scholarly journals To char or not to char? Review of technologies to produce solid fuels for resource recovery from faecal sludge

2019 ◽  
Vol 9 (2) ◽  
pp. 210-224 ◽  
Author(s):  
Nienke Andriessen ◽  
Barbara J. Ward ◽  
Linda Strande
Keyword(s):  
Solid Fuel ◽  
Calorific Value ◽  
Resource Recovery ◽  
Hydrothermal Carbonization ◽  
Pilot Scale ◽  
Market Potential ◽  
Sub Saharan Africa ◽  
Combustion Technology ◽  
Sub Saharan ◽  
Faecal Sludge

Abstract Resource recovery from faecal sludge can take many forms, including as a fuel, soil amendment, building material, protein, animal fodder, and water for irrigation. Resource recovery as a solid fuel has been found to have high market potential in Sub-Saharan Africa. Laboratory- and pilot-scale research on faecal sludge solid fuel production exists, but it is unclear which technology option is most suitable in which conditions. This review offers an overview and critical analysis of the current state of technologies that can produce a dried or carbonized solid fuel, including drying, pelletizing, hydrothermal carbonization, and slow-pyrolysis. Carbonization alters fuel properties, and in faecal sludge, it concentrates the ash content and decreases the calorific value. Overall, a non-carbonized faecal sludge fuel is recommended, unless a carbonized product is specifically required by the combustion technology or end user. Carbonized and non-carbonized fuels have distinct characteristics, and deciding whether to char or not to char is a key judgement in determining the optimal solid fuel technology option. Based on the existing evidence, this review provides a decision-making structure for selecting the optimal technology to produce a faecal sludge solid fuel and identifies the top research needs prior to full-scale implementation.

scholarly journals Faecal sludge as a solid industrial fuel: a pilot-scale study

2017 ◽  
Vol 7 (2) ◽  
pp. 243-251 ◽  
Author(s):  
Moritz Gold ◽  
Daniel Isaac Waya Ddiba ◽  
Alsane Seck ◽  
Patrick Sekigongo ◽  
Alassane Diene ◽  
...  
Keyword(s):  
Calorific Value ◽  
Pilot Scale ◽  
Wastewater Sludge ◽  
Sub Saharan Africa ◽  
Clay Bricks ◽  
Financial Benefits ◽  
Treatment Technologies ◽  
Sub Saharan ◽  
Faecal Sludge

Revenues from faecal sludge (FS) treatment end products could offset treatment costs and contribute to financially viable sanitation. In urban sub-Saharan Africa, energy-producing resource recovery has the potential to generate greater revenue than use as soil conditioner. In contrast with wastewater sludge, the technical feasibility of using dried FS as solid fuel in industries has not been investigated. This study evaluated it through characterization of dried FS from drying beds and by assessing the combustion performance in two pilot-scale kilns, in Kampala and Dakar. Results from the fuel characterization demonstrate that dried FS had comparable fuel characteristics as wastewater sludge considering calorific value and ash content. The calorific values and ash contents were 10.9–13.4 MJ/kg dry matter (DM) and 47.0–58.7%, respectively. Results from pilot-scale experiments suggest that dried FS can be effective in providing energy for industries. Temperatures in pilot-scale kilns fueled by FS were 800 °C, sufficient for curing of clay bricks, and 437 °C, sufficient for waste oil regeneration. In Kampala and Dakar, an estimated 20,000 tons of FS DM per year accumulate. Tapping the industrial fuel market and financial benefits could be realized through optimization of onsite sanitation and treatment technologies.

scholarly journals Faecal sludge drying beds: increasing drying rates for fuel resource recovery in Sub-Saharan Africa

2014 ◽  
Vol 5 (1) ◽  
pp. 72-80 ◽  
Author(s):  
Alsane Seck ◽  
Moritz Gold ◽  
Seydou Niang ◽  
Mbaye Mbéguéré ◽  
Cheikh Diop ◽  
...  
Keyword(s):  
Financial Incentive ◽  
Resource Recovery ◽  
Sub Saharan Africa ◽  
Fuel Production ◽  
Disposal Options ◽  
Sub Saharan ◽  
Drying Rates ◽  
Sludge Drying ◽  
Treatment And Disposal ◽  
Faecal Sludge

