Mitsubishi Chemical and Engineering partner to produce and sell zeolite membranes for ethanol dehydration; new process
Mitsubishi Chemical Corporation (MCC) and Mitsui Zosen Machinery & Service (MZM), a subsidiary of Mitsui Engineering & Shipbuilding are partnering to produce and sell zeolite membranes, with a focus on ethanol dehydration.
MCC will purchase MZM’s entire output of zeolite membranes and hold the sole sales rights in the US and other global markets. The agreement also provides proposals for new, more efficient dehydration processes that will draw upon both companies’ technologies—including the two different types of zeolites currently produced by each.
There are three main steps in the conventional production of anhydrous ethanol for fuel use: fermentation, which results in a “beer; distillation to separate the ethanol from the stillage, resulting in an ethanol concentration of ~95%; and dehydration to increase the concentration to close to 100%. The anhydrous ethanol is blended with about 5% denaturant (such as gasoline) to render it undrinkable and thus not subject to beverage alcohol tax.
There are multiple approaches to dehydration technologies, the most widely used (in Brazil and the US) being azeotropic distillation with cyclohexane; extractive distillation with ethylene glycol; and adsorption with molecular sieves (e.g., pressure swing adsorption (PSA) with pellet-form general-purpose zeolite).
Many plants adopted the PSA process more than 10 years ago, the Mitsubishi partners noted, and will need refurbishment of the zeolite beds in the next several years.
However, PSA’s zeolite beds use a absorption-desorption cycle every several minutes and must recycle about 20% of the refined bioethanol. Its vapor phase operation and continual recycling make the process very energy-intensive.
The US Environmental Protection Agency (EPA) is encouraging ethanol producers to make production process more energy efficient; ethanol derived from corn starch should meet a 20% lifecycle GHG reduction threshold.
To meet that requirement many producers have started installing energy-saving equipment and processes as they gear up to increase production, and that will require technologies such as MCC’s ZEBREX zeolite membrane dehydration process.
MZM has produced and marketed A-type zeolite (a reference to the specific structure of the zeolite) membranes since 1998, and its products have been adopted in more than 70 plants. Due to the A-type zeolite membrane’s strong dehydration performance, it has been adopted in industrial alcohol solvent collection systems and bioethanol water-removal processes.
MCC successfully developed its unique CHA-type zeolite membranes, which have superior resistance to water and acid. These have been adopted in the solvent collection system developed by Mitsubishi Chemical Engineering Corporation and in Japanese sake concentration, which requires both water resistance and acid resistance.
The ZEBREX dehydration system combines CHA-type zeolite membranes, which have high separation performance with high water content, and A-type zeolite membranes, which are highly effective in final dehydration. This zeolite membrane system does not require recycling, so ethanol producers can reduce energy costs and increase production up to 15% by replacing the PSA process with the ZEBREX dehydration system or by adding ZEBREX dehydration system to their current process.
MCC and MZM have already started joint marketing of a dehydration system using ZEBREX zeolite membranes in combination with A-type zeolite membranes and MCC-developed CHA-type zeolite membranes for bioethanol production processes in the US, along with Taiyo Nippon Sanso Corporation (TNSC).
The new business tie-up will help MCC and MZM further expand the zeolite business by taking advantage of MCC’s zeolite development technology, the Mitsubishi Chemical Holdings Group’s marketing capabilities, and MZM’s A-type zeolite production technology and product recognition.MZM will produce A-type zeolite membranes, and MCC will market them exclusively. In the US market, MCC will incorporate its marketing through the industrial gas sales network of TNSC’s wholly owned US subsidiary, Matheson Tri-Gas.
MCC will further develop proposals for customers to optimize their energy-saving processes and increase production by combining MZM’s A-type zeolite membranes and MCC’s CHA-type zeolite membranes.
Paola A. Bastidas, Iván D. Gil, Gerardo Rodríguez (2010) “Comparison of the main ethanol dehydration technologies through process simulation” 20th European Symposium on Computer Aided Process Engineering – ESCAPE20 S. Pierucci and G. Buzzi Ferraris (Editors) © 2010 Elsevier B.V.