Journal of Chemical Engineering

Industry Best Practice Risk based design for LPG Facility: Gap in Bangladesh practice

2017-12-07T07:15:59+00:00

Bangladesh safety regulations and practice is at nascent stage. Safety distance regulation for LPG installation does not match with prescriptive standard API 2510 or other international standards. No detail technical basis is available publicly for such decision making by authority. The present study focuses on risk based design best practice in industries and gap in Bangladesh safety regulations. World LPG industry faces major accidents with fatalities and huge damages. Setting up bigger safety distance with conventional firefighting equipment is not the only mitigation measures to solve complex safety issues of LPG facilities. These two parameters do not ensure whether facility risk is tolerable and ALARP. Apart from this, safety distance and protection system design varies with facility layout, wind flows, systems reliability and site ambient conditions. For accident cases, hazards consequence modeling is carried out to calculate safety distances. Industry best practice is to apply risk based design that quantify complex risk level of a facility, propose mitigation measures and thereby risk acceptance criteria in the early phase of the project for authority approval. Many countries follow such detail regulation. Regulations of API, ISO, HSE UK and NORSOK, petroleum authority Norway have been utilized as basic standards in this paper. Gap in Bangladesh safety regulations are identified. This need to be further assessed based on industry best practice risk based design standards and practices. Without appropriate regulation, Bangladesh LPG industry and society remains in enormous intolerable personnel, environmental and economic risk.

Journal of Chemical Engineering, Vol. 30, No. 1, 2017: 8-11

Mercury Removal From Produced Water Using Subcritical Water Assisted 1-Etyl-3- Methylimidazolium Chloride Ionic Liquid

2017-12-07T07:16:08+00:00

Production of produced water from oil and gas industries are increasing day by day for enhancement of oil recovery. Insoluble mercury such as mercury sulfide and oxide, and dissolved mercury such as organomercury, ionic mercury and elementary mercury are present in produced water along with the other impurities. Mercury is not only hazardous to human health and the environment but could also attack process equipment components that have mercury reactive materials, leading to potential catastrophic failure to the plant. So, removing mercury from produced water is now a pressing issue for the environmental point of view. A lot of mercury separation techniques such as adsorption, precipitation etc. have been developed all over the world. But the traditional mercury removal processes are not suitable to remove mercury from produced water. The aim of this paper is to remove mercury from produced water using subcritical water assisted ionic liquid (IL) for the first time. In this study, 1-etyl-3- methylimidazolium chloride, [EMIM][Cl], IL was utilized. The potential experiments were conducted in a batch type extractor at temperatures of 130 - 180^ºC, a pressure of 0.2 MPa and treatment times of 0 - 10 min. The concentration of mercury(II)ions in ILs were analyzed using UV-VIS spectrophotometer and IL was analyzed using FT-IR to study the structure of ILs. The results show that [EMIM][Cl] IL has the ability to absorb mercury from produced water and almost 99.5% mercury was removed at a temperature of 180oC, a pressure of 0.2 MPa and a treatment time of 10 min by the action subcritical water assisted [EMIM][Cl]. In addition, mercury removal follows first order kinetics with an activation energy of 2.52 kcal per mol and a pre-exponential factor of 1.093 s^-1. Therefore, the subcritical water assisted ILs can be used to remove mercury from produced water of oil and gas industries.

Journal of Chemical Engineering, Vol. 30, No. 1, 2017: 12-15

Popularizing Liquefied Petroleum Gas (LPG) as an Alternative to Piped Natural Gas for Domestic Use: Bangladesh Perspective

2017-12-07T07:16:16+00:00

The basic objective of this paper has been to carry out comparative cost analyses for popularizing Liquefied Petroleum Gas (LPG) as a commensurate alternative to piped natural gas for domestic use in Bangladesh. Costing of LPG in three alternative scenarios of LPG utilization-LPG in cylinder, LPG supply in pipeline network for certain area and LPG in reticulated system-have been studied. Pricing of LPG and piped natural gas for domestic use have also been studied so as to recommend cross-subsidy option in LPG pricing that involves raising the price of natural gas for domestic use in order to finance LPG for expected lowering of its price, thus ensuring its access to the common people of the country. Reticulated LPG option, a semi-automatic system, has been found to be suitable as an alternative to piped natural gas for domestic use in terms of cost, flexibility and safety consideration.

