• Energy Research

Biomass steam gasification with in-situ carbon dioxide capture using CaO exhibits good prospects for the production of hydrogen rich gas. In Malaysia, due to abundance of palm waste, it is a good candidate to be used as a feedstock for hydrogen production. The present work focuses on the mathematical modeling of detailed economic analysis and cost minimization of the flowsheet design for hydrogen production from palm waste using MATLAB. The influence of the operating parameters on the economics is performed. It is predicted that hydrogen cost decreasing by increasing both temperature and steam/biomass ratio. Meanwhile, the hydrogen cost increases when increasing sorbent/biomass ratio. Cost minimization solves to give optimum cost of 1.9105 USD/kg with hydrogen purity, hydrogen yield, hydrogen efficiency and thermodynamic efficiency are 79.9 mol%, 17.97 g/hr, 81.47% and 79.85% respectively. The results indicate that this system has the potential to offer low production cost for hydrogen production from palm waste.

Biomass steam gasification with in-situ carbon dioxide capture using CaO exhibits good prospects for the production of hydrogen rich gas. In Malaysia, due to abundance of palm waste, it is a good candidate to be used as a feedstock for hydrogen production. The present work focuses on the mathematical modeling of detailed economic analysis and cost minimization of the flowsheet design for hydrogen production from palm waste using MATLAB. The influence of the operating parameters on the economics is performed. It is predicted that hydrogen cost decreasing by increasing both temperature and steam/biomass ratio. Meanwhile, the hydrogen cost increases when increasing sorbent/biomass ratio. Cost minimization solves to give optimum cost of 1.9105 USD/kg with hydrogen purity, hydrogen yield, hydrogen efficiency and thermodynamic efficiency are 79.9 mol%, 17.97 g/hr, 81.47% and 79.85% respectively. The results indicate that this system has the potential to offer low production cost for hydrogen production from palm waste.

AbstractCoal–water slurry (CWS) has been targeted as a promising fuel and an alternative to fuel oil. CWS has numerous advantages of low and convenient transportation and high solid content. Pakistan is going through a severe energy crisis and among the top 10 countries facing energy crises reported by the United Nations. Besides, Pakistan has become the top seventh country in coal reserves (i.e., 185 billion tones) after the discovery of huge lignite coal reserves in Thar, Sind province. Previous studies investigated the use of additives to enhance CWS properties at a low shear rate and its utilization accordingly. Particularly, the present work studied the high range of shear rate to improve the properties of CWS for transportation and combustion purposes. This study on the improvement in performance of rheology properties of CWS is conducted to improve the properties by cost‐effective additives. The coal concentration varies from 20% to 60%, whereas runs were carried out with and without the cost‐effective additives. The results demonstrated that the coal slurry showed shear‐thinning property when viscosity was increased at high concentrations in the absence of additives. The addition of additive changed the rheological behavior from pseudoplastic to dilatant region. The presence of a high fraction of coal increased the apparent viscosity of CWS. The static stability test of all coal samples was performed using rod drop method at concentrations of 40% to 60%. The study found that stability was achieved earlier with a lower concentration of 40% as compared with higher concentrations of 50–60%. It is expected that this research would be helpful for the country facing adverse energy crises that badly affect the economy and other social aspects of human life.

AbstractCoal–water slurry (CWS) has been targeted as a promising fuel and an alternative to fuel oil. CWS has numerous advantages of low and convenient transportation and high solid content. Pakistan is going through a severe energy crisis and among the top 10 countries facing energy crises reported by the United Nations. Besides, Pakistan has become the top seventh country in coal reserves (i.e., 185 billion tones) after the discovery of huge lignite coal reserves in Thar, Sind province. Previous studies investigated the use of additives to enhance CWS properties at a low shear rate and its utilization accordingly. Particularly, the present work studied the high range of shear rate to improve the properties of CWS for transportation and combustion purposes. This study on the improvement in performance of rheology properties of CWS is conducted to improve the properties by cost‐effective additives. The coal concentration varies from 20% to 60%, whereas runs were carried out with and without the cost‐effective additives. The results demonstrated that the coal slurry showed shear‐thinning property when viscosity was increased at high concentrations in the absence of additives. The addition of additive changed the rheological behavior from pseudoplastic to dilatant region. The presence of a high fraction of coal increased the apparent viscosity of CWS. The static stability test of all coal samples was performed using rod drop method at concentrations of 40% to 60%. The study found that stability was achieved earlier with a lower concentration of 40% as compared with higher concentrations of 50–60%. It is expected that this research would be helpful for the country facing adverse energy crises that badly affect the economy and other social aspects of human life.

