Burckhardt, Lewa in carbon capture link

Winterthur, Switzerland – Lewa GmbH and Burckhardt Compression AG are to jointly manufacture systems for enhanced oil recovery (EOR) combined with carbon capture & storage (CCS).

A deal, signed 27 Aug, combines Lewa’s capabilities in process diaphragm pumps and metering and mixing packages, with those of Burckhardt as one of the world’s largest manufacturers of reciprocating compressors.

The companies have already developed a process that allows for a highly energy efficient compression. Unlike ordinary compression processes their ‘hybrid approach’ makes use of an intermediate step – gas liquefaction.

First, the semi isothermal compression is conducted in multiple stages by the reciprocating compressors from Burckhardt. After that, cooling and liquefaction follow. Eventually a LEWA triplex diaphragm pump boosts the liquid up to the required pressure (up to over 400 bar).

The overall power saving due to liquefaction can be up to 15 % because the power consumption for the compression of liquids is lower than for gases, the companies said.

Operators, they added, also benefit in other ways corrosion problems that in case of carbon dioxide occur in compressors at relatively low pressures can be avoided in the liquid phase.

Furthermore, variable flow rates and gas compositions can be handled by the use of speed control, thus enabling a constant high efficiency. Also changes in the reservoir pressure are not disruptive because the system boosts the liquid to the final pressure in one single step.

The limit for piston compressors and diaphragm pumps lies at approximately 150 t/h of acid gas. In terms of carbon capture & storage, the CO2 emissions of many carbon dioxide generating processes and fossil fuelled power plants of 200 - 300 MW can be handled with one set of machines.

Power plants of 200 - 400 MW would need two or three sets of machines. The range above (up to 1200 MW) would be the field of multistage turbo compressors. Such extreme requirements pose a big challenge to the sealing systems of a package.

In order to meet this challenge, hermetic tightness of Lewa’s diaphragm pumps and Burckhardt’s experience of n the field of CO2 compression, especially within the supercritical area, are crucial, said Burckhardt.