scholarly journals Biorefinery review: Wide-reaching products through kraft lignin

BioResources ◽  
2019 ◽  
Vol 14 (3) ◽  
pp. 7543-7581 ◽  
Author(s):  
Iara F. Demuner ◽  
Jorge Luiz Colodette ◽  
Antonio J. Demuner ◽  
Carolina M. Jardim

This review details the structure of lignin and curates information on the characteristics that this polymer must have for each specific use. Lignin is a by-product of the pulp and paper industry and the second most abundant biopolymer after cellulose. Approximately 50 million tons of lignin are produced worldwide annually, of which 98% to 99% is incinerated to produce steam, process energy. Just 1% to 2% of the lignin, derived from the sulfite pulp industry, is used in chemical conversion to produce lignosulfonates. Biorefining is a promising approach to promote the wider use of kraft lignin. However, using kraft lignin to produce high value-added products is a great challenge, due to its complex structure, low reactivity, and low solubility, which are factors that limit the lignin’s large-scale use in biorefineries. Recent studies show that kraft lignin can be used as lignosulfonates and dispersants, technical carbons, transportation fuels, bioplastics, and adhesives, but some technological hurdles must be overcome and several industrial tests must be developed to make these uses viable.

Author(s):  
Mahesh Kumar

India is the largest milk producing nation in the world. Milk is perishable in nature, thus it can not be stored for a very long period. In order to preserve it, more than half of milk produced in India is converted into a variety of traditional value added milk products which played a significant role in the Indian economy. Khoa is a heat desiccated value added indigenous milk product. Due to its large scale consumption about six lakh tones of khoa is being manufactured annually, which is equivalent to seven percent of India's total milk production. In this article, the brief overviews on traditional method of khoa making, technological up-gradation in khoa making process, energy requirements, shelf life, and storage of khoa are presented.


Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 899
Author(s):  
Djordje Mitrovic ◽  
Miguel Crespo Chacón ◽  
Aida Mérida García ◽  
Jorge García Morillo ◽  
Juan Antonio Rodríguez Diaz ◽  
...  

Studies have shown micro-hydropower (MHP) opportunities for energy recovery and CO2 reductions in the water sector. This paper conducts a large-scale assessment of this potential using a dataset amassed across six EU countries (Ireland, Northern Ireland, Scotland, Wales, Spain, and Portugal) for the drinking water, irrigation, and wastewater sectors. Extrapolating the collected data, the total annual MHP potential was estimated between 482.3 and 821.6 GWh, depending on the assumptions, divided among Ireland (15.5–32.2 GWh), Scotland (17.8–139.7 GWh), Northern Ireland (5.9–8.2 GWh), Wales (10.2–8.1 GWh), Spain (375.3–539.9 GWh), and Portugal (57.6–93.5 GWh) and distributed across the drinking water (43–67%), irrigation (51–30%), and wastewater (6–3%) sectors. The findings demonstrated reductions in energy consumption in water networks between 1.7 and 13.0%. Forty-five percent of the energy estimated from the analysed sites was associated with just 3% of their number, having a power output capacity >15 kW. This demonstrated that a significant proportion of energy could be exploited at a small number of sites, with a valuable contribution to net energy efficiency gains and CO2 emission reductions. This also demonstrates cost-effective, value-added, multi-country benefits to policy makers, establishing the case to incentivise MHP in water networks to help achieve the desired CO2 emissions reductions targets.


2021 ◽  
Vol 10 (1) ◽  
pp. 264-281
Author(s):  
Ao Li ◽  
Dezhong Xu ◽  
Lu Luo ◽  
Yalan Zhou ◽  
Wen Yan ◽  
...  

Abstract The rapid economic growth and environmental concerns have led to high demands on paper and paper-based products in terms of variety, quantity, quality, and specialty. Enhancement and functionalization with additives are constantly required. Moving away from traditional petroleum-based additives, researchers have attempted to use “green” nanoadditives by introducing renewable environmentally friendly nanocellulose. This article studies the functions of nanocellulose as bio-additives (enhancer, retention and filtration reagent, and coating aid) in paper and paper products, and overviews the research development of nanocellulose-based additives and their applications in the paper industry for both efficient production and paper functionalization. The review shows that (1) a variety of nanocellulose-based bioadditives have been reported for various applications in paper and paper-based products, while commercially viable developments are to be advanced; (2) nanocellulose was mostly formulated with other polymer and particles as additives to achieve their synergistic effects; (3) major interests have concentrated on the nanocellulose in the specialty papers as representing more value added products and in the efficient utilization of recycled fibers, which remains most attractive and promising for future development. This report shall provide most useful database information for researchers and industries for paper recycling and enhancement, and paper-based products innovation and application.


