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In the current study, the biogas production was carried out by using a semi-continuous stirring tank reactor (CSTR). Consequently, the producer biogas was scrubbed/enriched by the combination of three steps of scrubbing (H2S scrubber, packed column water scrubber (PCWS), and activated charcoal scrubber (CS)). In PCWS, the static water scrubbing (SWS) and flowing water scrubbing (FWS) techniques were employed. In SWS, the biogas was scrubbed at a defined water level for a defined time while in FWS, the biogas was scrubbed at different water/gas (w/g) flow rates. In case of SWS, removal of was up to 95% H2S removal, removal of was up to 89% CO2 removal and 97% methane refinement was achieved. While for FWS, 97% removal of H2S, 90% removal of CO2 and 97% methane refinement was achieved. Both processes proved remarkable impacts on methane refinement but FWS was found more practical because CO2 was found more soluble in flowing water as compared with static water scrubbing.

In this work, partial oxidation of methane (POM) was investigated using Mg-Ni-Al (MNA) hydrotalcite promoted CeO2 catalyst in a fixed bed reactor. MNA hydrotalcite was synthesized using the co-precipitation process, while CeO2 was incorporated via the wetness impregnation technique. The CeO2@MNA samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDS), thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET) technique. The catalytic activity of CeO2 promoted MNA (CeO2@MNA) for POM reaction was evaluated for various CeO2 loading kept the feed ratio CH4/O2 = 2 at 850 °C. The catalyst containing 10 wt% cerium loading (10%CeO2@MNA) showed 94% CH4 conversion with H2/CO ratio above 2.0, that is more suitable for FT synthesis. The performance of catalyst is attributed to highly crystalline stable CeO2@MNA with better Ce-MNA interactions withstand for 35 h time on stream. Furthermore, the spent catalyst was examined by TGA, SEM-EDS, and XRD to evaluate the carbon formation and structural changes during the span of reaction time.

In the recent development of structured materials, efficient and low-cost materials are highly demanding for hydrogen production. In this work, novel 3D graphitic carbon nitride hollow nanosheets (CNHNS) with controlled morphology loaded with Ru for photocatalytic hydrogen production has been investigated. Compared to CN, CNHNS improves H2 evolution of 2 times due to hollow structure with higher light absorption and proficient separation of charges within 3D structure. The highest H2 evolution was attained over 3% Ru loaded CNHNS with yield rate of 1580 μmol g−1 h−1, which was 11.9 times higher than it was evolved over CNHNS and 15.1 times more than using CN, respectively. This obvious augmented photoactivity can be assigned to boosted charges separation in hollow structure, whereas, Ru further promoted the transfer of electrons. The performance of 3D Ru/CNHNS was further increased in an externally reflected solar system, which was 1.30 times more than using photoreactor without reflector. This was evidently due to increasing light intensity inside the reactor by reflecting light, thus, promoting quantum efficiency under the same source of light. The stability results further confirm continuous H2 evolution even after six cycles. Thus, newly developed method for synthesis of hierarchical 3D hollow structures and externally reflector solar photoreactor will provide new directions for hydrogen production systems.

In this study, a comparative decomposition of toluene was investigated using a dielectric barrier discharge (DBD) reactor. The first-time decomposition of the tar model compound was investigated in pure CO gas. The effect of each carrier gas (N2, H2, CO2 and CO), which exists in product gas from the gasifier, was studied on the decomposition of tar analogue (toluene) and product distribution. The specific input energy (SIE) was also varied from 2.5 to 8.5 kJ/L to investigate the optimal removal of tar analogue. The maximum removal of toluene was 89.1% using N2 as carrier gas at 8.5 kJ/L and 1.43 s. However, the minimum removal of toluene was 62.5% using CO carrier gas under the same conditions. The decomposition of toluene in different carrier gases was in the following order: CO

In this study, Ce0.85-xLa0.15CaxO2-δ was synthesized using sol-gel combustion method and appliedfor partial oxidation of methane (POM). The physicochemical properties of catalyst were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and thermogravimetric analysis (TGA). Material shows a pure cubical structure and is highly stable up to 850 °C. The performance testing indicated the conversion of CH4 is 65% and selectivity of H2 and CO are 28% and 8%, respectively. The performance indicated the catalyst has a potential to be used for partial oxidation of methane on a larger scale. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

