Upgrading Techniques Research Articles

A systematic comparison of various upgrading techniques for heavy oil

This study evaluates the economic viability of various post-production upgrading techniques for heavy oil. Heavy oils represent 60% of overall crude oil resources, worldwide. However, there are challenges associated with all phases of operation chain owing to high viscosity and low API. In this study, we present a comparative study of five post-production processing techniques in terms of their recovery factors, and economics.We use five different techniques to study post-production processing of heavy oil: 1) dilution with lighter crude, 2) partial upgrading via visbreaking, and 3) wellsite mini-refinery with three various configurations. Two heavy oil samples are selected based on API gravity and sulfur content. Simulations have been conducted to study various processes for the chosen oil samples. Key parameters controlling each technique have been identified and impact of each parameter have been analyzed with sensitivity studies. Advantages and disadvantages of each process are compared to assess the performance at different operational conditions, including oil price.Results indicate an overall net margin of $1 per barrel for blending, between $7 to $9 per barrel for partial upgrading technique, and between $13 and $20 per barrel for mini-refinery. Moreover, when production rate or the crude price is low, blending yields the best performance as it requires the lowest capital cost. Mini-refinery becomes profitable when production exceeds 20,000 barrel per day or oil price surpasses $ 50 per barrel. In addition, for dilution process operation cost has the largest impact on NPV calculations whereas interest rate and capital cost are most dominant factors for visbreaking and mini-refinery techniques.The main contribution of this work is an economical comparison of different post-production heavy oil processing technologies to identify the optimal process under different conditions.

Numerical Investigation of Four Seismic Upgrading Techniques on a Masonry Bell Tower

This paper presents some preliminary results from the numerical investigations of different interventions for the seismic upgrading of a masonry bell tower. Masonry bell towers belong to the cultural and historical heritage, are very widespread in Italy and their conservation has been given special attention in recent years. Their high vulnerability is related to the combination of mechanical material properties, geometrical irregularities, presence of inclination, foundation settlements and seismicity of the area. The present tower is located in Emilia Romagna Region, Northern Italy, recently stricken by a strong seismic sequence in May 2012. Analyses results show that the retrofitting of masonry bell towers is highly recommended in order to mitigate their present seismic risk. Four different upgrading techniques, consisting of grouted mortar, FRP sheets, internal steel frame and prestressing vertical rods, are investigated and compared in terms of structural performance improvement. The grouted mortar and internal steel frame techniques are found to be reasonable solutions when compared to the other proposals for the specific seismic intensity level. Furthermore, the other techniques have a relatively high level of invasiveness which is recommended to be avoid where possible. Experience has shown that the most effective interventions are those that not only protect the structure, but also preserve the built heritage.

Physicochemical Property Changes and Volatile Analysis for Torrefaction of Oil Palm Frond

Torrefaction is an upgrading technique for biomass properties which involves the heating of biomass to moderate temperatures typically between 200 and 300 °C in an inert condition. Torrefied biomass has darker colour, high energy density, high heating value and exhibits hydrophobic characteristic that makes it easier for grinding. Therefore, the aim of this work is to conduct an experimental work in order to study the torrefaction effects on the physicochemical properties of oil palm frond (OPF) as well as to identify the evolution of volatiles composition during the torrefaction. Torrefaction experiments were performed at four different temperatures (240 – 330 °C) and three different residence times (15, 30 and 60 min). The higher heating value of raw and torrefied biomass were measured to establish a relationship between energy loss and mass loss during torrefaction. Scanning electron microscope (for physical analysis) was used to study the structure of raw and torrefied OPF. Elemental analysis was carried out by using Carbon, Hydrogen. Nitrogen and Sulphur (CHNS) analyser and the proximate analysis were measured based on the method specified by American Society for Testing and Materials (ASTM). Condensable and non-condensable gases were analysed by using high performance liquid chromatography (HPLC) and gas chromatography thermal conductivity detection (GC-TCD) respectively. Higher torrefaction temperature and longer residence time leads to severe decomposition which reduces the mass yield of the torrefied oil palm frond but increases the heating value of torrefied OPF. The carbon content increases with the increasing of temperature and residence time, while hydrogen and oxygen contents are decreases. The values of fixed carbon and ash content increases, while volatile matter value decreases when the oil palm frond is torrefied for a longer time at high temperature. For volatile release, carbon monoxide and carbon dioxide are the major compounds presence in non-condensable gas and traces of methane was only identified when OPF was torrefied at 300 °C and 330 °C. Acetic acid and methanol are the major compounds of condensable gases with the presence of formic acid and lactic acid at 330 °C. It can be concluded that high temperature gives significant effect on the chemical reaction for formation of condensable and non-condensable gases.

