Overview

The Solvent-based Carbon Capture Plant (SCCP) enables the development, evaluation and optimisation of a variety of solvents for post-combustion capture and related technologies. It is designed to remove up to 1 tonne/day of CO2 (based on MEA) from an equivalent of approximately 150kW conventional coal combustion flue gas. The plant incorporates 8m absorber and a cleaned flue gas wash column, re-boiler, desorber column and a condenser on top of the column, and fresh and spent solvent tanks.  The absorber and desorber columns are equipped with temperature and differential pressure sensors, solvent sampling ports, provisions for corrosion coupons and alternative materials test sites, and trace gas injection capability. The plant also has an integrated flue gas desulphurisation carbonate wash system. It is controlled and monitored through a dedicated control system.

The plant is connected directly to PACT combustion facilities: the 250kW Air Combustion Plant and the 300kW Gas Turbine System, enabling post-combustion capture research from real flue gases from natural gas power plants as well as pulverised fuel combustion plants including coal, biomass and co-firing. The facility is also connected to a dedicated gas mixing facility enabling carbon capture from any synthesised  flue gas compositions, including industrial effluent gas mixtures.
 

Example applications

The facility provides an opportunity to learn from design, build and operation, screen and compare CO2 capture solvents, and generate data for desktop and modelling studies. Through the integration with the Gas Mixing Facility and combustion facilities (250kW Air Combustion Plant and 300kW Gas Turbines), the plant allows R&D with real flue gases from pulverised fuel (coal/biomass/co-firing) combustion, natural gas plants and (synthesised) flue gases from industrial installations. Example test programmes that can be carried out on the rig include:

  • Benchmarking of solvents and comparison of energy requirements for range of solvents (MEA reference tests with heat and material balances and parametric studies)
  • Testing and development of alternative solvents eg. MDEA, hindered amines and blends
  • Development of bespoke capture solutions for particular power plant or industrial installations
  • Validation of baseline economics and assessment of plant flexibility
  • Investigating capture system performance with flue gas variability from different combustion systems, conditions and/or  fuels including biomass
  • Solvent assessment, including ‘real’ aged solvents
  • Development of detailed mechanisms for solvent degradation to inform enhancement strategies 
  • Research to improve control methods for capture systems on power plants and methods to optimise the level of CO2 capture.
  • Integrated system modelling for a variety of combustion and capture systems

System description

The plant is built over a 3 level platform structure with over 11m total height and incorporates 8m absorber and desorbed columns, re-boiler for solvent regeneration, fresh and spent solvent tanks, and a cleaned flue gas washing system on the absorber column and a condenser on the desorbed column.  The absorber and desorber columns are equipped with solvent sampling ports, provisions for corrosion coupons and alternative materials test sites, and trace gas injection capability. The plant also has an integrated flue gas desulphurisation and clean up (carbonate and water wash) system.

For amine type solvents the flue gas from the 250kW Air Combustion Plant (ACP) / Gas Turbine (GT)  system is passed through a Flue Gas Desulphurisation (FGD) Unit (a) for treatment. Fan (b) drives the gas through the plant. The flue gas then passes up through the absorber column (c) where the amine solution (d) mixes with it. A by-pass is fitted around the FGD unit enabling flue gases from the GT or the for synthetic gas mixtures from the Gas Mixing Facility (GMF) to pass directly to the absorber column. The Carbon Dioxide in the flue gas is absorbed into the amine solution, and is bound by a weak chemical reaction. The treated flue gas, which is mainly nitrogen and water vapour, leaves the top of the absorber, and goes thro ugh a clean-up stage (g) to remove traces of amine before being released. The amine solution (e) leaves the bottom of the absorber and is pumped through a heat exchanger (f) into the desorber (h). In this vessel heat is applied at the bottom (j). This breaks the chemical bond between the amine and the carbon dioxide. A stream of pure carbon dioxide leaves the top of the desorber and the regenerated amine solution is recycled back to the absorber. Water is removed from the carbon dioxide in the condenser (i) and the carbon dioxide that is removed can be disposed of safely.

Specification

The facility comprises adsorption and desorption columns as shown on the adjacent picture; a fresh amine storage tank and a spent amine tank; and an electric boiler providing steam for regeneration of the solvent and heat for general plant maintenance in idle state.

  • Amine solution circulation rate of 1 m3/h
  • Absorber: 300mm diameter, 8m overall height
  • Desorber: 300mm diameter, 8m overall height
  • Flue gas treated: 230 m3/h (263 kg/h)
  • Carbon dioxide removable: up to 50 kg/h with MEA
  • Removes 1 tonne of CO2 per day using MEA (>85% capture)
  • Treating flue gas equivalent to 150kW
  • Extended test periods using direct connection to GMF
  • 0.07MWe consumption (50kg/h CO2)
  • Multiple solvent sampling locations all along the columns
  • Provisions for corrosion coupons and alternative materials test sites
  • Trace gas injection capability
  • Use with coal or biomass co-firing in air or O2/CO2
  • Dedicated control system
  • Integrated Flue gas desulphurisation and clean-up using carbonate and water wash

 

 

Analytical capability

  • Gas analyser system for CO2 NOx, SOx, ammonia
  • Temperature control and monitoring on the system and columns
  • Pressure monitoring on the system and columns
  • Sampling points along the absorber and desorbed column
  • Analytical labs to enable analysis of solvent characteristics and degraded solvents