Chandra Mohan Sinnathambi

Thermodynamics analysis of refinery sludge gasification in adiabatic updraft gasifier.

Limited information is available about the thermodynamic evaluation for biomass gasification process using updraft gasifier. Therefore, to minimize errors, the gasification of dry refinery sludge (DRS) is carried out in adiabatic system at atmospheric pressure under ambient air conditions. The objectives of this paper are to investigate the physical and chemical energy and exergy of product gas at different equivalent ratios (ER). It will also be used to determine whether the cold gas, exergy, and energy efficiencies of gases may be maximized by using secondary air injected to gasification zone under various ratios (0, 0.5, 1, and 1.5) at optimum ER of 0.195. From the results obtained, it is indicated that the chemical energy and exergy of producer gas are magnified by 5 and 10 times higher than their corresponding physical values, respectively. The cold gas, energy, and exergy efficiencies of DRS gasification are in the ranges of 22.9–55.5%, 43.7–72.4%, and 42.5–50.4%, respectively. Initially, all 3 efficiencies increase until they reach a maximum at the optimum ER of 0.195; thereafter, they decline with further increase in ER values. The injection of secondary air to gasification zone is also found to increase the cold gas, energy, and exergy efficiencies. A ratio of secondary air to primary air of 0.5 is found to be the optimum ratio for all 3 efficiencies to reach the maximum values.

Recent advancement of hybrid materials used in chemical enhanced oil recovery (CEOR): A review

Depletion of natural oil reserves has forced oil industries to focus on tertiary recovery methods to extract residual oil after exhausting the primary and secondary methods. Among the Enhance Oil Recovery (EOR) technologies, Chemical EOR (CEOR) is gaining popularity. Despite research efforts to increase the recovery using CEOR, increasing complexity in extraction methods are encountered. With changes in reservoir conditions (high temperature, pressure and salinity) and crude oil properties, existing chemicals used in CEOR, such as alkali, polymers and surfactants do not function desirably. These conditions have detrimental effects on the performance of EOR chemicals, like precipitation, degradation, etc. Development and utilization of effective EOR hybrids such as surfactant-polymer, polymer-nanomaterial, surfactant-nanomaterial and polymer-surfactant-nanomaterial had prevailed the effects of harsh reservoir conditions, and their applications in oil fields in recent years have increased the success of EOR. The synergistic effects between the hybrid components play major roles in improving the properties that could withstand the effect of extreme reservoir conditions and changes in crude oil properties. Therefore, this paper is aimed at reviewing recent advances in CEOR hybrid technologies, and discusses the basic concept, applications, advancement and limitations of different hybrid materials used in CEOR processes.

Scaled down Design of a Cold and Hot Flow Model Based on a Bubbling Fluidized Bed Pilot Plant Gasifier

Bubbling fluidized bed (BFB) is a vital equipment in many applications in the energy, pharmaceuticals, and chemicals process industries due to its numerous advantages such as large heat capacity inside a bed, and rapid heat and mass transfer rate. In spite of numerous research activities, achieving high fluidization performances in BFB process is still a challenge of science. This research is being conducted to study the hydrodynamic regime of a BFB pilot plant gasifier. To this end, a lab-scale cold model was first designed based on the empirical equations and scaling laws. The scaling laws was used to scale down the Tenaga Nasional Berhad-PETRONAS (TNBR-PETRONAS) pilot plant gasifier into a small scale laboratory model. Moreover, the empirical equations were utilized to determine the critical parameters such as bed pressure drop, height of the bed, number of orifices of the distributor plate and the pitch size. Finally a lab-scale hot flow model will be designed based on the cold model geometric dimensions but under a real operating conditions as that of a pilot plant.

Laboratory Characterization of crude oil and sandstone reservoir for Chemical Enhanced Oil Recovery

Purpose Because of the increasing global oil demand, efforts have been made to further extract oil using chemical enhanced oil recovery (CEOR) methods. However, unlike water flooding, understanding the physicochemical properties of crude oil and its sandstone reservoir makeup is the first step before embarking to CEOR projects. These properties play major roles in the area of EOR technologies and are important for the development of reliable chemical flooding agents; also, they are key parameters used to evaluate the economic and technical feasibilities of production and refining processes in the oil industries. Consequently, this paper aims to investigate various important physicochemical properties of crude oil (specific gravity; American Petroleum Institute [API]; viscosity; pour point; basic sediment and water; wax; and saturate, aromatic, resins and asphaltenes components) and sandstone reservoir makeup (porosity, permeability, bulk volume and density, grain volume and density, morphology and mineral composition and distributions) obtained from Malaysian oil field (MOF) for oil recovery prediction and design of promising chemical flooding agents. Design/methodology/approach Three reservoir sandstones from different depths (CORE 1; 5601, CORE 2; 6173 and CORE 3; 6182 ft) as well as its crude oil were obtained from the MOF, and various characterization instruments, such as high temperature gas chromatography and column chromatography for crude’s fractions identification; GC-simulated distillation for boiling point distribution; POROPERM for porosity and permeability; CT-Scan and scanning electron microscopy-energy dispersive X-ray for morphology and mineral distribution; wax instrument (wax content); pour point analyser (pour point); and visco-rheometre (viscosity), were used for the characterizations. Findings Experimental data gathered from this study show that the field contains low viscous (0.0018-0.014 Pa.s) sweet and light-typed crude because of low sulfur content (0.03 per cent), API gravity (43.1o), high proportion of volatile components (51.78 per cent) and insignificant traces of heavy components (0.02 per cent). Similarly, the rock permeability trend with depth was found in the order of CORE 1 < CORE 2 < CORE 3, and other parameters such as pore volume (Vp), bulk volume (Vb) and grain volume (Vg) also decrease in general. For grain density, the variation is small and insignificant, but for bulk density, CORE 2 records lower than CORE 3 by more than 1 per cent. In the mineral composition analysis, the CORE 2 contains the highest identified mineral content, with the exception of quarts where it was higher in the CORE 3. Thus, a good flow crude characteristic, permeability trend and the net mineral concentrations identified in this reservoir would not affect the economic viability of the CEOR method and predicts the validation of the MOF as a potential field that could respond to CEOR method successfully. Originality/value This paper is the first of its kind to combine the two important oil field properties to scientifically predict the evaluation of an oil field (MOF) as a step forward toward development of novel chemical flooding agents for application in EOR. Hence, information obtained from this paper would help in the development of reliable chemical flooding agents and designing of EOR methods.

