Ali A. Rabah

Ali A. Rabah
University of Khartoum · Department of Chemical Engineering

PhD

About

64
Publications
47,413
Reads
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179
Citations
Citations since 2017
10 Research Items
116 Citations
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2017201820192020202120222023051015202530
2017201820192020202120222023051015202530
Introduction
Biomass gasification
Skills and Expertise
Additional affiliations
March 2010 - April 2014
University of Khartoum
Position
  • Professor (Associate)
January 2009 - present
University of Khartoum
Position
  • Senior Researcher
Description
  • 1. Energy Management 2. Thermophyical properties of hydrocarbons 3. Properties and applications of Gum Arabic
October 2007 - September 2008
Helmut Schmidt University / University of the Federal Armed Forces Hamburg
Position
  • PostDoc Position
Description
  • Grid independent solar cooling
Education
October 2007 - August 2008
April 2000 - June 2003
Leibniz Universität Hannover
Field of study
  • Mechanical Engineering (Energy)
October 1994 - October 1996
University of Nairobi
Field of study
  • Mechanical Engineering (Energy)

Publications

Publications (64)
Article
Sudan is facing an energy crisis caused by a large deficit in electric power supply and transportation fuels such as gasoline and diesel. Only about 32% of the population have access to electricity. Fuels subsidies have been removed causing a huge prices-hike. Therefore, Sudan is in urgent need to promote its abundant biomass resources to mitigate...
Article
Full-text available
The study is aimed at evaluating the availability of agriculture residues for syngas production, a case study for Sudan. 10 types of biomass are investigated: sugarcane (bagasse), cotton stalks, sesame straw, groundnut shells, maize straw, sorghum straw, millet straw, sunflower husks, wheat straw, and banana leaves. The available biomass is about 1...
Preprint
Full-text available
Penalties associated with heat exchangers fouling include: loss of thermal efficiency, increase in fuel consumption, increase of emissions and loss of throughput. Although cleaning projectiles have been used widely in industry for fouling inhibition, usage of online cleaning projectiles is limited to service temperatures up to 120. To extend temper...
Conference Paper
Full-text available
Pressure, volume and temperature (PVT) data is extensively used in the design of oil production and transportation facilities. The purpose of this study is to predict PVT properties for a Sudanese crude oil at pressures above boiling point pressure using Equations of State (EOSs). Eight of the most widely known EOSs are used; namely Patel-Teja (PT)...
Article
Full-text available
Since the independence of South Sudan, Sudan lost 75% of its oil reserves, this led to major fuel shortages country wide, the fuel shortage raised the fuel prices and the overall transport prices. Scarcity led to black market trade of fuel specially in states away from the Capital City (Khartoum). Managing the available stock comes first before inc...
Book
Full-text available
يُعتبر التّنوع العرقي الكبير من أكبر التحديات التي تواجه الدولة السودانية، وأن التنمية الشاملة هي التدبير الملائم لمواجهة هذا التحدي. لإرساء قواعد التنمية الشاملة يقترح الكتاب الأخذ بالدولة‏ التَّوافقيِّة التي تقوم على ثلاث ركائز أساسية: 1. ‏ الإنصهار كآلية لإدارة ‏ التّنوع 2. الفيدرالية كمعيار لتوزيع الثروة 3. الديمقراطية ‏ التَّوافقيِّة كمعيار ل...
Chapter
Historically, Acacia seyal gum in the Sudan ranks as the second most important gum product after Acacia senegal in terms of quantity. It contributed an average of 10% of gum products until 2011, and then the average contribution percentage within the last 4 years (2012-2015) jumped to almost 60%. A. seyal trees' coverage extend in an area of 36,000...
Article
Despite the significant contribution of A. seyal to the exports portfolio of Sudan, farmers have slightly poor knowledge regarding post-harvest cultural practices in terms of proper methods of gum drying, storage conditions and gum stacking which might significantly be resulted in colour deterioration and inferior quality. Nevertheless, the current...
Article
Full-text available
Water is one of the key resources for the normal life and is used extensively in many industries. The sugar industry is one of the largest water users and producers in food processing sector. This paper presents the analysis of freshwater used and wastewater discharged in a sugar manufacturing process. Also, this paper presents an analysis of cooli...
Article
