Haider Al-Rubaye, Ph.D | Missouri University of Science and Technology (original) (raw)

Papers by Haider Al-Rubaye, Ph.D

Processes

The most common scale-up approach for gas–solids fluidized beds is based on matching the governin... more The most common scale-up approach for gas–solids fluidized beds is based on matching the governing dimensionless parameters. In the literature, this approach has been validated only by means of measuring global parameters between different sizes of fluidized beds. However, such global measurements are not sufficient to depict all the interplaying hydrodynamic phenomena and hence verify the scale-up relationships. Therefore, to assess this approach, an advanced gas–solids optical probe and pressure transducer measurement techniques have been applied to quantify local hydrodynamic parameters in two different sized fluidized beds. Four different sets of experimental conditions were designed and conducted to examine the assessment of the scaling approach with matched and mismatched dimensionless groups between the two beds. The results indicated that the reported dimensionless groups are not adequate for achieving similarity between the two gas–solids fluidized beds in terms of solids h...

Biofuels

Tar is considered the main barrier to commercial power generation when using biomass gasification... more Tar is considered the main barrier to commercial power generation when using biomass gasification as it causes serious environmental issues, even after incorporating an efficient removal system. Moreover, the existing tar compositions contain high energy levels, thus lowering the heating value of produced syngas. In this paper, tar was blended with three types of plain biomass at ratios up to 10%; biomass and tar were gasified together at different equivalence ratios. Tar recycling was found beneficial to the syngas compositions. The size distribution of the biomass feed and the gasified char were studied. Experimental evidence shows that the isolation time of the shutdown procedure is proportional to the volume of the gasifier cores. This paper discusses the operation procedure and troubleshoots biomass gasifiers in detail, providing useful guidelines for future practical research.

Biofuels, 2022

Energy poverty, defined as a lack of access to reliable electricity and reliance on traditional b... more Energy poverty, defined as a lack of access to reliable electricity and reliance on traditional biomass resources for cooking, affects over a billion people daily. The World Health Organization estimates that household air pollution from inefficient stoves causes more premature deaths than malaria, tuberculosis, and HIV/AIDS). Increasing demand for energy has led to dramatic increases in carbon emissions. The need for reliable electricity and limiting carbon emissions drives research on Resil-ient Hybrid Energy Systems (RHES) that provide low-carbon energy through combined wind, so-lar, and biomass energy with traditional fossil energy, increasing production efficiency and relia-bility, and reducing generating costs and carbon emissions. Microgrids have been shown as an ef-ficient means of implementing RHES, with some focused mainly on reducing the environmental impact of electric power generation. The technical challenges of designing, implementing and ap-plying microgrids involve ...

Small modular reactors (SMR) (<300 MW) offer a potentially attractive nuclear energy option fo... more Small modular reactors (SMR) (<300 MW) offer a potentially attractive nuclear energy option for the middle-east region (MER). Currently, the MER uses a significant amount of fossil fuel to process heat applications such as water desalination and in petroleum refineries and chemical plants, besides generating electricity. SMR technologies represent an opportunity to meet future energy demand in the MER. This paper discusses issues related to the future development and use of SMR technology in nuclear-renewable hybrid energy systems for application in the middle east. SMRs have also been examined as part of a resilient hybrid energy system that combines nuclear energy with renewable energy and traditional fossil energy to produce chemicals, fuels, and electricity. This paper presents the results of a techno-economic analysis of a Nuclear-Renewable-Conventional Hybrid Energy System. The paper concludes that SMR technology will be an essential feature of future hybrid energy systems ...

Chemical Engineering and Processing - Process Intensification, 2018

Abstract Breweries wastewater containing high concentration of organic and inorganic compounds ra... more Abstract Breweries wastewater containing high concentration of organic and inorganic compounds ranks them among the top pollution generating industries. Anaerobic wastewater treatment with high organic loading rates can be achieved with lower COD strength at higher flowrates using a two–stage expanded granular sludge bed reactor. Hydraulic retention time (HRT), pH, temperature, and COD strength were varied for process optimization. Brewery wastewater with 20, 30, and 40 g COD/L as a substrate for two temperature ranges were evaluated. Under mesophilic conditions (36 °C), results show COD removal efficiency (R%) and biogas production rate increased by 6% and 40% respectively as HRTs increased, maintaining a constant OLR. Results imply for equivalent OLRs, better reactor performance is achieved when running high concentration COD at slower rate compared with a lower concentration at higher rate. This implies diffusion limitation where complex proteins and fats are passed through the reactor faster than their metabolism rate in the digester. Under thermophilic conditions (50 °C), results show COD removal efficiency (R%) and biogas production rate increased by 4% and 40% respectively as the HRTs increased, while maintaining a constant OLR. This implies the higher and stronger population of anaerobes are present under thermophilic condition rather than mesophilic condition.