Design, Development and Experimental Investigation on Various Biogas Upgrading Techniques

Design, Development and Experimental Investigation on Various Biogas Upgrading Techniques

Role of Potassium Exchange in Catalytic Pyrolysis of Biomass over ZSM-5: Formation of Alkyl Phenols and Furans

Catalytic fast pyrolysis of biomass with ZSM-5 type zeolites is a commonly considered in situ upgrading technique for the production of partially deoxygenated bio-oils. The acidity and structure of ZSM-5 catalysts favor the production of aromatic hydrocarbons from oxygenates present in the pyrolysis vapors, such as acids, anhydrosugars, ketones and aldehydes. However, these acid catalyzed deoxygenation pathways remove functional groups from the aromatic ring structure, which makes the liquid bio-oil more amenable to processing in current petroleum refineries while subsequently decreasing the value of the compounds as industrial chemical feedstocks. The observation of improved yields of alkyl phenols and furans during catalyst deactivation suggests a method for tuning the product distribution by altering the parent zeolite catalyst via changes in acidity and/or incorporation of alkali metals known to accumulate on the catalyst during pyrolysis. Here, we report the catalytic fast pyrolysis of three biomass ...

Review of the potential of biogas generation in India and a comparative study of various biogas upgrading techniques

In India, daily human activities generate large quantities of biodegradable waste. The quantities of solid and liquid organic waste produced every year amounts to 30 million tons and 4,400 cubic metres, respectively. The average municipal solid waste (MSW) generation is 0.45 kg/person/day. This easily accessible waste can be utilised as a source of energy by direct conversion into biogas that will partially offset the dependency of the country on the energy imports. The paper reviews the existing biogas potential in India and presents a comparative study of various biogas upgrading techniques. Various techniques have been rated based on different parameters like energy consumption, percentage removal of carbon dioxide (CO2), methane (CH4) losses, operating range of pressure and temperature, pumping system required, desulphurisation and possibility of regeneration. The study suggests that selection of an upgrading technique does not depend on the tropical conditions or climate of a country but more on the application, capital investment and the process parameters.

Review of the potential of biogas generation in India and a comparative study of various biogas upgrading techniques

In India, daily human activities generate large quantities of biodegradable waste. The quantities of solid and liquid organic waste produced every year amounts to 30 million tons and 4,400 cubic metres, respectively. The average municipal solid waste (MSW) generation is 0.45 kg/person/day. This easily accessible waste can be utilised as a source of energy by direct conversion into biogas that will partially offset the dependency of the country on the energy imports. The paper reviews the existing biogas potential in India and presents a comparative study of various biogas upgrading techniques. Various techniques have been rated based on different parameters like energy consumption, percentage removal of carbon dioxide (CO2), methane (CH4) losses, operating range of pressure and temperature, pumping system required, desulphurisation and possibility of regeneration. The study suggests that selection of an upgrading technique does not depend on the tropical conditions or climate of a country but more on the application, capital investment and the process parameters.

