Durable reaction material development for magnesium oxide/water chemical heat pump

Abstract

Durable reaction material for repetitive reaction operation of a chemical heat pump that used a reversible magnesium oxide/water reaction system was discussed to enhance the heat pump performance. Because a material for the heat pump use was required to fit multi-production process, a molding method was introduced for material preparation. Some molded samples under different preparation conditions were evaluated kinetically by a thermo-balance analysis. Magnesium hydroxide prepared from ultra fine particle magnesium oxide and purified water showed enough reactivity, and also stable durability to 70 of repetitive reaction cycles. Removal of impurity was effective for durability enhancement of magneslum hydroxide made from seawater precipitated precursor. The cost of the precipitated hydroxide was less than one several tenths of the ultra fine particle material. It was demonstrated that the molded reactant made from precipitated hydroxide was applicable for multi production and cost reduction of magnesium hydroxide material for the heat pump. The thermal performance of magnesium oxide/water chemical heat pump was evaluated from experimental results. Copyright © 2007 The Society of Chemical Engineers, Japan.