Methane hydrate growth and decomposition in the cellulose-based
materials containing water were studied. Cellulose microfibrils (CMFs)
and their composite with polyacrylamide (CMF@PAM) were employed as
carriers for methane hydrate formation and storage. Water distribution
over the CMF porous surface creates a developed water–gas interface,
which leads to enhanced gas hydrate formation. The tested water content
in the materials was 45 and 70 mass %. The efficiency of methane binding
in the hydrate state increased in the order of CMF@PAM70 < CMF@PAM45
< CMF70 < CMF45 (numbers mean the water content). The water-to-hydrate
conversion in 40 h was 3, 28, 73, and 83% in the same order. The most
intensive hydrate growth is observed in the first 100–200 min
after nucleation. In the case of CMF45, 70–90% of the water
turns into a hydrate during this time depending on the water distribution.
The presence of the hydrate in the studied samples was confirmed by
powder X-ray diffractometry and differential scanning calorimetry.
Partial decomposition of the methane hydrate in the CMF at atmospheric
pressure and a constant temperature (−20 °C) led to a
sharp decrease in the rate of its further dissociation. In the case
of the CMF@PAM material, the initial rate of hydrate decomposition
was an order of magnitude lower than that for the CMF one; it decreased
gradually. Thus, cellulose-based materials can be suggested as an
efficient carrier for gas hydrate production. CMFs provide a developed
water–gas interface that facilitates hydrate formation. Applying
polyacrylamide to the CMF allows one to reduce the rate of methane
hydrate decomposition formed in this material. However, it retards
the hydrate formation as well. Cellulose-based materials are easily
scalable and can be used in many technologies where a gas hydrate
needs to be produced fast.