In urban Sub-Saharan Africa, the collection and transport of faecal sludge (FS) typically ends up with FS directly dumped into the urban environment, as safe treatment and disposal options are too expensive or non-existent. Resource recovery from FS treatment, such as dried FS as an industrial fuel, could provide a financial incentive to increase access to FS management services. In Dakar, Senegal, enhanced drying to reduce the footprint of drying beds for fuel production was evaluated. Greenhouses did not increase drying rates over uncovered beds, however, daily mixing of FS on the surface of the beds resulted in a 6 day reduction to achieve 90% total solids (TS). FS was dried to 90% TS in 2 weeks for loading rates of 100 kg TS/m2*year, and 3 weeks for 150 kg TS/m2*year. The results indicate that with simple but innovative adaptations, footprints of treatment plants could be reduced and/or treatment capacities increased by 20%. FS can be adequately dried in Dakar to produce fuel, meaning 8.25 tons of dried FS could currently be produced daily, contributing 31,403 GJ/year fuel to industries. In addition, this financial incentive could reduce FS that is currently discharged untreated to the environment, and provide an additional 116,705 GJ/year.

scholarly journals Inhibition of Ammonia and Hydrogen Sulphide Using Plant Waste Materials for Faecal Sludge Odour Control in Dry Sanitation Toilet Facilities

2021 ◽  
Author(s):  
Bernice Mawumenyo Senanu ◽  
Patrick Boakye ◽  
Sampson Oduro-Kwarteng ◽  
Divine Damertey Sewu ◽  
Esi Awuah ◽  
...  
Keyword(s):  
Rice Husk ◽  
Hydrogen Sulphide ◽  
Cost Effective ◽  
Sub Saharan Africa ◽  
Open Defecation ◽  
Sub Saharan ◽  
Sanitation Systems ◽  
S Peak ◽  
Faecal Sludge ◽  
Peak Value

Abstract On-site dry sanitation facilities, although cheaper than wet sanitation systems, suffer from high malodour and insect nuisance as well as poor aesthetics. The high odour deters users from utilizing dry sanitation toilet as an improved facility leading to over 20% open defecation in Sub-Saharan Africa. To address this malodour concern, this study first assessed odour levels, using hydrogen sulphide (H2S) and ammonia (NH3) as indicators, on two (2) dry sanitation facilities (T1 and T2). The potential of using biomass (sawdust, rice husk, moringa leaves, neem seeds), ash (coconut husk, cocoa husk) or biochar (sawdust, rice husk, bamboo) as biocovers to remove or suppress odour from fresh faecal sludge (FS) over a 12-day period was investigated. Results showed high odour levels, beyond and below the threshold limit for unpleasantness for humans on H2S (peak value: T1 = 3.17 ppm; T2 = 0.22 ppm > 0.05 ppm limit) and NH3 (peak value: T1 = 6.88 ppm; T2 = 3.16 ppm < 30 ppm limit), respectively. The biomasses exhibited low pH (acidic = 5-7) whereas the biochars and ashes had higher pHs (basic = 8-13). Acidic biocovers generally reduced NH3 emission significantly (12.5% to 64.8%) whereas basic biocovers were more effective at H2S emission reduction (80.9% to 96.2%). In terms of H2S and NH3 removal, sawdust biochar was the most effective biocover with odour abatement values of 96.2% and 74.7%, respectively. The results suggest that locally available waste plant-based materials, like sawdust, when converted to biochar can serve as a cost-effective and sustainable way to effectively combat odour-related issues associated with dry sanitation facilities to help stop open defecation.

scholarly journals Effective strategies followed by multinational enterprises expanding into Africa

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Zihné Coetzee ◽  
Henri Bezuidenhout ◽  
Gabriel Mhonyera
Keyword(s):  
Multinational Enterprises ◽  
Market Potential ◽  
Sub Saharan Africa ◽  
Retail Sector ◽  
International Expansion ◽  
Structured Interviews ◽  
International Partnerships ◽  
Managerial Implications ◽  
Sub Saharan ◽  
Value Add