The objective of this study was to analyze the catalytic performance of series of cobalt-modified Zeolite-4A supported catalysts for the syngas (CO and H2) production at 800 °C via the partial oxidation of methane (POM). The Co/Zeolite-4A catalyst was synthesized using a two-step hydrothermal method from coal fly ash. The synthesized catalysts were characterized by X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX), and Thermogravimetric Analysis (TGA). The catalyst shows a crystalline structure with stability up to 900 °C. The catalytic performance analysis shows the CH4 conversion increases from 29 to 68% for 0 and 10 wt% Co over Zeolite-4A, respectively. The H2 selectivity was improved from 28–56% while CO selectivity increased from 24–52 % making H2/CO ratio > 1. The stability analysis shows the 10% Co/Zeolite-4A withstand for 24 h a time on stream (TOS). Finally, the spent catalyst analysis was carried out to check the carbon formation along with its structural analysis. The minimal carbon formation is analyzed in 24 h TOS for POM reaction. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Methane is the main component of biogas, which could be used as a renewable energy source for electricity, source of heat, and biofuel production after upgrading from biogas. It also contains toxic compounds which cause environmental and human health problems. Therefore, in this work, the removal of a toxic compound (toluene) from methane gas was studied using a dielectric barrier discharge (DBD) reactor. It was observed that the removal of the toxic compound could be achieved from methane carrier gas using a dielectric barrier discharge reactor, and it depends on plasma input power. The maximum removal of the toxic compound was 85.9% at 40 W and 2.86 s. The major gaseous products were H2 and lower hydrocarbons (LHC) and the yield of these products also increases with input power. In the current study, the yield of gaseous products depends on the decomposition of toxic compounds and methane, because the decomposition of methane also produces H2 and lower hydrocarbons. The percentage yield of H2 increases from 0.43–4.74%. Similarly, the yield of LHC increases from 0.56–7.54% under the same reaction conditions. Hence, input power promoted the decomposition of the toxic compound and enhanced the yield of gaseous products.

The excess emission of greenhouse gases (GHGs) such as CO2 and CH4 is posing an acute threat to the environment, and efficient ways are being sought to utilize GHGs to produce syngas (H2, CO) and lighter hydrocarbons (HCs). In this study, the dry reforming of methane (DRM) has been carried out at 700 °C using La2O3 co-supported Ni/MgAl2O4 nano-catalyst in a fixed bed thermal reactor. The catalyst is characterized using various techniques such as XRD, FESEM, EDX-mapping, CO2-TPD, H2-TPR and TGA. The modified MgAl2O4 shows the flake type structure after the addition of La2O3. The TPR and TPD analysis shows the highly dispersed metal and strong basic nature of the catalyst consequently enhances the conversion of CO2 and CH4. The highest conversion for CH4 is 87.3% while CO2 conversion is nearly 89.5% in 20 h of operation time. The selectivity of H2 and CO approached 50% making the H2/CO ratio above unity. In the longer time-on-stream (TOS) test, the catalyst shows elevated potential for longer runs showcasing better catalytic activity. The stability of the catalyst is indicated via a proposed reaction mechanism for DRM in operating conditions. Moreover, TGA indicates the lower weight loss of spent catalyst which ascribed the lower formation of carbon during TOS 20 h.

A kinetic study on dry reforming of methane (DRM) in hybrid dielectric barrier discharge (DBD) plasma reactor over La2O3 co-supported Ni/MgAl2O4 catalyst has been investigated. Three different parametric effects namely specific input energy (SIE), discharge volume (VD) and feed flow rate corresponding to GHSV (h−1) are studied using the modified power-law model. The developed kinetic model indicates instantaneous conversions of CH4 and CO2 are functions of SIE, VD and GHSV. Increasing SIE linearly enhances the conversion of CH4 and CO2, while VD displays a non-linear relation with conversion and selectivity. GHSV also shows a linear relation with instantaneous CH4 and CO2 conversion and selectivity of H2 and CO. The rate constants ( k C H 4 , k C O 2 ), determined using the proposed kinetic model and various process parameters, are compared with DRM experimental results for validation. The apparent activation energy (Ea), calculated for CH4 and CO2 using modified Arrhenius equation, are = 32.6 kJ mol−1 (CH4) and Ea = 35.2 kJ mol−1 (CO2), respectively. The modified power-law model is a good preliminary description for future understanding of the overall performance of a hybrid catalytic DBD plasma reactor for DRM.

