Gasification Process Development Research Articles

Aspen Plus model of a downdraft gasifier for lignocellulosic biomass adjusted by Principal Component Analysis

The development and improvement of biomass gasification processes have been accelerated by the use of computational tools for process simulation, exploring their feasibility under different conditions and identifying key parameters that are validated through real experiments, contributing to maturing a gasification technology from laboratory to commercial scale. This work presents an Aspen Plus model of a small-scale downdraft gasifier using biomasses with different elemental and proximate analyses, combining stoichiometric and non-stoichiometric equilibrium approaches. The pyrolysis, oxidation, and reduction processes in the proposed model were separated into distinct steps, with the first one based on Gibbs energy minimization and the latter based on stoichiometric equilibrium models. A representative tar composition, with a production ratio to gas production based on literature, was considered as an input parameter to the model. The obtained data were analyzed using principal component analysis (PCA) to investigate the relations between equivalence ratio (ER), fixed carbon and volatile material ratio FCMV, the CO conversion through methanation (Mconv), carbon conversion via hydrogasification (Hconv), and the mean residual sum of square MRSS. The most significant results obtained from this study include the successful adjustment of the model to represent the gasification of different biomasses, particularly in correcting the H2 and CH4 concentrations. Notably, the adjustment resulted in a substantial reduction of the MRSS deviation from an average of 94.7% to an average of 7.2% concerning reported results in the literature. These findings demonstrate the accuracy of the model in simulating the gasification process and highlight the importance of considering CH4 reactions adjustment for more reliable predictions. The achieved adjustments are valuable insights for advancing gasification technology towards engineering applications.

Modelling of Refuse-Derived Fuel Gasification Reactor

Landfilled municipal solid waste (MSW) emits significant quantities of greenhouse gases (GHG). The gasification process can reduce not only the amount of deposited waste, but also the amount of methane (CH4) emitted by landfills. With development of gasification processes, it is possible to chemically convert the waste into useful products, synthesis gas. This energy carrier can be used to generate electricity and produce other valuable materials such as hydrogen, methanol, etc. The raw material of gasification technology is the refused-derived fuel (RDF), which is the non-recyclable part of the MSW. Pyrolytic, oxidation and reduction processes can be separated in the downdraft moving bed reactor type.The aim of this work is to study the model and the reactions of the pyrolysis and oxidation zone and to investigate whether the model of oxidation zone can be integrated into the model of pyrolysis zone to reduce the computational capacity requirements. RDF pellet sample was milled, and representative samples were studied by thermogravimetric (TG). The kinetic parameters of the reactions were identified. The applied kinetic model can be used to calculate the mass of the produced gas, and a model suitable for determining the gas composition was added. The gas composition was estimated based on the mass balance of the elements. In the first approach, the composition and amount of gas obtained during the simulation of the pyrolysis zone was the raw material of the oxidation zone, then the composition of gas was calculated based on partial oxidation reactions. In the other approach, the gas composition was determined in one step. Both methods provided close to identical composition while the time of computation was almost the same. The biggest relative error in mass balance of the elements was 11.19 % in case of Approach 1 and it was less than 3 % in case of Approach 2.

Analysis of the role of Cu for improving the reactivity of Cu-modified Fe2O3 oxygen carriers in the chemical looping gasification process with coal

The design and optimization of high-performance oxygen carriers (OCs) are the key to the industrialization of chemical looping gasification processes. The addition of Cu to Fe-based OCs has been demonstrated to improve their reaction performance. However, the operative mechanisms behind this improvement, which must be understood for making accurate predictions and designing optimum Fe-Cu composite OCs, remain poorly understood. The present work addresses this issue by systematically investigating the gasification reactivity of Cu-modified Fe2O3 OCs with molar ratios of CuO/Fe2O3 in the range of 0.2–1.8 fabricated by mechanical mixing and calcination. The obtained Cu-modified Fe2O3 OCs are characterized by an array of methods, and employed in a fluidized bed reactor for conducting chemical looping gasification experiments with coal. The results indicate that the replacement of Fe with Cu atoms in the Fe2O3 lattice, resulting in the formation of CuxFe3-xO4, is the key feature in the improved reaction performance of Cu-modified Fe2O3 OCs. The effect of introducing Cu into the Fe2O3 OCs on the H2-OC reduction reaction is analyzed computationally from a molecular perspective based on density functional theory. The introduction of Cu is thereby demonstrated to improve the reactivity of Fe2O3 fundamentally by altering the reaction pathway of Fe2O3 and decreasing the reaction energy barrier between H2 molecules and the OC. This understanding of the mechanisms by which Cu affects the reactivity of Cu-modified Fe2O3 OCs provides significant support for the controllable preparation of highly active OCs, and thereby facilitates the industrial development of chemical looping gasification processes.

