Lignin is a kind of abundant, cheap and sustainable natural biomass resource. Recently, converting lignin to functional nanomaterials has greatly broadened its application. Meanwhile, this conversion greatly solved the typical problems for traditional materials. Here, in this paper, several preparation methods including preparation of lignin functional nanoparticles such as self-assembly, mechanical method, polymerization assembly, freeze-drying carbonization, etc were introduced. And then their different applications in catalysts, additives, adsorbents, UV protection and anti-oxidation, sterilization, carrier materials, aggregation-inducing emmision materials, etc were described. Also, an outlook about the prospect of its application was presented. Developing controllable preparation and functional modification will facilitate the further application of lignin-based nanoparticles in the fields of environmental protection, energy, catalysis and biomedicine.
To investigate self-ignition of crop straws in storage and pulverization, the self-heating process of storing rice straw(RS), wheat straw(WS) and corn stalk(CS) were carried out in Dewar device and the effect of moisture content was studied. Meanwhile, thermogravimetric analysis with slow heating rate were conducted to study the characteristics and kinetics of low temperature oxidation of three kinds of straw. The results of Dewar experiments showed that the self-heating process of crop straws followed the same pattern, which was divied into three stages including induction period, temperature rising period and stable period of temperature dropping, and the higher the moisture content was, the stronger the self-heating propensity was. Moreover, rice straw had the strongest self-heating capability and wheat straw had the weakest capability. Low temperature oxidation experiments showed that, compared with wheat straw, rice straw and corn stalk had stronger low temperature oxidation, pyrolysis activity and higher self-ignition risk in pulverization. In conclusion, rice straw and corn stalk were evaluated to have higher self-heating and self-ignition risks in storage and pulverization.
Activated carbon has unique physical and chemical properties and is widely used in many fields such as industry, civil and national defense, and has an irreplaceable important role. Common activated carbon can not meet the needs of human production and life expansion, so further research on modified activated carbon technology has become a hot spot.In this paper, the research results of chemical modification(oxidation modification, reduction modification, acid and alkali modification, loading metal modification and plasma modification) and physical modification(high temperature heat treatment and microwave modification) of activated carbon were summarized, the technical characteristics of different modification methods were compared and the furture development of the modification technology was prospected.
Star anise(Illicium verum) is a characteristic natural plant resources in China, and widely used in the field of spicery, food and medicine. More than 85% of star anise resources in the world are produced in Guangxi and Yunnan of China. The total cultivated area of star anise are 472 700 hm2, and the annual average yield of star anise is about 206 900 t. The use of star anise is mainly fruits, branches and leaves. The processing technology, quality requirements and detection method of star anise characteristic resources including primary products of dried fruit and anise oil, and deeply processed products of oleoresin, anethole, estragole, shikimic acid and anisaldehyde, and so on were introduced. The development status and trends of processing and utilization of star anise including processing of dried fruit, extraction of anise oil, deep processing and extraction of other high-value active ingredients were analyzed. The problems of direct consumption of dried fruit raw materials, the low proportion of deep processing and utilization, and the serious lag in deep processing technology and new products development were pointed out. In the future, the processing and utilization industry of star anise should focus on improving deep processing technology, expanding new product development and broadening product application.
This work focused with the assistance of the mechanism of pyrolysis carbonization of cellulose, lignin and hemicellulose were analysed by TG, TEM, Raman, XRD, and FT-IR based on the molecular restructuring behavior of three major components of cellulose, lignin and hemicellulose during pyrolysis. The results showed that hemicellulose was completely decomposed during pyrolysis; molecular rearrangement occurred during the pyrolysis of cellulose, forming crystallized areas in biomass char; lignin had a very complex cross-linked structure, melted during pyrolysis, forming amorphous carbon areas in biomass char. During the charring process, cellulose undergone mainly dehydration reactions when the temperature was lower than 200 ℃, and the temperature range of 200 to 400 ℃ was the main stage of pyrolysis; lignin was relatively structurally stable in the studied temperature range(200-500 ℃), with only partial structural transformation occurring while softening and melting.
Chinese gallnut is produced and processed mainly in our country. Gallnut output accounts for 95% of the world total output. At present, the processing and utilization industry of gallnut has established relatively mature utilization technology of the whole industrial chain of gallnut, including high efficient breeding, deep processing, new products and their applications. In this paper, the function and distribution of gallnut in China, development overview of gallnut processing and utilization industry, standards of products and their test methods are introduced. The problems of the development of the industry are pointed out. The development status and future industrial development trend is analyzed.