Ni/La2O3-MgAl2O4 has been investigated for dry reforming of methane (DRM) in a cold plasma dielectric barrier discharge (DBD) fixed-bed reactor. Ni/La2O3-MgAl2O4 was prepared according to the modif...

In this study, 10% Ni/La2O3 MgAl2O4 nano-flake catalyst was synthesized, characterized and tested in a catalytic dielectric barrier discharge (DBD) plasma for dry reforming of methane (DRM). With design of experiment (DoE), the influence of process parameters namely (1) total feed flow rate (ml min−1), (2) feed ratio (CO2/CH4), (3) input power (W) and (4) catalyst loading (g) were examined using multiple response surface methodology (RSM) through a four-factor, five-level central composite design (CCD). Second-order regression models were applied for evaluating the interaction between the process parameters and responses. Input power (X3) and total feed flow rate (X1) were the two most influential process parameters followed by catalyst loading (X4) and feed ratio (X2). The experimental and predicted results from the optimum conditions fitted-well with less than ±5% margin of error. The possible dynamic interactions between the process variables were elucidated. The optimum values are feed flow rate = 18.8 ml min−1, feed ratio = 1.05, input power = 125.6 W and catalyst loading = 0.6 g. At these conditions, the predicted CH4 and CO2 conversions are 79.86% and 84.03%, respectively. The H2 and CO yields are predicted as 41.37% and 40.47%, respectively while H2/CO ratio is above unity. The calculated EE from the RSM model is predicted as 0.135 mmol kJ−1. Low carbon deposition observed on the spent catalyst is attributed to the highly basic and oxidative nature of the La2O3 co-supported catalyst.

Dry reforming of methane (DRM) is one of the attractive methods for the utilisation of greenhouse gases (e.g., CH4, CO2) to produce valuable fuels. In the quest for an efficient development in DRM, several technologies have been practised, while dielectric barrier discharge (DBD) cold plasma technology garners special attention in the utilisation of CO2 and CH4 through DRM process due to easy upscaling opportunities and mild operating conditions. However, the low energy efficiency (EE) of DBD plasma is a distinct challenge and it offers an in-depth insight into its basic operational understandings. This review presents the overall status and current developments in DBD plasma for DRM. In the mainstream, challenges in DBD plasma technology, catalyst-plasma interactions and developments in plasma catalysts to improve the yield and selectivity of DRM have been discussed. The current status and developments in DBD reactor configuration based on reactor geometry, such as the electrode morphology, discharge gap (Dgap), discharge volume (VD) and material packing to maximise the productivity of DRM are specifically investigated. The effects of the operating parameters, such as gas hourly space velocity (GHSV), specific input energy (SIE) and feed ratio are critical for product distribution. The current status of reaction kinetics and prospects in fluid modelling of catalytic DBD plasma DRM reactor is reviewed to understand the underlying reaction mechanism. Finally, further advancements in the catalytic DBD plasma DRM has become a requisite to make it commercially viable for the successful production of valuable fuels.

In the present work, the decomposition of benzene as a tar model compound was studied in a gas mixture (CO2, H2, CO, and CH4) using a dielectric barrier discharge (DBD) non-thermal plasma reactor. The combined effect of temperature and power was studied to investigate the performance of the DBD reactor. The decomposition of tar compound increased from 49.9 to 96% with increasing specific input energy (SIE) from 2.05 to 16.4 kWh/m3. The major products were lower hydrocarbons (C2–C5) and solid residues. The higher temperature (400 °C) in the presence of plasma (40 W), decreased the conversion of tar compound from 96 to 78%. However, the selectivity of lower hydrocarbons increases substantially to 52%, and the formation of solid residues is significantly reduced. Hence, the problematic solid residues formation can be controlled at a higher temperature during the treatment of gasifier product gas using non-thermal plasma.