Circulating fluidized bed gasification of solid recovered fuels - Results from gasification and gas filtration tests

Fluidized bed gasification technology offers an attractive way to use inhomogeneous biomass residues and various waste-derived feedstocks in power and heat production as well as in various circular economy concepts based on the synthesis gas route. A fluidized bed gasification process development (PDU) plant of 200 kW capacity was operated with Solid Recovered Fuels (SRFs) and demolition wood. In part of the tests carried out with SRF, deposits were formed in the gas lines, and the pressure drop of the filter increased as well. However, optimal combination of gasification, gas cooling and filtration conditions were found to achieve a stable pressure drop, avoid deposit formation and to achieve efficient removal of gas contaminants. The effects of the operating conditions on the achieved carbon conversion and formation of tars and other gas contaminants were studied. The produced gas was filtered at 370-500 °C using two alternative filtration systems applying ceramic bag filters or ceramic fiber filters. The removal efficiency of waste-derived trace metals and chlorine was determined at different filtration temperatures.

PERSPECTIVE DIRECTIONS OF GASIFICATION OF THE REPUBLIC OF TUVA

Based on the analysis of the current situatim with gas supply in the Republic of Tuva (low gas supply to the population, lask of gas based heat generation), the article duscusses possible ways to solve the problem of gas supply to cites, towns and rural settlements of the republic in line with current trends in the development of gasification processes in the regions of Russia. The gas requirements of all categories of consumers: the population, heat generation enterprises, social and household spheres in the region are estimated. The prospects for gas supply in the centext of solving envitonmentae problems are to reduce air pollution in cities and towns. The directions of solving the problem of gasification of Tuva in the long term are substantiated, also considered option for transferring the economy of republic to the main gas supply, construction of an oil product pipeline are considered.
 The following effective ways to increase the level of gasification in Tuva are identified: the realization of the potential for gas production from coal deposits, the use of thermal energy from an underground fire and the development of autonomous gasification, which can be carried out during stage I of gasification. At the second stage, it is possible to transfer the economy and social sphere to the main gas supply though the construction of Tuva gas pipeline or the oil product pipeline.

Low-rank coal gasification using a bubbling fluidized bed reactor at low operating temperature

Coal gasification is one of coal utilizations that produces less CO2 emission than coal combustion. Coal gasification technology that has been used in Indonesia is generally a fixed bed gasification. Fixed bed is designed for high-rank coal and the majority of Indonesian coal is of a low-rank. Low ash and high moisture content of the Indonesian coal in a fixed bed can affect mechanical and thermal fragmentation, pressure drop, gas and particle flow distribution. The operation of gasifier may cause unstable condition. Another gasification technology is bubbling fluidized bed, which is operated above 1,200°C, so ash can melt. High operating temperature causes agglomeration and makes unstable gasification process. Therefore, in this study, low-rank coal is gasified in bubbling fluidized bed reactor at low operating temperature. The purpose of this study is to determine the optimal conditions of bubbling fluidized bed gasification. The research was conducted in bubbling fluidized bed coal gasification Process Development Unit (PDU) at Coal Utilization Technology Centre of R&D Centre of tekMIRA, Palimanan. Coal was fed continuously as many as 20 kg/hour into a gasifier then was gasified to produce gas using air as a gasifying agent and silica sand as a bed material at 850- 950°C. The produced gas from the gasification was analyzed using the Orsat Analyzer. A simulation using a ChemCAD 7.1 CC steady state was applied to validate the experiment result. From the analyzed result of yield gas composition, the produced CO and CO2 were about 10-15 wt%. Gas compositions that are close to criteria of producer gas, no agglomeration, and stable process condition during study indicate that bubbling fluidized bed gasification at low operating temperature is suitable to be applied as gasification technology for Indonesian low-rank coal.