Journal of Chemical Engineering, Vol. 30, No. 1, 2017: 16-20

Synthesis the Ni substituted Mn ferrites and Study the applications of ferrite

2017-12-07T07:16:23+00:00

With improved initial permeability and extremely low relative loss factor (RLF) of Nanocrystalline Ni-Cu ferrites were synthesized by combustion technique by doping excess amount of Mn at different sintering temperatures. Ferrites are ceramic magnetic oxides materials. It shows the property of electrical insulator and magnetic conductor with large number of applications in various fields. Structural characteristics were measures from the X-ray diffraction (XRD) patterns. It shows formation of pure single-phase cubic spinel structure with Nanocrystalline and good chemical homogeneity. From these data lattice constant was calculated. By the doping of Mn content it is found that lattice constant increases and these compositions obey the Vegard‟s law. From this study it was found that at the increasing of Mn content highly dense with lower porous and bigger grain of ferrite increases its magnetic and electric properties. High magnetization, high permeability, high quality factor, high mechanical stability, low loss factor were found in magnetic measurement.

Journal of Chemical Engineering, Vol. 30, No. 1, 2017: 21-26

Fuel Options for Bangladesh-2017

2017-12-07T07:16:30+00:00

Fuel is an essential commody supporting our daily life and economy. Until today, the majority of Bangladesh fuel is met from domestic natural gas production. With economy growing (like GDP 7⁺ %) in coming years, fuel use is also increasing and the local gas prodcution could not meet the requirement. Goverment has already taken steps for the import of LNG and LPG to support the shortfall. This paper describes different fuel options and suggests that the additional fuel requirement might be met with the imported LNG considering the environmental and cost of fuel. LPG is costly than imported LNG. So, emphasis on LPG use may be considered only to the areas where there is no pipe gas supply.

Journal of Chemical Engineering, Vol. 30, No. 1, 2017: 27-31

Fire Emergency Evacuation Simulation of a shopping mall using Fire Dynamic Simulator (FDS)

2017-12-07T07:16:35+00:00

Fire accident in a shopping mall, garments factory and other labor intensive industries nowadays has become a common incident in Bangladesh and poses a great threat to life, facilities and economy of our country. In this work, fire and evacuation simulation was performed for a single stored shopping complex utilizing computational fluid dynamic techniques. Fire Dynamic Simulator with evacuation (FDS+Evac) software was used to simulate a shopping mall fire and study the effects of fire on the emergency egress process of people. The shopping mall of area 64 m² comprises of seven rooms with a pool fire at the center of the mall is modeled for simulation. The total evacuation time (TET) for a fixed population density were estimated with the change of heat release rate, soot yield, soot density and the design pattern or geometry of shopping mall. The evacuation of agents in different time and different design pattern of the mall has been assessed using the data obtained from the simulation. FDS+Evac provides an integrating platform where the interaction between fire growth and evacuees can be taken into account by simultaneous simulation allowing a full coupling of the fire conditions and human behavior. This makes FDS is an effective tool for simulating large and high density crowds where the movement dynamics of evacuees is affected by the crowd pressure. Full scale fire experiment is often quite difficult to study the fine and crowds evacuation behavior. This paper illustrates a promising application of fire dynamic simulator (FDS+Evac) for fire and evacuation modeling to predict the total evacuation time.