Biofuels, 2017

ABSTRACT A process simulation model was developed for the anaerobic digestion (AD) process used f... more ABSTRACT A process simulation model was developed for the anaerobic digestion (AD) process used for biogas generation. Aspen Plus software was used for this purpose. The developed model predicts the production of biogas from any substrate at any given process condition. This model was validated against a variety of industrial data on anaerobic digestion. The four steps (Hydrolysis, Acidogenesis, Acetogenesis, Methanogenesis) with a total of 46 reactions that represent the AD process were simulated with appropriate kinetics. Sensitivity analysis was implemented for 5, 10, 20 and 30% substrates concentrations to increase the methane share in the biogas by studying the effects of hydrogen addition, HRT and pressure. The developed model is flexible and predicts enhancement of methane composition by hydrogen injection qualitatively and quantitatively.

Biofuels, 2020

Two-stage anaerobic reactors are being widely used in the organic waste management industry. In t... more Two-stage anaerobic reactors are being widely used in the organic waste management industry. In these reactors, up to one-third of the chemical oxygen demand (COD) content is naturally pre-acidifie...

Chemical Engineering & Technology

Chemical Engineering & Processing: Process Intensification, 2018

Breweries wastewater containing high concentration of organic and inorganic compounds ranks them ... more Breweries wastewater containing high concentration of organic and inorganic compounds ranks them among the top pollution generating industries. Anaerobic wastewater treatment with high organic loading rates can be achieved with lower COD strength at higher flowrates using a two-stage expanded granular sludge bed reactor. Hydraulic retention time (HRT), pH, temperature, and COD strength were varied for process optimization. Brewery wastewater with 20, 30, and 40 g COD/L as a substrate for two temperature ranges were evaluated. Under mesophilic conditions (36 °C), results show COD removal efficiency (R%) and biogas production rate increased by 6% and 40% respectively as HRTs increased, maintaining a constant OLR. Results imply for equivalent OLRs, better reactor performance is achieved when running high concentration COD at slower rate compared with a lower concentration at higher rate. This implies diffusion limitation where complex proteins and fats are passed through the reactor faster than their metabolism rate in the digester. Under thermophilic conditions (50 °C), results show COD removal efficiency (R%) and biogas production rate increased by 4% and 40% respectively as the HRTs increased, while maintaining a constant OLR. This implies the higher and stronger population of anaerobes are present under thermophilic condition rather than mesophilic condition.

A process simulation model was developed for the anaerobic digestion (AD) process used for biogas... more A process simulation model was developed for the anaerobic digestion (AD) process used for biogas generation. Aspen Plus software was used for this purpose. The developed model predicts the production of biogas from any substrate at any given process condition. This model was validated against a variety of industrial data on anaerobic digestion. The four steps (Hydrolysis, Acidogenesis, Acetogenesis, Methanogenesis) with a total of 46 reactions that represent the AD process were simulated with appropriate kinetics. Sensitivity analysis was implemented for 5, 10, 20 and 30% substrates concentrations to increase the methane share in the biogas by studying the effects of hydrogen addition, HRT and pressure. The developed model is flexible and predicts enhancement of methane composition by hydrogen injection qualitatively and quantitatively.

The present paper deals with the treatment of phosphate obtained from a commercial sample of Akas... more The present paper deals with the treatment of phosphate obtained from a commercial sample of Akashat phosphate ore in hydrochloric acid. The factors studied are effects of the temperature of dissolution, acid concentration, and the time required for mixing phases. The experiments were performed with 100 kg/m 3 of solid/liquid ratio, the size of the particles ranged 125-140 µm, the initial acid concentrations were 20, 30 and 40 wt% HCl, and the temperature of dissolution was kept constant at 30, 40, 50, 60 and 70 o C. The results indicated that the percentage of P 2 O 5 increases as the HCl concentration increased using different time and temperatures. Also, the results showed that the best conditions for P 2 O 5 recovery process according were acid concentration 40%, reaction time of 90 min, and temperature 30 o C.