Bio-syngas production from agro-industrial biomass residues by steam gasification

This study evaluated the steam gasification potential of three residues from Brazilian agro-industry by assessing their reaction kinetics and syngas production at temperatures from 650 to 850°C and a steam partial pressure range of 0.05 to 0.3bar. The transition temperature between kinetic control and diffusion control regimes was identified. Prior to the gasification tests, the raw biomasses, namely apple pomace, spent coffee grounds and sawdust, were pyrolyzed in a fixed-bed quartz tubular reactor under controlled conditions. Gasification tests were performed isothermally in a magnetic suspension thermobalance and the reaction products were analyzed by a gas chromatograph with TCD/FID detectors. According to the characterization results, the samples presented higher carbon and lower volatile matter contents than the biomasses. Nevertheless, all of the materials had high calorific value. Syngas production was influenced by both temperature and steam partial pressure. Higher concentrations of H2 and CO were found in the conversion range of 50–80% and higher concentrations of CO2 in conversions around 10%, for all the gasified biochars. The H2/CO decreased with increasing temperature, mainly in kinetic control regime, in the lower temperature range. The results indicate the gasification potential of Brazilian biomass residues and are an initial and important step in the development of gasification processes in Brazil.

Experimental investigations with a modified briquetting press as feeding system for brown coal into pressurized gasifiers

The development of gasification processes with higher operating pressures in order to increase the gasification process throughput and to avoid the densification of the syngas for the following processes requires also the design or adaptation of feeding systems to the new demanding process conditions. One of the most important requirements is the realization of a continuous lock-free and gas tight operation mode. The basic suitability of a briquetting press as an alternative feeding system has been studied within the framework of fundamental research on the test rig, which simulates the principle of the briquetting press with an open press channel. In the scope of preliminary investigations, the influence of briquetting parameters on the gas tightness of a briquette plug and the optimum press channel geometry for different types of coal were studied. Based on these fundamental research results, the modification of a briquetting press was made. The systematic investigations with a modified briquetting press on optimization of the operating parameters were carried out in order to ensure a stable briquetting pressure profile. This is a prerequisite for the sealing of the press channel between feeding system and pressurized gasifier. For the experimental simulation of the pressurized gasifier a pressure vessel with a volume about 250l and a maximum operating pressure of 65bar was constructed and built. In the feeding experiments, a stable continuous lock-free feeding against a gas pressure of 65bar could be realized and therefore the feasibility of the developed technical solution was successfully demonstrated.

The Deutsches EnergieRohstoff-Zentrum Freiberg: advanced prospects for applied organic petrology, focused on the generation of coal based chemical products

The Deutsches EnergieRohstoff-Zentrum Freiberg (DER) is a strategic partnership between government, science and industry to develop innovative concepts and technologies for the peak and post oil era. Researchers and practitioners collaborate to develop technical innovations to make the energy sources coal and biomass sustainable and future-oriented. The centre addresses the issues of energy supply, security and sustainability through research into the non-energetic utilisation of coal, where coal is not simply burnt to produce energy, but used as raw material in production processes for chemicals, especially hydrocarbons. Therefore, DER engages in the development of innovative gasification and hydrogenation processes, as bridging technology between conventional fossil energy sources and renewables. The intention of the DER is to achieve technological leadership in the field of non-energetic coal utilisation, and to develop the institution into an international centre of excellence in R&D for the utilisation of coal and recent biomass.

Gasification Performance of Australian Lignites in a Pressurized Fluidized Bed Gasifier Process Development Unit Under Air and Oxygen-enriched Air Blown Conditions

This paper discusses the gasification performance of a number of Australian lignites in a high temperature winkler (HTW) gasification process development unit (PDU) capable of running at a pressure, temperature, and feed rate of 10 bar, 1000°C, and 250 kg h−1 respectively. The fuels include three Victorian lignites, one South Australian lignite, and a char derived from a Victorian lignite. All fuels were pre-dried to less than 20% moisture content. The tests were of 3–32 h duration. The majority of the tests were conducted at 8 bar(g) pressure, 125–240 kg h−1 feed rate, 750–920°C average bed temperature, and involved steam and air or steam and oxygen-enriched air as reactants for gasification. Carbon conversion ranged between 70-87%, with further improvement limited by elutriation of carbon-rich fines originating from a large fraction of fine particles present in the feed, and brittle nature of these lignites which generate fines through attrition. An acceptable calorific value of 4 MJ kg−1 of the fuel gas has been attained. An assessment of the reasons and the extent of loss of char through elutriation has been investigated through tests in a 1:1 scale cold model and characterization of the char.