Orientation: Retail sector multinational enterprises (MNEs) face challenges and follow diverse strategies when they expand into foreign markets.Research purpose: The major aim of this article is to determine how three well-established retail sector MNEs, namely, Walmart, Carrefour and Shoprite, addressed the challenges they faced and structured their market entry strategies in the African continent.Motivation for the study: While the opportunities in Africa are perpetual, breaking into the African market is not so straightforward. It is in this regard that the importance of determining the challenges faced by established retail MNEs in Africa and the valuable lessons that can be drawn by small and upcoming MNEs, from the experiences of these prominent MNEs studied, is exposed.Research approach/design and method: This article employs a mixed-method approach (i.e. case study and semi-structured interviews) to determine the challenges faced by Walmart, Carrefour and Shoprite when they expanded into Africa, and how they overcame those challenges.Main findings: The findings reveal that Walmart and Shoprite possess a substantial footprint in sub-Saharan Africa, while Carrefour enjoys a substantial footprint in North Africa and Francophone Countries of west Africa. Furthermore, Walmart follows a risk-averse approach when expanding into the African continent and only expands into new foreign markets based on the market potential and the ability to succeed. Carrefour’s main strategy is to achieve international expansion into Africa through the acquisition of international partnerships with local and regional firms. Shoprite, on the other hand, maintains that no written strategy was followed when the retail MNE expanded into Africa. It is also evident that external factors are significant for MNEs seeking to invest in Africa.Practical/managerial implications: Not all MNEs expanding into Africa have been successful. Accordingly, the practical value of this article rests upon the lessons that small and upcoming MNEs can learn from the experiences of MNEs that are now well established in African markets.Contribution/value-add: This article contributes to existing foreign direct investment (FDI) literature by identifying challenges that Walmart, Carrefour and Shoprite faced when they expanded into Africa. In addition, lessons that aspiring and small MNEs, specifically in the retail sector, can learn from these three retail MNEs that are now well established in African markets are drawn.

scholarly journals Experimental Study on Hydrothermal Carbonization of Lignocellulosic Biomass with Magnesium Chloride for Solid Fuel Production

Processes ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 444 ◽  
Author(s):  
Samuel Carrasco ◽  
Javier Silva ◽  
Ernesto Pino-Cortés ◽  
Jaime Gómez ◽  
Fidel Vallejo ◽  
...  
Keyword(s):  
Lignocellulosic Biomass ◽  
Solid Fuel ◽  
Magnesium Chloride ◽  
Calorific Value ◽  
Hydrothermal Carbonization ◽  
Volatile Matter ◽  
Matter Content ◽  
Operating Conditions ◽  
Energy Yield ◽  
Mass Yield

The effect of magnesium chloride as an additive of hydrothermal carbonization (HTC) of lignocellulosic biomass (Pinus radiata sawdust) was studied. The HTC tests were carried out at fixed conditions of temperature and residence time of 220 °C and 1 h, respectively, and varying the dose of magnesium chloride in the range 0.0–1.0 g MgCl2/g biomass. The carbonized product (hydrochar) was tested in order to determine its calorific value (HHV) while using PARR 6100 calorimeter, mass yield by gravimetry, elemental analysis using a LECO TruSpec elemental analyzer, volatile matter content, and ash content were obtained by standardized procedures using suitable ovens for it. The results show that using a dose of 0.75 g MgCl2/g biomass results in an impact on the mass yield that was almost equal to change operating conditions from 220 to 270 °C and from 0.5 to 1 h, without additive. Likewise, the calorific value increases by 33% for this additive dose, resulting in an energy yield of 68%, thus generating a solid fuel of prominent characteristics.

scholarly journals Hydrothermal carbonization of medical wastes and lignocellulosic biomass for solid fuel production from lab-scale to pilot-scale

Energy ◽  
2017 ◽  
Vol 118 ◽  
pp. 312-323 ◽  
Author(s):  
Yafei Shen ◽  
Shili Yu ◽  
Shun Ge ◽  
Xingming Chen ◽  
Xinlei Ge ◽  
...  
Keyword(s):  
Lignocellulosic Biomass ◽  
Solid Fuel ◽  
Hydrothermal Carbonization ◽  
Pilot Scale ◽  
Fuel Production ◽  
Medical Wastes

scholarly journals Farmer Demand and Willingness-To-Pay for Sweetpotato Silage-Based Diet as Pig Feed in Uganda