Rheological behavior on treated Malaysian crude oil

Crude oil is always produced with water. This association causes many problems during oil production, arising from the formation of emulsion. Emulsion is an undesirable substance that increases operational and capital cost in the pipeline and processing equipment. To overcome this issue, demulsifiers are formulated to break the emulsion, where they are able to separate the water-oil emulsions to their respective phases. The emulsifier’s main function is to reduce the interfacial tension properties of the emulsion. For this research, both the EOR and natural water-in-oil emulsions were treated with low a concentration demulsifier. The main objective of this paper is to determine the dynamic viscosity and rheological properties of the treated EOR and natural emulsion. The dynamic viscosity was obtained using the Brook-field Digital Viscometer. The components that influence the emulsion’s rheological properties are the temperature, shear rate and shear stress. The results obtained demonstrate that the viscos...

Dynamic Studies of Refinery Sludge Gasification in Updraft Reactor

Many papers have been published about the gasification of different biomass fuels in fixed bed reactor. To date, no experimental analysis is available in the open literature on gasification of refinery sludge. Therefore the descriptions of dynamic temperature in an updraft reactor for a dry refinery sludge gasification are investigated in details. The rate of the temperature change with operation time and the temperature profiles inside the reactor are taken for various equivalent ratios. The dynamic results show that increasing the ER from 0.195 to 0.244 shift the combustion zone peak temperature from 858 °C to 986 °C and cause turbulence behavior in reduction zone temperature. With an ER of 0.195, the rate change of temperatures zones was found to be in the ± 50 OC min-1 indicating stable gasification process. The axial temperature for starting of a steady state gasification process was found to be between 20 to 60 min operation time in process.

N-Hexane, Methyl Ethyl Ketone and Chloroform Solvents for Oil Recovery from Refinery Waste

Considerable amount of oily waste is generated from petroleum refinery in Malaysia. A typical refinery produces about 40 tons of sludge per month. Disposing via land filling (common method) is becoming less accepted and more expensive. As a result, refineries and other facilities have accumulated large volumes of this waste in makeshift landfills or other storage areas. For this reason solvent extraction method has been selected for oil recovery and to minimize the solid waste. Three solvents (chloroform, MEK, and n-hexane) and two extraction methods (sludge–solvent mixing method , and Soxhlet apparatus) were applied to recover the oil from the refinery sludge. Soxhlet extraction method has shown higher efficiency in extraction than sludge-solvent mixing method. Soxhlet extraction method using MEK solvent can recover about 48.3 % of oil, as compared to mixing method which accounts to only about 32.5 % of recovered oil. It has an added recovery of about 7.1 %, 15.8 % and 5.7 % for n-hexane, MEK and chloroform solvents respectively. FTIR results confirmed that MEK has the highest capability to extract hydrocarbon from refinery waste.

Gasification of refinery sludge in an updraft reactor for syngas production

The study probes into the investigation on gasification of dry refinery sludge. The details of the study includes; influence of operation time, oxidation temperature and equivalence ratios on carbon gas conversion rate, gasification efficiency, heating value and fuel gas yield are presented. The results show that, the oxidation temperature increased sharply up to 858°C as the operating time increased up to 36 min then bridging occurred at 39 min which cause drop in reaction temperature up to 819 °C. This bridging was found to affect also the syngas compositions, meanwhile as the temperature decreased the CO, H2, CH4 compositions are also found to be decreases. Higher temperature catalyzed the reduction reaction (CO2+C = 450 2CO), and accelerated the carbon conversion and gasification efficiencies, resulted in more solid fuel is converted to a high heating value gas fuel. The equivalence ratio of 0.195 was found to be the optimum value for carbon conversion and cold gas efficiencies, high heating value of ...

Simulation study on the effect of air distribution on the bed height and bubble formation in bubbling fluidization reactor

This paper describes the numerical study on the effect of inlet air distribution in the Bubbling Fluidized Bed (BFB) riser of diameter 0.18 m and 1.44 m of length using a 3-hole orifice plate. A 2D model has been developed and meshed using Gambit software version 2.4.6 and was simulated using CFD code, fluent version 6.3. Laminar model has been used for the modeling and Eulerian-Eulerian multiphase model coupled with kinetic theory of granular flow was employed. For the drag, Gidaspow Drag Model was used to calculate the phase interaction between the gas and solid particles. The simulation results obtained for the validation purpose showed good agreement with the results available in the literature. The model with orifice plate gives a better and clear bubble shape with improved turbulent and better mixing compared to the model without the orifice plate. The model with orifice plate is also more realistic and ideal as compared to the model without the orifice plate.