Research on black-liquor conversion at the technical research centre of Finland

A broad programme of research and development on black-liquor gasification is being undertaken in Finland. The central activity in the programme consists of gasification experiments on a pressurized test facility, designed, built, and operated by the Technical Research Centre of Finland (VTT). The facility has played an important role in the process-development work being carried out in both the public and private sectors. Supporting activities in which VTT has been involved include laboratory-scale experiments, theoretical investigations, and system studies. Through these activities, significant contributions to the over-all process-development effort have been made. In fact, most of the basic data necessary for the present stage of development of black-liquor gasification processes have now been generated.

In-Situ Desulfurization in a Fluidized-Bed Coal Gasifier

Abstract A high-pressure coal gasification process development unit (PDU) has been used by the Institute of Gas Technology to study in-sim desulfurization in an ash-agglomerating, fluidiied-bed coal gasifier at elevated pressures. Previous work in this area has been limited to pressures up to about 225 psig. The current work extends this pressure range to 400 psig, well within the pressure range of the combustion turbines now being considered for application in integrated gasification combined cycle (IGCC) power plants. The coal used in this study was Pittsburgh No. 8 bituminous coal, and the sorbent used was New Enterprise limestone. Data were collected and analyzed to determine the effects of gasifier pressure and temperature on sulfur capture within the fluidized bed. The optimum temperature for maximum sulfur removal was determined as a function of the partial pressure of CO2 in the fluidized bed.

Gasifier development in France

From 1979 to 1987, the development of wood and biomass gasification processes in view of supplying fuel substitutes for road transport and for low-output electrical generators was assisted by the French Public Agencies for the development of solar energy (COMES) and for energy management (AFME). The different techniques developed at research and demonstration levels are given here, followed by a list and analysis of the main obstacles and key factors in the development of gasifier technology, as observed in over 30 different installations. Further demonstration programmes are needed in order to test equipment reliability and to define infrastructure requirements, before these products can be widely distributed.

Synchronous Luminescence Screening for Polynuclear Aromatic Compounds in Environmental Samples Collected at a Coal Gasification Process Development Unit

An evaluation of the synchronous luminescence screening technique for rapid analysis of environmental samples is described. Synchronous luminescence is employed to estimate the content of polynuclear aromatic species of product gas particulate samples, and the content in aqueous and solid waste samples collected at a coal gasification process development unit. The synchronous luminescence technique shows good agreement with results obtained by detailed gas chromatography/mass spectrometry and high-performance liquid chromatography.

Synchronous Luminescence Screening for Polynuclear Aromatic Compounds in Environmental Samples Collected at a Coal Gasification Process Development Unit

An evaluation of the synchronous luminescence screening technique for rapid analysis of environmental samples is described. Synchronous luminescence is employed to estimate the content of polynuclear aromatic species of product gas particulate samples, and the content in aqueous and solid waste samples collected at a coal gasification process development unit. The synchronous luminescence technique shows good agreement with results obtained by detailed gas chromatography/mass spectrometry and high-performance liquid chromatography.

Corrosion of FeCrAl , FeCrAlY , and FeCrAlHf Alloys in High Temperature H 2 ‐ H 2 O ‐ H 2 S Environments

not Available.

Possibilities and state of development of nuclear coal gasification processes

By the development work of the last years and the successful operation of a experimental reactor it is clear today that the high temperature reactor is capable to produce heat at a temperature level of 950° C. This heat can be used in different industrial processes, especially for coal gasification. The processes of hydrogasification and steam gasification have been tested in large pilot plants in the past and are thought to be feasible today in connection with use of nuclear energy. In this paper the main aspects of these processes, of the nuclear reactor and of the heat exchanger system are presented and discussed. Questions like the choice and qualification of high temperature materials, the tritium contamination of the product gas and the aspects of licensing are key points of the technical realisation of nuclear process heat applications. This paper tries to summarize some of these results of the development programm of the PNP-Project (Prototyp Nukleare Prozeβwärme) in Germany, which is a common Projekt of German Companies financed by the government.

