scholarly journals Potential Valorization of Organic Waste Streams to Valuable Organic Acids through Microbial Conversion: A South African Case Study

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 964
Author(s):  
Sesethu Gift Njokweni ◽  
Annica Steyn ◽  
Marelize Botes ◽  
Marinda Viljoen-Bloom ◽  
Willem Heber van Zyl
Keyword(s):  
Organic Acids ◽  
South African ◽  
Carboxylic Acids ◽  
Organic Waste ◽  
Agricultural Sector ◽  
Small Scale ◽  
Waste Streams ◽  
Biomass Waste ◽  
Carboxylate Platform

The notion of a “biobased economy” in the context of a developing country such as South Africa (SA) necessitates the development of technologies that utilize sustainable feedstocks, have simple and robust operations, are feasible at small scale and produce a variety of valuable bioproducts, thus fitting the biorefinery concept. This case study focuses on the microbial production of higher-value products from selected organic waste streams abundant in the South African agricultural sector using microbes adapted to utilize different parts of biomass waste streams. A ruminant-based carboxylate platform based on mixed or undefined anaerobic co-cultures of rumen microorganisms can convert the carbohydrate polymers in the lignocellulosic part of organic waste streams to carboxylic acids that can be upgraded to biofuels or green chemicals. Furthermore, yeast and fungi can convert the simpler carbohydrates (such as the sugars and malic acid in grape and apple pomace) to ethanol and high-value carboxylic acids, such as lactic, fumaric, succinic and citric acid. This review will discuss the combinational use of the ruminal carboxylate platform and native or recombinant yeasts to valorize biomass waste streams through the production of higher-value organic acids with various applications.

Development and techno-economic evaluation of a biorefinery based on biomass (waste) streams - case study in the Netherlands

2013 ◽  
Vol 8 (5) ◽  
pp. 635-644 ◽  
Author(s):  
Miet Van Dael ◽  
Nathalie Márquez ◽  
Patrick Reumerman ◽  
Luc Pelkmans ◽  
Tom Kuppens ◽  
...  
Keyword(s):  
Economic Evaluation ◽  
The Netherlands ◽  
Waste Streams ◽  
Biomass Waste

Emissions Performance of a Novel Combustor Burning Shredded Wood

2009 ◽  
Author(s):  
C. Lindsey ◽  
M. Sawyer ◽  
A. Schmidt ◽  
P. Aubrey ◽  
A. Webster
Keyword(s):  
Environmental Protection Agency ◽  
Energy System ◽  
Management Program ◽  
Department Of Energy ◽  
Waste To Energy ◽  
Biomass Combustion ◽  
Small Scale ◽  
Time Data ◽  
Waste Streams ◽  
Biomass Waste

The Air Force Research Laboratory, Airbase Technologies Division (AFRL/RXQ) is engineering and evaluating the Transportable Waste-to-Energy System (TWES). This trailer mounted system will convert military base waste and biomass waste streams to useful heat and power. The Department of Energy (DOE) Federal Energy Management Program (FEMP) is a TWES funding partner. The first stage of the project is a suspension-type combustor (furnace). The furnace has been built and tested. A key feature of the furnace system is its unique patented combustion coil design. The design is intended to maximize ablative heat transfer by increasing particle residence time near a radiant ignition source. The innovative features of the design are targeted at ensuring that the system can be highly fuel-flexible to convert a variety of biomass and other waste streams to energy while demonstrating very low emissions. In 2008, the unit underwent two days of emissions stack testing using established Environmental Protection Agency (EPA) testing protocols. During the testing, extensive real-time data were also collected. This paper presents the data and corresponding analysis of the recent emissions testing performed while utilizing dry wood chips as a control fuel. Detailed emission comparisons are presented using publicly available information from commercial units and from a similarly sized experimental system for small biomass combustion. Key combustion efficiency factors, such as carbon monoxide emissions and nitrogen oxide emissions are presented. The authors also provide commentary on the results for next generation units and the use of this mode of energy conversion for small scale systems.

