Project Long-term Plan
|Time Frame||Expected progress|
|Dec. 2019-Jun. 2020
|Jul. 2020-May. 2021
China is one of the largest countries which produces paper pulp each year and the gross productivity of paper pulp in 2016 is 79 million tons and continually increases. And waste paper pulp is about 63 million tons to produce paper. But some damages to environment and ecology appear and cause contaminant to water and air and waste of energy in our life. As the conscious of protecting environment spread all the world, some countries urge to change the way of making paper and produce add-value product to decrease the ruins for environment. If we utilize 10% of waste paper pulp in a paper mill, which produce 30 thousand tons waste paper pulp per year, to produce bacterial cellulose by Paper Transformer, we will treat approximately 17 thousand tons waste water and make profits.
Bacterial cellulose is recognized as a new biological material with good application prospects in the world. At present, in our country, the research and development of bacterial cellulose has been paid increasing attention by researchers.
Due to various excellent properties of bacterial cellulose, bacterial cellulose has been relatively popular in the Japanese paper industry. For example, Ajinomoto cooperated with Mitsubishi company to develop super paper for the production of circulating currency. The printed U.S. dollar has good quality, water resistance and high strength.
However, the application of bacterial cellulose in paper industry is less in Chinese factories at present. Therefore, bacterial cellulose has a broad market prospect in China.
In the food industry, people use bacterial cellulose to make coconuts due to the hydrophilic, viscous and stable properties of bacteria cellulose. Coconut as a high quality natural dietary fiber has been widely recognized in the food industry.Coconut has the advantages of low calories, no cholesterol, and has an obvious physiological regulation function to human body. Coconut is also a good health food raw materials,it's known that has many physiological mediation functions including promoting gastrointestinal motility, prevent constipation, improve human digestive function.
Due to the advantages of good mechanical toughness, permeability and water permeability, low surface roughness, high porosity and plasticity, good biocompatibility, bacterial cellulose has been successfully applied in wound excipients, such as skin transplantation and burns. In addition, because of the bacterial cellulose has a unique fiber mesh structure, high porosity, high mechanical strength and high elastic modulus and other properties, it is the ideal of epithelial cell growth stent and artificial skin, artery vein, an ideal replacement of bone scaffold material, and has been proven as an artificial blood vessels, and the feasibility of tissue engineering scaffolds.
BC also can be used for the preparation of bacterial cellulose wound dressing, with its produce BC/chitosan composite materials, mechanical properties, the water holdup increased 1.5 times and 1.4 times respectively, bandages and gauze, etc., it can reduce the incentive for the wound, effectively relieve pain, accelerate wound healing and other excellent properties, and the biodegradable characteristic of the bacterial cellulose conforms to the modern concept of environmental protection. Igem-ecuador2018 has also proposed cross-linking BC synthesis with the peptide ELP to produce dressings that can assist in bone injury recovery.
BC's high purity, high crystallization, high degree of polymerization and high molecular orientation and high mechanical strength ------after thermal treatment, young's modulus can reach 30 GPa, 4 times than the high strength organic synthetic fiber------ can satisfy the current top sound audio equipment vibration membrane materials required for sound transmission speed and internal friction characteristics of the high requirements.
It is reported that the Japanese company Sony and the company Ajinomizu jointly developed the vibration film of super audio, microphone and earphone made of bacterial cellulose. The transmission speed is as high as 5000m/s in an extremely wide frequency range, and the internal friction is as high as 0.04, and the reproduced sound is clear and bright. At present, the transmission speed of ordinary advanced audio aluminum vibrating film is 3000m/S, and the internal friction is 0.002. The transmission speed of vibration film of pine paper is 500m/S, and the internal friction is 0.04.
From what has been discussed above, BC has a very broad application prospect.
Cooperation and expectation
During the project, we visit a number of paper mills and get to know their production lines and operation modes. The technicians in the paper mills gives many useful suggestions for our project. In August, we visited Hangzhou Fulun Ecological Technology co., LTD., and they showed great interests in our project and praised our idea of turning waste into treasure. The company has been adhering to the concept of ecological regeneration, so it fits well with the concept of our project. Even after the competition, our communication with the paper factory will not stop. We hope to make paper transformer really benefit the paper industry and plan to cooperate with the factory to produce bacterial cellulose in the future.
With the recycle of paper pulp to make paper, there is a lot of white water and contaminants like ions, bactericide and alkali. If we use waste paper to produce bacterial cellulose, besides we can get product,we can reuse the fermentation liquor as manure after sterilization and use molasses, a kind of cheap medium, to culture strain. The biomanufacturing is better than chemical manufacturing for it low energy consumption, high conversion rate and no pollution. Nowadays, we design a 500L fermenter as a pilot scale,and in this fermentation we can utilize 4 tons waste pulp,9 tons molasses and produce about 2 tons bacterial cellulose per year, finally we can make a profit 3 thousand dollars each year. When we scale-up the fermentation, we can get more benefits for environment and ecology. If we use a 200 tons fermenter to have a manufacture, the utilization of waste paper pulp is up to two thousand tons and the decrease of waste water is about 17 thousand tons even make a profit 1.5 million dollars per year.
We analyzed the expense of all materials and items to evaluate economic benefits,if we build a plant and have such a produce process in 200 m3 fermentor ,we could make a profit 8,062,780 dollars per year,decrease waste water 412,200 ton ,reduce waste paper pulp 2,061 ton,so environmentally friendly and economical!
Figure 1. Expenditure Budget for producing 1 ton bacterial cellulose
Figure 2. Economic and Eviornmental Benefit of Different Fermenter Size
From the laboratory to industrial production
Fermentor scale-up is a method of industrial manufacturing which is from laboratorial explore for fermentation process through tests to perfect and enlarge to the application in the factory.
Fermentation process in laboratorial explore usually begins with shake flask to culture strain including the choice for medium, screen for strain and determination for fermentation conditions. Especially, for strain fermentation, the spore and mycelium are internal factors and inoculum, pH, and temperature etc. are external factors. Laboratorial experiment just provides basic scheme for fermentation process and is different from industrial scale.
Pilot scale is bigger than laboratorial explore and mainly consider the factors during the fermentation, like pressure, agitation speed, air flow rate, feed rate,power input, viscosity, dissolved CO2,cell concentration, oxygen transfer rate etc. A pilot plant is in reality a large-scale laboratory which has been designed to give flexibility for equipment accommodation (bioreactors, pumps, heat exchanges, storage facilities, electrical and piping services, etc.), and adaptability for process operation. Engineering design criteria will incorporate simplicity, economy of operation and containment of air and water waste. Pilot plant bioreactors range from 100L to 10000L total volume and the large pilot bioreactors can no occasion be used as production units. Full scale industrial bioreactors can range between 40000L and 400000L volume.
When moving from the laboratory to the industrial scale major problems arise with heat removal, oxygen transfer and availability and insufficient diffusion of the components in the medium, for example nutrients, toxic metabolites and acid or bases. The management of scale-up problems requires high capital investment in mixing and aeration, in monitoring and control devices, and in stringent maintenance of sterility.