Zum Stand der Kohlevergasung

AbstractGasification of coal – a status report. On the basis of industrially available conventional coal gasification processes (Winkler, Koppers‐Totzek, and Lurgi pressure gasification) the paper describes developmental trends in such processes. Elevated operating pressure is a common feature of all new processes, thus opening up new applications. An economic incentive to the development of new gasification processes also comes from combinations with new technologies, e. g. with direct reduction. Moreover, an advanced version of the high‐temperature Winkler process is described and evaluated in comparison with conventional commercial processes. Apart from processes conducted above ground, recent developments also include thoughts about underground gasification.

Development of the HYGAS Process for Converting Coal to Synthetic Pipeline Gas

A process for converting coal to synthetic pipeline-quality gas is in the final stage of development. A large pilot plant with a daily capacity of 80 tons of coal feed and 1.5 MMcf of gas product is now in operation. Three methods of generating hydrogen from coal char are being developed and will be tested with the HYGAS process, with the goal of establishing commercial operation by 1980. Introduction The development of the HYGAS process at the Institute of Gas Technology (IGT) has been a continuous effort since 1946. The need for pipeline-quality gas from coal to supplement pipeline-quality gas from coal to supplement a projected shortage of natural gas was long forecast by IGT and others as being inevitable in the face of a continuing 5 to 6 percent annual increase in demand for natural gas. Despite this, even recently researchers had to defend the need for coal gasification. However, in the last 2 years, the projected shortage etched an indelible mark on the consciousness of both the public and private sectors when the annual discovery rate of gas fell far short of our past additions to reserves. The "energy crunch" for natural gas is now being realized by all - so much so that the development of coal gasification processes no longer needs justification, but only processes no longer needs justification, but only immediate commercialization. Unfortunately, an industry for converting pipeline gas from coal cannot be established at will. To comprehend the sheer magnitude of such an industry we must realize that just to supply by coal gasification the incremental annual demand of about 1 Tcf/year would require an investment of about $2 billion and the development of more than 1 billion tons of coal deposit for an annual production of 50 million tons of coal. With these factors in mind, we shall discuss the status of HYGAS process development. Chronology Work on the HYGAS process began in 1946 and continued under the sole sponsorship of the American Gas Association (AGA) until 1964. During this period much work was done on the fundamentals of reaction kinetics, process yields, and the incorporation of several key process innovations. Experiments went from bench-scale batch studies to small continuous units at high temperatures and pressures that could handle throughputs of about 10 pressures that could handle throughputs of about 10 lb of coal feed per hour. In 1964 the U.S. Dept. of the Interior, of Office of Coal Research (OCR), joined AGA as co-sponsors in a 3-year program that ended with a preliminary design for a large HYGAS pilot plant. During this period, effort was pilot plant. During this period, effort was concentrated on the testing of different types of coal from the U.S. and on defining suitable operating conditions for each type of coal. Most of the work was done in units having, a throughput up to 100 lb of coal feed per hour. In 1967 the contract with OCR was amended to cover the engineering, construction, and operation of the HYGAS pilot plant. Out of this phase of the program will come the necessary scale-up phase of the program will come the necessary scale-up data for a demonstration plant. During, the construction phase, OCR provided the bulk of the funding. In 1971, phase, OCR provided the bulk of the funding. In 1971, the federal government and the gas industry started a joint program, administered by OCR and AGA, to accelerate the development of coal gasification through the demonstration plant stage. Funding is two-thirds by government and one-third by industry. Process Features Process Features There are two key features in the HYGAS process that should be clearly understood. JPT P. 1407

Trends in the Gasification of Light Petroleum Distillate in Europe.

Recently in Europe, the surplus of Light Petroleum Distillate has promoted its utilzation as a major raw material for Gas production, which, incidentally, made various new Gasification processes developed.In May, 1965, the authors had the priviledge of attending the 102nd General Meeting of the Institution of Gas Engineers held at Solihull, England. After the meeting the authors had an opportiunity of investigating the aspects on development of Gasification Processes in Europe for a month.This paper describes the development Process and the outlined feature of various processes which performed or are in developing stage, entitled “Trends for Gosification of light petroleum distillate in Europe, ” besides what Gasification process should be relating to the changing Situation of feedstocks in Europe in future on the basis of the information obtained through the observation.