Skip to main content

MEthane activation via integrated MEmbrane REactors

Periodic Reporting for period 2 - MEMERE (MEthane activation via integrated MEmbrane REactors)

Reporting period: 2017-04-01 to 2018-09-30

1.1 Objectives relevant to the reporting period
WP1 Management
WP1 is the work package on coordination.
This work package is proceeding as planned.
As planned, face to face meetings are being organized every 6 months. Other meetings (teleconferences) are being organized every 3 months. Additionally, work package leaders are organizing monthly teleconferences to discuss the work in their WP.

WP2 Catalyst Development
The objective of the WP2 is to develop, test and characterise an OCM catalyst suitable for the operating conditions dictated by the use of a membrane reactor. The catalyst must be active, selective and stable at high temperatures (820 °C and above) and under low oxygen partial pressures. The work package has proceeded as planned and all deliverables have been submitted. The catalyst has been provided for prototype testing (WP5).

WP3 Membrane Development
The objective of the WP3 is to develop oxygen separation membranes for OCM membrane reactor with improved flux and selectivity, and thermal, chemical and mechanical stability under operating conditions (T= 800-950 ºC). The membranes need to be CO2 tolerant as well.

WP4 Lab scale reactor
The aim of this WP is to merge the knowledge of WP2 (catalyst) and WP3 (membranes) to build up and test an OCM membrane reactor, thus providing useful information to quantify the benefits of this configuration when compared to conventional ones.

WP5 Prototype design and build
The objective of this work package is to design and build the pilot membrane reactor together with the needed Balance of Plant to test the pilot reactor in Work Package 6.
The pilot scale reactor for the OCM process was designed based upon the learnings and designs of WP4 (lab scale reactors) and models of WP7. The construction of the reactor has just started. Additionally, overall system controls for the different reactor types will be designed and constructed to ensure automatic operation of the systems.

WP7 System Design and Modelling
The activities of WP7 from month 19 until month 36 have been focused on the finalization of the mass and energy balances of the different cases investigated, a complete thermodynamic analysis comparison, a final cost estimation, and the submission of the deliverable 7.2. The four cases investigated are the naphtha steam cracking as benchmark technology, the conventional OCM with direct co-feeding of CH4 and oxygen, the innovative case with oxygen distribution along porous membranes, and finally the MEMERE case, where oxygen is separated and distributed using oxygen transport membranes immersed in the catalytic OCM reactor. All these cases have been implemented first in Aspen Plus; and have been subsequently optimized in order to find the optimal configuration.

WP8 Environmental LCA and economic assessment
The goal of WP8 is to use state-of-the-art environmental Life Cycle Assessment (LCA), Life Cycle Costing (LCC) and other economic assessment tools to evaluate the environmental and cost performance of the developed innovative OCM technology, compared to conventional OCM technology, porous OCM technology, as well as naphtha steam cracking for producing ethylene. The work performed in WP8 will include key assessments of environmental and economic sustainability of the new technology.

WP9 Dissemination and Exploitation
Facilitating the communication between the consortium partners, disseminating the information and results inside and outside the consortium, preparing for and intensifying the exploitation phase are the main activities that have been scheduled and performed in this work package (WP9) for the last 36 months. The actions which have been performed so far are: disseminations inside the consortium, communication and engagement with stakeholders outside the consortium and publications and dissemination of the results to targeted groups.
WP2 Catalyst Development
As described in the first periodic report, a modified preparation route allowed an improvement of the conversions achieved with the standard MnNa2WO4/SiO2 catalyst formulation, while maintaining its selectivity. It was also evidenced that the catalyst coking observed upon intermittent removal of oxygen has no significant long-term effect. The reference catalyst was analysed in situ and phase changes were observed, including the transformation of cristobalite to tridymite and ultimately quartz. The use of dopants such as cerium and silver were also found to have a significant impact on the performance. The modified catalysts are now completed and delivered to HyGear for the final test.
WP3 Membrane Development
The objective of this research is the development of CO2 tolerant membranes with the sufficient oxygen flux and selectivity for OCM membrane reactor, which also withstands the operating conditions of this reaction (e.g. high temperatures). Besides, the sealing needs to be gas-tight and stable under the operating conditions. The development of these types of membranes and sealings could be also used for other processes in which high temperature oxygen extraction/distribution is required.
WP4 Lab scale reactor
The main objective of this WP is to prove the feasibility of the membrane reactor concept at lab scale. A significant increase in C2 yield is expected because of the integration of catalyst and membrane in a single unit. To quantify this increase, the OCM conditions in a membrane reactor will be optimized. The results obtained in this WP should provide information for WP5, in which the membrane reactor concept will be tested at larger scale.
WP5 Prototype design and build
The PSA system to be used in the MEMERE pilot demonstration has been assembled and tested. The tests with the system showed that the purity needed for the operation with the OCM membrane is widely satisfactory. The system was tested in the range where the nitrogen content is kept below the maximum of 5 % defined in the project and was able to reach values even less than half this content. The design of the pilot scale reactor was completed. To the knowledge of the consortium, the design and construction of a reactor of the characteristics and scale addressed in the prototype of this project have never been done. This makes this OCM reactor first of its class at pilot scale. The tests with this system will bring promising knowledge to the academic and commercial communities involved in this field.
WP7 System Design and Modelling
From the techno-economic analysis it has been observed that with state-of-the-art technologies, C2H4 cannot be produced from CH4 at competitive prices. Therefore, membrane reactors appear as the only possible alternative when considering natural gas as feedstock. In particular, it is evidenced that membrane reactors using porous membranes for O2 distribution can already produce ethylene at a very competitive cost compared to the conventional naphtha steam cracking. When perovskite membranes are used instead, the cost of ethylene can be reduced, showing the potential of the MEMERE technology. However, still the long-term stability of these technologies should be assessed.
WP8 Environmental LCA and economic assessment
The project aims to increase the yield of ethylene from methane (from current limit of 25 % to potential 35-40%) while lowering production costs (-20-30 % CAPEX and -20 % OPEX) and reducing energy intensity (-50 %) and emissions (-60 %) compared to current state-of-the-art technologies.
figure1.jpg