Journal of Chemical Engineering, Vol. 30, No. 1, 2017: 32-36

Treatment of Spent Nuclear Fuel for Separation, Immobilization and Disposal of Heat Generating High Level Fission Products, Caesium and Strontium

2017-12-07T07:16:44+00:00

Separation of heat generating, high level fission product caesium and strontium from spent nuclear fuel boosts the capacity of waste repositories by as much as fifty times. For efficient use of already scarce repositories, separation of such fission products is mandatory. Separations of caesium and strontium using Chlorinated Cobalt Dicarbollide (CCD), PEG (Polyethylene Glycol), UNEX process and by Calixarenes or Fission Product Extraction Process (FPEX) were discussed. The UNEX method was then proposed as the most feasible method option. Following separation, nuclear waste immobilization techniques for such high-level fission product were discussed. The techniques included usage of concrete, glass and synthetic rock. Among them synthetic rock was identified as the most suitable one for immobilization of high-level nuclear waste. Finally, a safe disposal system with necessary required geology was shown for safe disposal of the waste.

Journal of Chemical Engineering, Vol. 30, No. 1, 2017: 37-42

A Computational Study on Mixed Convection Heat Transfer in an Inclined Rectangular Channel under Imposed Local Flow Modulation

2017-12-07T07:16:50+00:00

Numerical investigation of mixed convection heat transfer in an inclined 2D rectangular channel provided with partially heated bottom wall and a constant low temperature upper wall has been performed. The heated section of the bottom wall i.e. the heaters are maintained with constant heat flux and separated from each other by adiabatic segments. A fully developed parabolic velocity profile at constant low temperature is induced at the inlet. To enhance the heat transfer from the heaters, local flow field in the channel is modulated by placing circular cylinders rotating in counterclockwise direction (aiding flow) above each heater along the channel centerline. The fluid and the thermal fields within the rectangular channel are governed by the two-dimensional Navier-Stokes and Energy equations that have been solved by adapting Galerkin finite element method. The governing parameters of the present problem such as Reynolds number (Re) and Grashof number (Gr) are varied in the range of 1 ≤ Re ≤ 100 and 10³ ≤ Gr ≤ 10⁵. Air has been considered as working fluid having a Prandtl number, Pr = 0.71. In addition to these governing parameters, the inclination angle of the channel (α) and the speed ratio (ξ) that is the ratio of peripheral speed of the rotating cylinder and the maximum inlet flow velocity is also varied in the range of 0^° ≤ α ≤ 90^° and 0.5 ≤ ξ ≤ 2.0 respectively. The thermal and the fluid fields are visualized via the isotherm and the streamline plots. The efficacy of local flow modulation with rotating cylinder for heat transfer enhancement has been estimated in terms of normalized average Nusselt number over the heaters as Nu/Nu_nc, where Nu and Nu_nc represents the average Nusselt number with and without flow modulation respectively. Results obtain in the present study reveals that, for very weak flow (Re = 1), flow modulation results in lower heat transfer particularly at lower values of Gr on the contrary for moderate and higher values of Re (10, 100), flow modulation has been found to result in higher heat transfer particularly at lower values of Gr. For example, at Re = 100 and α= 0^°, about 32% to 55% enhancement in heat transfer has been obtained for 10³≤ Gr ≤ 105. Variation in heat transfer enhancement through flow modulation has also been noticed for different channel inclination angle (α) for various system configurations.

Journal of Chemical Engineering, Vol. 30, No. 1, 2017: 43-50

Overview of Major Industries in Bangladesh

2017-12-07T07:17:00+00:00

Industrialization is an essential prerequisite for rapid economic growth of a developing country like Bangladesh. This study shows the major industrial growth of the country and their impact on the national economic development, public safety, health and environment. The capacity, productivity and export/import values of industrial products are used to establish the baseline scenario. There are significant numbers of chemical intensive industries such as textile, leather, food, fertilizer and pharmaceutical industry that have direct impact on socio economic development of the country. It is worth noting that Bangladesh is not only importing industrial products from other countries but also exporting a substantial amount of product to over 100 countries of the world and shows an impressive growth in industrial sectors Rapid industrial growth often offers a huge burden of environmental pollution and associated risks. Thus, there are still lots of space for Bangladesh to flourish in this sector. This study presents the prospects, and recommendations for major industrial sectors to achieve safe and sustainable industrial growth in Bangladesh.