scholarly journals Insects as food and feed, a new emerging agricultural sector: a review

2020 ◽  
Vol 6 (1) ◽  
pp. 27-44 ◽  
Author(s):  
A. van Huis
Keyword(s):  
Organic Waste ◽  
Agricultural Sector ◽  
Economic Value ◽  
Industrial Sector ◽  
Waste Streams ◽  
Viable Option ◽  
Nutrition And Health ◽  
Food And Feed ◽  
Insects As Food ◽  
Processing Techniques

During the last five years the scientific knowledge on insects as food and feed has been growing exponentially. At the same time, the industrial sector is increasingly engaged in rearing, processing and marketing of edible insects. Considerable attention is given to the black soldier fly as it can convert organic waste streams and transform it into several feed, food and industrial products. The farming of insects has an environmental impact which is lower than that of livestock species. The profitability of industrial production of insects as feed depends very much on the availability and applicability of cheap non-utilised side-streams. Microbial communities and their relationship with insects deserve full attention as it may help in the conversion of organic side streams of low economic value. Nutrition and health benefits for animals and humans need further exploration, also considering that insects have the largest anti-microbial peptide reservoir of all animals. Plant health can also be promoted by using chitin-containing leftover substrates as fertiliser. As insects have only recently been considered as food or feed, legislation trails developments. Therefore, politicians need to be assured that rearing and processing techniques are such that insect products are guaranteed free of chemical and microbial contaminants. Consumers are becoming more and more aware that insects as food are a viable option. Insects need to be processed into ingredients, that can be applied for safe and appetising products. The insect sector is maturing fast, but still faces many challenges, which can only be met when all stakeholders closely cooperate.

scholarly journals The Case Study of an Innovative Small Scale Biomass Waste Gasification Heat and Power Plant Contextualized in a Farm

2015 ◽  
Vol 82 ◽  
pp. 335-342 ◽  
Author(s):  
Mauro Villarini ◽  
Enrico Bocci ◽  
Andrea Di Carlo ◽  
Elisa Savuto ◽  
Vanessa Pallozzi
Keyword(s):  
Power Plant ◽  
Small Scale ◽  
Biomass Waste ◽  
Waste Gasification

scholarly journals Komparatiewe voordeel in die landbou

1998 ◽  
Vol 1 (3) ◽  
pp. 498-512
Author(s):  
E. Kleynhans
Keyword(s):  
South African ◽  
Comparative Advantage ◽  
Agricultural Sector ◽  
Labour Productivity ◽  
International Competitiveness ◽  
The South ◽  
Low Level ◽  
Alternative Method ◽  
African Agriculture

The object of this paper is to demonstrate the use of an alternative method to measure and quantify international competitiveness. The South African agricultural sector is taken as a case study. The paper builds on Bela Balassa's method (1989) of measuring comparative advantage by means of historically revealed advantage. In practice this method is easy to use, readily applicable and the necessary data are usually available. The results of this measuring excercise are interesting and support the hypotheses that a low level of labour productivity contributes significantly to the low international competitiveness of South African agriculture.

scholarly journals Increasing Access to Electricity: An Assessment of the Energy and Power Generation Potential from Biomass Waste Residues in Tanzania

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1793
Author(s):  
Zahida Aslam ◽  
Hu Li ◽  
James Hammerton ◽  
Gordon Andrews ◽  
Andrew Ross ◽  
...  
Keyword(s):  
Electricity Generation ◽  
Fossil Fuels ◽  
Electrical Energy ◽  
Small Scale ◽  
Waste Biomass ◽  
Waste Streams ◽  
Energy Potential ◽  
Biomass Waste ◽  
Generation Capacity ◽  
Diesel Generators