2020 ◽  
Vol 12 (16) ◽  
pp. 6452
Author(s):  
Marsy Asindu ◽  
Emily Ouma ◽  
Gabriel Elepu ◽  
Diego Naziri
Keyword(s):  
Willingness To Pay ◽  
Smallholder Farmers ◽  
Secondary Data ◽  
Market Potential ◽  
Sub Saharan Africa ◽  
Structured Interviews ◽  
Livestock Feed ◽  
The Mean ◽  
Pig Feed ◽  
Sub Saharan

Smallholder livestock farmers across Sub-Saharan Africa are racing against time to find cheaper, nutritious, and sustainable feed alternatives to the more pronounced and expensive commercial concentrates amidst the increasing global demand for livestock products. Lately, many prominent feed conservation technologies have been developed, with a notable example being the sweetpotato silage technology that turns wasted sweetpotato components into a palatable and nutritious livestock feed. However, despite the potential benefits associated with these technologies, the level of demand and acceptance among smallholder farmers remains largely unknown. Thus, this paper assesses the farmer demand and willingness-to-pay (WTP) for sweetpotato silage-based diet as pig feed by smallholder farmers in Uganda. The information for the study was collected through secondary data review and semi-structured interviews to assess farmer WTP. The 256 semi-structured interviews were randomly drawn from 16 purposive clusters formed at a radius of 3 km around 16 farmers piloting sweetpotato silage-based diets for pig feed. The results show that pig farming is mainly the responsibility of women, with farmers’ mean willingness-to-pay price amounting to 0.20 USD per kilogram of sweetpotato silage-based diet. At the mean price, the annual demand for silage was estimated at 17,679 tons, with a market potential of approximately 3.59 million USD. The study concludes that, at the mean willingness-to-pay price, there is a substantial market potential that can be exploited by small and medium-sized enterprises (SMEs) venturing in the livestock feed industry.

scholarly journals Inhibition of ammonia and hydrogen sulphide as faecal sludge odour control in dry sanitation toilet facilities using plant waste materials

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bernice Mawumenyo Senanu ◽  
Patrick Boakye ◽  
Sampson Oduro-Kwarteng ◽  
Divine Damertey Sewu ◽  
Esi Awuah ◽  
...  
Keyword(s):  
Rice Husk ◽  
Hydrogen Sulphide ◽  
Cost Effective ◽  
Sub Saharan Africa ◽  
Open Defecation ◽  
Threshold Limit ◽  
Odour Control ◽  
Sub Saharan ◽  
Sanitation Systems ◽  
Faecal Sludge

AbstractOn-site dry sanitation facilities, although cheaper than wet sanitation systems, suffer from high malodour and insect nuisance as well as poor aesthetics. The high odour deters users from utilizing dry sanitation toilets as an improved facility leading to over 20% open defecation in Sub-Saharan Africa. To address this malodour concern, this study first assessed odour levels, using hydrogen sulphide (H2S) and ammonia (NH3) as indicators, on two dry sanitation facilities named T1 and T2. The potential of using biomass (sawdust, rice husk, moringa leaves, neem seeds), ash (coconut husk, cocoa husk) or biochar (sawdust, rice husk, bamboo) as biocovers to remove or suppress odour from fresh faecal sludge (FS) over a 12-day period was investigated. Results showed that the odour levels for H2S in both T1 (3.17 ppm) and T2 (0.22 ppm) were above the threshold limit of 0.05 ppm, for unpleasantness in humans and vice versa for NH3 odour levels (T1 = 6.88 ppm; T2 = 3.16 ppm; threshold limit = 30 ppm limit). The biomasses exhibited low pH (acidic = 5–7) whereas the biochars and ashes had higher pHs (basic = 8–13). Basic biocovers were more effective at H2S emission reduction (80.9% to 96.2%) than acidic biocovers. The effect of pH on suppression of NH3 was determined to be statistically insignificant at 95% confidence limit. In terms of H2S and NH3 removal, sawdust biochar was the most effective biocover with odour abatement values of 96.2% and 74.7%, respectively. The results suggest that biochar produced from locally available waste plant-based materials, like sawdust, can serve as a cost-effective and sustainable way to effectively combat odour-related issues associated with dry sanitation facilities to help stop open defecation.

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