In Situ Catalytic Pyrolysis of Low-Rank Coal for the Conversion of Heavy Oils into Light Oils

Lighter tars are largely useful in chemical industries but their quantity is quite little. Catalytic cracking is applied to improve the yield of light tars during pyrolysis. Consequently, in situ upgrading technique through a MoS2 catalyst has been explored in this research work. MoS2 catalyst is useful for the conversion of high energy cost into low energy cost. The variations in coal pyrolysis tar without and with catalyst were determined. Meanwhile, the obtained tar was analyzed using simulated distillation gas chromatograph and Elemental Analyzer. Consequently, the catalyst reduced the pitch contents and increased the fraction of light tar from 50 to 60 wt.% in coal pyrolysis tar. MoS2 catalyst increased the liquid yield from 18 to 33 (wt.%, db) and decreased gas yield from 27 to 12 (wt.%, db) compared to coal without catalyst. Moreover, it increased H content and hydrogen-to-carbon ratio by 7.9 and 3.3%, respectively, and reduced the contents of nitrogen, sulphur, and oxygen elements by 8.1%, 15.2%, and 23.9%, respectively, in their produced tars compared to coal without catalyst.

A multi‐performance design method for seismic upgrading of existing RC frames by BRBs

SummaryIn the world, many existing buildings with RC framed structure were designed according to old seismic standards and present structural deficiencies. Buckling Restrained Braces (BRBs) can be effective for seismic upgrading of these structures, as pointed out by many studies. Nevertheless, Eurocode 8 (EC8) does not provide any rules for design of BRBs. This lack represents a big obstacle for application of this seismic upgrading technique in Europe. For this reason, a method for the design of seismic upgrading interventions by BRBs is proposed in this paper. The method is obtained as the best between two variants developed, investigated and compared in this paper. Based on a numerical investigation, the parameters that control the design method are calibrated to ensure the fulfillment of the Near Collapse performance objective stipulated in EC8. Finally, the capability of the proposed design method in fulfilling also performance objectives not explicitly considered in design is investigated. Copyright © 2016 John Wiley & Sons, Ltd.

The Review of Upgrading Coal Techniques in South Korea

High-rank coals are limited, while low-rank coals are abundant. However, the low-rank coals needs upgradation so as to improve their quality. If not, the utilization of low-rank coals will lead to many operational difficulties. As this study was made in South Korea, this article discusses the energy and coal scenario of South Korea. The critique discusses the concerns of utilizing low-grade coal and the need for upgrading low-grade coal. The article also briefly discusses the currently practiced low-rank coal upgradation techniques. Also, the review paper suggests some best upgradation techniques.

Experimental study of the physicochemical structure and moisture readsorption characteristics of Zhaotong lignite after hydrothermal and thermal upgrading

Hydrothermal and thermal upgrading techniques are promising coal drying methods that enable the utilization of low rank coals. In this study, Zhaotong (ZT) lignite from the Yunnan province of China was hydrothermally upgraded at 150–300°C and thermally upgraded at 200–500°C; then, the correlation between the changes in the physical and chemical structures and the moisture readsorption characteristics were investigated. The maturity of lignite was improved by the upgrading treatment. The main hydrophilic oxygen-containing groups, including hydroxyl and carboxyl, were effectively removed as the upgrading temperature increased. In addition, the removal of hydroxyl groups was more remarkable during hydrothermal upgrading. Irreversible changes occurred in the pore structure of the treated lignites; the specific surface area and total pore volume first increased and then decreased with hydrothermal upgrading, whereas the specific surface area and total pore volume continually increased with thermal upgrading as the temperature increased. In addition, the gel-like structure of the lignite experienced violent shrinkages and collapses. The moisture readsorption performance was effectively inhibited under the synergy effects of the physicochemical structure such that the moisture readsorption ratio (MRR) and moisture holding capacity (MHC) decreased continuously with the increasing upgrading temperature. An MHC model built through multiple linear regressions proved suitable to describe the moisture readsorption of the upgraded lignites.

