A group of scientists from CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad, have designed a hybrid material to simulate capturing carbon dioxide in-situ (onsite) and converting it into clean hydrogen from non-fuel grade bioethanol.

The research details were published in the Elsevier scientific journal Chemical Engineering and Processing.

In a first for India, the scientists developed a fluidized bed reactor (FBR) facility in Hyderabad to perform sorption enhanced steam methane reforming (SESMR) to achieve clean hydrogen in its purest form. The facility was commissioned at CSIR-IICT in January this year.

The facility was commissioned under a Mission Innovation Project supported by the Department of Science and Technology.

The FBR system measures the performance of dual-functional materials for SESMR. The sorption enhanced steam methane reforming allows certain advantages of onsite carbon dioxide removal through sorbents, thereby overcoming the equilibrium restrictions of steam reforming, leading to clean hydrogen production.

The procedure

The researchers conducted a thermodynamic investigation using Aspen plus models (imperative programming language to study scientific computation) to discover two scientific schemes so that high purity hydrogen could be produced from non-fuel grade bioethanol.

The two schemes are based on the sorption process where a gas or vapor (sorbate) is captured or fixated by a substance in a condensed state (solid or liquid) called sorbent. The two methods studied by the team are chemical looping combustion (CLC) integrated processes; sorption enhanced steam reforming (CLC-SESR) and sorption enhanced chemical looping reforming (CLC-SECLR).

The two schemes are energy-wise self-sustainable. The heat and power demand in the two processes are achieved by integrating them with heat recovery, steam generation, and power generation mechanisms.

99.13% and 99.58% efficiency in carbon capture

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

The optimal hydrogen yield achieved by the team was 97.38%, and 82.45% after a demonstrated efficacy of the above two schemes in facilitating low temperature reforming of partially distilled bioethanol of 14 mole % (34.5% by volume), with a concentration maintained at 550 degrees and 500 degrees celsius.

Earlier this year, scientists at the Indian Institute of Science Education and Research (IISER), Kolkata, demonstrated a strategy to synthesize novel solid absorbents, to capture and utilize carbon specifically. The group discovered particular types of nanoparticles which capture carbon dioxide in their micro and mesoporous voids.

Many research institutes across the globe are focused on studies to capture carbon and control or reduce carbon emissions. Earlier this month, a U.S.-based electric public utility company, Cleco Power, announced an allocation of $12 million to develop a carbon capture facility in Lousiana’s Brame Energy Center.