Litsea cubeba (Lour.) Pers. is a traditional essential oil tree species. In recent years, it has also been regarded as an oil or energy tree species. Vigorously developing L. cubeba planting can effectively improve the ecological environment and increase the income of farmers in poor mountainous areas. At present, the processing of L. cubeba resources is mainly extensive in China. To increase the added value of L. cubeba resources, new products must be developed, and at the same time more energy-saving and economical extraction methods and purification processes should be sought. This article reviewed the general situation and resource distribution. The chemical composition, physicochemical property of L. cubeba essential oil and its applications in synthetic perfume, food additives, medical care, biological control, food fresh keeping were introduced, as well as the fattyacid composition, physicochemical of L. cubeba kernel oil and its applications in pomace feedstuff, liquid biofuels and surfactant. And the extraction, separation and purification techonoly of essential oil and kernel oil of L. cubeba were analyzed, as well as the industry scale and condition of supply and demand. The problems in the L. cubeba industry in raw material collection, production and processing technology, sales and brand establishment were explained. And provided countermeasures and suggestions for the future development of the problems encountered by the L. cubeba industry. In order to correctly understand and grasp the development direction of the L. cubeba industry, it provided a reference basis for the formation of a new situation of scientifically optimized allocation of resources, in-depth intensive development, and comprehensive and efficient utilization of L. cubeba resources.
Activated carbon industry is an efficient and comprehensive utilization for processing residues of forestry special resources. The yield of wooden activated carbon in China was more than 450 000 tons, and the total output value was about 4 billion yuan in 2018. The activated carbon is widely used in food, medicine, new energy resources, environmental protection, chemical engineering, military industry and other industries. The activated carbon industry strongly support high quality and sustainable development of all industries of national economy, ensure the safety of food and drug, improve the energy conservation, emission reduction and green development of forestry industry. As a leading enterprise in the activated carbon industry of China, Fujian Yuanli Active Carbon Co., Ltd. presents an activated carbon annual output of higher than 100 000 tons and an export volume of more than 29 000 tons in 2019. It has advantages of rich forest residual raw materials, large-scale, continuous and clean production capacity, good quality of medium and high-end products, etc. However, domestic wood activated carbon industry still exhibit weak process automation and intelligent level, has few high-end products, and lack of new technology for green and high-end manufacturing. Thus, several suggestions was proposed to promote the development of the activated carbon industry:innovation of industry development mode, addition of wood activated carbon industry into the resources recycling industry directory, increase of the scientific research projects from the national level, and support in fiscal, financial, tax and policy.
As a characteristic economic forest tree species in China, the planting area and annual output of Cinnamomum cassia Presl are the first in the world. The distribution area of cinnamon in Guangxi is 149 000 hm2 and that in Guangdong is 89 000 hm2, accounting for more than 95% of the country's total area. Cinnamon is not only a famous spice but also a valuable traditional Chinese medicine, which has a very high economic value, and developing Cinnamon industry is of great significance for increasing farmers' income and maintaining the health of China. In this paper, the resource quantity, distribution and utilization of cinnamon were reviewed, The main products and processing technology status, product quality control and its analysis and testing methods were introduced. The future development trend of the industry was analyzed. Countermeasures and measures for industrial development such as strengthen the construction of cinnamon standardized demonstration base, improve supply capacity of high-quality resource, improve the technical level of cinnamon processing and utilization and extent the industry chain, cultivate leading cinnamon enterpries and improve market competitiveness of products, were put forward.It provides some ideas for the sustainable development of the processing and utilization industry of cinnamon resources in China.
As a new type of nano-porous carbon-based materials, carbon aerogel has many unique characteristics such as high porosity, large specific surface area, high electrical conductivity, and high thermal stability, etc., which is widely used in the fields of catalyst, capacitors and adsorption materials.Compared with traditional carbon aerogels, biomass-based carbon aerogels have the advantage in abundant and renewable precursors, which opens an opportunity for the high-value and functionalized utilization of biomass. Based on a brief introduction of the preparation process of biomass-based carbon aerogels (including sol gelation, drying and carbonization), this review paper mainly introduced the preparation methods of three types of carbon aerogels from different biomass precursors (plant cellulose, bacterial cellulose and plants with three-dimensional porous structure), and the applications of carbon aerogels in catalyst, adsorption materials, ultracapacitors and lithium-ion batteries were elaborated as well. Finally, the research direction and development prospective of biomass derived carbon aerogels were discussed.
Biological pretreatment technology is applied to the extraction of natural products by the action of microorganisms or biological enzymes. Under appropriate conditions, the cell walls of natural resources are decomposed, which promotes the release of natural products into the extraction medium. Therefore, the efficiency of extraction and the activity of natural products are improved. Biological pretreatment technology includes microbial fermentation technology and biological enzyme assisted technology. This paper reviews the mechanism and application of two biological pretreatment techniques, aiming at providing reference for the development and utilization of natural products.