$Research paper thumbnail of Anaerobic co-digestion of sewage sludge and organic fraction of municipal solid wastes$

The paper presents the results of investigation of methane fermentation of sewage sludge and orga... more The paper presents the results of investigation of methane fermentation of sewage sludge and organic fraction of municipal solid wastes (OFMSW) as well as the cofermentation of both substrates under thermophilic and mesophilic conditions. In the first experiment the primary sludge and thickened excess activated sludge were fed into a 40 dm 3 bioreactor operated thermophilically. The second co-fermentation experiment was conducted with the mixture of sewage sludge (75%) and OFMSW (25%) in the same bioreactor arrangement. The other three experiments (III and IV, V) were carried out in quasi-continuous mode in two separated stages: acidogenic digestion in the continuous stirred tank bioreactor under thermophilic conditions (56 8C) and mesopholic methane fermentation (36 8C). The third experiment was conducted with the substrate-OFMSW only, in the fourth run sewage sludge from a municipal water treatment plant was used. In the fifth experiment a mixture of sewage sludge and OFMSW was used. In all experiments the following data were determined: biogas content and productivity, pH, total suspended and volatile solids, elemental content (C, H, N, S) of sludge, OFMSW and inoculum, total organic carbon, total alkalinity and volatile fatty acid content. Comparing the elemental analysis of sewage sludge and OFMSW it is evident that N content is higher in the sludge than in the OFMSW, however, the carbon content relation is the opposite, which may be beneficial to methane yield of co-digestion. Methane concentration in the biogas was above 60% in all cases. Biogas productivity varied between 0.4 and 0.6 dm yg VSS depending on substrate added to the digester. The 3 add obtained results are generally consistent with literature data. ᮊ

Drafts by Haider Al-Rubaye, Ph.D

The demand of the world economy for electrical and thermal energy in over 88% is covered from non... more The demand of the world economy for electrical and thermal energy in over 88% is covered from nonrenewable energy, mainly petroleum and natural gas, (Krzysztof & Magdalena, 2012). To address the growing need for increased sustainability for, this create the need for the alternative energy which will be cleaner and easier to handle and the world start pay attention towards the field. This work focuses on three areas: 1. Design a two stage digester using ASPEN. 2. Construct and operate a pilot facility to test this hybrid concept, and 3. Conduct a statistical analysis of the test data to identify the optimum operating conditions for the hybrid system. A hybrid digester-gasifier system to produce methane and chemicals from Grey Water (municipal waste water) and from solid municipal waste (biomass) has been designed. The gasifier is designed and built at Brigham Young University-Idaho. The unit is equipped with natural gas burner as combustion zone to supply heat to the reactor. This work focuses on the digester portion of this hybrid energy system. Digestion consists of three steps including: hydrolysis, acidogenesis, and finally methanogenesis: hydrolysis is considered the controlling rate-limiting reaction step. The digester includes a plug flow reactor followed by continuous stirred tank reactor and is used to produce methane from Grey water. Designing the digester focused on evaluating several operating parameters including pH level, temperature for both reactors, biomass content in waste water, and reactor residence time each of which has significant impact on methane production. This is a two-step method. First, develop the Aspen model and conduct the designed experiment to identify key operating factors. Second, using these results develop a bench-scale reactor system which can be used to conduct experiments to validate (refine) the Aspen model. Once validated, the Aspen model can be used to scale the process up to pilot scale and eventually industrial scale. Economics and sustainability of the overall process can also be evaluated using the Aspen based process model.

The present paper deals with the treatment of phosphate obtained from a commercial sample of Akas... more The present paper deals with the treatment of phosphate obtained from a commercial
sample of Akashat phosphate ore in hydrochloric acid. The factors studied are effects
of the temperature of dissolution, acid concentration, and the time required for mixing
phases. The experiments were performed with 100 kg/m3 of solid/liquid ratio, the size
of the particles ranged 125-140 μm, the initial acid concentrations were 20, 30 and 40
wt% HCl, and the temperature of dissolution was kept constant at 30, 40, 50, 60 and 70
oC. The results indicated that the percentage of P2O5 increases as the HCl concentration
increased using different time and temperatures. Also, the results showed that the best
conditions for P2O5 recovery process according were acid concentration 40%, reaction
time of 90 min, and temperature 30 oC.

Processes

Biofuels

Biofuels, 2022

Chemical Engineering and Processing - Process Intensification, 2018

Biofuels, 2017

Biofuels, 2020

Chemical Engineering & Technology

Chemical Engineering & Processing: Process Intensification, 2018

$Research paper thumbnail of Anaerobic co-digestion of sewage sludge and organic fraction of municipal solid wastes$

The present paper deals with the treatment of phosphate obtained from a commercial sample of Akas... more The present paper deals with the treatment of phosphate obtained from a commercial
sample of Akashat phosphate ore in hydrochloric acid. The factors studied are effects
of the temperature of dissolution, acid concentration, and the time required for mixing
phases. The experiments were performed with 100 kg/m3 of solid/liquid ratio, the size
of the particles ranged 125-140 μm, the initial acid concentrations were 20, 30 and 40
wt% HCl, and the temperature of dissolution was kept constant at 30, 40, 50, 60 and 70
oC. The results indicated that the percentage of P2O5 increases as the HCl concentration
increased using different time and temperatures. Also, the results showed that the best
conditions for P2O5 recovery process according were acid concentration 40%, reaction
time of 90 min, and temperature 30 oC.