Indian Scientists Produce Clean H2 With 99.58 % Carbon Capture Efficiency

A team of scientists from the CSIR-Indian Institute of Chemical Technology (CSIR-IICT) in Hyderabad created a hybrid material that simulates capturing carbon dioxide in-situ (on-site) and converting it into clean hydrogen from non-fuel grade bioethanol.

The findings of the study were published in the scientific journal Chemical Engineering and Processing by Elsevier.

In a first for India, the scientists built a fluidized bed reactor (FBR) facility in Hyderabad to perform sorption enhanced steam methane reforming (SESMR) to produce pure hydrogen. The facility at CSIR-IICT was inaugurated in January of this year.

The facility was built as part of the Department of Science and Technology's Mission Innovation Project. The FBR system assesses the SESMR performance of dual-functional materials. Sorption enhanced steam methane reforming provides the benefits of onsite carbon dioxide removal via sorbents, overcoming the equilibrium constraints of steam reforming and leading to clean hydrogen production.

The researchers used Aspen plus models (imperative programming language for studying scientific computation) to conduct a thermodynamic investigation and discover two scientific schemes for producing high purity hydrogen from non-fuel grade bioethanol.

The two schemes are based on the sorption process, which involves the capture or fixation of a gas or vapour (sorbate) by a substance in a condensed state (solid or liquid) known as sorbent. The team investigated two methods: chemical looping combustion (CLC) integrated processes, sorption enhanced steam reforming (CLC-SESR), and sorption enhanced chemical looping reforming (CLC-SECLR).

Both schemes are self-sustaining in terms of energy. Heat and power demand are met in the two processes by integrating heat recovery, steam generation, and power generation mechanisms.

99.13% & 99.58% Carbon Capture Efficiency

The IICT scientists achieved carbon capture efficiencies of 99.13 percent and 99.58 percent. The purity of hydrogen obtained in the process was 99.15 percent and 99.71 percent, respectively, with an energy efficiency of 39.47 percent and 37.30 percent.

The team achieved an optimal hydrogen yield of 97.38 percent and 82.45 percent after demonstrating the efficacy of the above two schemes in facilitating low temperature reforming of partially distilled bioethanol at 14-mole percent (34.5 percent by volume), with concentrations maintained at 550 degrees and 500 degrees Celsius, respectively.

Earlier this year, scientists at the Indian Institute of Science Education and Research (IISER) in Kolkata demonstrated a strategy for synthesizing novel solid absorbents with the specific goal of capturing and utilizing carbon. The researchers identified specific types of nanoparticles that capture carbon dioxide in their micro and mesoporous voids.