fig. 20. Effect of immobilization time within 18 h on the activity of immobilized pretreated C. rugosa lipase
Fig. 21. Effect of pretreating materials on the activity of immobilized R. oryzae lipase
Fig. 22. Effect of pretreating materials on the activity of immobilized C. rugosa lipase
Fig. 23. Reusability of immobilized R. oryzae lipase
Fig. 24. Reusability of immobilized C. rugosa lipase.
Fig. 25. Effect of pretreatment temperature on the activity of immobilized R. oryzae lipase
Fig. 26. Effect of pretreatment temperature on the activity of immobilized C. rugosa lipase
Fig. 27. Effect of agitation speed on the activity of immobilized R. oryzae lipase
Fig. 28. Effect of agitation speed on the activity of immobilized C. rugosa lipase
Fig. 29. Effect of pretreatment concentration on the activity of immobilized R. oryzae lipase
Fig. 30. Effect of pretreatment concentration on the activity of immobilized C. rugosa lipase
Fig. 31. Effect of pretreating time on the activity of immobilized R. oryzae lipase
Fig. 32. Effect of pretreating time on the activity of immobilized C. rugosa lipase
Fig. 33. Reusability of immobilized R. oryzae lipase
Fig. 34. Reusability of immobilized C. rugosa lipase.
Fig. 35. Effect of pH of phosphate buffers on the activity of immobilized pretreated R. oryzae lipase
Fig. 36. Effect of pH of Tris buffers on the activity of immobilized pretreated R. oryzae lipase
Fig. 37. Effect of pH of phosphate buffers on the activity of immobilized pretreated C. rugosa lipase
Fig. 38. Effect of pH of Tris buffers on the activity of immobilized pretreated C. rugosa lipase
Fig. 39. Effect of ionic strength of phosphate buffers on the activity of immobilized pretreated R. oryzae lipase
Fig. 40. Effect of ionic strength of Tris buffers on the activity of immobilized pretreated R. oryzae lipase.
Fig. 41. Effect of ionic strength of phosphate buffers on the activity of immobilized C. rugosa lipase
Fig. 42. Effect of ionic strength of Tris buffers on the activity of immobilized pretreated C. rugosa lipase
Fig. 43. Effect of temperature on biodiesel production using immobilized R. oryzae lipase
Fig. 44. Effect of agitation speed on biodiesel production using immobilized R. oryzae lipase
Fig. 45. Effect of molar ratio (methanol/ olive oil) on biodiesel production using immobilized R. oryzae lipase
Fig. 46. Biodiesel production using immobilized R. oryzae lipase
Fig. 47. Biodiesel production using an 1, 3-specific lipase relying on acyl migration mechanism.
Fig. 48. New approach to produce biodiesel using 1, 3-specific lipase and non-specific lipase without relying on acyl migration mechanism
Fig. 49. Biodiesel production using immobilized C. rugosa lipase
Fig. 50. Biodiesel production using mixture of immobilized R. oryzae and C. rugosa lipases at ratios of 1:3, 1:1, 3:1 (w:w)
Fig. 51. Biodiesel production by reusing a mixture of immobilized R. oryzae and C. rugosa lipase at the ratio of 1:1 (w:w)
Fig. 52. Effect of temperature on biodiesel production using a mixture of immobilized R. oryzae and C. rugosa lipases
Fig. 53. Effect of agitation speed on biodiesel production using a mixture of immobilized R. oryzae and C. rugosa lipases
Fig. 54. Effect of molar ratio (methanol/ soybean oil) on biodiesel production using a mixture of immobilized R. oryzae and C. rugosa lipases at the ratio of 1:3 (w:w).
Fig. 55. Effect of molar ratio (methanol/ soybean oil) on biodiesel production using a mixture of immobilized R. oryzae and C. rugosa lipases at the ratio of 1:1 (w:w).
Fig. 56. Effect of molar ratio (methanol/ soybean oil) on biodiesel production using a mixture of immobilized R. oryzae and C. rugosa lipases at the ratio of 3:1 (w:w)
Fig. 57. Biodiesel production using a mixture of R. oryzae and C. rugosa lipases at the ratio of 3:1(w:w) (feeding of 3 mmol of methanol)
Fig. 58. Biodiesel production using a mixture of R. oryzae and C. rugosa lipases at the ratio of 3:1(w:w) (feeding of 4 mmol of methanol)
Fig. 59. Effect of the concentration of immobilized lipase on biodiesel production
Fig. 60. Repeated biodiesel productions by reusing the mixture of immobilized R. oryzae and C. rugosa lipases
Fig. 61. Large scale production of biodiesel in a 300 ml jar reactor (Methanol feeding at every 1.5 h)
Fig. 62. Large scale production of biodiesel in a 300 ml jar reactor (Methanol feeding at every 3 h)
List of Tables
Table 1. Policies of developed countries about biodiesel usage
Table 2. Immobilization yields of R. oryzae and C. rugosa lipases
Table 3. Immobilization yields of pretreated R. oryzae and C. rugosa lipases for 2 h
Table 4. Immobilization yields of pretreated R. oryzae and C. rugosa lipases for ranging from 12 h to 36 h
Table 5. Effect of pretreating materials on the activity of immobilized R. oryzae lipase
Table 6. Effect of pretreating materials on the activity of immobilized C. rugosa lipase
Table 7. Comparison with other researches for biodiesel production by enzymatic processes
Overall Introduction
1. Biodiesel