2020 ◽  
pp. 136943322094719
Author(s):  
Xianrong Qin ◽  
Pengming Zhan ◽  
Chuanqiang Yu ◽  
Qing Zhang ◽  
Yuantao Sun

Optimal sensor placement is an important component of a reliability structural health monitoring system for a large-scale complex structure. However, the current research mainly focuses on optimizing sensor placement problem for structures without any initial sensor layout. In some cases, the experienced engineers will first determine the key position of whole structure must place sensors, that is, initial sensor layout. Moreover, current genetic algorithm or partheno-genetic algorithm will change the position of the initial sensor locations in the iterative process, so it is unadaptable for optimal sensor placement problem based on initial sensor layout. In this article, an optimal sensor placement method based on initial sensor layout using improved partheno-genetic algorithm is proposed. First, some improved genetic operations of partheno-genetic algorithm for sensor placement optimization with initial sensor layout are presented, such as segmented swap, reverse and insert operator to avoid the change of initial sensor locations. Then, the objective function for optimal sensor placement problem is presented based on modal assurance criterion, modal energy criterion, and sensor placement cost. At last, the effectiveness and reliability of the proposed method are validated by a numerical example of a quayside container crane. Furthermore, the sensor placement result with the proposed method is better than that with effective independence method without initial sensor layout and the traditional partheno-genetic algorithm.


2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Kaixuan Huang ◽  
Lalitendu Das ◽  
Jianming Guo ◽  
Yong Xu

Abstract Background Poplars are considered suitable dedicated energy crops, with abundant cellulose and hemicellulose, and huge surplus biomass potential in China. Xylan, the major hemicellulosic component, contributes to the structural stability of wood and represents a tremendous quantity of biobased chemicals for fuel production. Monomeric xylose conversion to value-added chemicals such as furfural, xylitol, and xylonic acid could greatly improve the economics of pulp-paper industry and biorefinery. Acetic acid (HAc) is used as a friendly and recyclable selective catalyst amenable to xylan degradation and xylooligosaccharides production from lignocellulosic materials. However, HAc catalyst usually works much feebly at inert woods than agricultural straws. In this study, effects of different iron species in HAc media on poplar xylan degradation were systematically compared, and a preferable Fe3+-assisted HAc hydrolysis process was proposed for comparable xylose-hydrolysate recovery (XHR) and enzymatic saccharification of cellulose. Results In presence of 6.5% HAc with 0.17–0.25 wt% Fe3+, xylose yield ranged between 72.5 and 73.9%. Additionally, pretreatment was effective in poplar delignification, with a lignin yield falling between 38.6 and 42.5%. Under similar conditions, saccharification efficiency varied between 60.3 and 65.9%. Starting with 100 g poplar biomass, a total amount of 12.7–12.8 g of xylose and 18.8–22.8 g of glucose were harvested from liquid streams during the whole process of Fe3+-HAc hydrolysis coupled with enzymatic saccharification. Furthermore, the enhancement mechanism of Fe3+ coupled with HAc was investigated after proof-of-concept experiments. Beechwood xylan and xylose were treated under the same condition as poplar sawdust fractionation, giving understanding of the effect of catalysts on the hydrolysis pathway from wood xylan to xylose and furfural by Fe3+-HAc. Conclusions The Fe3+-assisted HAc hydrolysis process was demonstrated as an effective approach to the wood xylose and other monosaccharides production. Synergistic effect of Lewis acid site and aqueous acetic acid provided a promising strategy for catalytic valorization of poplar biomass.


2010 ◽  
Vol 4 (1) ◽  
pp. 119-124 ◽  
Author(s):  
Göran Gellerstedt ◽  
Elisabeth Sjöholm ◽  
Ida Brodin

In this mini-review, various attempts to make carbon fiber from lignins are discussed. The replacement of construction steel in cars and trucks with a much lighter carbon fiber-based composite will ultimately result in more fuelefficient vehicles. To replace the precursors of carbon fiber, polyacrylonitrile (PAN), or other non-renewable materials such as pitch, by cheap (kraft) lignin, a comprehensive understanding of the physical and chemical characteristics of lignin and the development of methods for its homogeneous large-scale production must be achieved.