Full-text available
Gasoline demand of the Sudanese transportation sector is increasing. To meet the demand many measures have been developed in the last few years. These included efficiency improvement and supplement with bioethanol. The latter is blended with gasoline in the range of 5-27%; the blend is also called E85 and E90. The aim of this research was to foreca...
Book
A review, Proceedings Vol. 6 pp. 94-98 7th Annual Conference for Postgraduate Studies and Scientific Research Basic Sciences and Engineering Studies - University of Khartoum. Theme: Scientific Research and Innovation for Sustainable Development in Africa 20-23 February 2016, Friendship Hall, Khartoum, Sudan Available online at www.ejournals.uofk.ed...
Conference Paper
The objective of this research is to develop a generalized correlation for the prediction of thermal conductivity of n-Alkanes and Alkenes. There is a minority of research and lack of correlation for thermal conductivity of liquids in the open literature. The available experimental data are collected covering the groups of n-Alkanes and Alkenes.The...
Conference Paper
Full-text available
This paper aims to find empirical equation to calculate the vapor pressure of the mixture of crude oil from Sudan and taking advantage of some of the PVT properties that are measured experimentally. Where the data is retrieved from many fields and different wells to get the relationship between vapor pressure and properties available Emphasis was p...
Conference Paper
Full-text available
Historically Acacia seyal gums in the Sudan is ranking as a second important gum product after A. senegal in terms of quantities 10% in average until 2011. Thus the contribution percentages within the last four years (2012-2015) jumped to almost 60% in average. A. seyal trees coverage extend in an area of 36,000 square kilometers (3.6 million ha) i...
Conference Paper
Full-text available
The study aimed to develop energy Sankey diagram of the Sudan for the base year 2014. The developed Sankey diagram is the first of its kind in Sudan. The available energy balance for the base year 2012 is a simple line draw and did not count the energy supply by private and mixed sectors such as sugar and oil industries. They account for about 7% o...
Article
Full-text available
The study aimed to develop energy flow diagram (Sankey diagram) of Sudan for the base year 2014. The developed Sankey diagram is the first of its kind in Sudan. The available energy balance for the base year 2012 is a simple line draw and did not count the energy supply by private and mixed sectors such as sugar and oil industries and marine and ci...
Article
Gasoline also locally called benzene is one of the most extensive used fuel oil in Sudan. Gasoline is consumed mainly in the transportation sector. Currently, Sudan has a surplus of gasoline produced from local refineries. However, local demand of gasoline as fuel for vehicles is growing rapidly since import and local production of gasoline driven...
Article
Full-text available
Oil refining is one of the most complex chemical industries; the objective of refinery operations is to generate as much profit as possible by converting crude oils into valuable products. The current trend toward processing petroleum needs sufficient compositional information to understand the chemistry of reactions that are involved. The objectiv...
Article
Full-text available
Nanocomposites on the basis of natural rubber and highly anisotropic nanoclay have gained significant attention due to their excellent thermal, barrier, and mechanical (tensile) properties. A nanocomposite based-natural rubber (NR) with fatty amides (FAs) (which was synthesized from vegetable oil)-modified clay was prepared using montmorillonite (M...
Article
Full-text available
This work presents two developments in Antoine vapor pressure correlation: (1) Generalization of the correlation using the principle of corresponding state; (2) Prediction of the Antoine coefficients form molecular weight. The coefficients of the generalized correlation are correlated to molecular weight (r2=0.99) for the group of normal alkanes (C...
Article
Full-text available
The specific heats of ideal gas is generally available as a function of temperature and type of gas. The common form is Cp = aiT , where ai’s are type of gas dependent coefficients; hence a correlation for each gas. This paper is aimed to apply non parametric regression to existing ideal gas specific heat cor-relation to: (1) identify inconsistent...
Article
Full-text available