AbstractIt is important to build knowledge about the design of an integrated catalytic adsorption (ICA) steam gasification process in a bubbling fluidized bed, which can reduce CO2 content with enhanced hydrogen production. The value of this study is its presentation of detailed design considerations for the performance evaluation of an ICA system using palm oil waste as feedstock. The main advantage of using ICA gasification systems is the CO2 adsorption through a carbonation reaction (using CaO), which helps the water gas shift reaction to move forward. The activity of a catalyst improves steam methane reforming in parallel, which not only produces additional hydrogen but also releases CO to enhance the activity of the water gas shift reaction. The performance of the developed system has shown <1% of temperature variation inside the reactor, which suggested a positive role for exothermic reactions between reactive bed material (CaO) and CO2 in the product gas. The low pressure drop in the gasifier (100–130 mbar) further strengthens the design strategy for the ICA gasification system for hydrogen production. Challenges encountered during the pilot plant operations, and their potential solutions, are discussed to optimize the operation, especially for downstream equipment and auxiliaries. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd

AbstractIt is important to build knowledge about the design of an integrated catalytic adsorption (ICA) steam gasification process in a bubbling fluidized bed, which can reduce CO2 content with enhanced hydrogen production. The value of this study is its presentation of detailed design considerations for the performance evaluation of an ICA system using palm oil waste as feedstock. The main advantage of using ICA gasification systems is the CO2 adsorption through a carbonation reaction (using CaO), which helps the water gas shift reaction to move forward. The activity of a catalyst improves steam methane reforming in parallel, which not only produces additional hydrogen but also releases CO to enhance the activity of the water gas shift reaction. The performance of the developed system has shown <1% of temperature variation inside the reactor, which suggested a positive role for exothermic reactions between reactive bed material (CaO) and CO2 in the product gas. The low pressure drop in the gasifier (100–130 mbar) further strengthens the design strategy for the ICA gasification system for hydrogen production. Challenges encountered during the pilot plant operations, and their potential solutions, are discussed to optimize the operation, especially for downstream equipment and auxiliaries. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd

The conversion of palm oil waste into energy can complement the energy mix with renewable energy and bring economic benefits to the palm oil industry. A process simulation model for palm kernel shell (PKS) steam gasification for H2-enriched syngas with the integration of CO2 capturing using CaO has been investigated using Aspen Plus V10®. Techno-economic and energy analyses have also been conducted to identify energy-saving opportunities for commercialization. The effect of process variables, including reactor temperature (600–800 °C), Steam/PKS ratio (0.5–2 wt/wt), and CaO/PKS ratio (0–1.5 wt/wt), have been determined, with the predicted results compared to the reported experimental data. H2 concentration has been increased with 76–78 vol% with the temperature elevation from 650 to 750 °C. Additionally, a substantial increase in H2 content from 68 to 72vol% was observed when the steam flow rate was increased from 0.5 to 1.5. Conversely, the CO2 concentration decreased from 25 to 8vol% as the adsorbent ratio was raised from 0.5 to 1.5. The techno-economic analysis showed that the capital investment is $4.11 million, and the operating cost is $3.89 million per year, which is also very high due to the high raw material costs. In the case of energy, saving that 3.03 and 1.513 Gcal/hr can be saved in terms of utilities and gas cooling that economized the process which shows that utilization of these in heat exchange networks can significantly reduce costs, with up to 78 % savings in heat exchanger capital and 35 % in total energy consumption. The energy potential could be harnessed through the digitalization of the process.

The conversion of palm oil waste into energy can complement the energy mix with renewable energy and bring economic benefits to the palm oil industry. A process simulation model for palm kernel shell (PKS) steam gasification for H2-enriched syngas with the integration of CO2 capturing using CaO has been investigated using Aspen Plus V10®. Techno-economic and energy analyses have also been conducted to identify energy-saving opportunities for commercialization. The effect of process variables, including reactor temperature (600–800 °C), Steam/PKS ratio (0.5–2 wt/wt), and CaO/PKS ratio (0–1.5 wt/wt), have been determined, with the predicted results compared to the reported experimental data. H2 concentration has been increased with 76–78 vol% with the temperature elevation from 650 to 750 °C. Additionally, a substantial increase in H2 content from 68 to 72vol% was observed when the steam flow rate was increased from 0.5 to 1.5. Conversely, the CO2 concentration decreased from 25 to 8vol% as the adsorbent ratio was raised from 0.5 to 1.5. The techno-economic analysis showed that the capital investment is $4.11 million, and the operating cost is $3.89 million per year, which is also very high due to the high raw material costs. In the case of energy, saving that 3.03 and 1.513 Gcal/hr can be saved in terms of utilities and gas cooling that economized the process which shows that utilization of these in heat exchange networks can significantly reduce costs, with up to 78 % savings in heat exchanger capital and 35 % in total energy consumption. The energy potential could be harnessed through the digitalization of the process.