2015 ◽  
Vol 15 (6) ◽  
pp. 9767-9813 ◽  
Author(s):  
R. Paugam ◽  
M. Wooster ◽  
S. R. Freitas ◽  
M. Val Martin

Abstract. Landscape fires produce smoke containing a very wide variety of chemical species, both gases and aerosols. For larger, more intense fires that produce the greatest amounts of emissions per unit time, the smoke tends initially to be transported vertically or semi-vertically close by the source region, driven by the intense heat and convective energy released by the burning vegetation. The column of hot smoke rapidly entrains cooler ambient air, forming a rising plume within which the fire emissions are transported. This characteristics of this plume, and in particular the height to which it rises before releasing the majority of the smoke burden into the wider atmosphere, are important in terms of how the fire emissions are ultimately transported, since for example winds at different altitudes maybe quite different. This difference in atmospheric transport then may also affect the longevity, chemical conversion and fate of the plumes chemical consituents, with for example very high plume injection heights being associated with extreme long-range atmospheric transport. Here we review how such landscape-scale fire smoke plume injection heights are represented in larger scale atmospheric transport models aiming to represent the impacts of wildfire emissions on component of the Earth system. The use of satellite Earth observation (EO) data is commonly used for this, and detail the EO datasets capable of being used to remotely assess wildfire plume height distributions and the driving characteristics of the causal fires. We also discus both the physical mechanisms and dynamics taking place in fire plumes, and investigate the efficiency and limitations of currently available injection height parameterizations. Finally, we conclude by suggestion some future parameterization developments and ideas on EO data selection that maybe relevant to the instigation of enhanced methodologies aimed at injection height representation.


2021 ◽  
Author(s):  
Henry C. Edeh

Achieving the Sustainable Development Goals (SDGs) of poverty and inequality reduction through redistribution have indeed become critical concerns in many low- and middle-income countries, including Nigeria. Although redistribution results from the effect of tax revenue collections, micro household-level empirical analyses of the distributional effect of personal income tax (PIT) and value added tax (VAT) reforms in Nigeria have been scarcely carried out. This study for the first time quantitatively assessed both the equity and redistributive effects of PIT and VAT across different reform scenarios in Nigeria. Data used in this study was mainly drawn from the most recent large scale nationally representative Nigeria Living Standard Survey, conducted in 2018/2019. The Kakwani Index was used to calculate and compare the progressivity of PIT and VAT reforms. A simple static micro-simulation model was employed in assessing the redistributive effect of PIT and VAT reforms in the country. After informality has been accounted for, the PIT was found to be progressive in the pre- 2011 tax scheme, but turned regressive in the post-2011 tax scheme. It was also discovered that the newly introduced lump sum relief allowance in the post-2011 PIT scheme accrues more to the high-income than to the low-income taxpayers – confirming the regressivity of the current PIT scheme. However, the study further shows (through counterfactual simulations) that excluding the relatively high-income taxpayers from sharing in the variable part of the lump sum relief allowance makes PIT progressive in the post-2011 scheme. The VAT was uncovered to be regressive both in the pre-2020 scheme, and in the current VAT reform scheme. Further, after putting informality into consideration, the PIT was found to marginally reduce inequality but increase poverty in the pre-2011 scheme. The post-2011 PIT scheme reduced inequality and increased poverty, but by a smaller proportion – confirming a limited redistribution mainly resulting from the concentration of the lump sum relief allowance at the top of the distribution. However, if the variable part of the lump sum relief allowance is provided for ‘only’ the low-income taxpayers below a predefined income threshold, the post-2011 PIT scheme becomes largely redistributive. VAT was uncovered to marginally increase inequality and poverty in the pre-2020 scheme. Though the current VAT scheme slightly increased inequality, it considerably increased poverty in the country. It is therefore suggested that a better tax reform, with well-regulated relief allowance and differentiated VAT rates, will help to enhance the equity and redistribution capacity of the Nigeria tax system.


E-Management ◽  
2020 ◽  
Vol 3 (1) ◽  
pp. 68-74
Author(s):  
Ya. V. Miller

In the last decade unprecedented technological changes have taken place, resulting in the emergence of a fundamentally new economic model. Based on the widespread spread of smartphones, the world has become more “connected”. The digitalization of demand and supply contributed to the creation of entirely new digital markets managed by platform enterprises based on an open business model, that enabled external consumers and producers to connect and interact with each other. A more interconnected world generates vast amounts of data, allowing platform companies to invest in machine learning and artificial intelligence and ultimately improve their efficiency. Finally, a steady digitalization of business processes, markets and global value chains is observed. In these circumstances, approaches to value addition are fundamentally changing in the context of new dimensions of the digital economy, the analysis of which was the purpose of our study. It has been identified, that in the absence of a standardized international methodology for measuring the digital economy, the latter is so far possible on disparate development-left and national statistics. Initiatives taken at the international level to overcome national differential approaches are still insufficient, as there is a lack of statistics and variables related to digital data. It has been revealed, that the lack of quality statistics on key indicators of the digital economy makes it difficult to assess the value added in the world economy scale and international comparisons. Much of the challenges of measuring value added in the digital economy, as shown in the article, are related to the principle of “scale without mass,” the intangible nature of capital, the intense growth of large-scale cross-border data flows, and the emergence of new sources of value creation.


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