The objective of this work is to provide exergy analysis of the newly developed cryogenic air separation unit with flash separator. As a reference, exergy analysis to the conventional double column air separation process is made. The system of equations of heat and work exergy, material exergy and exergy destruction are solved numerically. Aspen Pl...
Article
Full-text available
In this study, new biopolymer nano-composites have been prepared. Fatty amides (FAs) which were synthesized from palm olein, have been used as an organic compound to modify natural clay, sodium montmorillonite. The clay modification was carried out by stirring the clay particles in an aqueous solution of FAs by which the clay layer distance increas...
Article
Full-text available
This work presents a generalized viscosity correlation for normal Alkanes (C2 to C20). The Arrhenius correlation is written in a generalized form by transforming their coefficients into fluid physical parameters of carbon number, normal boiling point temperature, critical temperature, critical pressure and accentric factor. Non parametric regressio...
Article
Full-text available
This work aims to measure the emission level of local heavy fuel oils used in boilers and furnaces. Two types of fuel oil are commonly used in the Sudan. These are heavy fuel oil (HFO) produced in Elobied refinery and heavy coker gas oil (HCGO) of Khartoum refinery. The experimental combustion set up consists of a combustion chamber, a burner, a st...
Article
Full-text available
A new cryogenic air separation process with flash separator is developed. A flash separator is added to the conventional double-column cryogenic air separation process. The flash separator is used to replace the turbine required to recover a portion of the energy in the double-column air separation process. The flash separator served dual purposes...
Article
Full-text available
الهدف من الورقه تسليط الضوء على عنق الزجاجة بالنسبة لصناعة السكر السودانية المتمثل فى التوليد المشترك للطاقة الكهربائية والحرارية. على الرغم من النجاحات التي حققتها صناعة السكر السودانية المتمثلة فى الاستدامته (sustainability) وزيادة الانتاج الذى قفز من 60000 طن فى العام فى ستينيات القرن الماضي الى حوالى المليون طن فى العام في 2012 ظل غياب تكامل كه...
Data
Full-text available
The potential use of polyaluminum chloride (PAC) on destabilizing oil-water emulsions was investigated. The phase separation for emulsions with different water cuts ranging from (10 to 60) % was studied. A wide range of PAC doses (0.5 and 8.0) mg/L was tested. A 30 % hexane and 70 % ethanol solvent was used for PAC dose preparation. PAC was found t...
Conference Paper
Full-text available
Conference Paper
Full-text available
Desiccant cooling systems have the potential to make a major contribution to the reduction of both CFC's emissions and electricity peak load. An experimental investigation on the sensible effectiveness of a desiccant wheel is conducted. Measurements were made for a range of rotational speeds (0-5 rpm), regeneration temperatures (50 to 60oC). A comp...
Article
Full-text available
This study investigated the enhancement of bottled water characteristics using gum arabic. A commercially available mechanical powder of Acacia senegal (hashab) originated from Kordofan, Sudan, was used. The physicochemical properties of the test material were as follows: moisture content (10%), ash content (3.5%), specific optical rotation (-29.8)...
Article
Full-text available
This work has investigated the influence of change in operation conditions on the performance of a Lithium Chloride (LiCl) wheel. A rigorous experimental rig that facilitates the measurement of temperature, pressure, pressure drop, relative humidity, airflow rate and rotational speed is used. The measurements covered balanced flow at a wide range o...
Article
Full-text available
The objective of this study is to provide rheological data of Acacia senegal (A. senegal) gum of Kordofan origin. The density of A. senegal gum at room temperature is found to be higher than that of water only at higher concentration (>5 g/L). The density is aslo found to be strong function of temperature. At medium temperature >45 °C becomes lower...
Article
This work presents analysis of historical data of four Sudanese sugar factories namely Assalaya, Sennar, Gunned and New Halfa. The historical data covers more than 40years (1966–2010). In about 38years (1966–2004) of this period the sugar industry operates with one set of evaporator. In 2005 a standby set of evaporator is installed in each factory....
Conference Paper
Full-text available
