scholarly journals A short review on the potential of coffee husk gasification for sustainable energy in Uganda

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 1809 ◽  
Author(s):  
Gilbert John Miito ◽  
Noble Banadda
Keyword(s):  
Fossil Fuels ◽  
Short Review ◽  
Energy Market ◽  
Energy Potential ◽  
Coffee Production ◽  
Heating Value ◽  
Coffee Husk ◽  
Gasification Process ◽  
High Dependency ◽  
Coffee Farmers

Agricultural biomass is widely recognized as a clean and renewable energy source, with increasing potential to replace conventional fossil fuels in the energy market. Uganda, like other developing countries, has a high dependency (91%) on wood fuel, leading to environmental degradation. With a coffee production of 233 Metric Tonnes per annum, relating to 46.6 Mega Tonnes of coffee husks from processing, transforming these husks into syngas through gasification can contribute to resolving the existing energy challenges. The objective of this article is to briefly review the energy potential of coffee husks through gasification, and how the gasification process could increase energy recoveries for coffee farmers. Previous  findings indicate that the 46.6 Mega Tonnes per year of coffee husks generated in Uganda, with a heating value of 18.34 MJ/kg, is capable of generating 24 GWh of energy. This will address a 0.7% portion of the energy situation in Uganda, while protecting the environment.

scholarly journals Adiabatic Fixed-Bed Gasification of Colombian Coffee Husk Using Air-Steam Blends for Partial Oxidation

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Javier Bonilla ◽  
Gerardo Gordillo
Keyword(s):  
Partial Oxidation ◽  
Fossil Fuels ◽  
Fixed Bed ◽  
Good Alternative ◽  
Operating Conditions ◽  
Small Scale ◽  
Heating Value ◽  
Coffee Husk ◽  
High Heating Value ◽  
Parametric Studies

The increasing energy consumption, mostly supplied by fossil fuels, has motivated the research and development of alternative fuel technologies to decrease the humanity’s dependence on fossil fuels, which leads to pollution of natural sources. Small-scale biomass gasification, using air-steam blends for partial oxidation, is a good alternative since biomass is a neutral carbon feedstock for sustainable energy generation. This research presents results obtained from an experimental study on coffee husk (CH) gasification, using air-steam blends for partial oxidation in a 10 kW fixed-bed gasifier. Parametric studies on equivalence ratio (ER) (1.53 < ER < 6.11) and steam-fuel (SF) ratio (0.23 < SF < 0.89) were carried out. The results show that increasing both SF and ER results in a syngas rich in CH4 and H2 but poor in CO. Also, decreased SF and ER decrease the peak temperature (Tpeak) at the gasifier combustion zone. The syngas high heating value (HHV) ranged from 3112 kJ/SATPm3 to 5085 kJ/SATPm3 and its maximum value was obtained at SF = 0.87 and ER = 4.09. The dry basis molar concentrations of the species, produced under those operating conditions (1.53 < ER < 6.11 and 0.23 < SF < 0.89), were between 1.12 and 4.1% for CH4, between 7.77 and 13.49% for CO, and between 7.54 and 19.07% for H2. Other species were in trace amount.

scholarly journals Physicochemical Characterisation and the Prospects of Biofuel Production from Rubberwood Sawdust and Sewage Sludge

2021 ◽  
Vol 13 (11) ◽  
pp. 5942
Author(s):  
Liaqat Ali ◽  
Khurshid Ahmed Baloch ◽  
Arkom Palamanit ◽  
Shan Ali Raza ◽  
Sawanya Laohaprapanon ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Physicochemical Properties ◽  
Fossil Fuels ◽  
Proximate Analysis ◽  
Raw Material ◽  
Biofuel Production ◽  
Energy Potential ◽  
Degradation Behaviour ◽  
Heating Value ◽  
Liquid Products

This study aims to evaluate the physicochemical properties of rubberwood sawdust (RWS) and sewage sludge (SS) for producing biofuel or liquid products via pyrolysis and co-pyrolysis. The chemical and thermal properties of both samples were observed to have superior bioenergy production capabilities. RWS and SS had significantly different physicochemical properties, such as particle-size distribution, bulk density, ultimate and proximate analysis, lignocellulose composition, thermal-degradation behaviour, and major and minor elements. The composition of extractives was found to only marginally affect the end product. Carbon and hydrogen content, the two main elements for biofuel enhancement, were found to correlate with the organic components of both RWS (48.49, 7.15 wt.%) and SS (32.29, 4.06 wt.%). SS had a higher elemental composition of iron, calcium, and potassium than RWS. Both samples had a higher heating value of 13.98 to 21.01 MJ/kg and a lower heating value of 11.65 to 17.66 MJ/kg, a lesser energy potential than that of fossil fuels. The findings from these blends are relatively moderate due to the related lignocellulosic potential composition. The novel contribution of this research was to optimize the use of local waste materials as a new raw material for biofuel production that could serve as a sustainable fuel source.