The study experimentally investigated a novel approach for producing hydrogen from methane cracking in dielectric barrier discharge catalytic plasma reactor using a nanocatalyst. Plasma-catalytic methane (CH4) cracking was undertaken in a dielectric barrier discharge (DBD) catalytic plasma reactor using Ni/MgAl2O4. The Ni/MgAl2O4 was synthesised through co-precipitation followed customised hydrothermal method. The physicochemical properties of the catalyst were examined using X-ray diffraction (XRD), scanning electron microscopy—energy dispersive X-ray spectrometry (SEM-EDX) and thermogravimetric analysis (TGA). The Ni/MgAl2O4 shows a porous structure spinel MgAl2O4 and thermal stability. In the catalytic-plasma methane cracking, the Ni/MgAl2O4 shows 80% of the maximum conversion of CH4 with H2 selectivity 75%. Furthermore, the stability of the catalyst was encouraging 16 h with CH4 conversion above 75%, and the selectivity of H2 was above 70%. This is attributed to the synergistic effect of the catalyst and plasma. The plasma-catalytic CH4 cracking is a promising technology for the simultaneous H2 and carbon nanotubes (CNTs) production for energy storage applications.

Dry reforming of methane (DRM) to syngas in a dielectric barrier discharge (DBD) plasma reactor over Ni-loaded ɤ-Al2O3-MgO nanocomposite catalysts has been investigated. The catalysts are prepared by modified incipient wetness impregnation method, assisted by cold plasma treatment. The samples are characterized by XRD, N2 adsorption-desorption, H2-TPR, CO2-TPD, FESEM and EDX. The performance of the catalyst for DRM is evaluated at various specific input energy (SIE J ml−1) and gas hourly space velocity (GHSV, h−1). The maximum conversion achieved are 74.5% and 73% for CH4 and CO2 respectively, over 10% Ni/ɤ-Al2O3-MgO at specific input energy (SIE) = 300 J ml−1 and gas hourly space velocity (GHSV) = 364 h−1. The main reaction products are H2 (29.5%), CO (30.5%) with H2/CO = 1 inferring RWGS reaction is suppressed for 12 h operation time. The enhanced conversion and yield are due to the strong metal-support interaction, high Lewis basicity and stable 10% Ni/ɤ-Al2O3-MgO catalyst as well as the plasma-catalyst interface. The energy efficiency (EE) of the plasma-catalytic DRM is higher (0.117 mmol kJ−1) compared to plasma only (0.087 mmol kJ−1) demonstrating the synergy between catalyst and plasma. The reaction mechanism is also proposed to postulate the steps involved in the DRM.

The utilisation of methane (CH4) to produce syngas (H2, CO) via partial oxidation of methane (POM) is an attractive technique, as syngas is a very valuable entity to produce liquid fuels and fuel cell applications. This work presents the hydrothermal growth of ZnO nanoprisms (ZnO-NPr) in a dual solvent for a controlled structure. The Co-Ni loaded ZnO-NPr catalysts were obtained in an aqueous solution by wetness impregnation method and tested for POM for the first time. The synthesized catalysts were characterized by employing XRD, SEM-EDX, TGA and RAMAN spectroscopy for structural and morphological analysis. The catalysts were analyzed for POM at 850 ᵒC and demonstrated high catalytic activity. It was observed that the catalytic activity of Co loaded ZnO-NPr, and Ni-Co loaded ZnO-NPr was more and demonstrated the stable behaviour for CH4 conversion in comparison to Ni loaded catalysts. The Co-Ni loaded ZnO-NPr has shown a high CH4 conversion (XCH4) (98%), and excellent stability over 56 h on stream. The average value of H2/CO for Co-Ni loaded ZnO-NPr was 2.11, above the theoretical value for POM. It is attributed to the better performance of catalyst towards the selectivity of H2 in reaction pathways.

In this work, the biomass fly ash (BFA) was investigated as a potential catalyst for the thermo-catalytic decomposition of methane and attractive approach for hydrogen (H2) production. The BFA based CeO2 nanowires promoted cobalt catalyst was synthesized for catalytic methane (CH4) decomposition and was tested in a fixed bed reactor. The physicochemical properties of the catalyst were investigated using various techniques such as X-ray powder diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, thermal gravimetric analysis, and Fourier transformed infrared. The pure crystalline micro-flake BFA was modified using synthesized CeO2 nanowires and the resulted micro flakes cross-linked with nanowires shown thermal stability up to 900 °C. The high stability of the catalyst makes it suitable for the thermal catalytic decomposition of methane. The activity of the catalyst was tested at 850 °C to analyze the H2 production and CH4 conversion. The obtained results revealed that support and promoter exhibit a strong impact on the CH4 conversion and H2 yield in catalyst screening tests. A maximum conversion of 71% for CH4 with 44.9% H2 yield was recorded for 34 h on stream activity while using 5% Co/CeO2-BFA as the catalyst. While BFA and Co-BFA as catalyst showed 36% and 47% conversion of CH4, respectively which indicates that the addition of promoter shows an increase in values of both conversion of CH4 and H2 yield. Compared to traditional catalyst support, the use of waste-sourced catalyst support for CH4 decomposition provides a greener and more economical route for H2 production.