Journal of Chemical Engineering, Vol. 30, No. 1, 2017: 51-58

An Assessment of Gasification of Lipid-Extracted Algae by Thermodynamic Simulation

2017-12-07T07:17:07+00:00

Thermodynamic simulation of gasification of Nannochloropsis gaditana (after lipid extraction and before lipid extraction) over a wide range of temperatures (800 – 1400 ^oC) was performed in this study. The reactor temperature variation with respect to the O₂ to fuel ratio and the syngas composition with temperature were evaluated for gasification performance. The results showed the H₂/CO ratio for lipid-extracted algae (LEA) was very similar to the gasification behavior of raw algae (RA) before lipid extraction. Only a slight variation was observed for the lower heating value (9.2 MJ/Nm3 for RA and 8.9 MJ/Nm³ for LEA at 1000 ^oC) of the syngas from the two feedstocks. The H₂/CO ratio for both RA and LEA remained almost the same over the range of temperatures (800-1400 oC) under consideration. The cold gas efficiency was found between 82 % to 75 % for RA and 75 % to 69 % for LEA at 1000 ^oC and 1400 ^oC respectively. As the overall gasification performance did not degrade significantly after extraction of lipid from algae, the LEA holds remarkable potential as a gasification feedstock in a biorefinery set up.

Journal of Chemical Engineering, Vol. 30, No. 1, 2017: 59-63

Prospects of Nanotechnology in Bangladesh Perspective

2017-12-07T07:17:12+00:00

Nanotechnology brings huge promise in the research and development in industrial sectors to increase the efficiency and productivity. It deals with matters at as small as billionth of a meter scale. At this nano scale, the physiochemical properties of matter dramatically change due to quantum confinement. So there are huge possibilities in developing applications by harnessing the nano scaled physiochemical properties of nano materials in numerous fields. Bangladesh, being a developing country lacks the proper guideline and investment to take advantage of this technology. Nanotechnology has a huge prospect in this country especially in agriculture and garments sector. If applied properly, nanotechnology can boost the economic growth as well as improve the capacity and quality in agriculture, food and other industrial sectors. This paper describes the current status of Nanotech research and development, applications in major industrial sectors, future prospects in the context of Bangladesh. This paper also discusses the safety, risks and challenges associated with nanotech and provide a general guideline and recommendations for the application of nanotechnology in major industrial sectors of Bangladesh.

Journal of Chemical Engineering, Vol. 30, No. 1, 2017: 64-68

Current status of plastic production, prospects and training of manpower in Bangladesh

2017-12-07T07:17:18+00:00

The main strategy for achieving accelerating growth and reducing poverty, income inequality and regional disparity include creation of productive employment in the manufacturing and organized service sector is to accelerate trade and investment in each and every sector. Development of small and medium enterprises (SMEs) is envisaged as a key element in this strategy. In this aspect, a survey on 43 plastic factories, 5 mold industries, 5 importers of plastic raw materials and machineries, 5 National & International Industries (RMG, Leather and plastic Sectors), 2 Association (BGMEA & BPGMEA) & 3 Government Agencies (Export Promotion Bureau (EPB), Ministry of Labor & Empowerment and Bangladesh Technical Education Board (BTEB)) was conducted on the name of ¡°Need assessment to set-up Bangladesh Institute of Plastic Engineering & Technology (BIPET)¡±. SMEF and BPGMEA offered this study on plastic sector. The plastic factories surveyed included micro, small, medium and large factories. About 80% factories belonged to the SMEs. Technical persons in the Management positions were interviewed using detailed questionnaire. The questionnaire was set to analyze the present status of production process, existing working conditions, hiring trends, education-training-technical skills- working experience of workers and technicians, wages framework, troubleshooting problems, types of machine, technology level, training facilities, need for testing, product quality, research & development facilities, existing factory owner.s qualification, their demand and facing challenges by entrepreneur & future prospect of plastic production in Bangladesh. Key recommendation for the development and future prospect of this sector is to support newly established Bangladesh Institute of Plastic Engineering & Technology under the supervision of BPGMEA and technical assistance from BUET.

Journal of Chemical Engineering, Vol. 30, No. 1, 2017: 69-76