Pakistan like other developing countries of the region, is facing a serious energy deficit and its energy demand is likely to increase three-fold by the year 2040. The currently used resources such as natural gas and oil will not be able to meet its future energy needs since the fossil fuel reserves are on the decline.

The country will face alarming low levels of natural gas by 2020. With its commercial energy share in power generation contributing 50.3 and six per cent for transport, the projected shortage has direct implications for power and transport sector. On this count, the power deficit could reach over 6000MW in 2010 and reduce supply of gas to over two million CNG vehicles.

To narrow this alarming deficit, emerging several business and technological opportunities exist for renewable and alternative sources such as wind, hydro, solar and biomass.

Biomass can exist in the form of agricultural waste residues or as dedicated energy crops grown on marginal and saline lands. Pakistan has a large abundance of both, agricultural wastes such as rice husk, straw etc, and availability of marginal and saline lands which, if utilised to grow energy crops have huge potential as a renewable energy. Of all the above, biomass derived energy stands out because of three reasons.

First, unlike other alternatives, biomass can be utilised in wide array of energy applications such as electricity generation, heating/cooling, synthetic natural gas and liquid fuels such as ethanol and bio-diesel. Second, biomass is the only renewable source with a defined effect of economics of scale which is important to lower production cost and maximise revenues in commercial settings. Third, the use of biomass offer flexibility to place power generation plants near to biomass availability and electric grid. This not only offers a possibility for centralised bio-energy generation plants but also for starting a localised small power generation plants, especially in an area without electricity.

A prime example is setting up a mobile biomass powered electricity production systems configured to power tube-wells and domestic usage. The raw material (biomass) is available to farmers which can be stored until next crop is available. This strategy is better than solar powered pumps which are climate dependent, are temporal in use, involve security issues and are 6-8 times more expensive than biomass powered technologies. Similar is the case with wind turbines with energy production dependant on wind speed varying through the year and a poor access to grid availability in remote regions.

Renewable synthetic natural gas Pakistan is a developing country with animal and human food production tightly associated with fertile land use. Therefore, conversion of non-edible biomass grown on marginal land is a successful strategy for cheap renewable, long-term, and large scale bio-energy applications. The prospect of growing energy crop is especially attractive since other agricultural biomass such as rice husk, bagasse and other residues are valued for their use as fodder, timber, paper industry or heating fuel in rural areas, and hence would compete with bio-energy industry.

We have experimented with energy crops such as switch grass, miscanthus and genetically modified sorghum for attaining maximum biomass on semi-arid land. Sorghum cultivation has shown yield potential of 150 ton per hectare, has resistance to weeds and major pests and other common diseases all of which can improve economics in energy production. By utilisng excess lands or degraded agricultural land for growing energy crop would earn extra income for farmers and landlords. Once a secure supply of biomass is achieved, it can be converted to synthetic renewable gas (non-manure biogas) which can be used in electricity generation, domestic use and the transportable sector. The country has developed technologies that can convert biomass into gas which is 800 times faster and 20 times more yielding than any other manure derived from biogas. It is possible to generate gross revenue of $3000 per hectare of semi-marginal land using the technology to produce synthetic gas compared to $1200 per hectare on a fertile land use to produce wheat.

Production of renewable synthetic natural gas from biomass holds maximum potential mainly because of three reasons. (1) the energy yield of biogas from a hectare of land is two to three times more than any other bio-fuels such as jatropha oil; (2) synthetic bio-methane is identical to natural gas in composition and energy contents and well suited in power generation and transportable fuels such as CNG;. (3) the available infrastructure to integrate biomass base bio-methane to current power plants and CNG transport cars would allow immediate integration of production with utilisation. In addition, such technologies can be integrated with coal gasification technologies to reduce the use of fossil fuels. These strategies would help mitigate climate control and earn carbon credit for industrialists and the government may be willing to explore a joint venture for a pilot scale 1MW to 1000MW or onward power generation facilities.

Bio-diesel production Recent large-scale trials conducted around the world including India and Brazil suggest that availability of water resource should be considered not only for plant growth but for oil accumulation. While the plant can survive and perhaps could grow well in little water, the ability to produce oil seems to be compromised under restricted water. Recent studies in the US and Netherlands have demonstrated that jatropha cultivation severely deprives water resources consuming as much as 20,000L of water to produce 1L of bio-diesel. Pakistan is one of the most water-deprived developing nation and although this approach utilises marginal land but does not take into account the scare supply of fresh water resources competing with food crops.

There exist other biomass wastes that can be utilised for energy production. The country produces several million tons of plant edible oil. Because of low oil extraction efficiencies of the by-product seed cake contains 10-15 per cent residual oil which can be directly converted to bio-diesel using our thermo-chemical technologies. The resulting oil-less cake can be sold back to animal market with higher nutritional value because the proteins are broken down to highly digestible amino acid.

Edible oil refineries could utilise activated earth bleach waste, currently used to refine vegetable cooking oil, containing 30-35 per cent non-extractable oil that can be converted and purified to bio-diesel with 98 per cent efficiencies within two minutes. Waste cooking oil, animal and poultry waste, fatty acid by-product in soap industry, inedible tallow and waste edible oil sludge can be converted to bio-diesel using thermochemical technologies.

The oil-extraction efficiency in seeds such as jatropha needs to be upgraded for improving process economics. The process requires gentle cracking the seeds and converting seed oil to bio-diesel without oil extraction. This saves time and losses in oil extraction, resulting in 99 per cent oil to diesel conversions and without the need of water purifications. The co-product of bio-diesel production, crude glycerine which has limited market application can also be converted to bio-diesel using genetically engineered yeast. Such expeditions can also be invited for joint ventures to develop bio-energy applications. The mid-long term commercialisation aspect of these potential projects will reduce green house gases and would secure carbon credit as international subsidy to further stimulate the economy.

The writer is a senior Bio-fuel and Energy Scientist at MIT and Director, BioEnergy Research in a private company in the US .e-mail hussain.abidi@ccc.oxon.org.