The effect of quartz and alumina dielectric materials on the efficiency of dielectric barrier discharge (DBD) cold plasma reactor using different configurations for dry reforming of methane (DRM) has been investigated. The performance of dielectric materials was analysed at different feed ratios, gas hourly space velocity (GHSV, h−1) and specific input energy (SIE, kJ L−1). In both reactors, the main products detected were CO and H2 with considerable amounts of C2H6. Alumina reactor prevailed in performance and the maximum conversion achieved was 74% and 68% for CH4 and CO2, respectively at GHSV (92 h−1) feed ratio (1:1), SIE (370 J ml−1) and discharge volume (VD = 15.7 cm3). The CO/H2 ratio and yields were also higher in alumina than the quartz reactor under the same experimental conditions. Furthermore, different reactor configurations displayed a significant impact in the performance of DBD plasma. Increasing discharge volume (VD) enhanced the conversion and selectivity for both dielectrics. The energy efficiency (EE) was of 0.085 and 0.078 mmol kJ−1 for alumina and quartz, respectively. The high EE in alumina reactor was evidently due to higher dielectric constant, which exhibited enhancement in power dissipation, discharge energy and reactor temperature. Stability test conferred alumina DBD plasma reactor performed better than the quartz.

Co/TiO2–MgAl2O4 was investigated in a fixed bed reactor for the dry reforming of methane (DRM) process. Co/TiO2–MgAl2O4 was prepared by modified co-precipitation, followed by the hydrothermal method. The active metal Co was loaded via the wetness impregnation method. The prepared catalyst was characterized by XRD, SEM, TGA, and FTIR. The performance of Co/TiO2–MgAl2O4 for the DRM process was investigated in a reactor with a temperature of 750 °C, a feed ratio (CO2/CH4) of 1, a catalyst loading of 0.5 g, and a feed flow rate of 20 mL min−1. The effect of support interaction with metal and the composite were studied for catalytic activity, the composite showing significantly improved results. Moreover, among the tested Co loadings, 5 wt% Co over the TiO2–MgAl2O4 composite shows the best catalytic performance. The 5%Co/TiO2–MgAl2O4 improved the CH4 and CO2 conversion by up to 70% and 80%, respectively, while the selectivity of H2 and CO improved to 43% and 46.5%, respectively. The achieved H2/CO ratio of 0.9 was due to the excess amount of CO produced because of the higher conversion rate of CO2 and the surface carbon reaction with oxygen species. Furthermore, in a time on stream (TOS) test, the catalyst exhibited 75 h of stability with significant catalytic activity. Catalyst potential lies in catalyst stability and performance results, thus encouraging the further investigation and use of the catalyst for the long-run DRM process.

The development of bifunctional electrocatalyst with effective activity and high stability for water splitting reactions is essential for hydrogen production and fuel cell technology. Herein, a 3D hierarchical heterostructure LSTN@NiMn-layered double hydroxide (La0.4Sr0.4Ti0.9Ni0.1O3-δ @NiMn-LDH) supported on highly conductive nickel foam, is presented as a novel bifunctional electrocatalyst with outstanding performance. LSTN heterostructure synthesized by sol-gel method followed by hydrothermal reaction to grow LDH layers (LSTN@NiMn-LDH) resulted in phenomenal bifunctional activity towards both the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER), by exhibiting a low overpotential of 125 mV at 15 mA cm−2 (OER) and 32 mV at 10 mA cm−2 (HER). Moreover, the 3D electrode showed good long-term durability for 24 hrs. stability test at a current density of 100 µA cm−2, as well as constant LSV results after operating HER for 1000 cycles. This approach of preparing heterostructure LSTN@NiMn-LDH combines the fundamental properties of La0.4Sr0.4Ti0.9Ni0.1O3-δ (highly efficient HER catalyst) with NiMn-LDH (catalytically active for OER) by using interface engineering, resultantly opens a new way of enhancing the overall activity of water splitting reactions.

