Halophytes: Potential source of ligno-cellulosic biomass for ethanol production

World reserves of petroleum are being consumed rapidly and expected to exhaust by the middle of this century. This realization has led to the introduction of various grades of ethanol supplemented fuel. However, ethanol demands met from sources used for food may cause food shortage. This necessitates exploiting saline lands to produce non-food ligno-cellulosic biomass which, may be converted into ethanol without compromising human food production. Halophytes which produce plenty of biomass using saline resources (water and soil) may be an important alternative. This study shows that species like Halopyrum mucronatum, Desmostachya bipinnata, Phragmites karka, Typha domingensis and Panicum turgidum found in the coastal region of Pakistan, have potential as bio-ethanol crops. These perennial grasses are salt tolerant with high growth rates to produce ligno-cellulosic biomass of good quality (26–37% cellulose, 24–38% hemi-cellulose and <10% lignin) for ethanol production.

► Constant depletion in fossil energy resources needs search for alternatives.
► Alternate source of energy is required.
► Utilizing saline land brackish water to produce lingo-cellulosic biomass for bio-ethanol may be a viable option.
► Halophytes could be that source without competing for good quality land and fresh water.
► Suitable halophytic plant species with potential for this purpose needs to be identified.
► Few perennial grasses are recommended as biofuel crop using saline resources.