Biochar(BC) was made by pyrolysis of rice husk, bamboo and Chinese fir sawdust at different temperature, which respectively labeled DBC, ZBC and MBC in turn. The physicochemical properties of the product were characterized by Fourier transform infrared spectroscopy(FT-IR), scanning electron microscope(SEM), energy dispersive X-ray(EDS) and X-ray diffraction(XRD). The adsorption characteristic and mechanism of BC to U(Ⅵ) were studied by batch adsorption experiments. The results showed that, as the temperature increased from 300 ℃ to 700 ℃, the pH value and ash content of the three kinds of biochars increased, but the yield decreased. Meanwhile, the characterization of both ZBC and DBC was also changing with increasing pyrolysis temperature, such as the crystallinity of the carbon fiber and content of oxygen-containing functional groups decreased, the proportions of inorganic elements and pore shapes increased, and the surface was rougher. The adsorption processes on the three kinds of BCs were more consistent with the pseudo-second-order kinetic model(R22>0.96), and the adsorption equilibrium time was 3 h at reaction temperature 25 ℃, pH value 4, solid-liquid ratio 1:1(g:L). The adsorption isotherms of the three kinds of BCs were more consistent with Langmuir model, which indicated that chemical adsorption was the main process. The largest adsorption capacity of ZBC700 was 18.55 mg/g. The abilities of ZBC and DBC to adsorb U(Ⅵ) were enhanced with increasing pyrolysis temperature, simultaneously, the contribution utility of cation-π and ion exchange was increasing. Nevertheless, the relationship between the ability of MBC to adsorb U(Ⅵ) and pyrolysis temperature was not obvious, and the adsorption capacities of ZBC and DBC were higher than that of MBC at the same pyrolysis temperature.
The antibacterial activities of dehydroabietic acid(1), dehydroabietylamine(2), dehydroabietamide derivatives(3a-3m), dehydroabietylamine benzaldehyde Schiff base derivatives (4a-4i), against six different pathogenic fungi were studied by using plate counting method. The results showed the antibacterial activity of dehydroabietylamine was better than that of dehydroabietic acid, and the antibacterial activities of dehydroabietylamine benzaldehyde Schiff base derivatives were better than that of dehydroabietamide. And the dehydroabietylamine p-chlorosalicylaldehyde Schiff base(4d), dehydroabietylamine m-fluorobenzaldehyde Schiff base(4f), dehydroabietylamine p-fluorobenzaldehyde Schiff base(4g) and dehydroabietylamine p-chlorobenzaldehyde Schiff base(4h) showed strong antibacterial activities. The inhibitory rates of sample 4h against Botrytis cinerea, Fusarium solani and Alternaria brassicae at 180 mg/L were up to 100%, which were close to the positive control, Actinomycin. The antibacterial activities of samples 4d, 4f, 4g and 4h at mass concentrations of 11.25, 22.5, 45 and 90 mg/L against six different pathogenic fungi were further studied. All the samples showed excellent antibacterial activities against Botrytis cinerea and Alternaria brassicae at different mass concentrations. The inhibitory rates of sample 4f at 22.5 mg/L against six different pathogenic fungi were more than 95%, but the sample 4g at 22.5 mg/L showed the lowest inhibitory rate. And the sample 4h at 45 mg/L showed the highest antibacterial activities. The above results demonstrated that the substitution position and the type of the halogen atom on the benzene ring affected the antibacterial activity at different mass concentrations and the concentration of the optimum antibacterial activity.
Ginkgo biloba is an important traditional economic forest and greening tree species in China. The productive value of G. biloba industry chain is 20 billion yuan, which is an important local agriculture and forestry industry. China's ginkgo resources account for 85% of the world, with ginkgo planting area of about 400 000 hm2 and the number of cultivation of more than 2.5 billion. This paper summarized the ginkgo resources, distribution and main use parts, introduced main ginkgo products (Ginkgo biloba leaves extract, ginkgo preparations and gingko seed) and the present situation of processing technology, product quality control and its analysis method, analyzed the trend of the development of industry. There is a clear gap between the processing technology of Ginkgo biloba leaves in China and the international advanced level. There are generally problems such as small scale, backward equipment, weak technical force, low production efficiency, poor product quality and product standard not up to international standards, and lack of high, fine and sharp deep processing ginkgo products. The future ginkgo industry needs to focus on the development of high-value-added products, high-end cosmetics and biological feed field. At the same time, aiming at the new form of revitalizing the mountain village and the characteristic small town, this paper puts forward the ideas of G. biloba industry in developing the characteristic Ginkgo cultural industry, G. biloba leisure sightseeing and G. biloba characteristic rural health care industry.