This work investigated the influence of airflow leakage on the regenerator performance factors of effectiveness (ε), airflow capacity (C *), matrix capacity (Cr *) and number of transfer unit (NTU). A sophisticated experimental setup that facilitates precise measurement of apparent airflow temperature, rate and pressure drop is used. The measuremen...
Article
Full-text available
The objective of this work is to provide analytical solution of the conservation equations governing the desiccant wheel. The conservation equations describing the moisture exchange between wheel matrix and airflows are complicated partial differential equations (PDEs). This complication is brought about by space and time variations of moisture con...
Article
Full-text available
A new three parameter Equation Of State (EOS) is developed based on well documented data, at three thermodynamic states of the critical point, the normal bubble point and standard condition. Besides these states, the EOS is designed to satisfy the condition of nearly zero Joule-Thomson (JT) coeecients at the normal boiling point. Critical propertie...
Article
Experimental investigation on the sensible effectiveness of LiCl wheel is reported. The measurements were made for balanced flow (C*=1) for a wide range of rotational speed 0–10rpm, regeneration temperature of 50–70°C and airflow rate 150–550kg/h. The results revealed that the operation rotational speed for LiCl wheel is about 5rpm which is signifi...
Article
This work presents an analytical solution for the periodic heat transfer problem of regenerators used in air conditioning, which are operating at low regeneration temperatures and mass flow rates. These types of regenerators are characterized by NTU/Cr ∗<1. The partial differential equations for hot and cold airflows as well as the regenerator matr...
Article
Full-text available
This paper provided important experimental PVT data of the Sudanese reservoir fluids. It includes composition analysis of 11 mixtures and about 148 PVT data points of constant mass expansion (CME) tests at pressures below the bubble point. The datasets are compared with eight equations of state (EOS), namely, Peng Robinson (PR), Soave-Redlich-Kwong...
Article
Full-text available
This work investigated the operation conditions of a rotary regenerator operating at low regeneration temperatures, which is widely used in solar desiccant air conditioning systems. A rigorous experimental rig that facilitates the measurement of axial, radial, and angular airflow temperature distribution is used. The measurements covered balanced f...
Article
Full-text available
This paper presents the operational conditions for wax production from Nile Blend; a Sudanese oil, characterized as sweet oil with a high level of wax content (25.87 wt%). The method of solvent extraction was employed using a Methyl Ethyl Ketone (MEK)Toluene mixture as a solvent. The study covered a wide range of mixing temperatures (28 to 70 °C) a...
Article
Local heat transfer coefficients for flow boiling of pure 1,1,1,2-tetrafluoroethane (R134a) and binary mixtures of propane (R290) and R134a were measured. The experimental setup employed a vapor heated plain horizontal tube (di = 10 mm, do = 12 mm, L = 500 mm). The measurements covered a wide range of saturation temperatures (233 ≤Ts≤278 K), mass f...
Article
Full-text available
Zugl.: Hannover, University, Diss., 2003.
Thesis
The Slow Sand Filter (SSF) is an effective device for water treatment with its proven excellent purification characteristics ill terms of turbidity and microorganisms removal, yielding potable water with no other treatment necessary. However, its large size and prohibitive cost has inhibited itswide-spread use, particularly within the poorer commun...

Questions

Questions (4)
Question
Unlike thermodynamics properties there is a minority of research in thermal conductivity and molecular diffusivity.
Question
 The critical pressure of Alkanes decreases with carbon number except for Ethane. The critical pressure of methane is 46.99 bar, ethane is 48.72 bar and propane is 42.48 bar.
Question
Open access journal are meant to break the commercialization and monopoly of knowledge imposed by publishers via the subscription fees. Now open access journal are doing the same and even more as they are requesting huge publication fees from authors about USD 300-600. This fees are more than the monthly salary of most of the researcher in the developing countries.
Question
I am looking for the English translation of the work of Prof. Otelbaev.

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