Geopolitics of Energy

2016 ◽  
Vol 3 (1) ◽  
pp. 78
Author(s):  
Blerina Muskaj
Keyword(s):  
Natural Gas ◽  
Qualitative Methodology ◽  
Scientific Literature ◽  
Point Of View ◽  
Energy Market ◽  
Energy Potential ◽  
Environmental Consequences ◽  
Regional Energy ◽  
Political Debates ◽  
Political Weapon

At the beginning of my paper I will explain the concept of "Geopolitics of Energy", this will be done for a quite simple reason, because I want everyone who can sit to read this article to understand more clearly what is at stake, therefore allow them the comprehension of what is being elaborated bellow at first sight. Geopolitics of energy is a concept that relates to policies choosing exporters to implement on importers, is the policy that has an impact on energy consumption, which includes consumer’s choice in the geopolitical context, taking into account the economy, foreign policy, the safety of energy, environmental consequences and priorities that carries the energy exporter. This concept permits the understanding of how works the politics that undertakes this initiative taking into account natural resources such as: natural gas and oil. Natural gas and oil are two main resources that produce energy but also two main elements on which arises all the topic in the energetics game. For this paper is used qualitative methodology, through which we were able to accomplish this work. I focused on scientific literature, official publications and reports on energy geopolitics. The main aim has been to show how in this decade, energy security is at the center of geopolitical agenda and has become the focus of numerous political debates. Regarding this point of view, Europe is taking the initiative to create a common energy market within the continent by creating projects, in which Albania appears as a new regional energy potential. Russia, which is aiming to play a role in the international arena, is seeking to position itself geopolitically in "its political weapon", hydrocarbon resources, in particular natural gas resources.

Evaluasi Prediksi Higher Heating Value (HHV) Biomassa Berdasarkan Analisis Proksimat

2020 ◽  
Vol 4 (1) ◽  
pp. 1-7
Author(s):  
Made Dirgantara ◽  
Karelius Karelius ◽  
Marselin Devi Ariyanti, Sry Ayu K. Tamba
Keyword(s):  
Renewable Energy ◽  
Natural Gas ◽  
Key Words ◽  
Critical Analysis ◽  
Fossil Fuels ◽  
Calorific Value ◽  
Proximate Analysis ◽  
Heating Value ◽  
Bomb Calorimeter ◽  
Hhv Prediction

Abstrak – Biomassa merupakan salah satu energi terbarukan yang sangat mudah ditemui, ramah lingkungan dan cukup ekonomis. Keberadaan biomassa dapat dimaanfaatkan sebagai pengganti bahan bakar fosil, baik itu minyak bumi, gas alam maupun batu bara. Analisi diperlukan sebagai dasar biomassa sebagai energi seperti proksimat dan kalor. Analisis terpenting untuk menilai biomassa sebagai bahan bakar adalah nilai kalori atau higher heating value (HHV). HHV secara eksperimen diukur menggunakan bomb calorimeter, namun pengukuran ini kurang efektif, karena memerlukan waktu serta biaya yang tinggi. Penelitian mengenai prediksi HHV berdasarkan analisis proksimat telah dilakukan sehingga dapat mempermudah dan menghemat biaya yang diperlukan peneliti. Dalam makalah ini dibahas evaluasi persamaan untuk memprediksi HHV berdasarkan analisis proksimat pada biomassa berdasarkan data dari penelitian sebelumnya. Prediksi nilai HHV menggunakan lima persamaan yang dievaluasi dengan 25 data proksimat biomassa dari penelitian sebelumnya, kemudian dibandingkan berdasarkan nilai error untuk mendapatkan prediksi terbaik. Hasil analisis menunjukan, persamaan A terbaik di 7 biomassa, B di 6 biomassa, C di 6 biomassa, D di 5 biomassa dan E di 1 biomassa.Kata kunci: bahan bakar, biomassa, higher heating value, nilai error, proksimat  Abstract – Biomass is a renewable energy that is very easy to find, environmentally friendly, and quite economical. The existence of biomass can be used as a substitute for fossil fuels, both oil, natural gas, and coal. Analyzes are needed as a basis for biomass as energy such as proximate and heat. The most critical analysis to assess biomass as fuel is the calorific value or higher heating value (HHV). HHV is experimentally measured using a bomb calorimeter, but this measurement is less effective because it requires time and high costs. Research on the prediction of HHV based on proximate analysis has been carried out so that it can simplify and save costs needed by researchers. In this paper, the evaluation of equations is discussed to predict HHV based on proximate analysis on biomass-based on data from previous studies. HHV prediction values using five equations were evaluated with 25 proximate biomass data from previous studies, then compared based on error value to get the best predictions. The analysis shows that Equation A predicts best in 7 biomass, B in 6 biomass, C in 6 biomass, D in 5 biomass, and E in 1 biomass. Key words: fuel, biomass, higher heating value, error value, proximate 

