Carbon Sequestration in Gasification Cycles
Development of Technology for Cleaning of Generator Gas Produced in Gasification of Coal and Coal Containing Materials
Tech Area / Field
- ENV-APC/Air Pollution and Control/Environment
- NNE-EPP/Electric Power Production/Non-Nuclear Energy
- NNE-FCN/Fuel Conversion/Non-Nuclear Energy
3 Approved without Funding
Keldysh Research Center, Russia, Moscow
- Institute of Oil and Gas Problems, Russia, Sakha (Yakutiya), Yakutsk
- General Electric Company / Energy and Environmental Research Corporation, USA, CA, Irvine\nIPHT-Jena / Institut für Physicalishe Hochtechnologie e.v., Germany, Jena\nNational Institute for Resources and Environment, Japan, Ibaraki
Project summaryThe Project’s objective is the development of technologies of environmentally safe and efficient use of various-type coals with the low-level emission of harmful substances and carbon dioxide, and their safe joint burial. This can be achieved in the course of the evolution of power engineering in the conditions of tough limitations for greenhouse gas and harmful substance emissions caused by man’s activity.
The urgency of the problems to be solved during the project execution is determined by certain limitations for carbon dioxide emissions into the atmosphere; stabilisation and even certain reduction, in the nearest decade, in natural gas consumption on the internal market; and essential reduction in liquid fuel production for power generation. Further increase in power generation in Russia can only be promoted by broad use of coal resources including local low-grade coal resources.
The main idea of the solution suggested in this project is to use combined cycles with the integrated coal gasification, combustible gas cleanup simultaneously of carbon dioxide, hydrogen sulphide, and other sulphur-bear products on the basis of a new technology developed within the framework of this project, the technology of those gases’ conversion into nonstoichiometric clatrate water (gas hydrates) compounds and their persion in the form of gas hydrates from the combustible gas composition with a subsequent carbon dioxide and hydrogen sulphide burial in the underground or bed sediments, and also in the form of gas hydrates.
The basis of the project is the development of a new technology of cleaning the combustible gases generated from coal gasification by way of creating in the entrained flow of thermodynamic conditions for the formation of non-stoichiometric clathrate compounds of water with carbon dioxide and sulphur-bearing products (gas hydrates) and perting of generated mixed gas hydrates from the cleaned combustible gas flow. It is presumed that the employment of the above gas-cleaning technology as a component of combined cycles with the integrated steam-and-aerial gasification will make it possible to cut capital costs on creating large-scale power-generating plants by not less than 21%, and the cost of the energy generated, by not less than 40%.
To attain the project’s objectives, the following technical approaches to solving the project’s specific problems are used.
– As concerns the development of a technology of cleaning the combustible gas from carbon dioxide and sulphur-bearing products, we suggest a method of isolating those products in the form of gas hydrates in the adiabatic expansion of combustible gas flow. Experimental and theoretical studies are planned into thermal, gas, and dynamic parameters of gas hydrate formation in the flow, the degree to which the combustible gas is cleaned, the methods and conditions of gas hydrate isolation from the combustible gas flow within the range of hydrate-generating gas concentrations in the combustible gas, and also studies into the processes of the dissociation of mixed gas hydrates of carbon dioxide and other products, and preparing them for disposal, depending on the coal type and its gasification method. Optimization of the technological procedures of cleaning gases generated from gasification of typical gases is envisaged using the complex of the pilot equipment being created, having the capacity, by the combustible gas, of about 100 g/s.
– As concerns the work on coal gasification, experimental studies are planned using laboratory and pilot equipment in 2 directions of the processes’ organization: steam-and-aerial dry-ash gasification of lump coal in a dense bed and gasification of water-and-coal suspensions in an air flow. Studies will be conducted into thermal and gas parameters, the composition and parameters of the combustible gas generated depending on the gasification pressure level (below 7.5 MPa) and the air and water discharge ratio, and also the level of air enrichment with oxygen (below 40%). Employment of various types of gasification ensures, on the one hand, a study into combustible gas cleaning technologies within a wide range of change in its composition and the inpidual component content, and, on the other hand, using for gasification of various coal types. The work implies the use of the previously created pilot plant for lump coal gasification in a dense moving bed and the creation of a corresponding pilot plant for aerial gasification of water-coal suspensions.
– As concerns the development of basic technical solutions for a safe underground burial of carbon dioxide, calculations and experimental studies are planned into the conditions of the formation of carbon dioxide’s gas hydrates and mixed gas hydrates in porous media, simulating layered conditions. Analysis will be conducted of most favourable conditions for a stable formation of a gas-hydrate deposit and a safe and lasting storage of carbon dioxide in a sedimentary rock mass in the gas-hydrate form, and of the technological schemes of preparing, transport, and feeding through the well system for the underground burial of carbon dioxide and other gases isolated in the process of combustible gas cleaning.
The project’s end results are:
– A technology of a joint gas-hydrate purification of combustible gases from carbon dioxide and sulphur-bearing gases aimed to be used as a component of combined cycles with the integrated coal gasification.
– A complex of pilot equipment having the thermal capacity of about 1 MW which includes: 2 alternative pilot plants of steam-and-aerial dry-ash coal gasification in a dense moving bed and an aerial gasification of water-coal suspension in an entrained flow; the equipment ensuring thermal-gas-and-dynamic conditions required for hydrate formation in combustible gas flow; a plant for cleaning combustible gases from carbon dioxide, sulphur-bearing and other components with a subsequent perting them from the process in the form of mixed gas hydrates and the localization; a device for burning of the cleaned combustible gas in the conditions simulating the combustion chamber of a power-generating aggregate.
– A complex of technical solutions of preparing the products isolated in the process of cleaning for burial, their haulage to the burial site, and formation of those products’ gas-hydrate deposit, ensuring the safety of the underground burial.
– A technical and economic analysis of the parameters of large-scale plants actualizing the complex of the given technologies as applied to the peculiarities and climatic conditions of Russia’s regions, including a comparative analysis of the proposed solutions’ efficiency.
Role of Foreign Collaborators:
– Discussions and information exchange aimed to specify the principal technological solution, technical concepts for the technology components, the work programme, methods, measurement tools, and investigation results.
– Specifying and co-ordination of requirements for parameters affecting environmental safety of inpidual processes and the entire process scheme.
– Joint analysis of the features of the process scheme and technical and economic efficiency of large power plants; development of recommendations for selection of basic equipment; and materialisation of the programme of commercialisation of work results.
– Participating in the technical monitoring of the activities under the project performed by ISTC workers.
– Organization of joint conferences and workshops.
– Presenting commentaries to the technical reports submitted by project participants to ISTC.