Biogas upgrading and utilization from ICEs towards stationary molten carbonate fuel cell systems

ABSTRACTBiogas production from anaerobic digestion has increased rapidly in the last years, in many parts of the world, mainly due to its local scale disposition and to its potential on greenhouse gases (GHG) emissions mitigation. Biogas can be used as fuel for combined heat and power systems (CHP), in particular for internal combustion engines (ICEs). In recent investigations, fuel cells have been considered as alternative CHP systems. In the present article, two different energy conversion systems are compared: a 1.4 MW class MCFC system, running on pipeline natural gas, and an in situ ICE, running on biogas. In the first case, biogas is considered as a source fuel to obtain upgraded gas to be injected in the natural gas grid. In such scenario, the location of the fuel cell power plant is no longer strictly connected to the anaerobic digester site. Several energy balances are evaluated, considering different upgrading techniques and different biogas methane/carbon dioxide ratios.

Upgrading biogas by a low-temperature CO2 removal technique

Biogas, a renewable energy source, is primarily composed of methane and carbon dioxide and other gaseous species. Biogas upgrading for removing CO2 from raw biogas is a necessary step before the biogas to be used as vehicle fuel or injected into the natural gas grid. Therefore, the present work aimed to propose a low-temperature CO2 removal process as an alternative to the conventional biogas upgrading technologies (water scrubbing, chemical and physical scrubbing, membranes and Pressure swing adsorption). A typical model biogas mixture of 60mol.% CH4 and 40mol.% CO2 is considered. The present process showed that a product purity of 94.5mol.% CH4 is obtained from compressed biogas by combining distillation, flash separation, auxiliary refrigeration and internal heat recovery with a potential specific energy consumption of 0.26kWh/Nm3 raw biogas. The process has been simulated in Aspen HYSYS with avoiding the occurrence of CO2 freeze-out. The process delivers the captured CO2 in liquid form with a purity of 99.7mol.% as a by-product for transport at 110bar. It is concluded that the proposed upgrading process can serve as a new environmentally friendly approach to CO2 removal with an interesting energy-efficient alternative to the conventional upgrading techniques.

Repair and FRP Strengthening of Earthquake-Damaged RC Shallow Beam-Column Joints

Three earthquake-resistant wide beam-column joint specimens (one interior, and two exterior) which developed beam plastic hinging mechanism and beam flexural failure under large drift reversals were repaired and FRP strengthened for restoring their structural function. The repair and strengthening technique consisted of: (i) sealing the major flexural cracks that developed within the beam plastic hinge region using epoxy injection; (ii) adding carbon fiber-reinforced polymer (CFRP) reinforcement at the top and bottom faces of the beam to control the growth of the flexural cracks, boost up the beam negative and positive flexural capacities and at the same time compensate in part for the loss in the joint lateral stiffness; and (iii) providing CFRP jacket at the potential hinging regions of the columns for confining the concrete and enhancing the bond capacity of the spliced reinforcement. The effectiveness of the upgrading technique is demonstrated by comparing the performance of the upgraded joints when subjected to lateral cyclic loading against the performance of the same joints before damage. With its simplicity in application, the upgrading technique succeeded in bringing the damaged joints back into service conditions and in restoring their flexural stiffness under lateral load which degraded due to large drift reversals.

Efficiency Upgrading Techniques of Diesel Engine Start-Up Process Analysis

This paper deals with the research aimed at the efficiency upgrading techniques of start-up process of the diesel engines of shunt locomotives. The application features are indicated and methods of reliable start of the diesel engines with using of the supercapacitors are developed. The issues of reliability and lifetime of the supercapacitors stacks in start-up systems improvement are considered. The mathematical and simulation modelsare developed, changing of current - and speed-time curve charts are also presented.

Energy Analysis of Different Municipal Sewage Sludge-derived Biogas Upgrading Techniques

Energy Analysis of Different Municipal Sewage Sludge-derived Biogas Upgrading Techniques

Global and initiative safety mechanism in industrial control system

With the development of information technology and industrial automation, industrial control systems have become increasingly complicated which increases the difficulty to detect running errors. Errors usually lead to industry incidences, which in turn threaten civil property and even national economy. In this paper, we propose a novel safety mechanism based on data mining. Complex network analysis, data prediction, expert analysis and self-adaptive downgrade and upgrade techniques are also applied to solve safety problems in industrial control systems. To protect industrial control system, we define a safety protection status. The system can be switched into protection status by specific operations, which finally transfer the system back to safe status. Using data mining techniques, we propose a general safety mechanism which has four operations, including global safety, initiative safety, real-time safety, and self safety.