Assessing policies to mitigate abandonment of shade-grown coffee production in forest systems amid low and uncertain prices

2020 ◽  
pp. 1-26
Author(s):  
Heidi J. Albers ◽  
Stephanie Brockmann ◽  
Beatriz Ávalos-Sartorio
Keyword(s):  
Ecosystem Services ◽  
Low Cost ◽  
Cost Effective ◽  
Biodiversity Hotspot ◽  
Payments For Ecosystem Services ◽  
Natural Forests ◽  
Coffee Production ◽  
Certification Programs ◽  
Coffee Farmers ◽  
Effective Policy

Abstract Low and highly variable prices plague the coffee market, generating concerns that coffee farmers producing in shade systems under natural forests, as in biodiversity hotspot Oaxaca, Mexico, will abandon production and contribute to deforestation and reduced ecosystem services. Using stakeholder information, we build a setting-informed model to analyze farmers' decisions to abandon shade-grown coffee production and their reactions to policy to reduce abandonment. Exploring price premiums for bird-friendly certified coffee, payments for ecosystem services, and price floors as policies, we find that once a farmer is on the path toward abandonment, it is difficult to reverse. However, implementing policies early that are low cost to farmers – price floors and no-cost certification programs – can stem abandonment. Considering the abandonment that policy avoids per dollar spent, price floors are the most cost-effective policy, yet governments prefer certification programs that push costs onto international coffee consumers who pay the price premium.

Performance Prediction of Gas Turbine Under Different Strategies Using Low Heating Value Fuel

2013 ◽  
Author(s):  
Edson Batista da Silva ◽  
Marcelo Assato ◽  
Rosiane Cristina de Lima
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Equivalence Ratio ◽  
Safe Operation ◽  
Engine Operation ◽  
Heating Value ◽  
Gasification Process ◽  
Surge Margin ◽  
And Performance ◽  
Industrial Gas Turbine

Usually, the turbogenerators are designed to fire a specific fuel, depending on the project of these engines may be allowed the operation with other kinds of fuel compositions. However, it is necessary a careful evaluation of the operational behavior and performance of them due to conversion, for example, from natural gas to different low heating value fuels. Thus, this work describes strategies used to simulate the performance of a single shaft industrial gas turbine designed to operate with natural gas when firing low heating value fuel, such as biomass fuel from gasification process or blast furnace gas (BFG). Air bled from the compressor and variable compressor geometry have been used as key strategies by this paper. Off-design performance simulations at a variety of ambient temperature conditions are described. It was observed the necessity for recovering the surge margin; both techniques showed good solutions to achieve the same level of safe operation in relation to the original engine. Finally, a flammability limit analysis in terms of the equivalence ratio was done. This analysis has the objective of verifying if the combustor will operate using the low heating value fuel. For the most engine operation cases investigated, the values were inside from minimum and maximum equivalence ratio range.

scholarly journals The U.S. Role and Policy in Central Asia: Energy and Beyond

2012 ◽  
pp. 33-51
Author(s):  
AKM Iftekharul Islam
Keyword(s):  
National Security ◽  
Central Asia ◽  
Fossil Fuels ◽  
The United States ◽  
Global Strategy ◽  
Energy Resources ◽  
Energy Potential ◽  
Alternative Source ◽  
The Arts ◽  
The U.S

A significant geopolitical consequence of the demise of the Soviet Union1 in the international arena is the rise of intense political and commercial competition for control of the vast energy resources of the newly independent and vulnerable states of the Caucasus and Central Asia. These energy resources and, in particular, the oil and natural gas deposits have now become the apple of discord in Central Asia introducing a new chapter in the Great Game of control over Eurasia (Hill 1997: 200). The region has great energy potential and is strategically important. The United States has varied and at times competing interests in Central Asia. In the past few years, real and present dangers to the U.S. national security especially Islamist terrorism and threats to the energy supply, have affected the U.S. policy in Central Asia. The region, which includes the five post-Soviet states of Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan, as well as Afghanistan and the Caspian basin, plays an important part in the U.S. global strategy in view of its proximity to Russia, China, India, Pakistan, Iran, and other key regional actors. No less important are its ethno-religious composition and vast deposits of oil, gas, coal, and uranium. Literally, the U.S. interests in Central Asia can be summarized in three simple words: security, energy, and democracy. Moreover, a key U.S. national security concern is the diversification of energy sources and the Caspian region is a significant alternative source of fossil fuels. In this article a critical analysis will be attempted on the U.S. policy and role in central Asia. DOI: http://dx.doi.org/10.3329/afj.v4i0.12931 The Arts Faculty Journal Vol.4 July 2010-June 2011 pp.33-51