Tanzania has a high rural population, of which many rely on off-grid diesel generators to produce electricity. The focus of this paper is to assess if the waste biomass residues in Tanzania have sufficient energy potential to produce renewable electrical energy for small-scale electricity generation using off-grid diesel generators coupled with anaerobic digestion (AD) and/or gasification. The gaseous fuel produced can then be used to substitute diesel fuel used in small-scale dual fuel diesel gen-sets; thus, providing more affordable electricity whilst reducing dependency on fossil fuels. The biomass waste streams estimated are those arising from agriculture, forestry, livestock, and urban human waste. To answer this question, the energy potentials of each of these biomass waste streams are quantified, followed by further calculations to determine the electricity generation capacity per stream based on overall efficiencies of 10 and 25%. The results show that combined these waste streams have an energy potential of 385 PJ (for the base year of 2018) generated from 26,924 kilotonnes (kt). Collectively, these residues can produce at least 1.2 times the electricity generated nationally in 2018 using AD and gasification coupled with a diesel gen-set engine.

scholarly journals Small-Scale Agriculture as a Panacea in Enhancing South African Rural Economies

2018 ◽  
Vol 10 (6) ◽  
pp. 33
Author(s):  
Mfaniseni Wiseman Mbatha ◽  
Mfundo Mandla Masuku
Keyword(s):  
Rural Communities ◽  
South African ◽  
Agricultural Sector ◽  
Rural Livelihoods ◽  
Small Scale ◽  
The South ◽  
Negative Effects ◽  
Rural Economic Development ◽  
Rural Economies ◽  
The Government

The small-scale agricultural sector is considered as an indispensable role player in improving the South African rural economies by means of enhancing sustainable rural livelihoods. This paper critically assesses the contribution of small-scale agriculture in enhancing the South African rural economies. The South African Government have numerous agricultural interventions as an approach to improving rural livelihoods. Despite various policies and interventions that have been in place to ensure that small-scale agriculture improves rural economies; there is still a dearth of research in understanding small-scale agriculture dynamics that affect rural economies. Some of the essential aspects of the findings reveal that rural communities in South Africa regard small-scale agriculture as a source of income generation and enhancing food security. These findings highlight the negative effects on the South African small-scale agriculture suffering from insufficient productivity, infertility of soil, insufficient water and climate change. The poor access to markets and inadequate financial support services were identified as the major constraints that hinder small-scale agriculture to contribute to the Gross Domestic Product (GDP) and rural economic development. The small-scale agricultural sector should come up with self-sufficient interventions to avoid dependence on the Government and other stakeholders.

Multi-Criteria Analysis, Evaluation and Modeling of Future Scenario for the Energy Generation Sector — A Case Study

2014 ◽  
Author(s):  
Seyed Aliakbar Mirmohammadi ◽  
Mohammad Reza Behi ◽  
Alexander B. Suma ◽  
Björn E. Palm
Keyword(s):  
Renewable Energy ◽  
Fossil Fuels ◽  
Renewable Energy Sources ◽  
Energy Generation ◽  
Current Status ◽  
Small Scale ◽  
Biomass Waste ◽  
University Of Technology ◽  
Solid Biomass

Renewable energy continues to attract much interest due to the depletion of fossil fuels and unsettled political disputes. This study aims to evaluate the current status of energy generation on the campus of Eindhoven University of Technology (TU/e). Furthermore, it looks for ways for the TU/e to improve sustainability by finding and proposing alternative solutions. Therefore, a broad scope of various renewable energy sources (RES) has been investigated. From many aspects, the analysis of RES proves that biomass is the most appropriate source of renewable energy for the TU/e campus. Thus, the capability of harvestable biomass fuel in energy generation throughout a year has been investigated for this project, and it has been concluded that solid biomass waste from the campus can provide 1314 MWh heat load annually. In order to achieve as much energy from biomass as possible, a combined heat and power unit (CHP), in order to produce both heat and electricity for new student houses on the campus, has been modeled. Finally, the project results show that a small-scale CHP cycle is capable of producing 366 MWh electricity, as well as 772 MWh heat, annually.

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