Taxus is the natural source of paclitaxel that is a broad-spectrum anti-tumor drug. Chinese Taxus resources account more than half of the global reserves and the exports account for a quarter of the world's total production, but the Taxus export value accounts only one tenth of the world's total output value. Therefore, how to quickly increase the added value of Taxus products and establish a complete high value-added industrial chain is the key to the development of Taxus industry. Consequently, the resource reserves, product types, product quality control and its analytical control methods, technical bottlenecks and industrial scale of Taxus were investigated in this study. The reasons for the lack of wild resources, unified planning and layout of artificial resources and high price products in current Chinese yew industry were analyzed. At last, the suggestion on the resource reserves, technological innovation directions and industrial development plans of Taxus were provided. This study may provide theoretical basis and data support for the green industrialization of Taxus.
Lignocellulose is the most abundant renewable biomass resource on the earth and cellulose is one of the three components of lignocellulose and is important raw material for the production of bio-based materials, fuels and chemicals. However, the complex chemical structure of lignin limits the application of lignocellulose. Conventional physical, chemical and physical-chemical lignin degradation methods often require high temperature and high pressure conditions, resulting in high energy consumption, inhibitors and environmental pollution. The biocatalysis process mediated by microorganisms is usually carried out under mild conditions, which can reduce energy input and provide a more specific and effective choice for the utilization of lignin. The degradation of lignin by fungi, represented by white-rot fungi, presents the problems of long pretreatment cycle and poor adaptability to the environment. Bacterium becomes the future potential of lignin degradation, owing to its rapid proliferation, profound environmental adaptability and easy genetic manipulation. This review introduced the progress of microbial degradation of lignin on the base of chemical structure, and mainly analyzed the microorganisms (fungi and bacteria), degrading enzymes (peroxidase and laccase) as well as the degradation mechanism. Besides, the applications of microbial degraded lignin in lipids, bioplastics, vanillin and wastewater treatment were summarized and the future development was suggested.
Plant cellulose-based carbon aerogel has the characteristics of low density, biodegradable, excellent adsorption and stable electrochemical properties. This paper analyzed the performance and development of plant cellulose-based carbon aerogels around its raw material, preparation process and application in environmental management and energy storage and transformation. The preparation methods of plant cellulose-based carbon aerogels of cotton, wood, bamboo fiber and other raw materials were described in detail, such as sol gel method, hydrothermal method, direct carbonization method, etc. The factors of drying method, solvent selection and replacement and composite modification during preparation were analyzed. And the applications of carbon aerogel in air cleaning, oil water separation, removal of toxic compound and heavy metal ion, environmental governance and energy conversion and storage were introduced.
Camellia oleifera Abel. is one of the four largest woody oil plants in the world, and it is also a unique high-quality woody oil resource in China. Camellia seed oil is a high-grade vegetable oil and rich in nutrients and health-care ingredients. In order to promote the rational allocation of oil-tea camellia resources, extend the oil-tea camellia industry chain, and improve overall benefits, this article summarized the distribution and total amount of oil-tea camellia resources, analyzed the functional components and utilization status of oil-tea camellia seed oil, camellia husk, and oil-tea cake. Looking at the development of the camellia industry, the popularization experience of the oil-tea camellia industry was summarized, the problems of the industry in the process of raw material harvesting and storage, product research and development, enterprise production and operation, and brand building were pointed out. Combining with the future development trend of the industry, the countermeasures that could be used for reference were proposed.
Benzoxazine resins, a new type of thermosetting resin, are featured by strong molecular design ability, flame retardancy, high corrosion resistance, independence on strong acids during thermosetting, and no release of small molecules and thus they are widely used in aviation, architecture, electronics and other fields. In this study, the methods of benzoxazine monomer(solvent method, solvent-free method and suspension method), the synthesis methods to reduce the ring opening polymerization temperature of benzoxazine(synthesis of benzoxazines with special groups and addition of catalysts), and the application of benzoxazine resins into shape memory polymers were introduced(mixed with other polymers and chemical modification of benzoxazine). Moreover, the existing problems concerning benzoxazine shape memory polymers were summarized. Finally, the prospects about the development of benzoxazine resins in shape memory polymers were proposed.
The preparation of hydrogen-rich syngas by biomass pyrolysis is a popular research. Catalytic reforming of biomass tar can not only effectively remove tar, but also increase the content of H2 and CO in the gas phase. In this paper, the research on biomass tar reforming catalysts in recent years was reviewed. The advantages and disadvantages of nickel-based catalysts, non-nickel transition metal catalysts and alkali metal catalysts were discussed. Nickel-based catalysts usually require the support when they are used. Although they have high catalytic activity, they are easily deactivated by carbon deposition and nickel sintering. Although precious metal catalysts in non-nickel transition metal catalysts have extremely high activity and stability, but they are expensive, and other non-nickel metal catalysts have lower activity than nickel-based catalysts. The alkali metal catalysts are volatile and permanently inactivated.