scholarly journals Mass conversion pathway during anaerobic digestion of wheat straw

RSC Advances ◽  
2020 ◽  
Vol 10 (46) ◽  
pp. 27720-27727 ◽  
Author(s):  
Jian Gao ◽  
Juan Li ◽  
Akiber Chufo Wachemo ◽  
Hairong Yuan ◽  
Xiaoyu Zuo ◽  
...  

A material flow analysis (MFA) method was employed to investigate elemental flow direction during the anaerobic digestion (AD) of wheat straw (WS) pretreated with potassium hydroxide.

2018 ◽  
Vol 190 ◽  
pp. 04003 ◽  
Author(s):  
Yang Liu ◽  
Marius Herrmann ◽  
Christian Schenck ◽  
Bernd Kuhfuss

In rotary swaging – an incremental cold forming production technique to reduce the diameter of axisymmetric parts – the material flow can be assumed to be predominantly axial and radial. The actual ratio of this axial and radial flow influences the mechanical properties and especially in tube forming the final geometry. It is known that during mandrel free infeed rotary swaging of tubes the wall thickness changes. The change is depending on the process parameters like incremental and cumulated strain. Hence, the ratio of axial and radial material flow changes. Consequently, the analysis of the wall thickness of rotary swaged tubes enables fundamental insight how to control the material flow direction. In this study, the infeed rotary swaging process of steel tubes with different wall thicknesses from 3 mm to 7 mm and rods were investigated with FEM under two feeding velocities. The axial and radial material flow and the resulting geometry were studied by the relative wall thickness. It could be seen that the relative wall thickness was affected by the feeding velocity as well as the initial wall thickness. The findings of the simulation were validated by rotary swaging experiments.


2021 ◽  
Vol 2 ◽  
Author(s):  
Daniel Danevad ◽  
Sandra Carlos-Pinedo

Greenhouse fruit and vegetable production uses large amounts of energy and other resources, and finding ways of reducing its impact may increase sustainability. Outputs generated from solid-state anaerobic digestion (SS-AD) are suitable for use in greenhouses, which creates a need to investigate the consequences of the possible interactions between them. Connecting the fruit and vegetable production with the resource flows from an SS-AD process, e.g., biogas and digestate, could increase circularity while decreasing the total environmental impact. There are currently no studies where a comprehensive assessment of the material flows between greenhouses and SS-AD are analyzed in combination with evaluation of the environmental impact. In this study, material flow analysis is used to evaluate the effects of adding tomato related waste to the SS-AD, while also using life cycle assessment to study the environmental impact of the system, including production of tomatoes in a greenhouse and the interactions with the SS-AD. The results show that the environmental impact decreases for all evaluated impact categories as compared to a reference greenhouse that used inputs and outputs usually applied in a Swedish context. Using the tomato related waste as a feedstock for SS-AD caused a decrease of biomethane and an increase of carbon dioxide and digestate per ton of treated waste, compared to the digestion of mainly food waste. In conclusion, interactions between a greenhouse and an SS-AD plant can lead to better environmental performance by replacing some of the fertilizer and energy required by the greenhouse.


2021 ◽  
Vol 298 ◽  
pp. 126695
Author(s):  
C. Urtnowski-Morin ◽  
F. Tanguay-Rioux ◽  
R. Legros ◽  
L. Spreutels

2021 ◽  
Vol 13 (14) ◽  
pp. 7939
Author(s):  
Sohani Vihanga Withanage ◽  
Komal Habib

The unprecedented technological development and economic growth over the past two decades has resulted in streams of rapidly growing electronic waste (e-waste) around the world. As the potential source of secondary raw materials including precious and critical materials, e-waste has recently gained significant attention across the board, ranging from governments and industry, to academia and civil society organizations. This paper aims to provide a comprehensive review of the last decade of e-waste literature followed by an in-depth analysis of the application of material flow analysis (MFA) and life cycle assessment (LCA), i.e., two less commonly used strategic tools to guide the relevant stakeholders in efficient management of e-waste. Through a keyword search on two main online search databases, Scopus and Web of Science, 1835 peer-reviewed publications were selected and subjected to a bibliographic network analysis to identify and visualize major research themes across the selected literature. The selected 1835 studies were classified into ten different categories based on research area, such as environmental and human health impacts, recycling and recovery technologies, associated social aspects, etc. With this selected literature in mind, the review process revealed the two least explored research areas over the past decade: MFA and LCA with 33 and 31 studies, respectively. A further in-depth analysis was conducted for these two areas regarding their application to various systems with numerous scopes and different stages of e-waste life cycle. The study provides a detailed discussion regarding their applicability, and highlights challenges and opportunities for further research.


2021 ◽  
Vol 173 ◽  
pp. 105732
Author(s):  
Xue Rui ◽  
Yong Geng ◽  
Xin Sun ◽  
Han Hao ◽  
Shijiang Xiao

2011 ◽  
Vol 347-353 ◽  
pp. 2961-2966
Author(s):  
Dian Ming Geng ◽  
Jia Xiang Liu

In order to study the development of regional recycling economy, the material inputs and outputs of the eco-economic system in Shandong Province during the period from 1996 to 2009 were systematically analyzed by the material flow analysis(MFA). The results show that, (1)excluding water, material inputs and outputs rose persistently, but both were lower than the rate of GDP growth. (2)Water supply had a turning point in 2003, from 25.239 billion tons down to 21.934 billion tons, followed by the total annual water supply has been maintained at 220 million tons. At the same time the amount of wastewater emissions is increasing, especially domestic wastewater emissions had faster growth and that increased pressure on the regional water environment;(3) Steady increase in material input intensity, material output intensity presented a first increased and then decreased trend, that showed since Shandong Province proposed the strategic planning to develop circular economy, the development of regional circular economy have improved the material utilization efficiency and made a material reduction in output in the case of material input growth achieved. The rapid increase of material input and output efficiency further illustrated the efficiency of resource comprehensive utilization and waste output have been significantly improved.


2008 ◽  
Vol 12 (5-6) ◽  
pp. 792-798 ◽  
Author(s):  
Hiroaki Takiguchi ◽  
Kazuhiko Takemoto

2016 ◽  
Vol 21 (5) ◽  
pp. 1237-1249 ◽  
Author(s):  
Paul Hoekman ◽  
Harro von Blottnitz

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