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The fight for energy security

By Adeel Ghayur

Pakistan State Oil supplies 20,000 to 38,000 tonnes of imported oil to thermal power plants in order to meet daily electricity demand. The maximum demand stands at 38,000 tonnes, however, in recent months the supply has been around 20,000 tonnes due to various issues. It’s the unbalanced demand and supply of oil that has led to excessive power outages and the ever increasing circular debt. The significance of circular debt cannot be overstated, thus a solution is urgently needed to resolve this issue. It’s essential to find alternatives. While the obvious solution would be indigenous oil resources, it’s better to put this option on hold in the short to medium term. Hence, in the absence of any significant increase in oil production and newer discoveries in the energy sector, the prevailing situation calls for exploring other options.

Since Pakistan has an enormous agricultural base, bioethanol from biomass serves as an attractive alternative to oil. Bioethanol from biomass is exactly the same as ethanol from any other source. The connotation of bio in bioethanol is only to inform about the original source of ethanol as being biomass. In practice, both bioethanol and ethanol are used interchangeably. Until recently, food crops had been used as the sole source of biofuels. But with the global increase in food prices since 2008 and biofuels being partly blamed for the rise, the global community has started looking towards non-food biomass sources.

Keeping in view the issue of food versus fuel, the obvious feedstock for bioethanol is waste biomass. Pakistan produces hundreds of millions of tonnes of crop wastes annually. A fraction of this waste would be sufficient to provide enough bioethanol to replace the 20,000 tonnes per day oil requirement, thereby overcoming power outages and resolving circular debt.

A bioethanol refinery has energy requirements in the form of heat. Heat costs are a major component of the biorefinery operations and play a significant role in determining the break even price of the product. Since the purpose of bioethanol production is power generation, the biorefinery could be placed near the power plant site, where it would be ideally suited to utilise the hot exhaust gases of the power plant. By cutting down the bill for heat generation, ethanol production costs could be significantly reduced. This, combined with low priced crop wastes, results in a final product that can be even lower in price than imported oil. The waste stream of the biorefinery could also be used to generate electricity or be converted into valuable biochemicals.

Pakistan has some experience with sugar-based bioethanol where molasses is converted into ethanol to fulfill the energy demands of the sugar refinery. The technology to generate ethanol from crop wastes is not very different than the one used in sugar refineries.

Since the main aim is to replace at least 20,000 tonnes per day oil requirement, a number of ethanol biorefineries would be needed. A biorefinery using 2,000 tonnes per day of wheat straw waste can optimally produce up to 600 tonnes of ethanol per day. With 3.5 tonnes per hectare wheat productivity, a 2,000 square kilometre land would provide enough straw to feed the biorefinery for the whole year. This is when only one crop waste is considered. If wastes from crops of two seasons are considered, the total land area could be halved to 1,000 square kilometres. Thus, with a total of 33 biorefineries and wastes from 33,000 square kilometres, Pakistan can supply 20,000 tonnes of ethanol daily for its thermal plants. Most importantly, bioethanol’s heating value is less than fossil oils. If the country’s thermal power plants are improved – as they are currently using least efficient technologies – the total ethanol requirement would fall considerably to below 20,000 tonnes per day.

Ethanol transportation, although needing infrastructure similar to fossil oils, would need some modifications. Ethanol can absorb moisture. Thus, the oil tankers transporting ethanol along with the storage tanks would need to be air tight. Besides this, there isn’t any issue with the transportation and storage of ethanol.

There are slight differences in the composition of ethanol and fossil oils, which is why modifications would be required at the thermal power plants if they are to use ethanol. However, as the thermal power plants are extremely inefficient, it would be appropriate to completely overhaul and upgrade them to match the efficiency of combined cycle power plants, while running on pure ethanol. This would considerably reduce the fuel demand at one end, while generating more revenue for the plant owners.

Globally, a fraction of total bioethanol is generated from crop wastes. This is because only recently technologies to generate ethanol from crop wastes have commercially matured. Furthermore, many corporations throughout the globe, such as Abengoa in Spain and Poet in US, are looking towards crop wastes to produce ethanol. This has two-pronged benefits. Firstly, it solves the issue of food versus fuel and secondly, crop wastes are much cheaper than food crops. For example, in Pakistan crop wastes such as wheat straw is up to 10 times less expensive than grain.

The current energy crisis is one of the worst challenges which the nation is facing. However, the issue cannot be resolved overnight. It requires dedicated efforts and support. There is no single magic bullet. With the use of ethanol, we cannot hope to completely overcome the energy crisis. However, this can prove a milestone in resolving circular debt and reducing power outages. This would be one of the biggest achievements in the fight for energy security – is anybody listening?

The writer is a Ph.D. candidate. ghayur.adeel@gmail.com

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