DECIPHER – De-risking CO2 capture at pilot scale at HVC bioenergy plant in Alkmaar

Publieke samenvatting / Public summary

HVC is running a carbon capture pilot unit (0,54 tonCO2/h) on the flue gas of its biomass energy plant which combusts demolition wood. The solvent of choice for the pilot is an aqueous blend of 40% methyldiethanolamine (MDEA) and 10% piperazine (PZ). This system is representative of many second-generation (2G) solvents. In the DECIPHER project, HVC and TNO will monitor the solvent quality and process emissions in a long-term campaign (3 years). The knowledge will be used to de-risk the operation of HVC's full scale demonstration plant (15 tonCO2/h), to be operational by 2022. Furthermore, a third-generation (3G) water lean solvent will be tested in DECIPHER. This test will be carried out at TNO's lab scale plant (1 kgCO2/h) and, based on the results, a decision will be taken whether to run a campaign at HVC's pilot. Water-lean solvents are promising, as they can lead to lower energy consumption, and therefore reduce the overall CO2 capture cost, but aspects such as emissions and degradation are knowledge gaps yet to be investigated.

The DECIPHER project aims at evaluating the overall costs and environmental impacts of CO2 capture solvents. This is done by measuring the process emissions as well as monitoring the solvents quality in long-term operation. It is well-established that solvent degradation and emissions are connected both to the nature of the solvent, the process conditions, and the flue gas itself. The use of MDEA/PZ solvent in a WtE plant is novel, and in particular with flue gas from a demolition wood biomass energy plant. Therefore, a long-term campaign in which the effects of solvent degradation are closely evaluated is required. In the case of third-generation water-lean solvents, solvent management aspects are unknown, and need to be clarified before these solvents can be proposed for operations at large scale. Moreover, the planned demonstration plant at the HVC site will provide CO2 to the greenhouse market. As a part of the demo project de-risking strategy, the DECIPHER project will measure the quality of the produced CO2 as a function of time (i.e., as solvent quality varies), for two different solvent systems (MDEA/PZ and a water-lean solvent).

Korte omschrijving
DECIPHER activities are divided into 4 work-packages: WP1 – 2G solvents: Within WP1, we will determine the emissions from the absorber to the atmosphere; assess the quality of the produced CO2; assess the solvent degradation rate and develop a solvent management strategy for MDEA/PZ. WP2 – 3G solvents: Within WP2, we will evaluate water-lean solvents based on blends of monoethanolamine (MEA) and an organic solvents, containing a reduced amount of water. The most promising composition will be tested at TNO's bench scale CO2 capture (TRL4) pilot and, based on the results, a decision will be taken to test the solvent at HVC's pilot (TRL7, up to 1 year). The testing protocol indicated in WP1 will be applied. WP3 – Economic evaluation: determine the most cost-effective solvent, taking into consideration the solvent management strategy and its impact on the CO2 price WP4 – Management and dissemination: organize project meetings to manage the project effectively, follow-up on the results, share the learnings in workshops with other Dutch WtE plant owners.

DECIPHER will evaluate second and third generation solvents as solutions for CO2 capture in the waste-to-energy sector. For each solvent, strategies for solvent management and emissions minimization will be developed for the HVC pilot plant. These strategies, which can be further applied to the full scale demonstration plant, will ensure the quality of the produced CO2, as well as prevent emissions of solvent degradation products to the environment. The solvent management strategies can lead to an operational cost reduction of 70% in case of second-generation solvents (as compared to no management strategy). Third generation solvents are expected to lower the energy demand of the process by up to 50%. This can lead to significant CO2 cost reduction. However, the implications on environmental impacts dur to solvent consumption and emissions are still unknown and will be investigated with DECIPHER.