Optimization of a Biomass Micro-Gasification Process for the Production of Synthesis Gas From Palm Shell

2015 ◽  
Author(s):  
Luz M. Ahumada ◽  
Arnaldo Verdeza ◽  
Antonio J. Bula
Keyword(s):  
Particle Size ◽  
Fixed Bed ◽  
High Energy ◽  
Operating Conditions ◽  
Air Velocity ◽  
Output Variable ◽  
Heating Value ◽  
Palm Shell ◽  
Gasification Process ◽  
Air Speed

This paper studied, through an experiment design, the significance of particle size, air speed and reactor arrangement for palm shell micro-gasification process in order to optimize the heating value of the syngas obtained. The range of variables was 8 to 13 mm for particle size, 0.8–1.4m/s for air velocity, and updraft or downdraft for the reactor type. It was found that the particle size and air velocity factors were the most significant in the optimization of the output variable, syngas heating value. A heating value of 2.69MJ / Nm3 was obtained using a fixed bed downdraft reactor, with a particle size of 13 mm and 1.4 m/s for air speed; verification of the optimum point of operation under these conditions verified that these operating conditions favor the production of a gas with a high energy value.

scholarly journals Investigation of the Coal Gasification Process Under Various Operating Conditions Inside a Two-Stage Entrained Flow Gasifier

2012 ◽  
Vol 4 (2) ◽  
Author(s):  
Armin Silaen ◽  
Ting Wang
Keyword(s):  
Coal Gasification ◽  
Operating Conditions ◽  
Coal Slurry ◽  
Two Stage ◽  
Heating Value ◽  
Fuel Distribution ◽  
Entrained Flow ◽  
One Stage ◽  
Gasification Process ◽  
Entrained Flow Gasifier

Numerical simulations of the coal gasification process inside a generic 2-stage entrained-flow gasifier fed with Indonesian coal at approximately 2000 metric ton/day are carried out. The 3D Navier–Stokes equations and eight species transport equations are solved with three heterogeneous global reactions, three homogeneous reactions, and two-step thermal cracking equation of volatiles. The chemical percolation devolatilization (CPD) model is used for the devolatilization process. This study is conducted to investigate the effects of different operation parameters on the gasification process including coal mixture (dry versus slurry), oxidant (oxygen-blown versus air-blown), and different coal distribution between two stages. In the two-stage coal-slurry feed operation, the dominant reactions are intense char combustion in the first stage and enhanced gasification reactions in the second stage. The gas temperature in the first stage for the dry-fed case is about 800 K higher than the slurry-fed case. This calls for attention of additional refractory maintenance in the dry-fed case. One-stage operation yields higher H2, CO and CH4 combined than if a two-stage operation is used, but with a lower syngas heating value. The higher heating value (HHV) of syngas for the one-stage operation is 7.68 MJ/kg, compared with 8.24 MJ/kg for two-stage operation with 75%–25% fuel distribution and 9.03 MJ/kg for two-stage operation with 50%–50% fuel distribution. Carbon conversion efficiency of the air-blown case is 77.3%, which is much lower than that of the oxygen-blown case (99.4%). The syngas heating value for the air-blown case is 4.40 MJ/kg, which is almost half of the heating value of the oxygen-blown case (8.24 MJ/kg).

scholarly journals Coffee: An Indian Ocean Perspective

2016 ◽  
Vol 11 (2) ◽  
pp. 61-81
Author(s):  
Shane J. Barter
Keyword(s):  
Indian Ocean ◽  
South Asia ◽  
Latin American ◽  
Eastern Africa ◽  
Coffee Production ◽  
Production And Consumption ◽  
History Of ◽  
Coffee Farmers ◽  
The Indian Ocean ◽  
Indian Ocean World

Abstract Studies of coffee production and consumption are dominated by emphases on Latin American production and American consumption. This paper challenges the Atlantic perspective, demanding an equal emphasis on the Indian Ocean world of Eastern Africa, the Middle East, South Asia, and Southeast Asia. A geographical approach to historical as well as contemporary patterns of coffee production and consumption provides an opportunity to rethink the nature of coffee as a global commodity. The Indian Ocean world has a much deeper history of coffee, and in recent decades, has witnessed a resurgence in production. The nature of this production is distinct, providing an opportunity to rethink dependency theories. Coffee in the Indian Ocean world is more likely to be produced by smallholders, countries are less likely to be economically dependent on coffee, farmers are more likely to harvest polycultures, and countries represent both consumers and producers. A balanced emphasis of Atlantic and Indian Ocean worlds allows us to better understand coffee production and consumption, together telling a more balanced, global story of this important commodity.

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