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Microalgae Based Biofertilizers And Biostimulants For Agricultural Crops
Published in Gustavo Molina, Zeba Usmani, Minaxi Sharma, Abdelaziz Yasri, Vijai Kumar Gupta, Microbes in Agri-Forestry Biotechnology, 2023
Alex Consani Cham Junior, Ana Claudia Zanata, Sofia de Souza Oliveira, Eduardo Bittencourt Sydney, Andréia Anschau
An example of the use of a forest-based wastewater for microalgae growth is described in patent BR 10 2018 074711 8 (Novak et al., 2018). The authors described the use of a black liquor from the Kraft production of paper to produce Spirulina. Black liquor is the result of the alkaline cooking of wood, where sodium hydroxide (NaOH) and sodium sulfide (Na2S) are used for the dissolution of fiber and lignin and is generally burned for electricity production (M'hamdi et al., 2017). Due to the alkaline pH, the Spirulina production would be possible without the need of acidification. Concentrations of 2–5% of black liquor were optimum to produce Spirulina biomass, but when the cells were immobilized using sodium alginate a black liquor content of up to 35% were possible, with optimized conditions at 20%.
Boilers
Published in Neil Petchers, Combined Heating, Cooling & Power Handbook: Technologies & Applications, 2020
Black liquor (which is a mixture of inorganic and organic solid by-products from paper and pulp industry processes that is partially dissolved in an aqueous solution) is a common by-product burned in recovery boilers. Black liquor firing is composed of drying, volatile burning, char burning, and smelt coalescence. Operating problems resulting from plugging and aggressive corrosion can be particularly prevalent. Plugging results from condensation of the fume or normal gases given off by black liquor combustion, as well as from the carryover of smelt, or unburned black liquor, into convection heat transfer sections of the boiler. With proper design and operation, condensation is limited to the furnace area where deposits can be controlled by soot blowers. Corrosion is mitigated through special furnace floor and lower wall designs featuring studded carbon steel tubes covered with refractory or bimetallic composite tubing. Additionally, special provisions must be made for emergency shut down if water is suspected to have entered the furnace of an operating boiler. This is critical to ensure avoidance of a potentially explosive smelt-water reaction.
Biofuels Production from Renewable Energy Sources
Published in Debabrata Das, Jhansi L. Varanasi, Fundamentals of Biofuel Production Processes, 2019
Debabrata Das, Jhansi L. Varanasi
Wood and forest residues mainly include primary wastes from forestry areas such as bark, off cuts, sawdust, and shavings. Unlike agricultural residues, wood and forest residues contain a high content of lignin and a low moisture content. These characteristics attribute to thermochemical processing of these feedstock for biofuel production. At present, most forest-based residues recovered are burned to generate heat and electricity (Drapcho et al. 2008). For example, black liquor, a by-product of paper and pulp industries (consists of lignin in the pulp form), is burned to generate thermal energy. Similarly, wood pellets, such as the wood chips, sawdust, and round wood, are co-fired to generate green electricity. Although these wastes can be obtained at affordable prices, their sustainability is debatable since the extraction of forest residues can lead to a reduction in soil fertility, lower the soil carbon, enhance soil erosion, and indirectly promote deforestation. Furthermore, their availability is concentrated to certain areas, which would lead to additional transportation costs to deliver the feedstock to the processing site.
Comprehensive depolymerization of lignin from lignocellulosic biomass: A review
Published in Critical Reviews in Environmental Science and Technology, 2023
Qinghua Ji, Xiaojie Yu, Li Chen, Abdullateef Taiye Mustapha, Clinton Emeka Okonkwo, Cunshan Zhou, Xianming Liu
KL is the lignin separated from kraft paper pulping process (Torres et al., 2020). During the preparation of KL, the wood is treated with a solution of NaOH and NaHS in the temperature range of 150–170 °C for several hours, causing the ether bonds in the lignin structure to be cleaved and converted into small lignin fragments, also known as alkali-soluble lignin. In the process of wood delignification, almost 90% of the lignin can be dissolved, and the resulting liquid mixture is also called black liquor. The ability of KL to be used as a fuel has a lot to do with its chemical properties. Since KL is hydrophobic and has low reactivity, it needs to be modified to increase its reactivity. The aliphatic mercaptan groups in KL contribute to its distinctive smell. In addition, the high water consumption in the KL production process increases the economic cost of large-scale industrialization.
Cement Catalyzed Valorization of Rice Straw into Upgraded Bio-Oil and Fuel Gases Using Pyrolysis Reactions
Published in Combustion Science and Technology, 2022
Ikram Uddin, Guijin Wang, Deyang Gao, Ning Li, Zahid Hussain, Baolin Hou
Biomass is an alternative and renewable energy source overcoming the energy crisis and CO2 emissions (Lu, Li, Zhu 2009). Rice straw is an attractive agricultural biomass source obtained as a by-product of the rice milling process. The world’s annual rice straw production is more than 731 million tons, and Asia alone contributes 92% to this sum (Binod et al. 2010). This waste biomass cannot be converted by common chemical methods due to lignin’s inactive property, which is often burned in the field or discarded, thus posing environmental concerns. Therefore, developing an efficient and simple robust process of converting these agricultural residues into useful products is important for reducing fossil fuel dependence and avoiding environmental problems. For this, recently, many processes have been developed and even experimented on a pilot scale. In these developed methods, the most direct conversion method is combustion to produce vapor or electricity but limited due to alkali metal’s corrosion to furnace in the high-temperature atmosphere. Besides, the agricultural residue could also be used as a raw material in paper-making (Gayubo et al. 2004; Wang et al. 2012). Nevertheless, lignin, which is considered a major component in rice straw, cannot be converted in the paper-making process. It must be discharged as black liquor and then cause a severe environmental problem (approximately 7 tons of black liquor is produced to obtain one ton of pulp). Hence, developing a cost-effective and efficient strategy for utilizing rice straw components is critically required (Li et al. 2015).
Performance optimization of multiple stage evaporator using interior-point method and metaheuristic approaches in environment of real-time plant complexities
Published in International Journal of Green Energy, 2021
Smitarani Pati, Om Prakash Verma
Black liquor is a biomass-based biofuel obtained as a residual stream from the digester during the paper mills’ Kraft recovery process (Verma, Manik, and Sethi 2019). This liquor is constituting 15–20% solids, containing chemicals, a rich amount of lignin, hemicellulose, and water (Clay 2016). There is an estimated global production of 170 million tons of Weak Black Liquor (WBL) per year, which leads to the energy content of 2EJ, thereby making it a very significant biomass source (IEA Bioenergy Summary and Conclusions from the IEA Bioenergy ExCo54 Workshop, 2007). For the utilization of WBL as a fuel, a green form of energy, its solid concentration needs to be augmented to a higher value of 65–85%, achieved by evaporating the amount of water present in it (Clay 2016). This concentration of WBL has been enhanced via Multiple Stage Evaporator (MSE), a cascade arrangement of several evaporator units. The fresh steam is supplied to the first stage, and the vapor obtained is fed as the input to the next stage. This MSE unit consumes more than 31.67% of the total steam used in the Kraft recovery process, which leads to an enhanced operating cost (Verma et al. 2017a). Therefore, it becomes essential to focus on reducing the operating cost of MSE with optimum utilization of steam energy and biomass energy inside the mill by introducing various Energy Reduction Schemes (ERSs).