Techno-economic Analysis of Hybrid Processes for Biogas Upgrading

Biogas upgrading is one piece in the framework of future energy supply. Commonly absorption and adsorption technology is applied for biogas upgrading where CO2, H2S, and water vapor have to be removed from CH4. Gas permeation technology offers an interesting alternative to conventional upgrading techniques. Combining gas permeation membranes and conventional separation equipment in membrane hybrid processes merges the advantages of both technologies. Hence, we analyze seven different membrane hybrid processes for biogas upgrading. A single gas permeation stage is combined with pressurized water scrubbing, amine absorption, cryogenic separation, and a particular process in which the permeate of the gas permeation stage drives a gas engine. Furthermore, we compare the specific upgrading costs to an individual three stage membrane process as well as to conventional separation processes. Simulation studies were performed in Aspen Plus to rigorously model the different hybrid process configurations. A full cos...

Pathways of lignocellulosic biomass conversion to renewable fuels

The increased worldwide demand for energy, particularly from petroleum-derived fuels has led to the search for a long-term solution of a reliable source of clean energy. Lignocellulosic biomasses appear to hold the key for a continuous supply of renewable fuels without compromising with the increasing energy needs. However, the major possible solutions to the current energy crisis include ethanol, bio-oils and synthesis gas (syngas) produced from lignocellulosic biomass. Recently, a great deal of research has been made in the fields of biomass conversion through biochemical, hydrothermal or thermochemical pathways to biofuels. However, a broad-spectrum assessment of the above pathways is rare in literature in terms of technology used, biofuel yields, potential challenges and possible outcomes. This review paper discusses different routes for biofuel production, particularly ethanol, bio-oil and syngas with the bio-oil upgrading techniques. This review highlights ethanol fermentation and available biomass pretreatment as the biochemical mode, not limiting to the pros and cons of the pretreatments. Supercritical water gasification (hydrothermal pathway) of biomass for syngas production followed by gas-to-liquid technologies (syngas fermentation and Fischer–Tropsch catalysis) has been discussed. In addition, thermochemical pathway dealing with biomass gasification for syngas and pyrolysis for bio-oils has been presented with compositional analysis of bio-oils and their upgrading technologies. The review focuses on various engineering limitations encountered during biomass conversion and bioprocessing with the potential solutions which do not restrict them to different biofuel production pathways.

Biogas Upgrading Techniques: State of Art Review in European Region

Upgrading biogas to high energy biomethane is commonly utilized to produce SNG (substitute natural gas used for injecting into grid) and/or CNG (compressed natural gas employed as a fuel in transportation). In this process the most crucial operation is a separation of CO2 from biogas, which is carried out by technology based on unit operations like absorption or permeation. Aim of this text is to introduce state of art in development of these technologies within European region: assess their pros and cons in order to alleviate orientation in this issue and point out research tendencies. There were chosen three aspects for the assessment: (1) process-technology, (2) energy-economy and (3) environmental impact. The review is based on research of studies, reports and other informational sources that come from the work of some research institutions and engineering companies. From process-technology perspective specifications like methane purity and flow rate range were evaluated. Aspect regarding energy and economy is mainly focused on assessment of consistency of available data and on utilization of the data for comparative analysis of given technology. From environmental point of view there was considered an important specification called methane losses.The review clearly suggests that in European region the highest share refers to water scrubbing technology which is followed by PSA method and chemical absorption. All kinds of absorption technology (water scrubbing, absorption with chemical or physical solvents) seem to be well established and conventional. On the other hand PSA method and especially membrane technology offer progressive research potential.