The biomass utilization for power generation is one of the efficient pathways to reduce greenhouse gas emissions. However, the high ash formation in biomass fed power plants raises several concerns, especially ash handling and its utilization. In this study, the biomass ash characterization, ash fusion analysis and its utilization as a catalyst in methane (CH4) decomposition were systematically investigated. The biomass bottom ash (BBA) and biomass fly ash (BFA) were modified using laboratory synthesized CeO2 nanoparticles to enhance the fusion temperature. The BBA, BFA and modified CeO2-BBA/BFA samples were characterized by ultimate analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), and X-ray fluorescence (XRF) analysis to investigate the physicochemical properties and its suitability for the catalysis applications. The detailed characterization inferred that BFA has significant potential in improving the ash fusion temperature as well as suitable for catalysis of fuel processing due to the presence of metal oxides such as Fe2O3, SiO2, CaO, Al2O3 and its porous structure. Furthermore, the most suitable BFA was impregnated with cobalt (Co). Co loaded BFA was employed for CH4 decomposition at 700 °C for H2 production in a fixed bed reactor. The Co/BFA demonstrated a stable catalytic activity of more than 330 min on stream with optimum H2 yield of 30%. The direct employment of BFA as catalyst support shows potential in further catalytic applications and material applications.

In this study, the waste eggshell has been utilised to synthesise structure modified CaO using organic acids and employed for CO2 capture in the thermogravimetric analysis (TGA) based systems. Different characterisation techniques were used such as XRD, SEM/EDS, XRF, N2 sorption-desorption (BET) and TGA to investigate the suitability for CO2 adsorption. The modified CaO using organic acids showed high surface area, easy upgradation of pore structure makes the CaO a suitable sorbent for CO2 capturing as an economical sorbent. Three of the organic acid modified sorbent achieved the highest conversion and stability over a period of 20 cycles. Citric acid modified sorbent (CaO CA-10%) obtained a CO2 uptake of 0.38 g CO2/g sorbent (CaO conversion of 55%) that was highest among the acid used whereas in term of stability malic acid modified sorbent (CaO MA-10%) has the lowest average decay rate of 4.43 mg CO2/cycle as compared to various acids used in this work. It is concluded that modified surface structure by employment of organic acids lead to the reduction of sintering and led towards better sorbents performance towards CO2 capturing for multiple cycles.

Catalytic and thermal cracking of polypropylene was performed in a batch reactor. Effect of hydrochloric acid activation on kaolin clay, effects of catalysts (acid-activated clays), promoter (5 wt% Ni), and cracking temperatures on the liquid oil yield were investigated. Results show optimized liquid yield (71.9%) obtained at 470°C with kaolin clay activated with 3 M HCl. Acid-activated catalysts were analyzed using XRD and the results reveal the reduction in peaks’ intensities. Weight loss of polypropylene was investigated by thermogravimetric analysis. FTIR and GCMS techniques were employed to analyze the liquid products.

The study was designed to compare the bioethanol production from Zymomonas mobilis and Saccharomyces cerevisiae using molasses as production medium. The focus was on the retention time at lab scale. Bioethanol and petroleum blend can be used in existing gasoline engines. Present study showed a more cost-effective procedure for production of ethanol from sugar-cane molasses by using bacterial strain "Z. mobilis". Laboratory scale unit was designed to perform the experiments through batch fermentation and to determine the impact of leading parameters, including fermentation temperature, pH, sugar concentration, and nutrients. S. cerevisiae produced 8.3% (v/v) bioethanol provided sugar concentration 14 g /100 ml with the fermentation efficiency of 92.5%. On the contrary, Z. mobilis produced 9.3% (v/v) bioethanol by utilizing 16 g/100 ml sugar with the fermentation efficiency of 90.5%. Effect of nutrients on fermentation was determined using molasses as feedstock. Thin layer chromatography was also performed to assess the possible impurities in molasses as compared to the pure sugar. The pH and fermentation temperature was optimized for the enhanced yield of bioethanol. Key words: Bioethanol, molasses, fermentation, Zymomonas mobilis, Saccharomyces cerevisiae.